Phytochemistry

Current research reports and chronological list of recent articles.


Phytochemistry is the international scientific journal of pure and applied plant chemistry, plant biochemistry and molecular biology. It is also a is a primary source for papers dealing with plant secondary compounds, especially with regard to their biosynthesis and diverse properties.

The publisher is Elsevier. The copyright and publishing rights of specialized products listed below are in this publishing house. This is also responsible for the content shown.

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Additional research articles see Current Chemistry Research Articles. Magazines with similar content (phytochemistry):

 - Phytochemical Analysis.

 - Phytochemistry Letters.

 - Phytochemistry Reviews.



Phytochemistry - Abstracts



Eremophilane sesquiterpenes from Hawaiian endophytic fungus Chaetoconis sp. FT087

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Chun-Shun Li, Yuanqing Ding, Bao-Jun Yang, Naomi Hoffman, Hong-Quan Yin, Taifo Mahmud, James Turkson, Shugeng Cao

Seven sesquiterpene derivatives, including chaetopenoids A–F and dendryphiellin A1, and 6-methyl-(2E, 4E, 6S) octadienoic acid were isolated from the culture broth of Chaetoconis sp. FT087. Their structures were determined through the analysis of HRMS and NMR spectroscopic data. The absolute configurations of chaetopenoids A–D were elucidated by comparison of their CD and optical rotation data with those in the literature. Chaetopenoids A–C and E belong to the eremophilane type of sesquiterpenoids, while chaetopenoids D and F and dendryphiellin A1 have a trinor-eremophilane skeleton. All compounds were tested against A2780 and cisplatin resistant A2780CisR cell lines, and dendryphiellin A1 was moderately active with IC50 values of 6.6 and 9.1μg/mL, respectively.

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Datum: 26.05.2016


A new view on the codonocarpine type alkaloids of Capparis decidua

Publication date: Available online 14 May 2016
Source:Phytochemistry

Author(s): Yvonne Forster, Abdul Ghaffar, Stefan Bienz

Several spermidine alkaloids are described in literature as constituents of the root bark of Capparis decidua. Since some of the proposed structures, however, are in conflict with the expected biosynthetic paths, an extract of the root bark of the plant was re-investigated. Four major spermidine alkaloids of the codonocarpine type were identified and their structures elucidated: of the four compounds, isocodonocarpine was described previously for C. decidua and cadabicine was proposed as a possible constituent as well. Codonocarpine was found for the first time in an extract of C. decidua but was previously isolated from a closely related plant. Capparidisinine, finally, is an alkaloid with a structure that has never been described before. The structures of the four alkaloids are substantiated by NMR and MS data, and the four compounds are in logical agreement with biosynthetic considerations: they would arise from α,ω-bis-adducts of spermidine with coumaric and/or ferulic acids, followed by phenol oxidation.

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Datum: 26.05.2016


Terpenoids from Flueggea virosa and their anti-hepatitis C virus activity

Publication date: Available online 21 April 2016
Source:Phytochemistry

Author(s): Chih-Hua Chao, Ju-Chien Cheng, De-Yang Shen, Hui-Chi Huang, Yang-Chang Wu, Tian-Shung Wu

Phytochemical study of the methanolic root extract of Flueggea virosa allowed for the characterization of 18 non-alkaloid terpenoids. Their structures have skeletons composed of six rearranged ent-podocarpanes, 11 ent-podocarpanes, and a 3,4-seco-30-nor-friedelane. These were characterized based on 2D NMR, IR, UV, and MS spectroscopic analysis and their absolute configurations were determined by single-crystal X-ray studies, as well as by 1H NMR spectroscopic analysis for the corresponding chiral derivatives. The isolates were evaluated for therapeutic potential against hepatitis C virus (HCV) infection to human hepatoma Huh7.5 cells.

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Datum: 26.05.2016


Mass spectrometric imaging of flavonoid glycosides and biflavonoids in Ginkgo biloba L.

Publication date: Available online 24 May 2016
Source:Phytochemistry

Author(s): Sebastian Beck, Julia Stengel

Gink g o biloba L. is known to be rich in flavonoids and flavonoid glycosides. However, the distribution within specific plant organs (e.g. within leaves) is not known. By using HPLC-MS and MS/MS we have identified a number of previously known G. biloba flavonoid glycosides and biflavonoids from leaves. Namely, kaempferol, quercetin, isorhamnetin, myricetin, laricitrin/mearnsetin and apigenin glycosides were identified. Furthermore, biflavonoids like ginkgetin/isoginkgetin were also detected. The application of MALDI mass spectrometric imaging, enabled the compilation of concentration profiles of flavonoid glycosides and biflavonoids in G. biloba L. leaves. Both, flavonoid glycosides and biflavonoids show a distinct distribution in leaf thin sections of G. biloba L.

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Datum: 26.05.2016


Graphical Contents List

Publication date: July 2016
Source:Phytochemistry, Volume 127










Datum: 26.05.2016


Quorum sensing inhibitory potential and molecular docking studies of sesquiterpene lactones from Vernonia blumeoides

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Abubakar Babando Aliyu, Neil Anthony Koorbanally, Brenda Moodley, Parvesh Singh, Hafizah Yousuf Chenia

The increasing incidence of multidrug-resistant Gram-negative bacterial pathogens has focused research on the suppression of bacterial virulence via quorum sensing inhibition strategies, rather than the conventional antimicrobial approach. The anti-virulence potential of eudesmanolide sesquiterpene lactones previously isolated from Vernonia blumeoides was assessed by inhibition of quorum sensing and in silico molecular docking. Inhibition of quorum sensing-controlled violacein production in Chromobacterium violaceum was quantified using violacein inhibition assays. Qualitative modulation of quorum sensing activity and signal synthesis was investigated using agar diffusion double ring assays and C. violaceum and Agrobacterium tumefaciens biosensor systems. Inhibition of violacein production was concentration-dependent, with ⩾90% inhibition being obtained with ⩾2.4mgml−1 of crude extracts. Violacein inhibition was significant for the ethyl acetate extract with decreasing inhibition being observed with dichloromethane, hexane and methanol extracts. Violacein inhibition ⩾80% was obtained with 0.071mgml−1 of blumeoidolide B in comparison with ⩾3.6mgml−1 of blumeoidolide A. Agar diffusion double ring assays indicated that only the activity of the LuxI synthase homologue, CviI, was modulated by blumeoidolides A and B, and V. blumeoides crude extracts, suggesting that quorum sensing signal synthesis was down-regulated or competitively inhibited. Finally, molecular docking was conducted to explore the binding conformations of sesquiterpene lactones into the binding sites of quorum sensing regulator proteins, CviR and CviR′. The computed binding energy data suggested that the blumeoidolides have a tendency to inhibit both CviR and CviR′ with varying binding affinities. Vernonia eudesmanolide sesquiterpene lactones have the potential to be novel therapeutic agents, which might be important in reducing virulence and pathogenicity of drug-resistant bacteria in vivo.

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Datum: 26.05.2016


Toxin distribution and sphingoid base imbalances in Fusarium verticillioides-infected and fumonisin B1-watered maize seedlings

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Silvina L. Arias, Verónica S. Mary, Santiago N. Otaiza, Daniel A. Wunderlin, Héctor R. Rubinstein, Martín G. Theumer

Fusarium verticillioides is a major maize pathogen and there are susceptible and resistant cultivars to this fungal infection. Recent studies suggest that its main mycotoxin fumonisin B1 (FB1) may be involved in phytopathogenicity, but the underlying mechanisms are mostly still unknown. This work was aimed at assessing whether FB1 disseminates inside the plants, as well as identifying possible correlations between the maize resistant/susceptible phenotype and the unbalances of the FB1-structurally-related sphingoid base sphinganine (Sa) and phytosphingosine (Pso) due to toxin accumulation. Resistant (RH) and susceptible hybrid (SH) maize seedlings grown from seeds inoculated with a FB1-producer F. verticillioides and from uninoculated ones irrigated with FB1 (20ppm), were harvested at 7, 14 and 21days after planting (dap), and the FB1, Sa and Pso levels were quantified in roots and aerial parts. The toxin was detected in roots and aerial parts for inoculated and FB1-irrigated plants of both hybrids. However, FB1 levels were overall higher in SH seedlings regardless of the treatment (infection or watering). Sa levels increased substantially in RH lines, peaking at 54-fold in infected roots at 14dap. In contrast, the main change observed in SH seedlings was an increase of Pso in infected roots at 7dap. Here, it was found that FB1 disseminates inside seedlings in the absence of FB1-producer fungal infections, perhaps indicating this might condition the fungus–plant interaction before the first contact. Furthermore, the results strongly suggest the existence of at least two ceramide synthase isoforms in maize with different substrate specificities, whose differential expression after FB1 exposure could be closely related to the susceptibility/resistance to F. verticillioides.

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Datum: 26.05.2016


Acetophenone derivatives from a freshwater fungal isolate of recently described Lindgomyces madisonensis (G416)

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Noemi D. Paguigan, Huzefa A. Raja, Cynthia S. Day, Nicholas H. Oberlies

The exploration of freshwater ascomycetes, which have undergone only limited investigation, may provide opportunities both to characterize new genera/species of fungi and to uncover new chemical diversity. In this study, seven acetophenone derivatives, madisone, 4′-methoxymadisone, dehydromadisone, 2″-methoxymadisone, dihydroallovisnaginone, dimadisone, and 4′-methoxydimadisone were characterized from an organic extract of a recently described Lindgomyces madisonensis (G416) culture, which was isolated from submerged wood collected in a stream in North Carolina. Madisone, dehydromadisone, 2″-methoxymadisone, dimadisone and 4′-demethoxydimadisone have not been reported previously, while 4′-methoxymadisone and dihydroallovisnaginone were previously unknown as natural products. Their structures were assigned on the basis of NMR and HRESIMS data, with the structure of madisone supported by X-ray crystallography. The antimicrobial activities of madisone, 4′-methoxymadisone and dihydroallovisnaginone were evaluated against a panel of bacteria and fungi. A heat map analysis of the surface of a G416 culture showed that most of the isolated compounds concentrated in the guttate compared with the vegetative mycelium of the fungus.

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Datum: 26.05.2016


A Solanum torvum GH3 β-glucosidase expressed in Pichia pastoris catalyzes the hydrolysis of furostanol glycoside

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Rungarun Suthangkornkul, Pornpisut Sriworanun, Hiroyuki Nakai, Masayuki Okuyama, Jisnuson Svasti, Atsuo Kimura, Saengchan Senapin, Dumrongkiet Arthan

Plant β-glucosidases are usually members of the glucosyl hydrolase 1 (GH1) or 3 (GH3) families. Previously, a β-glucosidase (torvosidase) was purified from Solanum torvum leaves that specifically catalyzed hydrolysis of two furostanol 26-O-β-glucosides, torvosides A and H. Furostanol glycoside 26-O-β-glucosides have been reported as natural substrates of some plant GH1 enzymes. However, torvosidase was classified as a GH3 β-glucosidase, but could not hydrolyze β-oligoglucosides, the natural substrates of GH3 enzymes. Here, the full-length cDNA encoding S. torvum β-glucosidase (SBgl3) was isolated by the rapid amplification of cDNA ends method. The 1887bp ORF encoded 629 amino acids and showed high homology to other plant GH3 β-glucosidases. Internal peptide sequences of purified native Sbgl3 determined by LC–MS/MS matched the deduced amino acid sequence of the Sbgl3 cDNA, suggesting that it encoded the natural enzyme. Recombinant SBgl3 with a polyhistidine tag (SBgl3His) was successfully expressed in Pichia pastoris. The purified SBgl3His showed the same substrate specificity as natural SBgl3, hydrolyzing torvoside A with much higher catalytic efficiency than other substrates. It also had similar biochemical properties and kinetic parameters to the natural enzyme, with slight differences, possibly attributable to post-translational glycosylation. Quantitative real-time PCR (qRT-PCR) showed that SBgl3 was highly expressed in leaves and germinated seeds, suggesting a role in leaf and seedling development. To our knowledge, a recombinant GH3 β-glucosidase that hydrolyzes furostanol 26-O-β-glucosides, has not been previously reported in contrast to substrates of GH1 enzymes.

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Datum: 26.05.2016


Quantitative analysis of glycerol in dicarboxylic acid-rich cutins provides insights into Arabidopsis cutin structure

Publication date: Available online 19 May 2016
Source:Phytochemistry

Author(s): Weili Yang, Mike Pollard, Yonghua Li-Beisson, John Ohlrogge

Cutin is an extracellular lipid polymer that contributes to protective cuticle barrier functions against biotic and abiotic stresses in land plants. Glycerol has been reported as a component of cutin, contributing up to 14% by weight of total released monomers. Previous studies using partial hydrolysis of cuticle-enriched preparations established the presence of oligomers with glycerol-aliphatic ester links. Furthermore, glycerol-3-phosphate 2-O-acyltransferases (sn-2-GPATs) are essential for cutin biosynthesis. However, precise roles of glycerol in cutin assembly and structure remain uncertain. Here, a stable isotope-dilution assay was developed for the quantitative analysis of glycerol by GC/MS of triacetin with simultaneous determination of aliphatic monomers. To provide clues about the role of glycerol in dicarboxylic acid (DCA)-rich cutins, this methodology was applied to compare wild-type (WT) Arabidopsis cutin with a series of mutants that are defective in cutin synthesis. The molar ratio of glycerol to total DCAs in WT cutins was 2:1. Even when allowing for a small additional contribution from hydroxy fatty acids, this is a substantially higher glycerol to aliphatic monomer ratio than previously reported for any cutin. Glycerol content was strongly reduced in both stem and leaf cutin from all Arabidopsis mutants analyzed (gpat4/gpat8, att1-2 and lacs2-3). In addition, the molar reduction of glycerol was proportional to the molar reduction of total DCAs. These results suggest “glycerol-DCA-glycerol” may be the dominant motif in DCA-rich cutins. The ramifications and caveats for this hypothesis are presented.

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Datum: 26.05.2016


Phytochemical study and biological evaluation of chemical constituents of Platanus orientalis and Platanus × acerifolia buds

Publication date: Available online 11 May 2016
Source:Phytochemistry

Author(s): Quoc Dang Thai, Job Tchoumtchoua, Maria Makropoulou, Athina Boulaka, Aggeliki K. Meligova, Dimitra J. Mitsiou, Sophia Mitakou, Sylvie Michel, Maria Halabalaki, Michael N. Alexis, Leandros A. Skaltsounis

One flavonol glycoside, two O-isoprenylated flavonols, one α,α-dimethylallyl flavonol, one dihydrochalcone, two furanocoumarins and one terpenoid previously undescribed, along with 42 known compounds were isolated from the buds of two European Platanaceae, Platanus orientalis and Platanus × acerifolia. Their chemical structures were elucidated on the basis of spectroscopic analysis, including homonuclear and heteronuclear correlation NMR (COSY, NOESY, HSQC, and HMBC) experiments, as well as HRMS data. The estrogen-like and antiestrogen-like activity of dichloromethane and methanol extracts of P. orientalis and P. × acerifolia buds and isolated compounds was evaluated using estrogen-responsive cell lines. The potency of selected estrogen agonists to regulate gene expression through ERα and/or ERβ was compared with their in vitro osteoblastogenic activity. Kaempferol and 8-C-(1,1-dimethyl-2-propen-1-yl)-5,7-dihydroxyflavonol displayed osteoblastogenic as well as ERα-mediated estrogenic activity similar to estradiol.

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Datum: 26.05.2016


Rare phenolic structures found in the aerial parts of Eriosema laurentii De Wild.

Publication date: Available online 7 May 2016
Source:Phytochemistry

Author(s): Sylvin Benjamin Ateba, Dieudonné Njamen, Claus Gatterer, Tamara Scherzer, Martin Zehl, Hanspeter Kählig, Liselotte Krenn

Recent pharmacological and toxicological investigations of Eriosema laurentii (Leguminosae) have underlined the plausibility of the use of this plant in traditional African medicine. A very complex pattern of phenolic compounds was detected in the tested extracts. Based on these preceding results a detailed phytochemical study was performed and resulted in the isolation and identification of eleven compounds. All are reported in this plant for the first time and four of those are previously undescribed secondary metabolites: 3,4′,6,8-tetrahydroxyflavanone-7-C-glucoside and 3,4′,6,8-tetrahydroxyflavone-7-C-glucoside with an extremely rare substitution pattern as well as 1-[2,4-dihydroxy-3-(2-hydroxy-3-methylbut-3-en-1-yl)phenyl]-3-phenylpropan-1-one and 1-[2,4-dihydroxy-3-(2-hydroxy-3-methylbut-3-en-1-yl)phenyl]-3-(4-methoxyphenyl)-propan-1-one. Their structures were elucidated unambiguously by extensive MS- and NMR-experiments.

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Datum: 26.05.2016


Functional characterisation of a tropine-forming reductase gene from Brugmansia arborea, a woody plant species producing tropane alkaloids

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Wei Qiang, Ke Xia, Qiaozhuo Zhang, Junlan Zeng, Yuanshe Huang, Chunxian Yang, Min Chen, Xiaoqiang Liu, Xiaozhong Lan, Zhihua Liao

Brugmansia arborea is a woody plant species that produces tropane alkaloids (TAs). The gene encoding tropine-forming reductase or tropinone reductase I (BaTRI) in this plant species was functionally characterised. The full-length cDNA of BaTRI encoded a 272-amino-acid polypeptide that was highly similar to tropinone reductase I from TAs-producing herbal plant species. The purified 29kDa recombinant BaTRI exhibited maximum reduction activity at pH 6.8–8.0 when tropinone was used as substrate; it also exhibited maximum oxidation activity at pH 9.6 when tropine was used as substrate. The Km, Vmax and Kcat values of BaTRI for tropinone were 2.65mM, 88.3nkatmg−1 and 2.93S−1, respectively, at pH 6.4; the Km, Vmax and Kcat values of TRI from Datura stramonium (DsTRI) for tropinone were respectively 4.18mM, 81.20nkatmg−1 and 2.40S−1 at pH 6.4. At pH 6.4, 6.8 and 7.0, BaTRI had a significantly higher activity than DsTRI. Analogues of tropinone, 4-methylcyclohexanone and 3-quinuclidinone hydrochloride, were also used to investigate the enzymatic kinetics of BaTRI. The Km, Vmax and Kcat values of BaTRI for tropine were 0.56mM, 171.62nkat.mg−1 and 5.69S−1, respectively, at pH 9.6; the Km, Vmax and Kcat values of DsTRI for tropine were 0.34mM, 111.90nkatmg−1 and 3.30S−1, respectively, at pH 9.6. The tissue profiles of BaTRI differed from those in TAs-producing herbal plant species. BaTRI was expressed in all examined organs but was most abundant in secondary roots. Finally, tropane alkaloids, including hyoscyamine, anisodamine and scopolamine, were detected in various organs of B. arborea by HPLC. Interestingly, scopolamine constituted most of the tropane alkaloids content in B. arborea, which suggests that B. arborea is a scopolamine-rich plant species. The scopolamine content was much higher in the leaves and stems than in other organs. The gene expression and TAs accumulation suggest that the biosynthesis of hyoscyamine, especially scopolamine, occurred not only in the roots but also in the aerial parts of B. arborea.

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Datum: 26.05.2016


Steroidal saponins from Chlorophytum deistelianum

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Turibio Kuiate Tabopda, Anne-Claire Mitaine-Offer, Thomas Paululat, Stéphanie Delemasure, Patrick Dutartre, Bonaventure Tchaleu Ngadjui, Marie-Aleth Lacaille-Dubois

Phytochemical investigation of the aerial parts of Chlorophytum deistelianum led to the isolation of four previously undescribed steroidal saponins called chlorodeistelianosides A–D with five known ones. Their structures were established mainly by extensive 1D and 2D NMR spectroscopic techniques and mass spectrometry as (25R)-3β-[(β-d-glucopyranosyl-(13)-[α-l-rhamnopyranosyl-(14)]-β-d-xylopyranosyl-(13)-[β-d-glucopyranosyl-(12)]-β-d-glucopyranosyl-(14)-β-d-galactopyranosyl)oxy]-5α-spirostan-12-one, (24S,25S)-24-[(β-d-glucopyranosyl)oxy]-3β-[(β-d-glucopyranosyl-(12)-[β-d-xylopyranosyl-(13)]-β-d-glucopyranosyl-(14)-β-d-galactopyranosyl)oxy]-5α-spirostan-12-one, (25R)-26-[(β-d-glucopyranosyl)oxy]-2α-hydroxy-22α-methoxy-5α-furostan-3β-yl β-d-glucopyranosyl-(12)-[β-d-xylopyranosyl-(13)]-β-d-glucopyranosyl-(14)-β-d-galactopyranoside, and (25R)-26-[(β-d-glucopyranosyl)oxy]-3β-[(β-d-glucopyranosyl-(12)-[β-d-xylopyranosyl-(13)]-β-d-glucopyranosyl-(14)-β-d-galactopyranosyl)oxy]-5α-furost-20(22)-en-12-one. Cytotoxicity of most compounds was evaluated against one human cancer cell line (SW480) and one rat cardiomyoblast cell line (H9c2). Among them, three known spirostane-type glycosides exhibited cytotoxicity on both cell lines with IC50 ranging from 8 to 10μM.

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Datum: 26.05.2016


Proteomic analysis of mature barley grains from C-hordein antisense lines

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Daiana Schmidt, Salete Aparecida Gaziola, Luis Felipe Boaretto, Ricardo Antunes Azevedo

Hordeins are the major storage proteins in barley grains and are responsible for their low nutritional quality. Previously, antisense C-hordein barley lines were generated and were shown to contain a more balanced amino acid composition and an altered storage protein profile. In the present study, a proteomic approach that combined two-dimensional gel electrophoresis (2-DE) and mass spectrometry was used to (1) identify the changes in the protein profile of non-storage proteins (salt soluble fraction) in antisense C-hordein barley lines (L1, L2 and L3) and (2) map the differentially expressed proteins compared to the non-transgenic control line (Hordeum vulgare cv. Golden Promise). Moreover, the changes in the proteins were correlated with the more balanced amino acid composition of these lines, with special attention to the lysine content. The results showed that suppression of C-hordein expression does not exclusively affect hordein synthesis and accumulation. The more balanced amino acid composition observed in the transgenic lines L1, L2 and L3 was an indirect result of the profound alterations in the patterns of the non-storage proteins. The observed changes included up-regulated expression of the proteins involved in stress and detoxification (L1), defence (L2 and L3), and storage globulins (L1, L2 and L3). To a lesser extent, the proteins involved in grain metabolism were also changed. Thus, the increased essential amino acids content results from changes in distinct protein sources among the three antisense C-hordein lines analyzed, although the up-regulated expression of lysine-rich proteins was consistently observed in all lines.

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Datum: 26.05.2016


Polyoxypregnane steroids with an open-chain sugar moiety from Marsdenia tenacissima and their chemoresistance reversal activity

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Sheng Yao, Kenneth Kin-Wah To, Liang Ma, Chun Yin, Chunping Tang, Stella Chai, Chang-Qiang Ke, Ge Lin, Yang Ye

A polyoxypregnane aglycone, 12β-O-acetyl-11α-O-isobutyryltenacigenin B, and four polyoxypregnane glycosides with a pachybionic acid ester moiety, 12β-O-acetyl-3-O-(6-deoxy-3-O-methyl-β-d-allopyranosyl-(1→4)-β-d-oleandronyl)-11α-O-isobutyryltenacigenin B, 12β-O-acetyl-3-O-(6-deoxy-3-O-methyl-β-d-allopyranosyl-(1→4)-β-d-oleandronyl)-11α-O-tigloyltenacigenin B, 12β-O-acetyl-3-O-(6-deoxy-3-O-methyl-β-d-allopyranosyl-(1→4)-β-d-oleandronyl)-11α-O-2-methylbutyryltenacigenin B, and 12β-O-acetyl-3-O-(β-d-glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-d-allopyranosyl-(1→4)-d-oleandronyl)-11α-O-tigloyltenacigenin B, were isolated from the canes of Marsdenia tenacissima, together with a disaccharide derivative. Their structures were elucidated by extensive spectroscopic analysis, and the absolute configurations were further determined by X-ray crystallographic analysis. With the exception of the disaccharide derivative, all five compounds are unusual naturally occurring polyoxypregnane glycosides bearing an open-chain sugar moiety. Two of these exhibit a wide spectrum of chemoresistance reversal activity, and potential mechanisms were studied accordingly.

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Datum: 26.05.2016


Functional characterization of CYP71D443, a cytochrome P450 catalyzing C-22 hydroxylation in the 20-hydroxyecdysone biosynthesis of Ajuga hairy roots

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Yuki Tsukagoshi, Kiyoshi Ohyama, Hikaru Seki, Tomoyoshi Akashi, Toshiya Muranaka, Hideyuki Suzuki, Yoshinori Fujimoto

20-Hydroxyecdysone (20HE), a molting hormone of insects, is also distributed among a variety of plant families. 20HE is thought to play a role in protecting plants from insect herbivores. In insects, biosynthesis of 20HE from cholesterol proceeds via 7-dehydrocholesterol and 3β,14α-dihydroxy-5β-cholest-7-en-6-one (5β-ketodiol), the latter being converted to 20HE through sequential hydroxylation catalyzed by four P450 enzymes, which have been cloned and identified. In contrast, little is known about plant 20HE biosynthesis, and no biosynthetic 20HE gene has been reported thus far. We recently proposed involvement of 3β-hydroxy-5β-cholestan-6-one (5β-ketone) in 20HE biosynthesis in the hairy roots of Ajuga reptans var. atropurpurea (Lamiaceae). In this study, an Ajuga EST library was generated from the hairy roots and P450 genes were deduced from the library. Five genes with a high expression level (CYP71D443, CYP76AH19, CYP76AH20, CYP76AH21 and CYP716D27) were screened for a possible involvement in 20HE biosynthesis. As a result, CYP71D443 was shown to have C-22 hydroxylation activity for the 5β-ketone substrate using a yeast expression system. The hydroxylated product, 22-hydroxy-5β-ketone, had a 22R configuration in agreement with that of 20HE. Furthermore, labeling experiments indicated that (22R)-22-hydroxy-5β-ketone was converted to 20HE in Ajuga hairy roots. Based on the present results, a possible 20HE biosynthetic pathway in Ajuga plants involved CYP71D443 is proposed.

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Datum: 26.05.2016


Phytochemical Society of Europe

Publication date: June 2016
Source:Phytochemistry, Volume 126










Datum: 26.05.2016


Cytotoxic sesquiterpenoids from Ligularia pleurocaulis

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Guang-Bo Xie, Ya Xie, Yang-Zhirong Hu, Zhi-Xiang Zhu

The phytochemical investigation of whole plants of Ligularia pleurocaulis led to isolation of five sesquiterpenoids, including an eremophilenolide dimer named biligupleurolide, along with eight known sesquiterpenoids. Their structures were determined by spectroscopic methods including 2D NMR techniques, and the structures of biligupleurolide and ligupleurolide were confirmed by X-ray diffraction analysis. All of the isolated compounds were tested for their cytotoxic activity against three cancer cell lines (HepG2, A549 and MCF-7), and biligupleurolide showed moderate inhibitory activities, with IC50 values of 5.2, 5.6 and 8.4μM against MCF-7, HepG2 and A549, respectively.

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Datum: 26.05.2016


Officimalonic acids A−H, lanostane triterpenes from the fruiting bodies of Fomes officinalis

Publication date: Available online 20 May 2016
Source:Phytochemistry

Author(s): Jianxin Han, Liya Li, Jialiang Zhong, Zeynep Tohtaton, Qing Ren, Li Han, Xueshi Huang, Tao Yuan

Phytochemical investigation of the methanolic extract of the fruiting bodies of Fomes officinalis led to the isolation of eight 24-methyl-lanostane triterpenes named officimalonic acids A−H, along with one known lanostane triterpene. Their structures were elucidated based on the analysis of spectroscopic data, single-crystal X-ray diffraction, and electronic circular dichroism. Officimalonic acid A represents a previously unknown triterpene type with a 24-methyl-7(8 → 9)abeo-lanostane skeleton, and all of the compounds possessed a malonate half-ester moiety at C-3. Anti-inflammatory assay revealed that officimalonic acids D, E, G, H, and fomitopsin A showed potent inhibitory effects (IC50 = 5.1–8.9 μM) on nitric oxide production in lipopolysaccharide-induced RAW264.7 cells. Officimalonic acids E, G, H showed moderate cytotoxicity against H460, HepG2 and BGC-823 human cell lines.

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Datum: 26.05.2016


Distinguishing commercially grown Ganoderma lucidum from Ganoderma lingzhi from Europe and East Asia on the basis of morphology, molecular phylogeny, and triterpenic acid profiles

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Florian Hennicke, Zakaria Cheikh-Ali, Tim Liebisch, Jose G. Maciá-Vicente, Helge B. Bode, Meike Piepenbring

In China and other countries of East Asia, so-called Ling-zhi or Reishi mushrooms are used in traditional medicine since several centuries. Although the common practice to apply the originally European name ‘Ganoderma lucidum’ to these fungi has been questioned by several taxonomists, this is still generally done in recent publications and with commercially cultivated strains. In the present study, two commercially sold strains of ‘G. lucidum’, M9720 and M9724 from the company Mycelia bvba (Belgium), are compared for their fruiting body (basidiocarp) morphology combined with molecular phylogenetic analyses, and for their secondary metabolite profile employing an ultra-performance liquid chromatography–electrospray ionization mass spectrometry (UPLC–ESIMS) in combination with a high resolution electrospray ionization mass spectrometry (HR-ESI-MS). According to basidiocarp morphology, the strain M9720 was identified as G. lucidum s.str. whereas M9724 was determined as Ganoderma lingzhi. In molecular phylogenetic analyses, the M9720 ITS and beta-tubulin sequences grouped with sequences of G. lucidum s.str. from Europe whereas those from M9724 clustered with sequences of G. lingzhi from East Asia. We show that an ethanol extract of ground basidiocarps from G. lucidum (M9720) contains much less triterpenic acids than found in the extract of G. lingzhi (M9724). The high amount of triterpenic acids accounts for the bitter taste of the basidiocarps of G. lingzhi (M9724) and of its ethanol extract. Apparently, triterpenic acids of G. lucidum s.str. are analyzed here for the first time. These results demonstrate the importance of taxonomy for commercial use of fungi.

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Datum: 26.05.2016


Truncations of xyloglucan xylosyltransferase 2 provide insights into the roles of the N- and C-terminus

Publication date: Available online 15 May 2016
Source:Phytochemistry

Author(s): Alan T. Culbertson, Adrienne L. Smith, Matthew D. Cook, Olga A. Zabotina

Xyloglucan is the most abundant hemicellulose in the primary cell wall of dicotyledonous plants. In Arabidopsis, three xyloglucan xylosyltransferases, XXT1, XXT2, and XXT5, participate in xylosylation of the xyloglucan backbone. Despite the importance of these enzymes, there is a lack of information on their structure and the critical residues required for substrate binding and transferase activity. In this study, the roles of different domains of XX2 in protein expression and catalytic activity were investigated by constructing a series of N- and C-terminal truncations. XXT2 with an N-terminal truncation of 31 amino acids after the predicted transmembrane domain showed the highest protein expression, but truncations of more than 31 residues decreased protein expression and catalytic activity. XXT2 constructs with C-terminal truncations showed increased protein expression but decreased activity, particularly for truncations of 44 or more amino acids. Site-directed mutagenesis was also used to investigate six positively charged residues near the C-terminus and found that four of the mutants showed decreased enzymatic activity. We conclude that the N- and C-termini of XXT2 have important roles in protein folding and enzymatic activity: the stem region (particularly the N-terminus of the catalytic domain) is critical for protein folding and the C-terminus is essential for enzymatic activity but not for protein folding.

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Datum: 26.05.2016


Editorial Board/Publication Information

Publication date: July 2016
Source:Phytochemistry, Volume 127










Datum: 26.05.2016


Anthocyanins of the anthers as chemotaxonomic markers in the genus Populus L.. Differentiation between Populus nigra, Populus alba and Populus tremula

Publication date: Available online 11 May 2016
Source:Phytochemistry

Author(s): Cristina Alcalde-Eon, Ignacio García-Estévez, Julián C. Rivas-Gonzalo, David Rodríguez de la Cruz, María Teresa Escribano-Bailón

Three main species of Popululs L. (Salicaceae) have been reported to occur in the Iberian Peninsula: Populus nigra L., Populus alba L. and Populus tremula L. The degree of pilosity of the bracts of the male catkins is a key character for their differentiation. The anthers of these poplar species possess anthocyanins that provide them a red colouration. Since these poplars are wind-pollinated and, consequently, do not need to attract pollinators, anthocyanins in the anthers might be acting as photoprotectors, shielding pollen grains from excessive sunlight. In order to verify this hypothesis, the first objective of this study was to establish if there is any relationship between the degree of pilosity of the bracts (related to the physical shading of the pollen grains) and the levels and types of anthocyanins in the anthers of these three species. This study also aimed to check the usefulness of the anthocyanins of the anthers as chemotaxonomic markers, through the study of the differences in the anthocyanin composition between these poplar species. Anthocyanins were identified from the data supplied by HPLC-DAD-MSn analyses. Seventeen different compounds, including mono-, di- and triglycosides and anthocyanin-derived pigments (F-A+ dimers) have been identified. Cyanidin 3-O-glucoside was the major compound in all the samples (>60% of the total content), which may be in accordance with the photoprotective role proposed for them. However, qualitative and quantitative differences were detected among samples. Cyanidin and delphinidin 3-O-sambubiosides have been detected only in the anthers of P. tremula as well as cyanidin 3-O-(2″-O-xyloxyl)rutinoside, making them valuable chemotaxonomic markers for this species. Hierarchical Cluster and Principal Components Analyses (HCA and PCA) carried out with the anthocyanin percent composition data have allowed a separation of the samples that is in accordance with the initial classification of the samples made from the morphological characters of the specimens. Furthermore, these analyses have revealed intraspecific differences among samples that point out to different clones or varieties of a same species.

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Datum: 26.05.2016


Prenylfuranocoumarin–HMGA–flavonol glucoside conjugates and other constituents of the fruit peels of Citrus hystrix and their anticholinesterase activity

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Chonticha Seeka, Pakawadee Sutthivaiyakit, Juthamanee Youkwan, Norbert Hertkorn, Mourad Harir, Philippe Schmitt-Kopplin, Somyote Sutthivaiyakit

Sixteen compounds including dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid conjugates and dihydroxy prenylfuranocoumarins/3-hydroxy-3-methylglutaric acid/1-O-flavonyl-β-d-glucopyranoside conjugates, together with other dihydroxyprenylfuranocoumarins conjugates, were isolated from the ethyl acetate extract of the fruit peels of Citrus hystrix. Some of the isolates were evaluated for their cholinesterase inhibitory activity, but only one compound possessing a 3-O-β-d-glucopyranosyl-3,5,7,4′-tetrahydroxy-6,8,3′-trimethoxyflavonol nucleus in the prenylfuranocoumarin–HMGA conjugate showed strong activity.

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Datum: 26.05.2016


Phenylbenzoisoquinolindione alkaloids accumulate in stamens of Xiphidium caeruleum Aubl. flowers

Publication date: Available online 11 May 2016
Source:Phytochemistry

Author(s): Yu Chen, Christian Paetz, Riya C. Menezes, Bernd Schneider

Xiphidium caeruleum (Haemodoraceae) flower organs such as carpels, pedicels, petals, and stamens were separately investigated for their phytochemical profile. The stamens appeared to be a rich source of previously undescribed phenylbenzoisoquinolindiones, a group of phenylphenalenone-derived alkaloids, also named aza-phenylphenalenones. Nine previously undescribed compounds with an identical aza-phenylphenalenone core structure but different amino acid-derived side chains at position 2 were isolated and their structures elucidated by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). In addition, some previously reported phenylbenzoisoquinolindiones, phenylbenzoisochromenones and flavonoids were found in stamens and other parts of the flowers. The specific occurrence of heterocyclic phenylphenalenone-type compounds in X. caeruleum suggests these are involved in physiological or ecological processes.

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Datum: 26.05.2016


Effects of meteorological conditions and plant growth stage on the accumulation of carvacrol and its precursors in Thymus pulegioides

Publication date: Available online 9 May 2016
Source:Phytochemistry

Author(s): Vaida Vaičiulytė, Rita Butkienė, Kristina Ložienė

The effects of meteorological conditions (temperature, rainfall, photosynthetically active solar radiation (PAR) and sunshine duration) and plant growth stages on the quantitative composition of a secondary metabolite – essential oil and its main compounds, in the carvacrol chemotype of Thymus pulegioides L. (Lamiaceae) cultivated in open ground were studied under the same micro-edaphoclimatic environmental conditions for six years. The essential oil was isolated by hydrodistillation, the analysis of monoterpenic phenol carvacrol and the biogenetic precursors (monoterpene hydrocarbons p-cymene and γ-terpinene) were carried out annually using GC-FID and GC-MS. In the carvacrol chemotype investigated in this study, the yield of essential oil varied from 0.72% to 0.98% (CV = 12%) at full flowering stage. Regression analysis showed a significant negative relationship between the amount of essential oil and both temperature and rainfall during T. pulegioides flowering (July) and the period from April (beginning of vegetation) to July, but a strong positive relationship with photosynthetically active solar radiation during April–July (beta = 0.658, p < 0.05). The percentage of carvacrol, p-cymene and γ-terpinene ranged between 16.88 and 29.29% (CV = 18%), 5.54–11.33% (CV = 23%) and 20.60–24.43% (CV = 6%) respectively. Regression analysis showed the significant positive relationship between the percentage of carvacrol and sunshine duration at the flowering stage (in July) (beta = 0.699, p < 0.05); while the negative relationship was established between the percentages of precursors of carvacrol and photosynthetically active solar radiation and sunshine duration. The accumulation of p-cymene, the percentage of which varied most strongly from all investigated chemical compounds, showed significant positive relationships with temperature and rainfall during the period April–July and temperature in July (beta = 0.617, beta = 0.439 and beta = 0.429 respectively, p < 0.05). The analysis of plant growth stages showed that the highest amount of essential oil in carvacrol chemotype of T. pulegioides accumulated at ripening/seed maturity stage. The percentage of carvacrol increased gradually from the stem elongation to the post-flowering/seed maturity stage, overtaking the full flowering stage by 22%. The highest carvacrol content in the T. pulegioides carvacrol chemotype coincided with the highest oil yield during the fruiting stage. The amount of essential oil was also measured at the second full flowering stage, because after cutting the aerial part of the plant at the full flowering stage T. pulegioides often bloom for a second time: the carvacrol chemotype accumulated by 21% lower yield of essential oil at this stage compared to the first flowering, however, only traces of carvacrol and its precursors were found at the second full flowering stage.

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Datum: 26.05.2016


Isolation and characterisation of 13 pterosins and pterosides from bracken (Pteridium aquilinum (L.) Kuhn) rhizome

Publication date: Available online 10 May 2016
Source:Phytochemistry

Author(s): Rizgar Hassan Mohammad, Mohammad Nur-e-Alam, Martina Lahmann, Ifat Parveen, Graham J. Tizzard, Simon J. Coles, Mark Fowler, Alex F. Drake, Derren Heyes, Vera Thoss

Systematic phytochemical investigations of the underground rhizome of Pteridium aquilinum (L.) Kuhn (Dennstaedtiaceae) afforded thirty-five pterosins and pterosides. By detailed analysis of one- and two-dimensional nuclear magnetic resonance spectroscopy, circular dichroism (CD) and high-resolution mass spectrometric data, thirteen previously undescribed pterosins and pterosides have been identified. Interestingly, for the first time 12-O-β-D-glucopyranoside substituted pterosins, rhedynosides C and D, and the sulfate-containing pterosin, rhedynosin H, alongside the two known compounds, histiopterosin A and (2S)-pteroside A2, were isolated from the rhizomes of subsp. aquilinum of bracken. In addition, six-membered cyclic ether pterosins and pterosides, rhedynosin A and rhedynoside A, are the first examples of this type of pterosin-sesquiterpenoid. Additionally, the three previously reported compounds (rhedynosin I, (2S)-2-hydroxymethylpterosin E and (2S)-12-hydroxypterosin A) were obtained for the first time from plants as opposed to mammalian metabolic products. Single crystal X-ray diffraction analysis was applied to the previously undescribed compounds (2R)-rhedynoside B, (2R)-pteroside B and (2S)-pteroside K, yielding the first crystal structures for pterosides, and three known pterosins, (2S)-pterosin A, trans-pterosin C and cis-pterosin C. Rhedynosin C is the only example of the cyclic lactone pterosins with a keto group at position C-14. Six selected pterosins ((2S)-pterosin A, (2R)-pterosin B and trans-pterosin C) and associated glycosides ((2S)-pteroside A, (2R)-pteroside B and pteroside Z) were assessed for their anti-diabetic activity using an intestinal glucose uptake assay; all were found to be inactive at 300 μM.

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Datum: 26.05.2016


Phenylethanoid glycosides and phenolic glycosides from stem bark of Magnolia officinalis

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Zhenzhen Xue, Renyi Yan, Bin Yang

An investigation of the hydrophilic constituents of the stem bark of Magnolia officinalis was performed and which led to isolation and identification of twenty-one previously unreported glycosides. These included eleven phenylethanoid glycosides, magnolosides F–P, and ten phenolic glycosides, magnolosides Q–Z, along with eight known compounds. Their structures were elucidated on the basis of extensive spectroscopic analyses and chemical hydrolysis methods, as well as by comparison with literature data. Most of the phenylethanoid glycosides contained an allopyranose moiety, which is rare in the plant kingdom. Magnolosides I and K as well as 2-(3,4-dihydroxyphenyl) ethanol 1-O-[4-O-caffeoyl-2-O-α- l -rhamnopyranosyl-3-O-α- l -rhamnopyranosyl-6-O-β- d -glucopyranosyl]-β- d -glucopyranoside showed more potent α-glucosidase inhibitory effects (IC50 values of 0.13, 0.27, and 0.29mM, respectively) than the positive control, acarbose (IC50 value of 1.09mM) in vitro. Magnolosides H, E and D also showed moderate cytotoxicity against MGC-803 and HepG2 cells with IC50 values of 13.59–17.16μM and 29.53–32.46μM, respectively.

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Datum: 26.05.2016


High concentrations of aromatic acylated anthocyanins found in cauline hairs in Plectranthus ciliatus

Publication date: Available online 8 May 2016
Source:Phytochemistry

Author(s): Monica Jordheim, Kate Calcott, Kevin S. Gould, Kevin M. Davies, Kathy E. Schwinn, Øyvind M. Andersen

Vegetative shoots of a naturalized population of purple-leaved plectranthus (Plectranthus ciliatus, Lamiaceae) were found to contain four main anthocyanins: peonidin 3-(6″-caffeoyl-β-glucopyranoside)-5-β-glucopyranoside, peonidin 3-(6″-caffeoyl-β-glucopyranoside)-5-(6‴-malonyl-β-glucopyranoside), peonidin 3-(6″-E-p-coumaroyl-β-glucopyranoside)-5-(6‴-malonyl-β-glucopyranoside), and peonidin 3-(6″-E-p-coumaroyl-β-glucopyranoside)-5-β-glucopyranoside. The first three of these pigments have not been reported previously from any plant. They all follow the typical anthocyanin pattern of Lamiaceae, with universal occurrence of anthocyanidin 3,5-diglucosides and aromatic acylation with p-coumaric and sometimes caffeic acids; however, they differ by being based on peonidin. The four anthocyanins were present in the leaves (22.2 mg g−1 DW), and in the xylem and interfascicular parenchyma of the stem. They were exceptionally abundant, among the highest reported for any plant organ, in epidermal hairs on some of the stem internodes (101 mg g−1 DW). Anthocyanin content in these hairs increased more than three-fold from the youngest to the fourth-youngest internodes. In situ absorbances (λmax ≈ 545 nm) were bathochromic in comparison to absorbances of the isolated anthocyanins in their flavylium form in acidified aqueous solutions (λmax = 525 nm), suggesting that the anthocyanins occur both in quinoidal and flavylium forms in constant proportions in the anthocyanic hair cells. The most distinctive observation with respect to relative proportions of individual anthocyanins was found in de-haired internodes, for which anthocyanin caffeoyl-derivatives decreased, and anthocyanin coumaroyl-derivatives increased, from the youngest to the fourth-youngest internode.

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Datum: 26.05.2016


Graphical Contents List

Publication date: May 2016
Source:Phytochemistry, Volume 125










Datum: 26.05.2016


Editorial Board/Publication Information

Publication date: May 2016
Source:Phytochemistry, Volume 125










Datum: 26.05.2016


Structures and biological activities of triterpenes and sesquiterpenes obtained from Russula lepida

Publication date: July 2016
Source:Phytochemistry, Volume 127

Author(s): Jong-Soo Lee, Wilmar Maarisit, Delfly B. Abdjul, Hiroyuki Yamazaki, Ohgi Takahashi, Ryota Kirikoshi, Syu-ichi Kanno, Michio Namikoshi

A seco-cucurbitane triterpene and two aristolane sesquiterpenes, named (24E)-3,4-seco-cucurbita-4,24-diene-3-hydroxy-26,29-dioic acid, (+)-1,2-didehydro-9-hydroxy-aristlone, and (+)-12-hydroxy-aristlone, were isolated from fruiting bodies of the medicinal mushroom Russula lepida, together with (24E)-3,4-seco-cucurbita-4,24-diene-3,26,29-trioic acid and (+)-aristlone. The structures of the first three compounds, including their absolute configurations, were assigned on the basis of their NMR and ECD spectra. Two seco-cucurbitane triterpenes, (24E)-3,4-seco-cucurbita-4,24-diene-3-hydroxy-26,29-dioic acid and (24E)-3,4-seco-cucurbita-4,24-diene-3,26,29-trioic acid, inhibited the activity of protein tyrosine phosphatase 1B (PTP1B), with IC50 values of 20.3 and 0.4μM, respectively. All isolated compounds did not show cytotoxicity against human cancer cell lines, Huh-7 (hepatoma) and EJ-1 (bladder), at 50μM.

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Datum: 26.05.2016


Tetrandrine – A molecule of wide bioactivity

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): N. Bhagya, K.R. Chandrashekar

Stephania tetrandra and other related species of Menispermaceae form the major source of the bisbenzylisoquinoline alkaloid – tetrandrine. The plant is extensively referenced in the Chinese Pharmacopoeia for its use in the Chinese medicinal system as an analgesic and diuretic agent and also in the treatment of hypertension and various other ailments, including asthma, tuberculosis, dysentery, hyperglycemia, malaria, cancer and fever. Tetrandrine, well-known to act as a calcium channel blocker, has been tested in clinical trials and found effective against silicosis, hypertension, inflammation and lung cancer without any toxicity. Recently, the efficacy of tetrandrine was tested against Mycobaterium tuberculosis, Candida albicans, Plasmodium falciparum and Ebola virus. Tetrandrine’s pharmacological property has been proved to be through its action on different signalling pathways like reactive oxygen species, enhanced autophagic flux, reversal of multi drug resistance, caspase pathway, cell cycle arrest and by modification of calcium channels. The present review summarises current knowledge on the synthesis, distribution, extraction, structural elucidation, pharmacological properties and the mechanism of action of tetrandrine. Future perspectives in the clinical use of tetrandrine as a drug are also considered.

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Datum: 26.05.2016


Developmental patterning and segregation of alkaloids in areca nut (seed of Areca catechu) revealed by magnetic resonance and mass spectrometry imaging

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Amitava Srimany, Christy George, Hemanta R. Naik, Danica Glenda Pinto, N. Chandrakumar, T. Pradeep

Areca nut (seed of Areca catechu) is consumed by people from different parts of Asia, including India. The four major alkaloids present in areca nut are arecoline, arecaidine, guvacoline and guvacine. Upon cutting, the nut reveals two kinds of regions; white and brown. In our present study, we have monitored the formation of these two regions within the nut during maturation, using the non-invasive techniques of magnetic resonance imaging (MRI) and volume localized magnetic resonance spectroscopy (MRS). Electrospray ionization mass spectrometry (ESI MS) and desorption electrospray ionization mass spectrometry (DESI MS) imaging have been used to study the associated change in the alkaloid contents of these two regions during the growth of the nut. Our study reveals that white and brown regions start forming within the nut when the liquid within starts solidifying. At the final stage of maturity, arecoline, arecaidine and guvacoline get segregated in the brown region whereas guvacine gets to the white region of the nut. The transport of molecules with maturity and corresponding pattern formation are expected to be associated with a multitude of physiochemical changes.

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Datum: 26.05.2016


Variability in the carbon isotope composition of individual amino acids in plant proteins from different sources: 1 Leaves

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Anthony H. Lynch, Nicholas J. Kruger, Robert E.M. Hedges, James S.O. McCullagh

The natural carbon isotope composition of individual amino acids from plant leaf proteins has been measured to establish potential sources of variability. The plant leaves studied, taken from a range of plant groups (forbs, trees, grasses, and freshwater aquatic plants), showed no significant influence of either season or environment (water and light availability) on their Δδ13C values. Plant groups did, however, differ in carbon isotope composition, although no consistent differences were identified at the species level. A discriminant analysis model was constructed which allowed leaves from (1) nettles, (2) Pooideae, (3) other Poales, (4) trees and (5) freshwater higher plants to be distinguished from each other on the basis of their natural abundance 13C/12C ratios of individual amino acids. Differences in carbon isotope composition are known to be retained, to some extent, in the tissues of their consumers, and hence an understanding of compound-specific variation in 13C/12C fractional abundance in plants has the potential to provide dietary insights of value in archaeological and ecological studies.

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Datum: 26.05.2016


Editorial Board/Publication Information

Publication date: June 2016
Source:Phytochemistry, Volume 126










Datum: 26.05.2016


Regulation of sesquiterpenoid metabolism in recombinant and elicited Valeriana officinalis hairy roots

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Vincent Ricigliano, Santosh Kumar, Scott Kinison, Christopher Brooks, S. Eric Nybo, Joe Chappell, Dianella G. Howarth

The medicinal properties of Valerian (Valeriana officinalis) root preparations are attributed to the anxiolytic sesquiterpenoid valerenic acid and its biosynthetic precursors valerenal and valerenadiene, as well as the anti-inflammatory sesquiterpenoid β-caryophyllene. In order to study and engineer the biosynthesis of these pharmacologically active metabolites, a binary vector co-transformation system was developed for V. officinalis hairy roots. The relative expression levels and jasmonate-inducibility of a number of genes associated with sesquiterpenoid metabolism were profiled in roots: farnesyl pyrophosphate synthase (VoFPS), valerendiene synthase (VoVDS), germacrene C synthase (VoGCS), and a cytochrome P450 (CYP71D442) putatively associated with terpene metabolism based on sequence homology. Recombinant hairy root lines overexpressing VoFPS or VoVDS were generated and compared to control cultures. Overexpression of the VoFPS cDNA increased levels of the corresponding transcript 4- to 8-fold and sesquiterpene hydrocarbon accumulation by 1.5- to 4-fold. Overexpression of the VoVDS cDNA increased the corresponding transcript levels 5- to 9-fold and markedly increased yields of the oxygenated sesquiterpenoids valerenic acid and valerenal. Our findings suggest that the availability of cytoplasmic farnesyl diphosphate and valerenadiene are potential bottlenecks in Valeriana-specific sesquiterpenoid biosynthesis, which is also subject to regulation by methyl jasmonate elicitation.

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Datum: 26.05.2016


Biosynthesis of natural and novel C-glycosylflavones utilising recombinant Oryza sativa C-glycosyltransferase (OsCGT) and Desmodium incanum root proteins

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): B. Hao, J.C. Caulfield, M.L. Hamilton, J.A. Pickett, C.A.O. Midega, Z.R. Khan, J. Wang, A.M. Hooper

The rice C-glycosyltransferase (OsCGT) is one of only a small number of characterised plant C-glycosyltransferases (CGT) known. The enzyme C-glucosylates a 2-hydroxyflavanone substrate with UDP-glucose as the sugar donor to produce C-glucosyl-2-hydroxyflavanones. We tested substrate specificity of the enzyme, using synthetic 2-hydroxyflavanones, and showed it has the potential to generate known natural CGFs that have been isolated from rice and also other plants. In addition, we synthesised novel, unnatural 2-hydroxyflavanone substrates to test the B-ring chemical space of substrate accepted by the OsCGT and demonstrated the OsCGT capacity as a synthetic reagent to generate significant quantities of known and novel CGFs. Many B-ring analogues are tolerated within a confined steric limit. Finally the OsCGT was used to generate novel mono-C-glucosyl-2-hydroxyflavanones as putative biosynthetic intermediates to examine the potential of Desmodium incanum biosynthetic CGTs to produce novel di-C-glycosylflavones, compounds implicated in the allelopathic biological activity of Desmodium against parasitic weeds from the Striga genus.

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Datum: 26.05.2016


Biological activity of ellagitannins: Effects as anti-oxidants, pro-oxidants and metal chelators

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Johanna Moilanen, Maarit Karonen, Petri Tähtinen, Rémi Jacquet, Stéphane Quideau, Juha-Pekka Salminen

Ellagitannins are a subclass of hydrolysable tannins that have been suggested to function as defensive compounds of plants against herbivores. However, it is known that the conditions in the digestive tracts of different herbivores are variable, so it seems reasonable to anticipate that the reactivities and modes of actions of these ingested defensive compounds would also be different. A previous study on a few ellagitannins has shown that these polyphenolic compounds are highly oxidizable at high pH and that their bioactivity can be attributed to certain structural features. Herein, the activities of 13 ellagitannins using the deoxyribose assay were measured. The results provided information about the anti-oxidant, pro-oxidant and metal chelating properties of ellagitannins. Surprisingly, many of the tested ellagitannins exhibited pro-oxidant activities even at neutral pH and only moderate to low radical scavenging activities, although the metal chelating capacities of all tested ellagitannins were relatively high.

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Datum: 26.05.2016


Graphical Contents List

Publication date: June 2016
Source:Phytochemistry, Volume 126










Datum: 26.05.2016


Galactinol synthase enzyme activity influences raffinose family oligosaccharides (RFO) accumulation in developing chickpea (Cicer arietinum L.) seeds

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Manu P. Gangola, Sarita Jaiswal, Udhaya Kannan, Pooran M. Gaur, Monica Båga, Ravindra N. Chibbar

To understand raffinose family oligosaccharides (RFO) metabolism in chickpea (Cicer arietinum L.) seeds, RFO accumulation and corresponding biosynthetic enzymes activities were determined during seed development of chickpea genotypes with contrasting RFO concentrations. RFO concentration in mature seeds was found as a facilitator rather than a regulating step of seed germination. In mature seeds, raffinose concentrations ranged from 0.38 to 0.68 and 0.75 to 0.99g/100g, whereas stachyose concentrations varied from 0.79 to 1.26 and 1.70 to 1.87g/100g indicating significant differences between low and high RFO genotypes, respectively. Chickpea genotypes with high RFO concentration accumulated higher concentrations of myo-inositol and sucrose during early seed developmental stages suggesting that initial substrate concentrations may influence RFO concentration in mature seeds. High RFO genotypes showed about two to three-fold higher activity for all RFO biosynthetic enzymes compared to those with low RFO concentrations. RFO biosynthetic enzymes activities correspond with accumulation of individual RFO during seed development.

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Datum: 26.05.2016


Phytochemical Society of Europe

Publication date: May 2016
Source:Phytochemistry, Volume 125










Datum: 26.05.2016


Synthesis of rebaudioside A from stevioside and their interaction model with hTAS2R4 bitter taste receptor

Publication date: May 2016
Source:Phytochemistry, Volume 125

Author(s): Ramit Singla, Vikas Jaitak

Steviol glycosides (SG’s) from Stevia rebaudiana (Bertoni) have been used as a natural low-calorie sweeteners. Its aftertaste bitterness restricts its use for human consumption and limits its application in food and pharmaceutical products. In present study, we have performed computational analysis in order to investigate the interaction of two major constituents of SG’s against homology model of the hTAS2R4 receptor. Molecular simulation study was performed using stevioside and rebaudioside A revealed that, sugar moiety at the C-3′′ position in rebaudioside A causes restriction of its entry into the receptor site thereby unable to trigger the bitter reception signaling cascade. Encouraged by the current finding, we have also developed a greener route using β-1,3-glucanase from Irpex lacteus for the synthesis of de-bittered rebaudioside A from stevioside. The rebaudioside A obtained was of high quality with percent conversion of 62.5%. The results here reported could be used for the synthesis of rebaudioside A which have large application in food and pharmaceutical industry.

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Datum: 26.05.2016


Talarolutins A–D: Meroterpenoids from an endophytic fungal isolate of Talaromyces minioluteus

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Amninder Kaur, Huzefa A. Raja, Dale C. Swenson, Rajesh Agarwal, Gagan Deep, Joseph O. Falkinham, Nicholas H. Oberlies

Four meroterpenoids [talarolutins A–D] and one known compound [purpurquinone A] were characterized from an endophytic fungal isolate of Talaromyces minioluteus (G413), which was obtained from the leaves of the medicinal plant milk thistle [Silybum marianum (L.) Gaertn. (Asteraceae)]. The structures of talarolutins A–D were determined by the analysis of various NMR and MS techniques. The relative and absolute configuration of talarolutin A was determined by X-ray diffraction analysis. A combination of NOESY data and comparisons of ECD spectra were employed to assign the relative and absolute configuration of the other analogs. Talarolutins B–D were tested for cytotoxicity against human prostate carcinoma (PC-3) cell line, antimicrobial activity, and induction of quinone reductase; no notable bioactivity was observed in any assay.

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Datum: 26.05.2016


HIV-inhibitory michellamine-type dimeric naphthylisoquinoline alkaloids from the Central African liana Ancistrocladus congolensis

Publication date: Available online 29 April 2016
Source:Phytochemistry

Author(s): Gerhard Bringmann, Claudia Steinert, Doris Feineis, Virima Mudogo, Julia Betzin, Carsten Scheller

Five michellamine-type dimeric naphthylisoquinoline alkaloids (NIQs), named michellamines A2, A3, A4, B2, and B3, have been isolated from the root bark of the Central African liana Ancistrocladus congolensis J. L é onard (Ancistrocladaceae), along with their two known parent compounds, the michellamines A and B, which had so far only been detected in the Cameroonian species Ancistrocladus korupensis. Five monomeric representatives, viz., korupensamine D, ancistrobrevine B, hamatine, 5′-O-demethylhamatine, and 6-O-methylhamatine, already known from related Ancistrocladus species, have likewise been identified. The structure elucidation was achieved by spectroscopic analysis including HRESIMS, 1D and 2D NMR, and by chemical and chiroptical methods. The michellamines A2, A3, B3, and A4 were evaluated for their cytotoxic and anti-HIV activities at a concentration range of 0–100 μM against the HIV reference strain IIIB/LAI in A3.01 T lymphoblast cell cultures, and their effects were compared to the ones displayed by the known michellamines A and B. Inhibitory activities for HIV replication were monitored for the michellamines A2 (IC50 = 29.6 μM), A3 (IC50 = 15.2 μM), A4 (IC50 = 35.9 μM), and B (IC50 = 20.4 μM). The michellamines A and B3, by contrast, did not inhibit HIV replication. No cytotoxicity was observed. Furthermore, the chemotaxonomic significance of the previously undescribed michellamines is discussed.

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Datum: 26.05.2016


Graphical Contents List

Publication date: April 2016
Source:Phytochemistry, Volume 124










Datum: 26.05.2016


Editorial Board/Publication Information

Publication date: April 2016
Source:Phytochemistry, Volume 124










Datum: 26.05.2016


Benzoylsalicylic acid isolated from seed coats of Givotia rottleriformis induces systemic acquired resistance in tobacco and Arabidopsis

Publication date: June 2016
Source:Phytochemistry, Volume 126

Author(s): Samuel Kamatham, Kishore Babu Neela, Anil Kumar Pasupulati, Reddanna Pallu, Surya Satyanarayana Singh, Padmaja Gudipalli

Systemic acquired resistance (SAR), a whole plant defense response to a broad spectrum of pathogens, is characterized by a coordinated expression of a large number of defense genes. Plants synthesize a variety of secondary metabolites to protect themselves from the invading microbial pathogens. Several studies have shown that salicylic acid (SA) is a key endogenous component of local and systemic disease resistance in plants. Although SA is a critical signal for SAR, accumulation of endogenous SA levels alone is insufficient to establish SAR. Here, we have identified a new acyl derivative of SA, the benzoylsalicylic acid (BzSA) also known as 2-(benzoyloxy) benzoic acid from the seed coats of Givotia rottleriformis and investigated its role in inducing SAR in tobacco and Arabidopsis. Interestingly, exogenous BzSA treatment induced the expression of NPR1 (Non-expressor of pathogenesis-related gene-1) and pathogenesis related (PR) genes. BzSA enhanced the expression of hypersensitivity related (HSR), mitogen activated protein kinase (MAPK) and WRKY genes in tobacco. Moreover, Arabidopsis NahG plants that were treated with BzSA showed enhanced resistance to tobacco mosaic virus (TMV) as evidenced by reduced leaf necrosis and TMV-coat protein levels in systemic leaves. We, therefore, conclude that BzSA, hitherto unknown natural plant product, is a new SAR inducer in plants.

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Datum: 26.05.2016


Secondary metabolites of seagrasses (Alismatales and Potamogetonales; Alismatidae): Chemical diversity, bioactivity, and ecological function

Publication date: April 2016
Source:Phytochemistry, Volume 124

Author(s): Christian Zidorn

Seagrasses are the only higher plants living in fully marine environments; they play a significant role in coastal ecosystems. Seagrasses inhabit the coastal shelves of all continents except Antarctica and can grow in depths of up to 90m. Because of their eminent ecological importance, innumerous studies have been dedicated to seagrasses and their ecology. However, the phytochemistry has not been equally well investigated yet and many of the existing studies in chemical ecology are only investigating the chemistry at the level of compound classes, e.g. phenolics, and not at the level of chemically defined metabolites. In the present review, the existing literature on secondary metabolites of seagrasses, their known source seagrasses, their bioactivity, and ecological function are compiled and critically assessed. Moreover, research gaps are highlighted and avenues for future research are discussed. Currently, a total of 154 chemically defined natural products have been reported from the about 70 seagrass species known worldwide. Compounds reported include simple phenols derivatives (four compounds), phenylmethane derivatives (14 compounds), phenylethane derivatives (four compounds), phenylpropane derivatives including their esters and dimers (20 compounds), chalkones (four compounds), flavonoids including catechins (57 compounds), phenylheptanoids (four compounds), one monoterpene derivative, one sesquiterpene, diterpenoids (13 compounds), steroids (31 compounds), and one alkaloid. Most of the existing bioactivity studies of seagrass metabolites and extracts have been directed to potential cytotoxic, antimicrobial, or antimacrofouling activity. Antimicrobial studies have been performed towards panels of both human pathogens and ecologically relevant pathogens. In the antimacrofouling studies, investigations of the potential of zosteric acid from the genus Zostera are the most numerous and have yielded so far the most interesting results. Studies on the chemical ecology of seagrasses often have been focused on variation in phenolic compounds and include but are not limited to studies on variation due to abiotic factors, seasonal variation, variation in response to grazing by fish or sea urchins, or following microbial attack.

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Datum: 26.05.2016






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