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Phytochemistry - Current Research Articles



Current research articles: Phytochemistry

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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:



Volatile compounds in cryptic species of the Aneura pinguis complex and Aneura maxima (Marchantiophyta, Metzgeriidae)

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Rafa? Wawrzyniak , Wies?aw Wasiak , Alina B?czkiewicz , Katarzyna Buczkowska

Aneura pinguis is one of the liverwort species complexes that consist of several cryptic species. Ten samples collected from different regions in Poland are in the focus of our research. Eight of the A. pinguis complex belonging to four cryptic species (A, B, C, E) and two samples of closely related species Aneura maxima were tested for the composition of volatile compounds. The HS-SPME technique coupled to GC/FID and GC/MS analysis has been applied. The fiber coated with DVB/CAR/PDMS has been used. The results of the present study, revealed the qualitative and quantitative differences in the composition of the volatile compounds between the studied species. Mainly they are from the group of sesquiterpenoids, oxygenated sesquiterpenoids and aliphatic hydrocarbons. The statistical methods (CA and PCA) showed that detected volatile compounds allow to distinguish cryptic species of A. pinguis. All examined cryptic species of the A. pinguis complex differ from A. maxima. Species A and E of A. pinguis, in CA and PCA, form separate clusters remote from two remaining cryptic species of A. pinguis (B and C) and A. maxima. Relationship between the cryptic species appeared from the chemical studies are in accordance with that revealed on the basis of DNA sequences.

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Posted on 30 July 2014 | 6:45 pm


Rare biscoumarin derivatives and flavonoids from Hypericum riparium

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Serge Alain Fobofou Tanemossu , Katrin Franke , Norbert Arnold , Jürgen Schmidt , Hippolyte Kamdem Wabo , Pierre Tane , Ludger A. Wessjohann

Hypericum riparium A. Chev. is a Cameroonian medicinal plant belonging to the family Guttiferae. Chemical investigation of the methanol extract of the stem bark of H. riparium led to the isolation of four natural products, 7,7?-dihydroxy-6,6?-biscoumarin (1), 7,7?-dihydroxy-8,8?-biscoumarin (2), 7-methoxy-6,7?-dicoumarinyl ether (3), 2?-hydroxy-5?-(7?-methoxycoumarin-6?-yl)-4?-methoxyphenylpropanoic acid (4), together with one known 7,7?-dimethoxy-6,6?-biscoumarin (5), two flavones, 2?-methoxyflavone (6) and 3?-methoxy flavone (7), and two steroids, stigmast-4-en-3-one (8) and ergosta-4,6,8,22-tetraen-3-one (9). In addition, tetradecanoic acid (10), n-pentadecanoic acid (11), hexadecanoic acid (12), cis-10-heptadecenoic acid (13), octadecanoic acid (14) campesterol (15), stigmasterol (16), ?-sitosterol (17), stigmastanol (18), ?-eudesmol (19), 1-hexadecanol (20), and 1-octadecanol (21) were identified by GC–MS analysis. Compound 4 consists of a phenylpropanoic acid derivative fused with a coumarin unit, while compounds 2 and 3 are rare members of C8–C8? and C7–O–C6 linked biscoumarins. Their structures were elucidated by UV, IR, extensive 1D- and 2D-NMR experiments and electrospray (ESI) high resolution mass spectrometry (MS) including detailed MS/MS studies. This is the first report on the isolation of biscoumarins from the genus Hypericum, although simple coumarin derivatives have been reported from this genus in the literature. The cytotoxic activities of compounds 25 were evaluated against the human prostate cancer cell line PC-3 and the colon cancer cell line HT-29. They do not exhibit any significant cytotoxic activity.

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Posted on 30 July 2014 | 6:45 pm


Cytotoxic diterpenoids from Salvia yunnanensis

Publication date: Available online 28 July 2014
Source:Phytochemistry

Author(s): Chun-Yan Wu , Yang Liao , Zi-Gang Yang , Xing-Wei Yang , Xiao-Ling Shen , Rong-Tao Li , Gang Xu

Forty-six abietane type diterpenoids possessing nine different fused ring systems were characterized from the roots of Salvia yunnanensis, six of which (salyunnanins A–F, 16) had different nor-abietane, homo-abietane, seco-abietane, and normal abietane architectures. Their structures were elucidated by comprehensive NMR and MS spectroscopic analyses. The inhibitory activities of these isolates against six human tumor lines were tested in vitro. Several of the compounds exhibited substantial cytotoxicity with IC50 values of 0.86–10.1?M.

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Posted on 30 July 2014 | 6:45 pm


Purple anthocyanin colouration on lower (abaxial) leaf surface of Hemigraphis colorata (Acanthaceae)

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Irene Skaar , Christopher Adaku , Monica Jordheim , Robert Byamukama , Bernard Kiremire , Øyvind M. Andersen

The functional significance of anthocyanin colouration of lower (abaxial) leaf surfaces is not clear. Two anthocyanins, 5-O-methylcyanidin 3-O-(3?-(?-glucuronopyranosyl)-?-glucopyranoside) (1) and 5-O-methylcyanidin 3-O-?-glucopyranoside (2), were isolated from Hemigraphis colorata (Blume) (Acanthaceae) leaves with strong purple abaxial colouration (2.2 and 0.6mg/gfr.wt., respectively). The glycosyl moiety of 1, the disaccharide 3?-(?-glucuronopyranosyl)-?-glucopyranoside), has previously been reported to occur only in a triterpenoid saponin, lindernioside A. The structural assignment of the aglycone of 1 and 2 is the first complete characterisation of a natural 7-hydroxy-5-methoxyanthocyanidin. Compared to nearly all naturally occurring anthocyanidins, the 5-O-methylation of this anthocyanidin limits the type of possible quinoidal forms of 1 and 2 to be those forms with keto-function in only their 7- and 4?-positions.

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Purple abaxial colouration of leaves of Hemigraphis colorata (Acanthaceae) is caused by two unusual anthocyanins.





Posted on 30 July 2014 | 6:45 pm


Graphical Contents List

Publication date: September 2014
Source:Phytochemistry, Volume 105









Posted on 30 July 2014 | 6:45 pm


Cytotoxic and antifungal activities of melleolide antibiotics follow dissimilar structure–activity relationships

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Markus Bohnert , Hans-Wilhelm Nützmann , Volker Schroeckh , Fabian Horn , Hans-Martin Dahse , Axel A. Brakhage , Dirk Hoffmeister

The fungal genus Armillaria is unique in that it is the only natural source of melleolide antibiotics, i.e., protoilludene alcohols esterified with orsellinic acid or its derivatives. This class of natural products is known to exert antimicrobial and cytotoxic effects. Here, we present a refined relationship between the structure and the antimicrobial activity of the melleolides. Using both agar diffusion and broth dilution assays, we identified the ?2,4-double bond of the protoilludene moiety as a key structural feature for antifungal activity against Aspergillus nidulans, Aspergillus flavus, and Penicillium notatum. These findings contrast former reports on cytotoxic activities and may indicate a different mode of action towards susceptible fungi. We also report the isolation and structure elucidation of five melleolides (6?-dechloroarnamial, 6?-chloromelleolide F, 10-hydroxy-5?-methoxy-6?-chloroarmillane, and 13-deoxyarmellides A and B), along with the finding that treatment with an antifungal melleolide impacts transcription of A. nidulans natural product genes.

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Posted on 30 July 2014 | 6:45 pm


Lathyrane-type diterpenoids from the seeds of Euphorbia lathyris

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Jin Lu , Guoyu Li , Jian Huang , Cui Zhang , Lan Zhang , Ke Zhang , Pingya Li , Ruichao Lin , Jinhui Wang

Ten lathyrane-type diterpenoids named Euphorbia Factor L12–L21 (110) and twelve known diterpenoids (1122) were isolated from seeds of Euphorbia lathyris. The structures of these compounds were determined by extensive spectroscopic (UV, IR, HRESIMS, 1D and 2D NMR) analyses. In addition, the configuration of Euphorbia Factor L12 (1) was further confirmed by X-ray crystallographic and circular dichroism (CD) analyses. A putative biogenetic relationship to these compounds was proposed. Cytotoxicity of the isolated compounds against C6 and MCF-7 cell lines were evaluated. Compounds 1, 5, 7, 12 and 17 exhibited considerable cytotoxic activities (IC50 12.4–36.2?M).

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Posted on 30 July 2014 | 6:45 pm


Biotransformation of 20(R)-panaxadiol by the fungus Rhizopus chinensis

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Xiong-Hao Lin , Ming-Nan Cao , Wen-Ni He , Si-Wang Yu , De-An Guo , Min Ye

Microbial transformation of 20(R)-panaxadiol by the fungus Rhizopus chinensis CICC 3043 yielded seven metabolites. Their structures were elucidated on the basis of extensive spectroscopic analyses. R. chinensis could catalyze hydroxylation and further dehydrogenation at C-24 of 20(R)-panaxadiol, as well as hydroxylation at C-7, C-15, C-16, and C-29. Three of these compounds at 10?M could moderately inhibit growth of HepG2 human hepatocellular carcinoma cells with an inhibition rate of about 40%. Three compounds (also at 10?M) showed approximately 30% inhibition on NF-?B transcriptional activity in SW480 human colon carcinoma cells stably transfected with NF-?B luciferase reporter and induced by LPS.

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Posted on 30 July 2014 | 6:45 pm


Frank A. Loewus (1919–2014): A life well spent and well remembered

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Norman G. Lewis







Posted on 30 July 2014 | 6:45 pm


Ambiguanine A–G, hexahydrobenzophenanthridine alkaloids from Corydalis ambigua var. amurensis

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Zhi-You Yang , Bao-Hong Jiang , Fu-Kang Teng , Na Han , Zhi-Hui Liu , Jing-Jing Zhou , Yu Wang , De-An Guo , Jun Yin

Seven hexahydrobenzophenanthridine-type alkaloids, Ambiguanine A–G, along with eight known alkaloids, were isolated from tubers of Corydalis ambigua var. amurensis. Their structures were elucidated based on extensive spectroscopic analyses, with absolute configurations determined by CD experiments.

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Posted on 30 July 2014 | 6:45 pm


Guaiane sesquiterpenes and isopimarane diterpenes from an endophytic fungus Xylaria sp.

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Shao-Hua Wu , Jian He , Xiao-Nian Li , Rong Huang , Fei Song , You-Wei Chen , Cui-Ping Miao

Nine oxygenated guaiane-type sesquiterpenes and three isopimarane diterpenes were isolated from the culture broth of an endophytic fungus, Xylaria sp. YM 311647, obtained from Azadirachta indica. The structures of these compounds were elucidated by interpretation of spectroscopic data. The absolute configurations of two of these were confirmed by X-ray crystallographic analysis. All of the compounds were tested for their antifungal activities against five pathogenic fungal cells. The results showed that nine sesquiterpenes were moderately active against Candida albicans and Hormodendrum compactum with MIC values ranging from 32 to 256?g/ml, while the diterpenes were more active; One of these exhibited the most potent inhibitory activity against C. albicans and Pyricularia oryzae with MIC values of 16?g/ml.

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Posted on 30 July 2014 | 6:45 pm


A chitinolytic endochitinase and ?-N-acetylglucosaminidase-based system from Hevea latex in generating N-acetylglucosamine from chitin

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Pannawich Sukprasirt , Rapepun Wititsuwannakul

An endochitinase and ?-N-acetylglucosaminidase (NAGase) were purified and characterised from fresh rubber latex serum. These enzymes were used in a total enzyme-based system to produce pure N-acetylglucosamine (NAG) from chitin. The N-terminal amino acid sequences of both purified endochitinase (KEESRRRRHR) and NAGase (AAVDSDTLEI) lacked homology with other known chitinases, including hevamine from rubber latex lutoids. The apparent kinetic parameters, K m and V max, for the endochitinase using 4-MU-?-(NAG)3 as a substrate were 99.73?M and 29.49pkatmg?1, respectively. For NAGase, using 4-MU-?-NAG as a substrate, the corresponding K m and V max values were 20.4?M and 25.82pkatmg?1. When an enzyme incubation mixture containing a 1:1 (pkat/pkat) activity mixed ratio of endochitinase: NAGase was employed, the maximum yield of N-acetylglucosamine (NAG) obtained was 98% from ?-chitin and 20% from ?-chitin. These yields were obtained after 4days of hydrolysis of equal amounts of ?-chitin and ?-chitin in the mixture. Thus, ?-chitin was the preferred substrate compared to ?-chitin by a ratio of nearly five to one. Mass spectroscopic analysis, using electrospray ionisation mass spectrometry (ESI-MS), of the product obtained from ?-chitin after digestion (for 24h) depicted one distinct major molecular ion peak m/z 260.1, a small minor ion peak m/z 481.2, a potassium adduct of NAG and a potassium adduct of two NAG molecules. Furthermore, experiments to establish the commercial production of NAG using crude enzymes of Hevea latex serum are currently in progress.

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Posted on 30 July 2014 | 6:45 pm


Expression of terpene synthase genes associated with the formation of volatiles in different organs of Vitis vinifera

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Fabiola Matarese , Angela Cuzzola , Giancarlo Scalabrelli , Claudio D’Onofrio

Plants produce a plethora of volatile organic compounds (VOCs) which are important in determining the quality and nutraceutical properties of horticultural food products, including the taste and aroma of wine. Given that some of the most prevalent grape aroma constituents are terpenoids, we investigated the possible variations in the relative expression of terpene synthase (TPS) genes that depend on the organ. We thus analysed mature leaves, young leaves, stems, young stems, roots, rachis, tendrils, peduncles, bud flowers, flowers and berries of cv Moscato bianco in terms of their VOC content and the expression of 23 TPS genes. In terms of the volatile characterization of the organs by SPME/GC–MS analysis, flower buds and open flowers appeared to be clearly distinct from all the other organs analysed in terms of their high VOC concentration. Qualitatively detected VOCs clearly separated all the vegetative organs from flowers and berries, then the roots and rachis from other vegetative organs and flowers from berries, which confirms the specialization in volatile production among different organs. Our real-time RT-PCR results revealed that the majority of TPS genes analysed exhibited detectable transcripts in all the organs investigated, while only some were found to be expressed specifically in one or just a few organs. In most cases, we found that the known products of the in vitro assay of VvTPS enzymes corresponded well to the terpenes found in the organs in which the encoding gene was expressed, as in the case of (E)-?-caryophyllene synthases, ?-terpineol synthase and ?-farnesene synthase. In addition, we found groups of homologous TPS genes, such as (E)-?-caryophyllene and ?-ocimene synthases, expressed distinctively in the various tissues. This thus confirmed the subfunctionalization events and a specialization on the basis of the organs in which they are mostly expressed.

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Posted on 30 July 2014 | 6:45 pm


Dimeric guaianolides from Artemisia absinthium

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Ablajan Turak , She-Po Shi , Yong Jiang , Peng-Fei Tu

Five dimeric guaianolides, absinthins A–E, and seven known dimeric guaianolides were isolated from Artemisia absinthium. Their structures were elucidated based on 1D- and 2D-NMR experiments, including 1H NMR, 13C NMR, DEPT, 1H–1H COSY, HSQC, HMBC, and NOESY, and through HRESIMS data analysis. The absolute configuration of the known compound, anabsinthin, was determined by X-ray crystallographic analysis. The isolated compounds were tested to assess their inhibitory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV-2 cells; absinthin C and isoanabsinthin exhibited significant inhibitory effects with IC50 values of 1.52 and 1.98?M, respectively.

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Posted on 30 July 2014 | 6:45 pm


Structural alteration of cell wall pectins accompanies pea development in response to cold

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Laëtitia Baldwin , Jean-Marc Domon , John F. Klimek , Françoise Fournet , Hélène Sellier , Françoise Gillet , Jérôme Pelloux , Isabelle Lejeune-Hénaut , Nicholas C. Carpita , Catherine Rayon

Pea (Pisum sativum) cell wall metabolism in response to chilling was investigated in a frost-sensitive genotype ‘Terese’ and a frost-tolerant genotype ‘Champagne’. Cell walls isolated from stipules of cold acclimated and non-acclimated plants showed that cold temperatures induce changes in polymers containing xylose, arabinose, galactose and galacturonic acid residues. In the tolerant cultivar Champagne, acclimation is accompanied by increases in homogalacturonan, xylogalacturonan and highly branched Rhamnogalacturonan I with branched and unbranched (1?5)-?-arabinans and (1?4)-?-galactans. In contrast, the sensitive cultivar Terese accumulates substantial amounts of (1?4)-?-xylans and glucuronoxylan, but not the pectins. Greater JIM7 labeling was observed in Champagne compared to Terese, indicating that cold acclimation also induces an increase in the degree of methylesterification of pectins. Significant decrease in polygalacturonase activities in both genotypes were observed at the end of cold acclimation. These data indicate a role for esterified pectins in cold tolerance. The possible functions for pectins and their associated arabinans and galactans in cold acclimation are discussed.

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Posted on 30 July 2014 | 6:45 pm


Cadinane sesquiterpenoids from the basidiomycete Stereum cf. sanguinolentum BCC 22926

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Taridaporn Bunyapaiboonsri , Seangaroon Yoiprommarat , Rujirek Nopgason , Somjit Komwijit , Sukitaya Veeranondha , Pucharapa Puyngain , Thitiya Boonpratuang

Stereumins Q–U, together with known stereumins A, B, K, L, and N, as well as ent-strobilols E and G were isolated from the culture of Stereum cf. sanguinolentum BCC 22926. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of stereumins A and Q, as well as ent-strobilol E were established by application of the modified Mosher’s method. Stereumin T displayed antibacterial activity against Bacillus cereus with a MIC value of 3.97?M.

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Highlights

Stereumins Q–U were isolated from the liquid culture of Stereum cf. sanguinolentum BCC 22926. Stereumin T displayed antibacterial activity against Bacillus cereus with a MIC value of 3.97?M.





Posted on 30 July 2014 | 6:45 pm


Molecular and biochemical characterization of caffeine synthase and purine alkaloid concentration in guarana fruit

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Flávia Camila Schimpl , Eduardo Kiyota , Juliana Lischka Sampaio Mayer , José Francisco de Carvalho Gonçalves , José Ferreira da Silva , Paulo Mazzafera

Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein.

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Posted on 30 July 2014 | 6:45 pm


?-Hydroxynitrile glucosides from the seeds of Prinsepia utilis

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Bin Guan , Tao Li , Xi-Ke Xu , Xu-Feng Zhang , Pan-Lei Wei , Cheng-Cheng Peng , Jian-Jun Fu , Qi Zeng , Xiang-Rong Cheng , Shou-De Zhang , Shi-Kai Yan , Hui-Zi Jin , Wei-Dong Zhang

?-Hydroxynitrile glucosides (prinsepicyanosides A–E) were isolated alongside 11 known compounds from seeds of Prinsepia utilis Royle. Their structures were determined by detailed analysis of NMR and MS spectroscopic data. The relative configuration of prinsepicyanoside C was established by Cu-K? X-ray crystallography. Prinsepicyanoside A, osmaronin, and 4-(hydroxylmethyl)-5H-furan-2-one exhibited borderline antibacterial activity against Salmonella gallinarum, Vibrio parahaemolyticus, and Vibrio cholera with MIC values of 30.1, 20.7, and 22.8?g/mL, respectively.

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Posted on 30 July 2014 | 6:45 pm


Isochromenones, isobenzofuranone, and tetrahydronaphthalenes produced by Paraphoma radicina, a fungus isolated from a freshwater habitat

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Tamam El-Elimat , Huzefa A. Raja , Mario Figueroa , Joseph O. Falkinham III , Nicholas H. Oberlies

Six isochromenones (16), clearanols F (5) and G (6), one isobenzofuranone (7), and two tetrahydronaphthalene derivatives (8 and radinaphthalenone (9)), were isolated and identified from a culture of the fungus Paraphoma radicina, which was isolated from submerged wood in a freshwater lake. Compounds 5, 6 and 9 were previously unknown. The structures were elucidated using a set of spectroscopic and spectrometric techniques; the absolute configurations of compounds 5 and 6 were determined by comparison of their experimental ECD measurements with values predicted by TDDFT calculations. Compounds 19 were evaluated for antimicrobial activity against an array of bacteria and fungi. The inhibitory activity of compound 4 against Staphylococcus aureus biofilm formation was evaluated.

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Posted on 30 July 2014 | 6:45 pm


UHPLC–MS/MS based target profiling of stress-induced phytohormones

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Kristýna Floková , Danuše Tarkowská , Otto Miersch , Miroslav Strnad , Claus Wasternack , Ond?ej Novák

Stress-induced changes in phytohormone metabolite profiles have rapid effects on plant metabolic activity and growth. The jasmonates (JAs) are a group of fatty acid-derived stress response regulators with roles in numerous developmental processes. To elucidate their dual regulatory effects, which overlap with those of other important defence-signalling plant hormones such as salicylic acid (SA), abscisic acid (ABA) and indole-3-acetic acid (IAA), we have developed a highly efficient single-step clean-up procedure for their enrichment from complex plant matrices that enables their sensitive quantitative analysis using hyphenated mass spectrometry technique. The rapid extraction of minute quantities of plant material (less than 20mg fresh weight, FW) into cold 10% methanol followed by one-step reversed-phase polymer-based solid phase extraction significantly reduced matrix effects and increased the recovery of labile JA analytes. This extraction and purification protocol was paired with a highly sensitive and validated ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method and used to simultaneously profile sixteen stress-induced phytohormones in minute plant material samples, including endogenous JA, several of its biosynthetic precursors and derivatives, as well as SA, ABA and IAA.

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Posted on 30 July 2014 | 6:45 pm


Membrane-forming lipids of wild halophytes growing under the conditions of Prieltonie of South Russia

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Olga A. Rozentsvet , Victor N. Nesterov , Elena S. Bogdanova

The composition of membrane-forming lipids has been examined for 10 wild halophyte species growing in southern Russian on alkaline soil. The plants belong to seven taxa of family rank: by their life form, which are semi-shrubs, herbaceous annuals, and perennial plants; their salt tolerance, which are classified as the euhalophytes, crynohalophytes, and glycohalophytes; and by their sensitivity to water, classifications of mesoxerophytes and xeromesophytes. Parallels have been found between the lipid composition and the ecological status of the plants. It has also been revealed that the similarity in the glyco- and phospholipid composition of different plant groups relates to the water factor and the type of salt accumulation, respectively. The fatty acid compositions of the examined plants is determined at the species level.

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Posted on 30 July 2014 | 6:45 pm


Chemical constituents of Abies delavayi

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Xian-Wen Yang , Su-Mei Li , Yong-Li Li , Lin Feng , Yun-Heng Shen , Shen Lin , Jun-Mian Tian , Hua-Wu Zeng , Ning Wang , Andre Steinmetz , Yonghong Liu , Wei-Dong Zhang

Systematic phytochemical investigations on Abies delavayi afforded 110 compounds, including 49 terpenoids, 13 lignans, 20 flavonoids, three coumarins, and 25 other chemical constituents. By detailed analysis of one- and two-dimensional NMR spectroscopic and high-resolution mass spectrometric data, 10 previously unreported compounds were identified: they comprised three sesquiterpenoids, two diterpenoids, one triterpenoid, one monoterpenoid, one flavonoid, and two phenols. These 10 compounds and some previously known ones were subjected to two cytotoxic bioassays against three human tumor cell lines and NO production inhibition on RAW264.7 macrophages, respectively. (25R)-24,25-Dihydroabieslactone had the strongest cytotoxic activity against Colo-205 cells with an IC50 value of 19.0±3.7?g/mL. (+)-T-cadinol, 8,11,13-abietatrien-15-ol-18-yl acetate, 18-acetoxy-13-epi-manool, imperatorin, bergapten, and 5,7-O-dimethyl poriol exhibited weak inhibitory activity against LPS-induced NO production in RAW264.7 macrophages with IC50 values of approximately 50?g/mL.

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Highlights

Ten previously unreported compounds above were isolated from Abies delavayi together with 100 known ones. (25R)-24,25-Dihydroabieslactone had the strongest cytotoxic activity against Colo-205 cells. Six known compounds showed weak inhibitory activity against LPS-induced NO production in RAW264.7 macrophages.





Posted on 30 July 2014 | 6:45 pm


Editorial Board/Publication Information

Publication date: September 2014
Source:Phytochemistry, Volume 105









Posted on 30 July 2014 | 6:45 pm


Grape anthocyanin oligomerization: A putative mechanism for red color stabilization?

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Joana Oliveira , Natércia F. Brás , Mara Alhinho da Silva , Nuno Mateus , A. Jorge Parola , Victor de Freitas

The equilibrium forms of malvidin-3-O-glucoside trimer present in grape skins were studied in aqueous solution at different pH values through UV–Visible spectroscopy. It was observed that the reactivity of this compound is strongly dominated by acid–base chemistry (pK a1 =3.61±0.03; pK a2 =6.83±0.06), with the reaction sequence hydration–tautomerization–isomerization accounting less than 10% of the overall reactivity. The decrease of hydration of this flavylium cation derivative when compared to the original anthocyanins results from the formation of a cluster of the pigment with a high-energy of solvation that inhibits the access of water molecules to the flavylium cation core preventing by this way the hydration reactions. Overall of these results raise the hypothesis that polymerization may be a natural stabilization mechanism for the red color of anthocyanins.

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Posted on 30 July 2014 | 6:45 pm


Cytogeography of essential oil chemotypes of Eremophila longifolia F. Muell (Scrophulariaceae)

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Nicholas John Sadgrove , Graham Lloyd Jones

Previous studies have demonstrated that the widely distributed desert plant Eremophila longifolia has at least six geographically defined essential oil chemotypes. The focus of the present study is to extend and enhance information concerning known chemotypes and to investigate the involvement of cell nuclei ploidy in this variation. Forty field collected specimens of E. longifolia were taken from most of the mainland states of Australia then subjected to hydrodistillation to produce essential oils, which were then chemically characterised. Ploidy was determined using relative fluorescence of cell nuclei stained with propidium iodide, measured in a flow cytometer. Using principal component analysis (PCA), at least three essential oil chemotypes, in addition to the six already described, were identified in the present study. Previously described high yielding essential oil chemotypes were also characterised in terms of diploidy. For the first time diploid populations were identified in New South Wales, correlating with high yielding isomenthone/menthone and karahanaenone chemotypes. Furthermore, the separate diploid population previously described from Western Australia was demonstrated to be the safrole/methyl eugenol type, which is restricted to a small geographic range in far north-west Western Australia (Murchison District). All other chemotypes were shown to be tetraploid, including apparently randomly emerging individuals, representative of chemotypes producing low yields of isomenthone/menthone and karahanaenone similar in composition to the high yielding diploid types.

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Posted on 30 July 2014 | 6:45 pm


Screening for potential co-products in a Miscanthus sinensis mapping family by liquid chromatography with mass spectrometry detection

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Ifat Parveen , Thomas Wilson , Michael D. Threadgill , Jakob Luyten , Ruth E. Roberts , Paul R.H. Robson , Iain S. Donnison , Barbara Hauck , Ana L. Winters

Society is demanding more green chemicals from sustainable sources. Miscanthus is a potential source of platform chemicals and bioethanol through fermentation. Miscanthus sinensis (M. sinensis) has been found to contain particularly high levels of soluble phenols (hydroxycinnamates and flavonoids) which may have application in the nutraceutical, cosmetic and pharmaceutical industries. Here, we describe the first study on the identification and quantification of phenols from the leaf tissue of a bi-parental M. sinensis mapping family. Parents and progeny showed complex profiles of phenols with highly related structures which complicated characterisation of individual phenotypes. Separation of semi-purified extracts by reverse-phase liquid chromatography, coupled with detection by diode array and ESI-MS/MS, enabled distinction of different profiles of phenols. Ten hydroxycinnamates (O-cinnamoylquinic acids) and several flavones (one mono-O-glycosyl flavone, eight mono-C-glycosyl flavones, two di-C-glycosyl flavones, five O-glycosyl-C-glycosyl flavones and nine 2?-O-glycosyl-C-glycosyl flavones) were identified and quantified in leaf tissue of two hundred progeny and maternal and paternal plants during the seedling stage. Progeny exhibiting high, moderate and low amounts of hydroxycinnamates and flavonoids and both parents were selected and screened at seven months’ growth to determine the abundance of these phenols at their highest biomass and compared with seedlings. Concentrations of phenols generally decreased as leaves matured. Several flavone-glycosides were identified. This technique can be used for rapid screening of plants in a mapping family to identify genotypes with high phenol content to add value in the biorefinery chain. This comparative study provides information on the content of potentially valuable compounds from readily renewable resources and possible biomarkers for identification in breeding programmes.

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Editorial Board/Publication Information

Publication date: August 2014
Source:Phytochemistry, Volume 104









Posted on 30 July 2014 | 6:45 pm


Announcement for the Phytochemical Society of North America (PSNA)

Publication date: September 2014
Source:Phytochemistry, Volume 105









Posted on 30 July 2014 | 6:45 pm


Indolosesquiterpene alkaloids from the Cameroonian medicinal plant Polyalthia oliveri (Annonaceae)

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Simeon Fogue Kouam , Alain Wembe Ngouonpe , Marc Lamshöft , Ferdinand Mouafo Talontsi , Jonathan O. Bauer , Carsten Strohmann , Bonaventure Tchaleu Ngadjui , Hartmut Laatsch , Michael Spiteller

The stem bark of Polyalthia oliveri was screened for its chemical constituents using liquid chromatography high resolution mass spectrometry resulting in the isolation of three indolosesquiterpene alkaloids named 8?-polyveolinone (1), N-acetyl-8?-polyveolinone (2) and N-acetyl-polyveoline (3), together with three known compounds, dehydro-O-methylisopiline (4), N-methylurabaine (5) and polycarpol (6). The structures of the compounds were elucidated by means of high resolution mass spectrometry and different NMR techniques and chemical transformations. Their absolute configurations were assigned by ab-initio calculation of CD and ORD data (for 2 and 3) and X-ray diffraction analysis (for 2). Compounds 2 and 3 exhibited moderate antiplasmodial activity against erythrocytic stages of chloroquine-sensitive Plasmodium falciparum NF54 strain and low cytotoxicity on rat skeletal myoblast (L6) cell line.

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Graphical Contents List

Publication date: August 2014
Source:Phytochemistry, Volume 104









Posted on 30 July 2014 | 6:45 pm


Blue light-promoted rice leaf bending and unrolling are due to up-regulated brassinosteroid biosynthesis genes accompanied by accumulation of castasterone

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Masashi Asahina , Yuji Tamaki , Tomoaki Sakamoto , Kyomi Shibata , Takahito Nomura , Takao Yokota

In this study the relationship between blue light- and brassinosteroid-enhanced leaf lamina bending and unrolling in rice was investigated. Twenty-four hours (h) irradiation with white or blue light increased endogenous brassinosteroid levels, especially those of typhasterol and castasterone, in aerial tissues of rice seedlings. There was an accompanying up-regulation of transcript levels of CYP85A1/OsDWARF, encoding an enzyme catalyzing C-6 oxidation, after 6h under either white or blue light. These effects were not observed in seedlings placed under far-red or red light regimes. It was concluded that blue light up-regulates the levels of several cytochrome P450 enzymes including CYP85A1, thereby promoting the synthesis of castasterone, a biologically active brassinosteroid in rice. Based on these findings, it is considered that blue light-mediated rice leaf bending and unrolling are consequences of the enhanced biosynthesis of endogenous castasterone. In contrast to aerial tissues, brassinosteroid synthesis in roots appeared to be negatively regulated by white, blue and red light but positively controlled by far-red light.

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Two types of alcohol dehydrogenase from Perilla can form citral and perillaldehyde

Publication date: August 2014
Source:Phytochemistry, Volume 104

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

Studies on the biosynthesis of oil compounds in Perilla will help in understanding regulatory systems of secondary metabolites and in elucidating reaction mechanisms for natural product synthesis. In this study, two types of alcohol dehydrogenases, an aldo–keto reductase (AKR) and a geraniol dehydrogenase (GeDH), which are thought to participate in the biosynthesis of perilla essential oil components, such as citral and perillaldehyde, were isolated from three pure lines of perilla. These enzymes shared high amino acid sequence identity within the genus Perilla, and were expressed regardless of oil type. The overall reaction from geranyl diphosphate to citral was performed in vitro using geraniol synthase and GeDH to form a large proportion of citral and relatively little geraniol as reaction products. The biosynthetic pathway from geranyl diphosphate to citral, the main compound of citral-type perilla essential oil, was established in this study.

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Elaeodendron orientale as a source of cytotoxic cardenolides

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Alex A. Osorio , Manuel R. López , Ignacio A. Jiménez , Laila M. Moujir , Matías L. Rodríguez , Isabel L. Bazzocchi

In the present study, we report six cardiac glycosides (16) along with four known ones (710) isolated from the leaves and fruits of Elaeodendron orientale. Their stereostructures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR, and the absolute configuration of 1 was determined by X-ray diffraction analysis. The compounds were evaluated for growth inhibitory activity against a panel of human cancer cell lines, HeLa, A-549, MCF-7 and HL-60, and normal Vero cells. Four compounds from this series (5 and 79, IC50 values ranging from 0.01 to 0.07?M) exhibited cytotoxicity against three of the cancer cell lines assayed that was similar to or higher than the well-known therapies digoxin and digitoxigenin. Taking into account the narrow safety range of cardiac glycosides used in clinic, this series shows a selectivity index higher than 3 for three of the cancer cell lines assayed, increasing their interest for further study.

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Characterization of an uncharacterized aldo-keto reductase gene from peach and its role in abiotic stress tolerance

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Yoshinori Kanayama , Ryosuke Mizutani , Shino Yaguchi , Ayano Hojo , Hiroki Ikeda , Manabu Nishiyama , Koki Kanahama

The aldo-keto reductase (AKR) superfamily is a large enzyme group of NADP-dependent oxidoreductases with numerous roles in metabolism, but many members in this superfamily remain uncharacterized. Here, PpAKR1, which was cloned from the rosaceous peach tree (Prunus persica), was investigated as a member of the superfamily. While PpAKR1 had amino acids that are important in AKRs and which belonged to the AKR4 group, PpAKR1 did not seem to belong to any of the AKR4 subgroups. PpAKR1 mRNA abundance increased with abscisic acid, oxidative stress, and cold and salt stress treatments in peach. NADP-dependent polyol dehydrogenase activity was increased in Arabidopsis thaliana transformed with PpAKR1. Salt tolerance increased in Arabidopsis transformed with PpAKR1. PpAKR1, which was a previously uncharacterized member of the AKR superfamily, could be involved in the abiotic stress tolerance.

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Chemogeography and antimicrobial activity of essential oils from Geijera parviflora and Geijera salicifolia (Rutaceae): Two traditional Australian medicinal plants

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Nicholas J. Sadgrove , Maximilien Gonçalves-Martins , Graham L. Jones

Essential oils were hydrodistilled from 27 specimens of Geijera parviflora Lindl., (Rutaceae) and nine specimens of Geijera salicifolia Schott, collected over a wide geographic range in New South Wales, Queensland and South Australia. Essential oils were produced by traditional hydrodistillation and characterised using GC–MS. From one specimen a serendipitous discovery was made of bioactive coumarins dissolved in the hydrosol, which were the coumarins isopsoralen, xanthyletine and osthole. These coumarins were not present in the essential oil from that specimen. Using essential oil composition from all specimens, principal component analysis (PCA) demonstrated nine clusters for G. parviflora and three for G. salicifolia. Some clusters are representative of previously described chemotypes and some are reflective of possible chemotypes requiring more comprehensive sampling for confirmation. Thus, another three or four possible chemotypes of G. parviflora and one of G. salicifolia have been tentatively identified. Using micro-titre plate broth dilution assays, antibacterial and antifungal activity of all chemotypes was investigated. In this regard, the ‘green oil’ chemotype, restricted to G. parviflora, with major components linalool, geijerene/pregeijerene, 1,8-cineol and bicyclogermacrene, demonstrated the highest antimicrobial and free radical scavenging activity. Thus, in the light of traditional use reports of local analgaesia and bioactivity demonstrated in the current study, oils from select chemotypes of G. parviflora may be useful in suitably compounded lotions and creams designed for topical antimicrobial applications and local pain relief. In addition, because major components are known for insecticidal activities, such lotions may also be useful as topically applied insect repellents.

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Lysophosphatidylcholine enhances susceptibility in signaling pathway against pathogen infection through biphasic production of reactive oxygen species and ethylene in tobacco plants

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Soo Jin Wi , So yeon Seo , Kyoungwon Cho , Myung Hee Nam , Ky Young Park

It was previously reported that the amounts of lysophosphatidylcholines (lysoPCs), which are naturally occurring bioactive lipid molecules, significantly increase following pathogen inoculation, as determined using ultraperformance liquid chromatography–quadrupole-time of flight/mass spectrometry analyses. Here, real-time quantitative RT-PCR was performed for the phospholipase A2 (PLA2) genes, Nt1PLA2 and Nt2PLA2 , which are responsible for LysoPCs generation. The transcription level of Nt2PLA2 in pathogen-infected tobacco plants transiently peaked at 1h and 36h, whereas induction of Nt1PLA2 transcription peaked at 36h. A prominent biphasic ROS accumulation in lysoPC (C18:1(9Z))-treated tobacco leaves was also observed. Transcription of NtRbohD, a gene member of NADPH oxidase, showed biphasic kinetics upon lysoPC 18:1 treatment, as evidenced by an early transient peak in phase I at 1h and a massive peak in phase II at 12h. Each increase in NtACS2 and NtACS4 transcription, gene members of the ACC synthase family, was followed by biphasic peaks of ethylene production after lysoPC 18:1 treatment. This suggested that lysoPC (C18:1)-induced ethylene production was regulated at the transcriptional level of time-dependent gene members. LysoPC 18:1 treatment also rapidly induced cell damage. LysoPC 18:1-induced cell death was almost completely abrogated in ROS generation-impaired transgenic plants (rbohD-as and rbohF-as), ethylene production-impaired transgenic plants (CAS-AS and CAO-AS), and ethylene signaling-impaired transgenic plants (Ein3-AS), respectively. Taken together, pathogen-induced lysoPCs enhance pathogen susceptibility accompanied by ROS and ethylene biosynthesis, resulting in chlorophyll degradation and cell death. Expression of PR genes (PR1-a, PR-3, and PR-4b) and LOX3 was strongly induced in lysoPC 18:1-treated leaves, indicating the involvement of lysoPC 18:1 in the defense response. However, lysoPC 18:1 treatment eventually resulted in cell death, as evidenced by metacaspase gene expression. Therefore, a hypothesis is proposed that the antipathogenic potential of lysoPC 18:1 is dependent on how quickly it is removed from cells for avoidance of lysoPC toxicity.

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Comprehensive approach for the detection of antifungal compounds using a susceptible strain of Candida albicans and confirmation of in vivo activity with the Galleria mellonella model

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Quentin Favre-Godal , Stéphane Dorsaz , Emerson Ferreira Queiroz , Céline Conan , Laurence Marcourt , Bambang Prajogo Eko Wardojo , Francine Voinesco , Aurélie Buchwalder , Katia Gindro , Dominique Sanglard , Jean-Luc Wolfender

An efficient screening strategy for the identification of potentially interesting low-abundance antifungal natural products in crude extracts that combines both a sensitive bioautography assay and high performance liquid chromatography (HPLC) microfractionation was developed. This method relies on high performance thin layer chromatography (HPTLC) bioautography with a hypersusceptible engineered strain of Candida albicans (DSY2621) for bioactivity detection, followed by the evaluation of wild type strains in standard microdilution antifungal assays. Active extracts were microfractionated by HPLC in 96-well plates, and the fractions were subsequently submitted to the bioassay. This procedure enabled precise localisation of the antifungal compounds directly in the HPLC chromatograms of the crude extracts. HPLC-PDA-mass spectrometry (MS) data obtained in parallel to the HPLC antifungal profiles provided a first chemical screening about the bioactive constituents. Transposition of the HPLC analytical conditions to medium-pressure liquid chromatography (MPLC) allowed the efficient isolation of the active constituents in mg amounts for structure confirmation and more extensive characterisation of their biological activities. The antifungal properties of the isolated natural products were evaluated by their minimum inhibitory concentration (MIC) in a dilution assay against both wild type and engineered strains of C. albicans. The biological activity of the most promising agents was further evaluated in vitro by electron microscopy and in vivo in a Galleria mellonella model of C. albicans infection. The overall procedure represents a rational and comprehensive means of evaluating antifungal activity from various perspectives for the selection of initial hits that can be explored in more in-depth mode-of-action studies. This strategy is illustrated by the identification and bioactivity evaluation of a series of antifungal compounds from the methanolic extract of a Rubiaceae plant, Morinda tomentosa, which was used as a model in these studies.

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Dibenzocyclooctadiene lignans from Schisandra chinensis and their inhibitory activity on NO production in lipopolysaccharide-activated microglia cells

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Di Hu , Zhiyou Yang , Xuechun Yao , Hua Wang , Na Han , Zhihui Liu , Yu Wang , Jingyu Yang , Jun Yin

Four dibenzocyclooctadiene lignans, schisanchinins A–D, and 10 known compounds were isolated from the EtOAc extract of fruits of Schisandra chinensis (Turcz.) Baill. Structures of compounds 14 were elucidated using a combination of spectroscopic techniques, including MS, UV and IR, NMR (1H NMR, 13C NMR, HMQC, HMBC). The stereochemistry of the chiral centers and the biphenyl configuration were determined using NOESY, as well as analysis of CD spectra. In vitro activity assays showed that 11 of the 14 compounds exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary murine BV2 microglia cells.

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Production of structured triacylglycerols from microalgae

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Tomáš ?ezanka , Jaromír Lukavský , Linda Nedbalová , Karel Sigler

Structured triacylglycerols (TAGs) were isolated from nine cultivated strains of microalgae belonging to different taxonomic groups, i.e. Audouinella eugena, Balbiania investiens, Myrmecia bisecta, Nannochloropsis limnetica, Palmodictyon varium, Phaeodactylum tricornutum, Pseudochantransia sp., Thorea ramosissima, and Trachydiscus minutus. They were separated and isolated by means of NARP-LC/MS-APCI and chiral LC and the positional isomers and enantiomers of TAGs with two polyunsaturated, i.e. arachidonic (A) and eicosapentaenoic (E) acids and one saturated, i.e. palmitic acid (P) were identified. Algae that produce eicosapentaenoic acid were found to biosynthesize more asymmetrical TAGs, i.e. PPE or PEE, whereas algae which produced arachidonic acid give rise to symmetrical TAGs, i.e. PAP or APA, irrespective of their taxonomical classification. Nitrogen and phosphorus starvation consistently reversed the ratio of asymmetrical and symmetrical TAGs.

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Chemical constituents from cultures of the basidiomycete Trichaptum pargamenum

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Xiao-Yan Yang , Tao Feng , Gang-Qiang Wang , Jian-Hai Ding , Zheng-Hui Li , Yan Li , Shuang-Hui He , Ji-Kai Liu

Four cadinane-type sesquiterpenes and four 13-carbon ?-lactones, together with three known compounds, were isolated from cultures of the basidiomycete Trichaptum pargamenum. Their structures were elucidated on the basis of extensive spectroscopic methods. The absolute configurations of two of the cadinene type sesquiterpenes 1 and 3 were confirmed by single crystal X-ray diffractions.

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Asphodosides A-E, anti-MRSA metabolites from Asphodelus microcarpus

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Mohammed M. Ghoneim , Khaled M. Elokely , Atef A. El-Hela , Abd-Elsalam I. Mohammad , Melissa Jacob , Mohamed M. Radwan , Robert J. Doerksen , Stephen J. Cutler , Samir A. Ross

Bioassay guided fractionation of the ethanolic extract of Asphodelus microcarpus Salzm. et Viv. (Xanthorrhoeaceae or Asphodelaceae) resulted in isolation of five compounds identified as asphodosides A-E (15). Compounds 24 showed activity against methicillin resistant Staphylococcus aureus (MRSA) with IC50 values of 1.62, 7.0 and 9.0?g/mL, respectively. They also exhibited activity against Staphylococcus aureus (non-MRSA) with IC50 values of 1.0, 3.4 and 2.2?g/mL, respectively. The structure elucidation of isolated metabolites was carried out using spectroscopic data (1D and 2D NMR), optical rotation and both experimental and calculated electronic circular dichroism (ECD).

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Posted on 30 July 2014 | 6:45 pm


Quinoid glycosides from Forsythia suspensa

Publication date: August 2014
Source:Phytochemistry, Volume 104

Author(s): Chang Li , Yi Dai , Shu-Xiang Zhang , Ying-Hui Duan , Ming-Li Liu , Liu-Yuan Chen , Xin-Sheng Yao

Phytochemical investigation on Forsythia suspensa (Thunb.) Vahl afforded 10 compounds, including quinoid glycosides, lignan glycosides, phenylethanoid glycoside and allylbenzene glycoside together with 13 known ones. Their structures were established based on extensive spectroscopic data analyses, including IR, UV, HRESIMS, 1D NMR and 2D NMR. Absolute configurations were determined by ECD calculation method and chemical degradation. In addition, all compounds were evaluated for their antiviral activity against influenza A (H1N1) virus and several were further evaluated against respiratory syncytial virus (RSV) in vitro. Among them, two previously known compounds showed significant activities against RSV with EC50 values of 3.43 and 6.72?M.

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Posted on 30 July 2014 | 6:45 pm


Extracellular lipids of Camelina sativa: Characterization of chloroform-extractable waxes from aerial and subterranean surfaces

Publication date: Available online 28 July 2014
Source:Phytochemistry

Author(s): Fakhria M. Razeq , Dylan K. Kosma , Owen Rowland , Isabel Molina

Camelina sativa (L.) Crantz is an emerging low input, stress tolerant crop with seed oil composition suitable for biofuel and bioproduct production. The chemical compositions and ultrastructural features of surface waxes from C. sativa aerial cuticles, seeds, and roots were analyzed using gas chromatography and microscopy. Alkanes, primary fatty alcohols, and free fatty acids were common components of all analyzed organs. A particular feature of leaf waxes was the presence of alkyl esters of long-chain fatty acids and very long-chain fatty alcohols, ranging from C38 to C50 and dominated by C42, C44 and C46 homologues. Stem waxes were mainly composed of non-sterol pentacyclic triterpenes. Flowers accumulated significant amounts of methyl-branched iso-alkanes (C29 and C31 total carbon number) in addition to straight-chain alkanes. Seed waxes were mostly primary fatty alcohols of up to 32 carbons in length and unbranched C29 and C31 alkanes. The total amount of identified wax components extracted by rapid chloroform dipping of roots was 280?gg?1 (fresh weight), and included alkyl hydroxycinnamates, predominantly alkyl coumarates and alkyl caffeates. This study provides qualitative and quantitative information on the waxes of C. sativa root, shoot, and seed boundary tissues, allowing the relative activities of wax biosynthetic pathways in each respective plant organ to be assessed. This detailed description of the protective surface waxes of C. sativa may provide insights into its drought-tolerant and pathogen-resistant properties, and also identifies C. sativa as a potential source of renewable high-value natural products.

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Analyses of chloroform-extractable waxes of Camelina sativa’s aerial and subterranean surfaces show both overlapping and distinctive chemical compositions within the same species.





Posted on 30 July 2014 | 6:45 pm


Announcement for the Phytochemical Society of Europe (PSE)

Publication date: August 2014
Source:Phytochemistry, Volume 104









Posted on 30 July 2014 | 6:45 pm


Phytotoxic cis-clerodane diterpenoids from the Chinese liverwort Scapania stephanii

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Rui-Juan Li , Yi Sun , Bin Sun , Xiao-Ning Wang , Shan-Shan Liu , Jin-Chuan Zhou , Jian-Ping Ye , Yu Zhao , Lei Liu , Kuo-Hsiung Lee , Hong-Xiang Lou

Five cis-clerodane diterpenoids, stephanialides A?E, along with seven known cis-clerodanes, scaparvins A?C, parvitexins B and C, 3-chloro-4-hydroxy-parvitexin A, and scapanialide B, were isolated from the Chinese liverwort Scapania stephanii. Their structures were established unequivocally on the basis of spectroscopic data. The absolute configuration of stephanialide A was determined by analysis of CD data using the octant rule. Phytotoxic activity evaluation showed that this type of diterpenoids can significantly inhibit root elongation of the seeds of Arabidopsis thaliana, Lepidium sativum and Brassica pekinensis.

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Posted on 30 July 2014 | 6:45 pm


Effects of N source concentration and NH4+/NO3? ratio on phenylethanoid glycoside pattern in tissue cultures of Plantago lanceolata L.: A metabolomics driven full-factorial experiment with LC–ESI–MS3

Publication date: Available online 28 July 2014
Source:Phytochemistry

Author(s): Sándor Gonda , Attila Kiss-Szikszai , Zsolt Sz?cs , Csaba Máthé , Gábor Vasas

Tissue cultures of a medicinal plant, Plantago lanceolata L. were screened for phenylethanoid glycosides (PGs) and other natural products (NPs) with LC–ESI–MS3. The effects of N source concentration and NH4 +/NO3 ? ratio were evaluated in a full-factorial (FF) experiment. N concentrations of 10, 20, 40 and 60mM, and NH4 +/NO3 ? ratios of 0, 0.11, 0.20 and 0.33 (ratio of NH4 + in total N source) were tested. Several peaks could be identified as PGs, of which, 16 could be putatively identified from the MS/MS/MS spectra. N source concentration and NH4 +/NO3 ? ratio had significant effects on the metabolome, their effects on individual PGs were different despite these metabolites were of the same biosynthethic class. Chief PGs were plantamajoside and acteoside (verbascoside), their highest concentrations were 3.54±0.83% and 1.30±0.40% of dry weight, on media 10(0.33) and 40(0.33), respectively. NH4 +/NO3 ? ratio and N source concentration effects were examined on a set of 89 NPs. For most NPs, high increases in abundance were observed compared to Murashige–Skoog medium. Abundances of 42 and 10 NPs were significantly influenced by the N source concentration and the NH4 +/NO3 ? ratio, respectively. Optimal media for production of different NP clusters were 10(0), 10(0.11) and 40(0.33). Interaction was observed between NH4 +/NO3 ? ratio and N source concentration for many NPs. It was shown in simulated experiments, that one-factor at a time (OFAT) experimental designs lead to sub-optimal media compositions for production of many NPs, and alternative experimental designs (e.g. FF) should be preferred when optimizing medium N source for optimal yield of NPs. If using OFAT, the N source concentration is to be optimized first, followed by NH4 +/NO3 ? ratio, as this reduces the likeliness of suboptimal yield results.

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Tissue cultures of Plantago lanceolata L. were grown on media with different N source compositions. Phenylethanoid glycosides were quantified by LC–MS, non-linear responses for yields were observed. The full-factorial experimental design and the applied metabolomic approach was shown to be superior to simpler designs with respect to optimization of yields.





Posted on 30 July 2014 | 6:45 pm


Chemical interactions between plants in Mediterranean vegetation: The influence of selected plant extracts on Aegilops geniculata metabolome

Publication date: Available online 26 July 2014
Source:Phytochemistry

Author(s): Monica Scognamiglio , Vittorio Fiumano , Brigida D’Abrosca , Assunta Esposito , Young Hae Choi , Robert Verpoorte , Antonio Fiorentino

Allelopathy is the chemical mediated communication among plants. While on one hand there is growing interest in the field, on the other hand it is still debated as doubts exist at different levels. A number of compounds have been reported for their ability to influence plant growth, but the existence of this phenomenon in the field has rarely been demonstrated. Furthermore, only few studies have reported the uptake and the effects at molecular level of the allelochemicals. Allelopathy has been reported on some plants of Mediterranean vegetation and could contribute to structuring this ecosystem. Sixteen plants of Mediterranean vegetation have been selected and studied by an NMR-based metabolomics approach. The extracts of these donor plants have been characterized in terms of chemical composition and the effects on a selected receiving plant, Aegilops geniculata, have been studied both at the morphological and at the metabolic level. Most of the plant extracts employed in this study were found to have an activity, which could be correlated with the presence of flavonoids and hydroxycinnamate derivatives. These plant extracts affected the receiving plant in different ways, with different rates of growth inhibition at morphological level. The results of metabolomic analysis of treated plants suggested the induction of oxidative stress in all the receiving plants treated with active donor plant extracts, although differences were observed among the responses. Finally, the uptake and transport into receiving plant leaves of different metabolites present in the extracts added to the culture medium were observed.

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Metabolomics highlighted the allelopathic potential of selected Mediterranean plants, allowing the identification of putative active compounds, as well as the study of the observed responses and the fate of allelochemicals.





Posted on 30 July 2014 | 6:45 pm


Chemical constituents of Abies nukiangensis

Publication date: Available online 28 July 2014
Source:Phytochemistry

Author(s): Yong-Li Li , Yan-Xia Gao , Hui-Zi Jin , Lei Shan , Xue-Song Liang , Xi-Ke Xu , Xian-Wen Yang , Ning Wang , Andre Steinmetz , Zhilei Chen , Wei-Dong Zhang

During a survey on chemical constituents of Abies nukiangensis, seven previously unreported compounds, including six triterpenes (16) and one phenol (7) were isolated and characterized, together with 37 known miscellaneous chemical constituents. The structures of compounds 17 were established mainly by extensive analysis of the 1D and 2D NMR, as well as HRMS data. The absolute configurations of compounds 1 and 8 were confirmed unambiguously by the Cu-K? X-ray crystallography. Compounds 3 and 810 showed significant anti-hepatitis C virus effects with EC50 values of 3.73, 2.67, 1.33 and 2.25?M, respectively.

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Posted on 30 July 2014 | 6:45 pm


Phytotoxic steroidal saponins from Agave offoyana leaves

Publication date: September 2014
Source:Phytochemistry, Volume 105

Author(s): Andy J. Pérez , Ana M. Simonet , Juan M. Calle , ?ukasz Pecio , José O. Guerra , Anna Stochmal , Francisco A. Macías

A bioassay-guided fractionation of Agave offoyana leaves led to the isolation of five steroidal saponins (15) along with six known saponins (611). The compounds were identified as (25R)-spirost-5-en-2?,3?-diol-12-one 3-O-{?-l-rhamnopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (1), (25R)-spirost-5-en-3?-ol-12-one 3-O-{?-l-rhamnopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (2), (25R)-spirost-5-en-3?-ol-12-one 3-O-{?-d-xylopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (3), (25R)-26-O-?-d-glucopyranosylfurost-5-en-3?,22?,26-triol-12-one 3-O-{?-l-rhamnopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (4) and (25R)-26-O-?-d-glucopyranosylfurost-5-en-3?,22?,26-triol-12-one 3-O-{?-d-xylopyranosyl-(1?3)-O-?-d-glucopyranosyl-(1?2)-O-[?-d-xylopyranosyl-(1?3)]-O-?-d-glucopyranosyl-(1?4)-O-?-d-galactopyranoside} (5) by comprehensive spectroscopic analysis, including one- and two-dimensional NMR techniques, mass spectrometry and chemical methods. The phytotoxicity of the isolated compounds on the standard target species Lactuca sativa was evaluated.

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Posted on 30 July 2014 | 6:45 pm


Diterpenes and phenolic compounds from Sideritis pullulans

Publication date: Available online 26 July 2014
Source:Phytochemistry

Author(s): Laura Faiella , Fabrizio Dal Piaz , Ammar Bader , Alessandra Braca

Phytochemical investigation of Sideritis pullulans aerial part and root extracts allowed to isolate six ent-kaurane diterpenes, two phenylpropanoids, and one coumarin, identified as 1?,3?,7?,18-tetrahydroxy-ent-kaur-16-ene (sideripullol A) (1), 3?,11?,18-trihydroxy-ent-kaur-16-ene (sideripullol B) (2), 3?,7?,18-trihydroxy-17-nor-ent-kauran-16-one (sideritone A) (3), 3?,7?-dihydroxy-18-acetyloxy-17-nor-ent-kauran-16-one (sideritone B) (4), 3?,7?,16?,17-tetrahydroxy-18-acetyloxy-ent-kaurane (sideripullol C) (5), 7?,16?,17,18-tetrahydroxy-ent-kaurane (sideripullol D) (6), ?-(3-methoxy-4-hydroxyphenyl)-ethyl-O-?-l-arabinopiranosyl-(1?2)-?-l-rhamnopyranosyl-(1?3)-6-O-t-feruloyl-?-d-glucopyranoside (sideritiside A) (7), ?-(3,4-dihydroxyphenyl)-ethyl-O-?-l-arabinopiranosyl-(1?2)-?-l-rhamnopyranosyl-(1?3)-6-O-t-feruloyl-?-d-glucopyranoside (sideritiside B) (8), and 7-demethyl-8-methoxycoumarsabin (9), respectively. Twenty known compounds, including phenolics, flavonol glycosides, iridoids, diterpenes, sesquiterpenes, lignans, coumarins, and phenylpropanoids were also isolated and characterized. All diterpenes were evaluated for their cytotoxic activity.

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Posted on 30 July 2014 | 6:45 pm





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