[Sitemap] [Contact] [Imprint] Deutsche Version Search site 

Phytochemistry - Current Research Articles



Current research articles: Phytochemistry

The author- or copyrights of the listed research articles below are held by the respective authors or site operators, who are also responsible for the content of the presentations.

More current articles from Chemistry Journals same topic: see the navigation menu on the left.

To list your article here please contact us by eMail.

To search this web page for specific words type "Ctrl" + "F" on your keyboard (Command + "F" on a Mac). Then: type the word you are searching for in the window that pops up!




On this page considered journals:



Phytochemistry - published by Elsevier

Phytochemistry is the international journal of pure and applied plant chemistry, plant biochemistry and molecular biology.




Current articles of the journal:



Neolignans as xanthine oxidase inhibitors from Hyptis rhomboides

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Sheng-Fa Tsai , Shoei-Sheng Lee

The active fraction from the EtOH extract of Hyptis rhomboides against xanthine oxidase was identified by use of an HPLC microfractionation–centrifugal vacuum evaporation–bioassay hyphenated technique. Scale-up separation of the active subfractions using semi-preparative RP-HPLC provided 13 phenylpropanoid compounds, including O-styrenylneolignans, hyprhombins A–C, epihyprhombin B, and hyprhombin B methyl ester, and O-caffeoylnorneolignans, hyprhombins D and E. All of these compounds shared a common 1,4-benzodioxane skeleton, as established by spectroscopic analyses. Hyprhombin C and epihyprhombin B exhibited better anti-xanthine oxidase activity than allopurinol, with IC50 values of 0.6 and 2.0?M, respectively.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Bisbenzylisoquinoline and hasubanane alkaloids from Stephania abyssinica (Dillon & A. Rich) (Menispermeceae)

Publication date: Available online 12 April 2014
Source:Phytochemistry

Author(s): Ruth A. Omole , Jeremiah Gathirwa , Hosea Akala , Hamisi M. Malebo , Alex K. Machocho , Ahmed Hassanali , Isaiah O. Ndiege

Two bisbenzylisoquinoline and one hasubanane alkaloids: (?)-pseudocurine (1), (?)-pseudoisocurine (2) and (?)-10-oxoaknadinine (3), were isolated from leaf extract of Stephania abyssinica, a plant used in traditional medicine in South Nyanza region of Kenya. They were characterized using 1D (1H, 13C and DEPT) and 2D (COSY, NOESY, HMQC and HMBC) NMR techniques. (?)-Pseudocurine (1) and (?)-pseudoisocurine (2) exhibited strong to moderate anti-plasmodial activity while (?)-10-oxoaknadinine (3) showed moderate to mild activity.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Floral scent emitted by white and coloured morphs in orchids

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): L. Dormont , R. Delle-Vedove , J.-M. Bessière , B. Schatz

Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined.

Graphical abstract

image

Highlights

Floral volatiles emitted by white- and coloured-flowered morphs of Orchis mascula, Orchis simia, and Anacamptis coriophora fragrans were not different between white and coloured morphs, except for O. simia.





Posted on 19 April 2014 | 6:58 am


Nitrogen supply affects anthocyanin biosynthetic and regulatory genes in grapevine cv. Cabernet-Sauvignon berries

Publication date: Available online 12 April 2014
Source:Phytochemistry

Author(s): Eric Soubeyrand , Cyril Basteau , Ghislaine Hilbert , Cornelis van Leeuwen , Serge Delrot , Eric Gomès

Accumulation of anthocyanins in grape berries is influenced by environmental factors (such as temperature and light) and supply of nutrients, i.e., fluxes of carbon and nitrogen feeding the berry cells. It is established that low nitrogen supply stimulates anthocyanin production in berry skin cells of red varieties. The present works aims to gain a better understanding of the molecular mechanisms involved in the response of anthocyanin accumulation to nitrogen supply in berries from field grown-plants. To this end, we developed an integrated approach combining monitoring of plant nitrogen status, metabolite measurements and transcript analysis. Grapevines (cv. Cabernet-Sauvignon) were cultivated in a vineyard with three nitrogen fertilization levels (0, 60 and 120kgha?1 of nitrogen applied on the soil). Anthocyanin profiles were analyzed and compared with gene expression levels. Low nitrogen supply caused a significant increase in anthocyanin levels at two ripening stages (26days post-véraison and maturity). Delphinidin and petunidin derivatives were the most affected compounds. Transcript levels of both structural and regulatory genes involved in anthocyanin synthesis confirmed the stimulation of the phenylpropanoid pathway. Genes encoding phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), flavonoid-3?,5?-hydroxylase (F3?5?H), dihydroflavonol-4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX) exhibited higher transcript levels in berries from plant cultivated without nitrogen compared to the ones cultivated with 120kgha?1 nitrogen fertilization. The results indicate that nitrogen controls a coordinated regulation of both positive (MYB transcription factors) and negative (LBD proteins) regulators of the flavonoid pathway in grapevine.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Graphical Contents List

Publication date: May 2014
Source:Phytochemistry, Volume 101









Posted on 19 April 2014 | 6:58 am


Steroidal glycosides from the underground parts of Yucca glauca and their cytotoxic activities

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Akihito Yokosuka , Tomoka Suzuki , Satoru Tatsuno , Yoshihiro Mimaki

Six steroidal glycosides and 14 known compounds were isolated from the underground parts of Yucca glauca (Agavaceae). Their structures were determined from extensive spectroscopic analysis, including analysis of two-dimensional NMR data, and from chemical transformations. The compounds were also evaluated for cytotoxic activities against HL-60 human leukemia cells and A549 human lung adenocarcinoma cells. Four spirostanol glycosides and three furostanol glycosides exhibited cytotoxic activities against both HL-60 and A549 cells. Two of the compounds induced apoptosis in HL-60 cells.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Hikiokoshins A–I, diterpenes from the leaves of Isodon japonicus

Publication date: Available online 2 April 2014
Source:Phytochemistry

Author(s): Naonobu Tanaka , Eri Tsuji , Kanae Sakai , Tohru Gonoi , Jun’ichi Kobayashi

Diterpenes, hikiokoshins A–I, and twelve known diterpenes were isolated from the leaves of Isodon japonicus (Burm. f.) H. Hara (Lamiaceae). The hikiokoshins A–I possess various skeletons such as ternifonane {hikiokoshin A}, ent-6,7:8,15-diseco-6,8-cyclokauran-7,20-olide {hikiokoshin B}, ent-6,7-secokauran-7,20-olide {hikiokoshin C}, and ent-7,20-epoxykaurane {hikiokoshins D–I}. Their structures were elucidated on the basis of spectroscopic analysis. Antimicrobial activities of hikiokoshins A and B were evaluated.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Chemical constituents and their antibacterial and antifungal activity from the Egyptian herbal medicine Chiliadenus montanus

Publication date: Available online 17 April 2014
Source:Phytochemistry

Author(s): Mohamed-Elamir F. Hegazy , Hisashi Matsuda , Seikou Nakamura , Taha A. Hussein , Masayuki Yoshikawa , Paul W. Paré

Phytochemical investigations of the CH2Cl2/MeOH (1:1) extract of air-dried aerial parts of Chiliadenus montanus afforded eight metabolites, in addition to eight other previously reported compounds, of which two were isolated for the first time as free acids. Structures were established by spectroscopic methods, including HREIMS, 1H, 13C, DEPT, 1H–1H COSY, HMQC and HMBC NMR analysis. Antimicrobial activity against an array of common bacterial and fungal strains was measured via a colorimetric assay with minimal growth inhibition observed in the ?g/mL range for one of the tested metabolites.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Purification and characterization of tyrosinase from walnut leaves (Juglans regia)

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Florime Zekiri , Christian Molitor , Stephan G. Mauracher , Claudia Michael , Rupert L. Mayer , Christopher Gerner , Annette Rompel

Polyphenol oxidase (PPO) is a type-3 copper enzyme catalyzing the oxidation of phenolic compounds to their quinone derivates, which are further converted to melanin, a ubiquitous pigment in living organisms. In this study a plant originated tyrosinase was isolated from walnut leaves (Juglans regia) and biochemically characterized. It was possible to isolate and purify the enzyme by means of an aqueous two-phase extraction method followed by chromatographic purification and identification. Interestingly, the enzyme showed a rather high monophenolase activity considering that the main part of plant PPOs with some exceptions solely possess diphenolase activity. The average molecular mass of 39,047Da (Asp101 ?Arg445) was determined very accurately by high resolution mass spectrometry. This proteolytically activated tyrosinase species was identified as a polyphenol oxidase corresponding to the known jrPPO1 sequence by peptide sequencing applying nanoUHPLC–ESI-MS/MS. The polypeptide backbone with sequence coverage of 96% was determined to start from Asp101 and not to exceed Arg445.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Isolation and characterization of six labdane diterpenes and one pregnane steroid of Turraeanthus africanus

Publication date: Available online 12 April 2014
Source:Phytochemistry

Author(s): Laurice Bracine Njanang Chenda , Simeon Fogue Kouam , Marc Lamshöft , Souvik Kusari , Ferdinand Mouafo Talontsi , Bonaventure Tchaleu Ngadjui , Michael Spiteller

Six labdane diterpene derivatives, named turraeanins F–J (36, 8) and epi-turraeanin J (7), and a pregnane steroid derivative named turraeasterodionene (2), were isolated by preparative high performance liquid chromatography together with thirteen known compounds from the Cameroonian medicinal plant Turraeanthus africanus. Their structures were elucidated by means of nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry in conjunction with the published data for the analogs, as well as the fragmentation patterns of each compound. Most of the known compounds were obtained for the first time from this plant. The compounds (27) were tested for their antibacterial efficacies against both Gram-positive and Gram-negative bacteria, including some clinically-important Risk group 2 human pathogens. Compound 4 exhibited the most pronounced antibacterial effectiveness comparable to standard reference streptomycin, with more potency against Gram-positive than Gram-negative bacteria. By comparing compounds 3, 4 and 5, a tentative structure–activity relationship could be drawn; selected oxidations at C-16 and C-18 drastically reduced the antibacterial efficacy of the parent compound (4). These results revealed the potential of compound 4 as a suitable antibacterial lead compound that might be used for further development of other derivatives to increase the antimicrobial efficacy.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


A seco-laurane sesquiterpene and related laurane derivatives from the red alga Laurencia okamurai Yamada

Publication date: Available online 11 April 2014
Source:Phytochemistry

Author(s): Xiao-Qing Yu , Wen-Fei He , Ding-Quan Liu , Mei-Tang Feng , Yi Fang , Bin Wang , Li-Hua Feng , Yue-Wei Guo , Shui-Chun Mao

A ring-cleaved sesquiterpene, named seco-laurokamurone, four laurane-type sesquiterpenes, laurepoxyene, 3?-hydroperoxyaplysin, 3?-hydroperoxy-3-epiaplysin, and 8,10-dibromoisoaplysin, one laurokamurane-type sesquiterpene, laurokamurene D, and one bisabolane-type sesquiterpene, (5S)-5-acetoxy-?-bisabolene, have been isolated from a re-collection of the red alga Laurencia okamurai Yamada, together with six other known sesquiterpenes. Their structures, including relative configuration, were elucidated by detailed analysis of spectroscopic data, and by comparison with data for related known compounds. In addition, on the basis of chemical conversions, degradation results, and biogenetic considerations, the absolute configurations of several of these compounds were also tentatively proposed. seco-Laurokamurone possesses an unprecedented carbon skeleton, formed from an oxidative cleavage of the laurokamurane skeleton, and laurokamurene D represents the fourth example of a laurokamurane-type sesquiterpene from a natural source. The in vitro antifungal activity of many of these compounds was evaluated against four fungi (Cryptococcus neoformans, Candida glabrata, Trichophyton rubrum, and Aspergillus fumigatus), as well as assessing cytotoxicity against HL-60 and A-549 human cancer cell lines. The compounds studied displayed moderate activities, relative to controls.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Chemical and genetic similarity and diversity of Ligularia anoleuca and L. fischeri collected in the Hengduan Mountains of China

Publication date: Available online 8 April 2014
Source:Phytochemistry

Author(s): Anna Shimizu , Yurika Suzuki , Ryo Hanai , Yasuko Okamoto , Motoo Tori , Xun Gong , Chiaki Kuroda

The sesquiterpenoid composition in the root and the DNA sequences of evolutionarily neutral regions were studied in Ligularia anoleuca and Ligularia fischeri (Asteraceae) collected in the Sichuan Province of China. LC–MS analysis showed that L. anoleuca populations from different localities had different chemical compositions. However, the isolated compounds were similar to each other, indicating that the differences in chemical composition were not large. The DNA analysis suggested that the two species were indistinguishable. Seventeen furanoeremophilanes and an eremophilane acetal were isolated.

Graphical abstract

image

Highlights

The two title species were indistinguishable both in the root chemicals and in neutral DNA sequences examined.





Posted on 19 April 2014 | 6:58 am


Differential antibiosis against Helicoverpa armigera exerted by distinct inhibitory repeat domains of Capsicum annuum proteinase inhibitors

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Rakesh S. Joshi , Vidya S. Gupta , Ashok P. Giri

Plant defensive serine proteinase inhibitors (PIs) are known to have negative impact on digestive physiology of herbivore insects and thus have a crucial role in plant protection. Here, we have assessed the efficacy and specificity of three previously characterized inhibitory repeat domain (IRD) variants from Capsicum annuum PIs viz., IRD-7, -9 and -12 against gut proteinases from Helicoverpa armigera. Comparative study of in silico binding energy revealed that IRD-9 possesses higher affinity towards H. armigera serine proteinases as compared to IRD-7 and -12. H. armigera fed on artificial diet containing 5TIU/g of recombinant IRD proteins exhibited differential effects on larval growth, survival rate and other nutritional parameters. Major digestive gut trypsin and chymotrypsin genes were down regulated in the IRD fed larvae, while few of them were up-regulated, this indicate alterations in insect digestive physiology. The results corroborated with proteinase activity assays and zymography. These findings suggest that the sequence variations among PIs reflect in their efficacy against proteinases in vitro and in vivo, which also could be used for developing tailor-made multi-domain inhibitor gene(s).

Graphical abstract

image

Highlights

Glimpses of performance variability of Capsicum annum proteinase inhibitors IRD-variants against target proteases of Helicoverpa armigera growth. IRDs show differential antibiosis on Helicvoerpa armigera.




Posted on 19 April 2014 | 6:58 am


The haploinsufficiency profile of ?-hederin suggests a caspofungin-like antifungal mode of action

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Thomas A.K. Prescott , Luke P. Rigby , Nigel C. Veitch , Monique S.J. Simmonds

The leaves of common ivy (Hedera helix) contain the cytotoxic saponin ?-hederin, which is inhibitory to Candida albicans at low concentrations. To investigate the mode of action of ?-hederin, a haploinsufficiency screen was carried out using a library of 1152 Saccharomyces cerevisiae deletion strains. An ethanol ivy extract containing ?-hederin was used in the initial screen to reduce the amount of compound required. Strains exhibiting disproportionately low growth were then examined in more detail by comparing growth curves in the presence and absence of ?-hederin. This approach identified three hypersensitive strains carrying gene deletions for components of the transcription related proteins SWI/SNF, RNA polymerase II and the RSC complex. Saponin cytotoxicity is often attributed to membrane damage, however ?-hederin did not induce hypersensitivity with an aminophospholipid translocase deletion strain that is frequently hypersensitive to membrane damaging agents. The haploinsufficiency profile of ?-hederin is most similar to that reported for drugs such as caspofungin that inhibit synthesis of the fungal cell wall. Screening with plant extracts rather than isolated compounds, provides a valuable shortcut in haploinsufficiency screening provided hypersensitive strains are then confirmed as such using purified active principles.

Graphical abstract

image

Highlights

A yeast haploinsufficiency screen of ?-hederin (the cytotoxic principle of Hedera helix) identifies three genes (ARP7, RSC58 and RPB7) suggesting a caspofungin-like mode of action.





Posted on 19 April 2014 | 6:58 am


Ultraviolet-B radiation modifies the quantitative and qualitative profile of flavonoids and amino acids in grape berries

Publication date: Available online 5 April 2014
Source:Phytochemistry

Author(s): J. Martínez-Lüscher , N. Torres , G. Hilbert , T. Richard , M. Sánchez-Díaz , S. Delrot , J. Aguirreolea , I. Pascual , E. Gomès

Grapevine cv. Tempranillo fruit-bearing cuttings were exposed to supplemental ultraviolet-B (UV-B) radiation under controlled conditions, in order to study its effect on grape traits, ripening, amino acids and flavonoid profile. The plants were exposed to two doses of UV-B biologically effective (5.98 and 9.66kJm?2 d?1), applied either from fruit set to ripeness or from the onset of veraison to ripeness. A 0kJm?2 d?1 treatment was included as a control. UV-B did not significantly modify grape berry size, but increased the relative mass of berry skin. Time to reach ripeness was not affected by UV-B, which may explain the lack of changes in technological maturity. The concentration of must extractable anthocyanins, colour density and skin flavonols were enhanced by UV-B, especially in plants exposed from fruit set. The quantitative and qualitative profile of grape skin flavonols were modified by UV-B radiation. Monosubstituted flavonols relative abundance increased proportionally to the accumulated UV-B doses. Furthermore, trisubstituted forms, which where predominant in non-exposed berries, were less abundant as UV-B exposure increased. Although total free amino acid content remained unaffected by the treatments, the increased levels of gamma-aminobutyric acid (GABA), as well as the decrease in threonine, isoleucine, methionine, serine and glycine, revealed a potential influence of UV-B on the GABA-mediated signalling and amino acid metabolism. UV-B had an overall positive impact on grape berry composition.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Announcement for the Phytochemical Society of North America (PSNA)

Publication date: May 2014
Source:Phytochemistry, Volume 101









Posted on 19 April 2014 | 6:58 am


7-Deoxyloganetic acid synthase catalyzes a key 3 step oxidation to form 7-deoxyloganetic acid in Catharanthus roseus iridoid biosynthesis

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Vonny Salim , Brent Wiens , Sayaka Masada-Atsumi , Fang Yu , Vincenzo De Luca

Iridoids are key intermediates required for the biosynthesis of monoterpenoid indole alkaloids (MIAs), as well as quinoline alkaloids. Although most iridoid biosynthetic genes have been identified, one remaining three step oxidation required to form the carboxyl group of 7-deoxyloganetic acid has yet to be characterized. Here, it is reported that virus-induced gene silencing of 7-deoxyloganetic acid synthase (7DLS, CYP76A26) in Catharanthus roseus greatly decreased levels of secologanin and the major MIAs, catharanthine and vindoline in silenced leaves. Functional expression of this gene in Saccharomyces cerevisiae confirmed its function as an authentic 7DLS that catalyzes the 3 step oxidation of iridodial–nepetalactol to form 7-deoxyloganetic acid. The identification of CYP76A26 removes a key bottleneck for expression of iridoid and related MIA pathways in various biological backgrounds.

Graphical abstract

image

Highlights

Iridodial oxidase is a microsomal CYP whose biochemical function has been identified by a bioinformatic candidate gene approach, by virus induced gene silencing and by functional expression in a recombinant yeast system.





Posted on 19 April 2014 | 6:58 am


Acylated flavonol glycosides from the flower of Elaeagnus angustifolia L.

Publication date: Available online 15 April 2014
Source:Phytochemistry

Author(s): Sarah Bendaikha , Méredith Gadaut , Dominique Harakat , Alabdul Magid

Seven acylated flavonol glycosides named elaeagnosides A–G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the abilities of these flavonoids to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and to inhibit tyrosinase activity were evaluated. Results revealed that two of these compounds had significant anti-oxidant effect and one compound showed weak tyrosinase-inhibitory activity compared with kojic acid, quercetin, or ascorbic acid, which were used as positive control.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


OsAlba1, a dehydration-responsive nuclear protein of rice (Oryza sativa L. ssp. indica), participates in stress adaptation

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Jitendra Kumar Verma , Saurabh Gayali , Suchismita Dass , Amit Kumar , Shaista Parveen , Subhra Chakraborty , Niranjan Chakraborty

Alba proteins have exhibited great functional plasticity through the course of evolution and constitute a superfamily that spans across three domains of life. Earlier, we had developed the dehydration-responsive nuclear proteome of an indica rice cultivar, screening of which led to the identification of an Alba protein. Here we describe, for the first time, the complete sequence of the candidate gene OsAlba1, its genomic organization, and possible function/s in plant. Phylogenetic analysis showed its close proximity to other monocots as compared to dicot Alba proteins. Protein–DNA interaction prediction indicates a DNA-binding property for OsAlba1. Confocal microscopy showed the localization of OsAlba1–GFP fusion protein to the nucleus, and also sparsely to the cytoplasm. Water-deficit conditions triggered OsAlba1 expression suggesting its function in dehydration stress, possibly through an ABA-dependent pathway. Functional complementation of the yeast mutant ?Pop6 established that OsAlba1 also functions in oxidative stress tolerance. The preferential expression of OsAlba1 in the flag leaves implies its role in grain filling. Our findings suggest that the Alba components such as OsAlba1, especially from a plant where there is no evidence for a major chromosomal role, might play important function in stress adaptation.

Graphical abstract

image

Highlights

Screening of the dehydration-responsive nuclear proteome of indica rice identified an Alba-family protein, designated OsAlba1, distantly related to the archaeal DNA/RNA-binding Alba protein. We describe, for the first time, the complete sequence of OsAlba1, its genomic organization, and possible function/s.




Posted on 19 April 2014 | 6:58 am


Wounding stress causes rapid increase in concentration of the naturally occurring 2?,3?-isomers of cyclic guanosine- and cyclic adenosine monophosphate (cGMP and cAMP) in plant tissues

Publication date: Available online 12 April 2014
Source:Phytochemistry

Author(s): Thomas Van Damme , Dieter Blancquaert , Pauline Couturon , Dominique Van Der Straeten , Pat Sandra , Frédéric Lynen

3?,5?-Cyclic guanosine monophosphate (cGMP) and 3?,5?-cyclic adenosine monophosphate (cAMP) are well reported second messenger molecules involved in cellular signal transduction, in physiological functions such as neurotransmission in animals and in the modulation of cell growth and differentiation. In plants, 3?,5?-cyclic nucleotides have been implicated in the regulation of ion homeostasis, hormone and stress responses. The behavior of the 2?,3?-cyclic nucleotide variants is also known in animal tissue but no quantitative information is available about 2?,3?-cAMP and 2?,3?-cGMP in plant material. A recently developed HILIC–SPE/LC–MS/MS method for the analysis of cyclic nucleotides in blood and animal tissue was therefore adapted to measure 2?,3?-cAMP and 2?,3?-cGMP concentrations in plant material. Cyclic nucleotide concentrations were measured in Arabidopsis thaliana (Col-0) leaves before and after the application of wounding stress. A significant (?5-fold) up-regulation of 2?,3?-cAMP and 2?,3?-cGMP was measured in Arabidopsis leaves compared to the control samples. The results indicate a thus far unreported strong correlation between plant stress and both 2?,3?-cAMP and 2?,3?-cGMP levels in plant material, and may open new avenues towards understanding the role of cyclic nucleotides in plants.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Cloning and characterization of chitinases from interior spruce and lodgepole pine

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): N. Kolosova , C. Breuil , J. Bohlmann

Chitinases have been implicated in the defence of conifers against insects and pathogens. cDNA for six chitinases were cloned from interior spruce (Picea glauca x engelmannii) and four from lodgepole pine (Pinus contorta). The cloned interior spruce chitinases were annotated class I PgeChia1-1 and PgeChia1-2, class II PgeChia2-1, class IV PgeChia4-1, and class VII PgeChia7-1 and PgeChia7-2; lodgepole pine chitinases were annotated class I PcChia1-1, class IV PcChia4-1, and class VII PcChia7-1 and PcChia7-2. Chitinases were expressed in E scherichia coli with maltose-binding-protein tags and soluble proteins purified. Functional characterization demonstrated chitinolytic activity for the three class I chitinases PgeChia1-1, PgeChia1-2 and PcChia1-1. Transcript analysis established strong induction of most of the tested chitinases, including all three class I chitinases, in interior spruce and lodgepole pine in response to inoculation with bark beetle associated fungi (Leptographium abietinum and Grosmannia clavigera) and in interior spruce in response to weevil (Pissodes strobi) feeding. Evidence of chitinolytic activity and inducibility by fungal and insect attack support the involvement of these chitinases in conifer defense.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Biofilm blocking sesquiterpenes from Teucrium polium

Publication date: Available online 12 April 2014
Source:Phytochemistry

Author(s): Wael A. Elmasri , Mohamed-Elamir F. Hegazy , Mina Aziz , Ekrem Koksal , Wail Amor , Yehia Mechref , Abdul N. Hamood , David B. Cordes , Paul W. Paré

The chemical composition and antibacterial activity of Teucrium polium L. (Lamiaceae) were assessed; sixteen compounds were isolated from a CH2Cl2/MeOH extract of the aerial parts of the plant including four sesquiterpenes 4?,5?-epoxy-7?H-germacr-10(14)-en-6?-ol-1-one, 4?,5?-epoxy-7?H-germacr-10(14)-en,1?-hydroperoxyl,6?-ol, 4?,5?-epoxy-7?H-germacr-10(14)-en,1?-hydroperoxyl,6?-ol and 4?,5?-epoxy-7?H-germacr-10(14)-en,1?-hydroperoxyl,6?-ol, together with seven known sesquiterpenes, one known iridoid glycoside, two known flavonoids, and one known phenylpropanoid glycoside. Structures were elucidated on the basis of spectroscopic (UV, 1H and 13C NMR) data, as well as two-dimensional NMR (1H–1H COSY, HMQC, NOESY and HMBC), and ESI-MS analysis. The relative stereochemistry of the ketone was established by X-ray crystallography, while its absolute configuration was attained by a modified Mosher’s method. Antibacterial activity of the crude extract, as well as with four of the isolated metabolites, was observed with Staphylococcus aureus anti-biofilm activity in the low ?Mol range. Diverse sesquiterpene-skeleton structure and corresponding comprehensive enzyme capacity is discussed.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Editorial Board/Publication Information

Publication date: May 2014
Source:Phytochemistry, Volume 101









Posted on 19 April 2014 | 6:58 am


Comparative plant sphingolipidomic reveals specific lipids in seeds and oil

Publication date: Available online 11 April 2014
Source:Phytochemistry

Author(s): Frédérique Tellier , Alessandra Maia-Grondard , Isabelle Schmitz-Afonso , Jean-Denis Faure

Plant sphingolipids are a highly diverse family of structural and signal lipids. Owing to their chemical diversity and complexity, a powerful analytical method was required to identify and quantify a large number of individual molecules with a high degree of structural accuracy. By using ultra-performance liquid chromatography with a single elution system coupled to electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS) in the positive multiple reaction monitoring (MRM) mode, detailed sphingolipid composition was analyzed in various tissues of two Brassicaceae species Arabidopsis thaliana and Camelina sativa. A total of 300 molecular species were identified defining nine classes of sphingolipids, including Cers, hCers, Glcs and GIPCs. High-resolution mass spectrometry identified sphingolipids including amino- and N-acylated-GIPCs. The comparative analysis of seedling, seed and oil sphingolipids showed tissue specific distribution suggesting metabolic channeling and compartmentalization

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Exogenously applied 24-epi brassinolide reduces lignification and alters cell wall carbohydrate biosynthesis in the secondary xylem of Liriodendron tulipifera

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Hyunjung Jin , Jihye Do , Soo-Jeong Shin , Joon Weon Choi , Young Im Choi , Wook Kim , Mi Kwon

The roles of brassinosteroids (BRs) in vasculature development have been implicated based on an analysis of Arabidopsis BR mutants and suspension cells of Zinnia elegans. However, the effects of BRs in vascular development of a woody species have not been demonstrated. In this study, 24-epi brassinolide (BL) was applied to the vascular cambium of a vertical stem of a 2-year-old Liriodendron, and the resulting chemical and anatomical phenotypes were characterized to uncover the roles of BRs in secondary xylem formation of a woody species. The growth in xylary cells was clearly promoted when treated with BL. Statistical analysis indicated that the length of both types of xylary cells (fiber and vessel elements) increased significantly after BL application. Histochemical analysis demonstrated that BL-induced growth promotion involved the acceleration of cell division and cell elongation. Histochemical and expression analysis of several lignin biosynthetic genes indicated that most genes in the phenylpropanoid pathway were significantly down-regulated in BL-treated stems compared to that in control stems. Chemical analysis of secondary xylem demonstrated that BL treatment induced significant modification in the cell wall carbohydrates, including biosynthesis of hemicellulose and cellulose. Lignocellulose crystallinity decreased significantly, and the hemicellulose composition changed with significant increases in galactan and arabinan. Thus, BL has regulatory roles in the biosynthesis and modification of secondary cell wall components and cell wall assembly during secondary xylem development in woody plants.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Stable, water extractable isothiocyanates from Moringa oleifera leaves attenuate inflammation in vitro

Publication date: Available online 11 April 2014
Source:Phytochemistry

Author(s): Carrie Waterman , Diana M. Cheng , Patricio Rojas-Silva , Alexander Poulev , Julia Dreifus , Mary Ann Lila , Ilya Raskin

Moringa (Moringa oleifera Lam.) is an edible plant used as both a food and medicine throughout the tropics. A moringa concentrate (MC), made by extracting fresh leaves with water, utilized naturally occurring myrosinase to convert four moringa glucosinolates into moringa isothiocyanates. Optimum conditions maximizing MC yield, 4-[(?-L-rhamnosyloxy)benzyl]isothiocyanate, and 4-[(4?-O-acetyl-?-L-rhamnosyloxy)benzyl]isothiocyanate content were established (1:5 fresh leaf weight to water ratio at room temperature). The optimized MC contained 1.66% isothiocyanates and 3.82% total polyphenols. 4-[(4?-O-acetyl-?-L-rhamnosyloxy)benzyl]isothiocyanate exhibited 80% stability at 37°C for 30days. MC, and both of the isothiocyanates described above significantly decreased gene expression and production of inflammatory markers in RAW macrophages. Specifically, both attenuated expression of iNOS and IL-1? and production of nitric oxide and TNF? at 1 and 5?M. These results suggest a potential for stable and concentrated moringa isothiocyanates, delivered in MC as a food-grade product, to alleviate low-grade inflammation associated with chronic diseases.

Graphical abstract

image

Highlights

Fresh leaf concentrate of Moringa oleifera (MC) utilized in situ for bioconversion of glucosinolates (14) to chemically stable isothiocyanates (58). MC significantly reduced inflammatory biomarkers in macrophages.





Posted on 19 April 2014 | 6:58 am


Abscisic acid analogs as chemical probes for dissection of abscisic acid responses in Arabidopsis thaliana

Publication date: Available online 9 April 2014
Source:Phytochemistry

Author(s): Chantel L. Benson , Michal Kepka , Christian Wunschel , Nandhakishore Rajagopalan , Ken M. Nelson , Alexander Christmann , Suzanne R. Abrams , Erwin Grill , Michele C. Loewen

Abscisic acid (ABA) is a phytohormone known to mediate numerous plant developmental processes and responses to environmental stress. In Arabidopsis thaliana, ABA acts, through a genetically redundant family of ABA receptors entitled Regulatory Component of ABA Receptor (RCAR)/Pyrabactin Resistant 1 (PYR1)/Pyrabactin Resistant-Like (PYL) receptors comprised of thirteen homologues acting in concert with a seven-member set of phosphatases. The individual contributions of A. thaliana RCARs and their binding partners with respect to specific physiological functions are as yet poorly understood. Towards developing efficacious plant growth regulators selective for specific ABA functions and tools for elucidating ABA perception, a panel of ABA analogs altered specifically on positions around the ABA ring was assembled. These analogs have been used to probe thirteen RCARs and four type 2C protein phosphatases (PP2Cs) and were also screened against representative physiological assays in the model plant Arabidopsis. The 1?-O methyl ether of (S)-ABA was identified as selective in that, at physiologically relevant levels, it regulates stomatal aperture and improves drought tolerance, but does not inhibit germination or root growth. Analogs with the 7?- and 8?-methyl groups of the ABA ring replaced with bulkier groups generally retained the activity and stereoselectivity of (S)- and (R)-ABA, while alteration of the 9?-methyl group afforded an analog that substituted for ABA in inhibiting germination but neither root growth nor stomatal closure. Further in vitro testing indicated differences in binding of analogs to individual RCARs, as well as differences in the enzyme activity resulting from specific PP2Cs bound to RCAR-analog complexes. Ultimately, these findings highlight the potential of a broader chemical genetics approach for dissection of the complex network mediating ABA-perception, signaling and functionality within a given species and modifications in the future design of ABA agonists.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Diterpenoids and phenylethanoid glycosides from the roots of Clerodendrum bungei and their inhibitory effects against angiotensin converting enzyme and ?-glucosidase

Publication date: Available online 9 April 2014
Source:Phytochemistry

Author(s): Qing Liu , Hai-Jun Hu , Peng-Fei Li , Ying-Bo Yang , Li-Hong Wu , Gui-Xin Chou , Zheng-Tao Wang

Abietane derivatives, bungnates A, B, 15-dehydrocyrtophyllone A and 15-dehydro-17-hydroxycyrtophyllone A, and two phenylethanoid glycosides, bunginoside A and 3?,4?-di-O-acetylmartynoside, together with nine known abietane derivatives and fourteen known phenylethanoid glycosides, were isolated from dried roots of Clerodendrum bungei. Their structures were determined on the basis of detailed spectroscopic analyses and acidic hydrolysis. The absolute configuration of bunginoside A was established from analysis of CD data. Selected compounds were evaluated for inhibitory effects against angiotensin converting enzyme (ACE) and ?-glucosidase. 15-Dehydrocyrtophyllone A showed an ACE inhibitory effect, and verbascoside, leucosceptoside A and isoacteoside exhibited strong inhibitory capacity against ?-glucosidase.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Characterization of two genes for the biosynthesis of abietane-type diterpenes in rosemary (Rosmarinus officinalis) glandular trichomes

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Kathleen Brückner , Dragana Boži? , David Manzano , Dimitra Papaefthimiou , Irini Pateraki , Ulschan Scheler , Albert Ferrer , Ric C.H. de Vos , Angelos K. Kanellis , Alain Tissier

Rosemary (Rosmarinus officinalis) produces the phenolic diterpenes carnosic acid and carnosol, which, in addition to their general antioxidant activities, have recently been suggested as potential ingredients for the prevention and treatment of neurodegenerative diseases. Little is known about the biosynthesis of these diterpenes. Here we show that the biosynthesis of phenolic diterpenes in rosemary predominantly takes place in the glandular trichomes of young leaves, and used this feature to identify the first committed steps. Thus, a copalyl diphosphate synthase (RoCPS1) and two kaurene synthase-like (RoKSL1 and RoKSL2) encoding genes were identified and characterized. Expression in yeast (Saccharomyces cerevisiae) and Nicotiana benthamiana demonstrate that RoCPS1 converts geranylgeranyl diphosphate (GGDP) to copalyl diphosphate (CDP) of normal stereochemistry and that both RoKSL1 and RoKSL2 use normal CDP to produce an abietane diterpene. Comparison to the already characterized diterpene synthase from Salvia miltiorrhiza (SmKSL) demonstrates that the product of RoKSL1 and RoKSL2 is miltiradiene. Expression analysis supports a major contributing role for RoKSL2. Like SmKSL and the sclareol synthase from Salvia sclarea, RoKSL1/2 are diterpene synthases of the TPS-e group which have lost the internal gamma-domain. Furthermore, phylogenetic analysis indicates that RoKSL1 and RoKSL2 belong to a distinct group of KSL enzymes involved in specialized metabolism which most likely emerged before the dicot-monocot split.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


A domain swapping approach to elucidate differential regiospecific hydroxylation by geraniol and linalool synthases from perilla

Publication date: Available online 8 April 2014
Source:Phytochemistry

Author(s): Naoko Sato-Masumoto , Michiho Ito

Geraniol and linalool are acyclic monoterpenes found in plant essential oils that have attracted much attention for their commercial use and in pharmaceutical studies. They are synthesized from geranyl diphosphate (GDP) by geraniol and linalool synthases, respectively. Both synthases are very similar at the amino acid level and share the same substrate; however, the position of the GDP to which they introduce hydroxyl groups is different. In this study, the mechanisms underlying the regiospecific hydroxylation of geraniol and linalool synthases were investigated using a domain swapping approach and site-directed mutagenesis in perilla. Sequences of the synthases were divided into ten domains (domains I to IV-4), and each corresponding domain was exchanged between both enzymes. It was shown that different regions were important for the formation of geraniol and linalool, namely, domains IV-1 and -4 for geraniol, and domains III-b, III-d, and IV-4 for linalool. These results suggested that the conformation of carbocation intermediates and their electron localization were seemingly to be different between geraniol and linalool synthases. Further, five amino acids in domain IV-4 were apparently indispensable for the formation of geraniol and linalool. According to three-dimensional structural models of the synthases, these five residues seemed to be responsible for the different spatial arrangement of the amino acid at H524 in the case of geraniol synthase, while N526 is the corresponding residue in linalool synthase. These results suggested that the side-chains of these five amino acids, in combination with several relevant domains, localized the positive charge in the carbocation intermediate to determine the position of the introduced hydroxyl group.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


3-?-d-Glucopyranosyl-6-methoxy-2-benzoxazolinone (MBOA-N-Glc) is an insect detoxification product of maize 1,4-benzoxazin-3-ones

Publication date: Available online 5 April 2014
Source:Phytochemistry

Author(s): Daniel Maag , Claudio Dalvit , Damien Thevenet , Angela Köhler , Felipe C. Wouters , Daniel G. Vassão , Jonathan Gershenzon , Jean-Luc Wolfender , Ted C.J. Turlings , Matthias Erb , Gaetan Glauser

In order to defend themselves against arthropod herbivores, maize plants produce 1,4-benzoxazin-3-ones (BXs), which are stored as weakly active glucosides in the vacuole. Upon tissue disruption, BXs come into contact with ?-glucosidases, resulting in the release of active aglycones and their breakdown products. While some aglycones can be reglucosylated by specialist herbivores, little is known about how they detoxify BX breakdown products. Here we report on the structure of an N-glucoside, 3-?-d-glucopyranosyl-6-methoxy-2-benzoxazolinone (MBOA-N-Glc), purified from Spodoptera frugiperda faeces. In vitro assays showed that MBOA-N-Glc is formed enzymatically in the insect gut using the BX breakdown product 6-methoxy-2-benzoxazolinone (MBOA) as precursor. While Spodoptera littoralis and S. frugiperda caterpillars readily glucosylated MBOA, larvae of the European corn borer Ostrinia nubilalis were hardly able to process the molecule. Accordingly, Spodoptera caterpillar growth was unaffected by the presence of MBOA, while O. nubilalis growth was reduced. We conclude that glucosylation of MBOA is an important detoxification mechanism that helps insects tolerate maize BXs.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Triterpenoid saponins from the roots of two Gypsophila species

Publication date: Available online 8 April 2014
Source:Phytochemistry

Author(s): David Pertuit , Sibel Avunduk , Anne-Claire Mitaine-Offer , Tomofumi Miyamoto , Chiaki Tanaka , Thomas Paululat , Stéphanie Delemasure , Patrick Dutartre , Marie-Aleth Lacaille-Dubois

Two triterpenoid saponins with two known ones have been isolated from the roots of Gypsophila arrostii var. nebulosa, and two new ones from the roots of Gypsophila bicolor. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-?-d-galactopyranosyl-(1?2)-[?-d-xylopyranosyl-(1?3)]-?-d-glucuronopyranosylquillaic acid 28-O-?-d-xylopyranosyl-(1?4)-[?-d-glucopyranosyl-(1?3)]-?-l-rhamnopyranosyl-(1?2)-[?-d-glucopyranosyl-(1?4)]-?-d-fucopyranosyl ester (1), 3-O-?-d-galactopyranosyl-(1?2)-[?-d-xylopyranosyl-(1?3)]-?-d-glucuronopyranosylgypsogenin 28-O-?-d-xylopyranosyl-(1?4)-[?-d-glucopyranosyl-(1?3)]-?-l-rhamnopyranosyl-(1?2)-[?-d-glucopyranosyl-(1?4)]-?-d-fucopyranosyl ester (2), 3-O-?-d-galactopyranosyl-(1?2)-[?-d-xylopyranosyl-(1?3)]-?-d-glucuronopyranosylgypsogenin 28-O-?-d-xylopyranosyl-(1?3)-?-d-xylopyranosyl-(1?4)-?-l-rhamnopyranosyl-(1?2)-[(4-O-acetyl)-?-d-quinovopyranosyl-(1?4)]-?-d-fucopyranosyl ester (3), gypsogenic acid 28-O-?-d-glucopyranosyl-(1?3)-{6-O-[3-hydroxy-3-methylglutaryl]-?-d-glucopyranosyl-(1?6)}-?-d-galactopyranosyl ester (4). Three compounds were evaluated against one human colon cancer cell line SW480 and one rat cardiomyoblast cell line H9c2.

Graphical abstract

image

Highlights

Four triterpene saponins and two known compounds were isolated from two species of the genus Gypsophila. Their structures were established by spectroscopic methods. The cytotoxic activity of three saponins was evaluated against SW480 and H9c2 cell lines.





Posted on 19 April 2014 | 6:58 am


Formation of oxidized phosphatidylinositol and 12-oxo-phytodienoic acid containing acylated phosphatidylglycerol during the hypersensitive response in Arabidopsis

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Anders K. Nilsson , Oskar N. Johansson , Per Fahlberg , Feray Steinhart , Mikael B. Gustavsson , Mats Ellerström , Mats X. Andersson

Plant membranes are composed of a wide array of polar lipids. The functionality of these extends far beyond a pure structural role. Membrane lipids function as enzyme co-factors, establish organelle identity and as substrates for enzymes such as lipases and lipoxygenases. Enzymatic degradation or oxidation (enzymatic or non-enzymatic) of membrane lipids leads to the formation of a diverse group of bioactive compounds. Plant defense reactions provoked by pathogenic microorganisms are often associated with substantial modifications of the lipidome. In this study, we profiled changes in phospholipids during the hypersensitive response triggered by recognition of the bacterial effector protein AvrRpm1 in Arabidopsis thaliana. A simple and robust LC–MS based method for profiling plant lipids was designed to separate all the major species of glycerolipids extracted from Arabidopsis leaf tissue. The method efficiently separated several isobaric and near isobaric lipid species, which otherwise are difficult to quantify in direct infusion based profiling. In addition to the previously reported OPDA-containing galactolipids found to be induced during hypersensitive response in Arabidopsis, three OPDA-containing sulfoquinovosyl diacylglycerol species, one phosphatidylinositol species as well as two acylated OPDA-containing phosphatidylglycerol species were found to accumulate during the hypersensitive response in Arabidopsis. Our study confirms and extends on the notion that the hypersensitive response in Arabidopsis triggers a unique profile of Allene Oxide Synthase dependent oxidation of membrane lipids. Primary targets of this oxidation seem to be uncharged and anionic lipid species.

Graphical abstract

image

Highlights

Glycerolipids obtained from Arabidopsis leaf tissue undergoing the hypersensitive response triggered by the bacterial effector protein AvrRpm1 were analyzed by a new reverse phase LC-MS/MS method. Among the lipids discovered by untargeted phospholipid profiling were phosphatidylglycerol species acylated with 12-oxo-phytodienoic acid.




Posted on 19 April 2014 | 6:58 am


NO signaling in plant immunity: A tale of messengers

Publication date: Available online 5 April 2014
Source:Phytochemistry

Author(s): Pauline Trapet , Anna Kulik , Olivier Lamotte , Sylvain Jeandroz , Stéphane Bourque , Valérie Nicolas-Francès , Claire Rosnoblet , Angélique Besson-Bard , David Wendehenne

Nitric oxide (NO) is a free radical gas involved in a myriad of plant physiological processes including immune responses. How NO mediates its biological effects in plant facing microbial pathogen attack is an unresolved question. Insights into the molecular mechanisms by which it propagates signals reveal the contribution of this simple gas in complex signaling pathways shared with reactive oxygen species (ROS) and the second messenger Ca2+. Understanding of the subtle cross-talks operating between these signals was greatly improved by the recent identification and the functional analysis of proteins regulated through S-nitrosylation, a major NO-dependent post-translational protein modification. Overall, these findings suggest that NO is probably an important component of the mechanism coordinating and regulating Ca2+ and ROS signaling in plant immunity.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Sesquiterpenes from the saprotrophic fungus Granulobasidium vellereum (Ellis & Cragin) Jülich

Publication date: Available online 3 April 2014
Source:Phytochemistry

Author(s): Christina L. Nord , Audrius Menkis , Christofer Lendel , Rimvydas Vasaitis , Anders Broberg

Twelve sesquiterpenes comprising either the protoilludane or the rare cerapicane carbon skeletons were obtained from the saprotrophic wood decomposing fungus Granulobasidium vellereum; 2a-hydroxycoprinolone (1), 3-hydroxycoprinolone (2), coprinolone diol B (3), granulodiene A (4), granulodiene B (5), granulone A (6), 8-deoxy-4a-hydroxytsugicoline B (7), granulone B (8), demethylgranulone (9), cerapicolene (10), as well as the known compounds radudiol and ?6-coprinolone. The structures were determined using spectroscopic methods and biosynthetic considerations. Granulone A had growth stimulating effect on the total elongation of lettuce seedlings. None of the isolated compounds showed any antifungal effect.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Genotypes of Fraxinus excelsior with different susceptibility to the ash dieback pathogen Hymenoscyphus pseudoalbidus and their response to the phytotoxin viridiol – A metabolomic and microscopic study

Publication date: Available online 4 April 2014
Source:Phytochemistry

Author(s): M.R. Cleary , P.F. Andersson , A. Broberg , M. Elfstrand , G. Daniel , J. Stenlid

Eight European ash (Fraxinus excelsior) genotypes with different known susceptibility to Hymenoscyphus pseudoalbidus were tested against the phytotoxin viridiol and their response described at the microscopic and metabolomic level. All ash genotypes were sensitive to the toxin and necrosis was detectable after 24h. Among the three viridiol concentrations used in the experiment, the lowest concentration (14.7?M) yielded markedly lower mean damage scores compared to those resulting from seedlings tested at higher dosages. The highest damage scores were associated with the susceptible ash clones S-101, S-106 and S-125, but also with resistant clone R-104. Three resistant clones (R-131, R-121, and R-118) had lower mean damage scores compared to susceptible clones. Wilting of leaves was more common 48h after treatment and more pronounced on seedlings with high damage scores. The resulting lesions generally lacked browning of tissue and displayed only surface disruption of cells in direct contact with the toxin. A delay in symptom development was evident on all five resistant clones tested with the two higher concentrations of viridiol. LC-HRMS and MS/MS analyses of ash seedling extracts suggest several secoiridoid compounds as well as compounds related to abscisic acid (ABA) to be produced in response to viridiol. ABA-cysteine and xanthoxin were found at significantly higher concentrations in susceptible clones compared to resistant clones after treatment with viridiol, suggesting a primary role of ABA in response to stress. The results observed in this study suggest that genetic resistance to H. pseudoalbidus among ash genotypes may be explained, in part, by the varied response to phytotoxins produced by the fungus.

Graphical abstract

image

Highlights

The sensitivity of (a) susceptible and (b) resistant genotypes of European ash (Fraxinus excelsior) following treatment with the phytotoxin viridiol produced by the ascomycete Hymenoscyphus pseudoalbidus, compared to the (c) susceptible control.





Posted on 19 April 2014 | 6:58 am


Diversity of fatty acid composition of symbiotic dinoflagellates in corals: Evidence for the transfer of host PUFAs to the symbionts

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Andrey B. Imbs , Irina M. Yakovleva , Tatiana N. Dautova , Long H. Bui , Paul Jones

High diversity of fatty acid (FA) composition of endosymbiotic dinoflagellates of the Symbiodinium group (zooxanthellae) isolated from different cnidarian groups has been found. To explain this diversity, FA composition of the total lipids of pure symbiont fractions (SF) and host cell tissue fractions (HF) isolated from one hydrocoral, two soft coral, and seven hard coral species inhabiting the shallow waters of the South China Sea (Vietnam) were compared. Symbiodinium phylogenetic clade designation for each SF was also determined, however, the relationship between the clade designation and FA composition of Symbiodinium was not found. The profiles of marker polyunsaturated FAs (PUFAs) of symbionts (18:4n-3, 18:5n-3, 20:5n-3) did not depend on taxonomic designation of the host and reflected only a specimen-specific diversity of the SF lipids. Several FAs such as 20:0, C24 PUFAs, 22:5n-6, and 18:2n-7 concentrated in HF lipids but were also found in SF lipids. For ten cnidarian species studied, the principal components analysis of total FAs (27 variables) of the symbiotic fractions was performed. The clear division of the symbiotic dinoflagellates according to the host systematic identity was found on a subclass level. This division was mainly caused by the FAs specific for the host lipids of each cnidarian subclasses such as hard corals, soft corals, and hydrocorals. Thus, the coral hosts affect the FA profile of their symbionts and cause the diversity of FA composition of Symbiodinium. The transfer of FAs from the coral host to their symbiotic dinoflagellates and modulation of PUFA biosynthesis in symbionts by the host are considered as possible reasons of the diversity studied.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Elucidation of antioxidant properties of wood bark derived saturated diarylheptanoids: A comprehensive (DFT-supported) understanding

Publication date: Available online 3 April 2014
Source:Phytochemistry

Author(s): Jevgenija Ponomarenko , Patrick Trouillas , Nicolas Martin , Tatyana Dizhbite , Jelena Krasilnikova , Galina Telysheva

A series of diarylheptanoids, namely 1,7-bis-(3,4-dihydroxyphenyl)-heptan-3-one-5-O-d-xylopyranoside (oregonin), 1,7-bis-(3,4-dihydroxyphenyl)-3-hydroxyheptane-5-O-?-d-xylopyranoside and 1,7-bis-(4-hydroxyphenyl)-heptane-3-one-5-O-?-d-glucopyranoside (platyphylloside), were isolated from the bark of alder family trees, a species widely spread over in Europe. As antioxidants, these natural polyphenols have a promising potential in various fields of application, but their redox reactivity is insufficiently characterized. In this work, their antioxidant activity is described using assays based on DPPH and ABTS + radical scavenging, oxygen anion radicals ( O 2 - ) quenching. The standardized ORAC assay was also achieved, which measures the capacity to protect fluorescent molecules against oxidative degradation. The measured antioxidant activity was higher than that of the well-known antioxidant and biologically active diarylheptanoid curcumin. Molecular modeling was used to rationalize the differences in activity and the mechanisms of action. Thermodynamic descriptors mainly O–H bond dissociation enthalpies (BDEs) establish a clear structure–activity relationship.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Graphical Contents List

Publication date: April 2014
Source:Phytochemistry, Volume 100









Posted on 19 April 2014 | 6:58 am


Editorial Board/Publication Information

Publication date: April 2014
Source:Phytochemistry, Volume 100









Posted on 19 April 2014 | 6:58 am


Chemical constituents from aerial parts of Caryopteris incana and cytoprotective effects in human HepG2 cells

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Sunmi Park , Min Jeong Son , Chang-Soo Yook , Changbae Jin , Yong Sup Lee , Hyoung Ja Kim

An ethyl acetate fraction of the aerial parts of Caryopteris incana (Verbenaceae) showed potent cytoprotective effects against damage to HepG2 cells induced by tert-butylhydroperoxide (t-BHP). To search for hepatoprotective components of C. incana, various chromatographic separations of the ethyl acetate soluble fraction of C. incana led to isolation of three phenylpropanoid glycosides, 6?-O-feruloylincanoside D, 6?-O-sinapoylincanoside D and caryopteroside, and two iridoid glycosides, incanides A and B, together with 17 known compounds. Structures of these compounds were determined by spectroscopic analyses. The absolute stereochemistry of the caryopteroside was established with the help of circular dichroism data and in comparison with literature data. All isolated substances were determined for their cytoprotective effects against t-BHP-induced toxicity in HepG2 cells. Among the tested compounds, 6?-O-caffeoylacteoside exhibited the most potent cytoprotective activity with an IC50 value of 0.8±0.1?M against t-BHP-induced toxicity. Structure–activity relationships of the assay results indicated an important role of the catechol moiety in phenylpropanoid, iridoid and flavonoid derivatives in eliciting cytoprotective effects.

Graphical abstract

image

Highlights

Three phenylpropanoid glycosides and two iridoid glycosides, together with 17 known compounds, were isolated from the aerial parts of Caryopteris incana. Structures of these compounds were determined by spectroscopic analyses. Among the isolates, 6?-O-caffeoylacteoside exhibited the most potent cytoprotective activity with an IC50 value of 0.8±0.1?M against t-butylhydroperoxide-induced cytotoxicity.





Posted on 19 April 2014 | 6:58 am


Antibodies against CKI1RD, a receiver domain of the sensor histidine kinase in Arabidopsis thaliana: From antigen preparation to in planta immunolocalization

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Petra Borkovcová , Blanka Pekárová , Martina Válková , Radka Dopitová , B?etislav Brzobohatý , Lubomír Janda , Jan Hejátko

Immunodetection is a powerful tool in functional studies of all organisms. In plants, the gene redundancy and presence of gene families composed of highly homologous members often impedes the unambiguous identification of individual gene products. A family of eight sensor histidine kinases (HKs) mediates the transduction of diverse signals into Arabidopsis thaliana cells, thereby ensuring the initiation of appropriate adaptive responses. Antibodies recognizing specific members of the HK family would be valuable for studying their functions in Arabidopsis and other plant species including important crops. We have focused on developing and applying antibodies against CYTOKININ-INDEPENDENT 1 (CKI1), which encodes a constitutively active membrane-bound sensor HK that regulates the development of female gametophytes and vascular tissue in Arabidopsis. A coding sequence delimiting the C-terminal receiver domain of CKI1 (CKI1RD) was expressed in Escherichia coli using the IPTG-inducible expression system and purified to give a highly pure target protein. The purified CKI1RD protein was then used as an antigen for anti-CKI1RD antibody production. The resulting polyclonal antibodies had a detection limit of 10ng of target protein at 1:20,000 dilution and were able to specifically distinguish CKI1, both in vitro and in situ, even in a direct comparison with highly homologous members of the same HK family AHK4, CKI2 and ETR1. Finally, anti-CKI1RD antibodies were able to selectively bind CKI1–GFP fusion protein in a pull-down assay using crude lysate from an Arabidopsis cell suspension culture. Our results suggest that the receiver domain is a useful target for the functional characterization of sensor HKs in immunological and biochemical studies.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Lipidomic profiling of snow algae by ESI-MS and silver-LC/APCI-MS

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Tomáš ?ezanka , Linda Nedbalová , Lenka Procházková , Karel Sigler

The main analytical benefit of this study is the development of methods enabling a rapid determination of total lipids of algae by lipidomic analysis and detailed identification and quantification of a complex mixture of natural TAGs by silver-LC/APCI-MS and NARP-LC/APCI-MS. Both types of chromatography can readily identify, both qualitatively and semiquantitatively, triacylglycerols containing 16:3 and 16:4 acids in the molecule. We conclude that the genus Chloromonas is a major producer of C16 PUFAs mostly contained in TAGs. Since more detailed studies in this field have been stymied by the shortage of 16:3 and 16:4 FAs, we decided to study the alga Chloromonas as a potential biotechnological source of C16 PUFAs.

Graphical abstract

image

Highlights

The development is described of methods enabling a rapid determination of total lipids of algae by lipidomic analysis and detailed identification and quantification of a complex mixture of natural TAGs by silver-LC/APCI-MS and NARP-LC/APCI-MS. This approach can readily identify, both qualitatively and semiquantitatively, triacylglycerols containing 16:3 and 16:4 acids in the molecule. We conclude that the genus Chloromonas is a major producer of C16 PUFAs mostly contained in TAGs. Since more detailed studies in this field have been stymied by the shortage of 16:3 and 16:4 FAs, we decided to study the alga Chloromonas as a potential biotechnological source of C16 PUFAs.




Posted on 19 April 2014 | 6:58 am


Identification and stress-induced expression of three 3?-hydroxysteroid dehydrogenases from Erysimum crepidifolium Rchb. and their putative role in cardenolide biosynthesis

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Jennifer Munkert , Mona Ernst , Frieder Müller-Uri , Wolfgang Kreis

3?-Hydroxysteroid dehydrogenases (3?HSD) are supposed to be involved in cardenolide biosynthesis in plants. Erysimum crepidifolium Rchb., a member of the Brassicaceae accumulating cardenolides, is a close relative to Arabidopsis thaliana. Full length cDNAs encoding for three individual 3?HSDs (EcHSD1, EcHSD2, EcHSD3) were isolated from E. crepidifolium leaves. EcHSD1 and EcHSD2 encode proteins assembled from 257 amino acids whereas EcHSD3 encodes a protein assembled from 260 amino acids. All three proteins qualify as members of the short-chain dehydrogenases/reductases family of proteins (SDRs). EcHSD1 and EcHSD2 shared a high amino acid sequence identity of about 86% and 91% with putative 3?HSDs of A. thaliana (AT2G47140 and AT2G47130). EcHSD3 showed high homology to the A. thaliana SDRs AT2G47150 (74%) and AT2G47120 (81%). All three EcHSD genes were expressed in Escherichia coli and the recombinant enzymes were characterized biochemically. All three recombinant EcHSDs catalyzed the dehydrogenation of pregnenolone and the 3-reduction of 5?/?-pregnane-3,20-dione when NAD and NADH were used as cosubstrates, respectively. After exposure to different stress conditions, no increased transcription was seen for EcHSD1 whereas EcHSD2 was expressed four times higher under osmotic stress than under control conditions. EcHSD3 expression was 10 times and 6 times higher after osmotic stress and MeJA treatment, respectively, than in controls.

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Monoterpene glycosides, phenylpropanoids, and acacetin glycosides from Dracocephalum foetidum

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Erdenechimeg Selenge , Toshihiro Murata , Shiho Tanaka , Kenroh Sasaki , Javzan Batkhuu , Fumihiko Yoshizaki

Chemical investigation of the acetone extract from the aerial parts of the Mongolian medicinal plant Dracocephalum foetidum resulted in the isolation of three limonene glycosides, a caffeic acid trimer, four rosmarinic acid glucosides, and five acacetin acyl glycosides, together with 13 known natural products. The chemical structures of all of the compounds were determined by spectroscopic analyses. Among these compounds three showed hyaluronidase inhibitory activity. In addition, one other compound showed stronger 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity than the positive control Trolox, whereas three other compounds demonstrated a similar activity to that of Trolox.

Graphical abstract

image

Highlights

From the Mongolian medicinal plant Dracocephalum foetidum, three limonene glycosides, a caffeic acid trimer, four rosmarinic acid glucosides, five acacetin acyl glycosides, and 13 known natural products were isolated. Hyaluronidase inhibitory activity and DPPH radical scavenging activity of the isolates were evaluated.





Posted on 19 April 2014 | 6:58 am


Characterization and heterologous expression of a PR-1 protein from traps of the carnivorous plant Nepenthes mirabilis

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Franziska Buch , Yannick Pauchet , Matthias Rott , Axel Mithöfer

Carnivorous plants capture and digest prey to obtain additional nutrients. Therefore, different trapping mechanisms were developed in different species. Plants of the genus Nepenthes possess pitfall-traps filled with a digestive fluid, which is secreted by the plants themselves. This pitcher fluid is composed of various enzymes to digest the captured prey. Besides hydrolytic enzymes, defense-related proteins have been identified in the fluid. The present study describes the identification and heterologous expression of a pathogenesis-related protein, NmPR-1, from pitchers of Nepenthes mirabilis with features that are unusual for PR-1 proteins. In particular, it was proven to be highly glycosylated and, furthermore, it exhibited antibacterial instead of antifungal activities. These properties are probably due to the specific environment of the pitcher fluid.

Graphical abstract

image

Highlights

Carnivorous Nepenthes plants catch prey or additional nutrients. The digestive fluid contains hydrolytic enzymes as well as defensive proteins such as PR-1 protein to suppress microbial growth.




Posted on 19 April 2014 | 6:58 am


Attraction of pea moth Cydia nigricana to pea flower volatiles

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Gunda Thöming , Geir K. Knudsen

The pea moth Cydia nigricana causes major crop losses in pea (Pisum sativum) production. We investigated attraction of C. nigricana females to synthetic pea flower volatiles in a wind tunnel and in the field. We performed electroantennogram analysis on 27 previously identified pea plant volatiles, which confirmed antennal responses to nine of the compounds identified in pea flowers. A dose-dependent response was found to eight of the compounds. Various blends of the nine pea flower volatiles eliciting antennal responses were subsequently studied in a wind tunnel. A four-compound blend comprising hexan-1-ol, (E)-2-hexen-1-ol, (Z)-?-ocimene and (E)-?-ocimene was equally attractive to mated C. nigricana females as the full pea flower mimic blend. We conducted wind-tunnel tests on different blends of these four pea flower compounds mixed with a headspace sample of non-flowering pea plants. By considering the effects of such green leaf background odour, we were able to identify (Z)- and (E)-?-ocimene as fundamental for host location by the pea moths, and hexan-1-ol and (E)-2-hexen-1-ol as being of secondary importance in that context. In the field, the two isomers of ?-ocimene resulted in trap catches similar to those obtained with the full pea flower mimic and the four-compound blend, which clearly demonstrated the prime significance of the ?-ocimenes as attractants of C. nigricana. The high level of the trap catches of female C. nigricana noted in this first field experiment gives a first indication of the potential use of such artificial kairomones in pea moth control.

Graphical abstract

image

Highlights

Wind tunnel and field experiments identified four synthetic pea flower volatiles as important attractants of pea moth, Cydia nigricana.




Posted on 19 April 2014 | 6:58 am


Accumulation and tolerance of lead in two contrasting ecotypes of Dianthus carthusianorum

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Ma?gorzata Wójcik , Anna Tukiendorf

Dianthus carthusianorum is one of the dominant plant species colonising the Zn–Pb waste deposits in Boles?aw, Southern Poland. It differs in terms of morphology and genetics from ecotypes inhabiting non-metal-polluted areas. The response of waste-heap (metallicolous, M) and reference (nonmetallicolous, NM) ecotypes of D. carthusianorum to Pb in hydroponics was investigated and compared in this study. The plants of the M ecotype were more tolerant to Pb than these of the NM ecotype in spite of accumulation of higher concentrations of Pb. In both ecotypes, about 70–78% of Pb was retained in roots. In non Pb-treated plants, a higher glutathione (GSH) level was found in the M ecotype. After the Pb exposure, the GSH level decreased and was similar in both ecotypes. Lead treatment induced synthesis of phytochelatins (PCs) only in the plant roots, with significantly higher concentrations thereof detected in the NM ecotype. Malate and citrate concentrations were higher in the M ecotype; however, they did not change significantly upon any Pb treatment in either ecotype. The results indicated that neither PCs nor organic acids were responsible for the enhanced Pb tolerance of the waste-heap plants.

Graphical abstract

image

Highlights

Growth parameters, Pb accumulation as well as thiol peptide and organic acid concentrations were determined in metalliferous (M) and nonmetalliferous (NM) ecotypes of Dianthus carthusianorum cultivated hydroponically in the presence of Pb.





Posted on 19 April 2014 | 6:58 am


Polar lipids from the marine macroalga Palmaria palmata inhibit lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells

Publication date: May 2014
Source:Phytochemistry, Volume 101

Author(s): Arjun H. Banskota , Roumiana Stefanova , Sandra Sperker , Santosh P. Lall , James S. Craigie , Jeff T. Hafting , Alan T. Critchley

The EtOAc soluble fraction of a MeOH/CHCl3 extract of Palmaria palmata showed strong nitric oxide (NO) inhibitory activity against lipopolysaccharide (LPS)-induced NO production in murine RAW264.7 cells. NO inhibition-guided isolation led to identification of three new polar lipids including a sulfoquinovosyl diacylglycerol (SQDG) (2S)-1-O-eicosapentaenoyl-2-O-myristoyl-3-O-(6-sulfo-?-d-quinovopyranosyl)-glycerol (1) and two phosphatidylglycerols, 1-O-eicosapentaenoyl-2-O-trans-3-hexadecenoyl-3-phospho-(1?-glycerol)-glycerol (3) and 1-O-eicosapentaenoyl-2-O-palmitoyl-3-phospho-(1?-glycerol)-glycerol (4) from the EtOAc fraction. Seven known lipids were also isolated including a SQDG (2), a phospholipid (5) and five galactolipids (6–10). Structures of the isolated lipids were elucidated by spectral analyses. The isolated SQDGs, phosphatidylglycerols and phospholipid possessed strong and dose-dependent NO inhibitory activity compared to NG-methyl-l-arginine acetate salt (l-NMMA), a well-known NO inhibitor used as a positive control. Further study suggested that these polar lipids suppressed NO production through down-regulation of inducible nitric oxide synthase (iNOS).

Graphical abstract

image




Posted on 19 April 2014 | 6:58 am


Terpenoid indole alkaloids from Mappianthus iodoides Hand.-Mazz.

Publication date: April 2014
Source:Phytochemistry, Volume 100

Author(s): Hai-Jian Cong , Qing Zhao , Shu-Wei Zhang , Jiao-Jiao Wei , Wen-Qiong Wang , Li-Jiang Xuan

Ten terpenoid indole alkaloids, mappiodines A–C and mappiodosides A–G, together with eight known compounds, were isolated from stems of Mappianthus iodoides Hand.-Mazz. Their structures were elucidated by spectroscopic analyses including 1D, 2D NMR, MS and CD methods. The ten compounds were evaluated for their cytotoxic activity, but were inactive.

Graphical abstract

image

Highlights

Ten terpenoid indole alkaloids were isolated from stems of Mappianthus iodoides Hand.-Mazz. Their structures were elucidated by spectroscopic analyses including 1D, 2D NMR and MS methods. Absolute configurations of two of these were assigned from their CD spectra.




Posted on 19 April 2014 | 6:58 am





Other notes:



 Information about this site:


 
The author- or copyrights of the listed Internet pages are held by the respective authors or site operators, who are also responsible for the content of the presentations.
 
To see your page listed here: Send us an eMail! Condition: Subject-related content on chemistry, biochemistry and comparable academic disciplines!
Citation:
http://www.internetchemistry.com/rss/phytochemistry.php
Keywords:
Chronological list of recent articles on Chemistry, Phytochemistry, Phytochemistry.
Update:
28.09.2013


Internetchemistry ChemLin © 1996 - 2013 A. J.