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



Phytohormone profile in Lactuca sativa and Brassica oleracea plants grown under Zn deficiency

Publication date: Available online 16 August 2016
Source:Phytochemistry

Author(s): Eloy Navarro-León, Alfonso Albacete, Alejandro de la Torre-González, Juan M. Ruiz, Begoña Blasco

Phytohormones, structurally diverse compounds, are involved in multiple processes within plants, such as controlling plant growth and stress response. Zn is an essential micronutrient for plants and its deficiency causes large economic losses in crops. Therefore, the purpose of this study was to analyse the role of phytohormones in the Zn-deficiency response of two economically important species, i.e. Lactuca sativa and Brassica oleracea. For this, these two species were grown hydroponically with different Zn-application rates: 10 μM Zn as control and 0.1 μM Zn as deficiency treatment and phytohormone concentration was determined by U-HPLC-MS. Zn deficiency resulted in a substantial loss of biomass in L. sativa plants that was correlated with a decline in growth-promoting hormones such as indole-3-acetic acid (IAA), cytokinins (CKs), and gibberellins (GAs). However these hormones increased or stabilized their concentrations in B. oleracea and could help to maintain the biomass in this species. A lower concentration of stress-signaling hormones such as ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA), salicylic acid (SA) and jasmonic acid (JA) and also CKs might be involved in Zn uptake in L. sativa while a rise in GA4, isopentenyl adenine (iP), and ACC and a fall in JA and SA might contribute to a better Zn-utilization efficiency (ZnUtE), as observed in B. oleracea plants.

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Datum: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


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: 25.08.2016


Absolute configurations of phytotoxic inuloxins B and C based on experimental and computational analysis of chiroptical properties

Publication date: Available online 3 August 2016
Source:Phytochemistry

Author(s): Marco Evidente, Ernesto Santoro, Ana G. Petrovic, Alessio Cimmino, Jun Koshoubu, Antonio Evidente, Nina Berova, Stefano Superchi

The absolute configuration of phytotoxins inuloxins B and C, produced by Inula viscosa, and with potential herbicidal activity for the management of parasitic plants, has been determined by Time-dependent density functional theory computational prediction of electronic circular dichroism and optical rotatory dispersion spectra. The inuloxin B has been converted to its 5-O-acetyl derivative, which due to its more constrained conformational features facilitated the computational analysis of its chiroptical properties. The analysis based on experimental and computed data led to assignment of absolute configuration to naturally occurring (+)-inuloxin B and (−)-inuloxin C as (7R,8R,10S,11S) and (5S,7S,8S,10S), respectively.

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Datum: 25.08.2016


Graphical Contents List

Publication date: September 2016
Source:Phytochemistry, Volume 129










Datum: 25.08.2016


Nitric oxide inhibitory xanthones from the pericarps of Garcinia mangostana

Publication date: Available online 22 August 2016
Source:Phytochemistry

Author(s): Qianyu Liu, Dan Li, Anqi Wang, Zhen Dong, Sheng Yin, Qingwen Zhang, Yang Ye, Liangchun Li, Ligen Lin

Mangosteen (Garcinia mangostana, Clusiaceae) is called “queen of fruit” in Southeast Asia. In the current study, three dimeric xanthones, garcinoxanthones A–C, and four monomeric xanthones, garcinoxanthones D–G, together with 18 known xanthones, were isolated from the pericarps of G. mangostana, collected in Thailand. The structures of garcinoxanthones A–G were elucidated by analysis of their 1D and 2D NMR and other spectroscopic data, and their absolute configurations were determined by the CD spectra. All seven compounds were tested for nitric oxide (NO) inhibitory activity on lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Garcinoxanthones B and C significantly inhibited NO production with IC50 values of 11.3 ± 1.7 and 18.0 ± 1.8 μM, respectively, which were comparable with the positive control indomethacin (IC50 3.9 ± 0.3 μM). Moreover, garcinoxanthone B suppressed inducible NO synthase expression in a dose-dependent manner. These results reveal the presence of rare dimeric xanthones in G. mangostana and their NO inhibitory effect on LPS-stimulated murine macrophage cells.

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Datum: 25.08.2016


Editorial Board/Publication Information

Publication date: July 2016
Source:Phytochemistry, Volume 127










Datum: 25.08.2016


A volatolomic approach for studying plant variability: the case of selected Helichrysum species (Asteraceae)

Publication date: Available online 5 August 2016
Source:Phytochemistry

Author(s): Claudia Giuliani, Lorenzo Lazzaro, Roberto Calamassi, Luca Calamai, Riccardo Romoli, Gelsomina Fico, Bruno Foggi, Marta Mariotti Lippi

The species of Helichrysum sect. Stoechadina (Asteraceae) are well-known for their secondary metabolite content and the characteristic aromatic bouquets. In the wild, populations exhibit a wide phenotypic plasticity which makes critical the circumscription of species and infraspecific ranks. Previous investigations on Helichrysum italicum complex focused on a possible phytochemical typification based on hydrodistilled essential oils. Aims of this paper are three-fold: (i) characterizing the volatile profiles of different populations, testing (ii) how these profiles vary across populations and (iii) how the phytochemical diversity may contribute in solving taxonomic problems. Nine selected Helichrysum populations, included within the H. italicum complex, Helichrysum litoreum and Helichrysum stoechas, were investigated. H. stoechas was chosen as outgroup for validating the method. After collection in the wild, plants were cultivated in standard growing conditions for over one year. Annual leafy shoots were screened in the post-blooming period for the emissions of volatile organic compounds (VOCs) by means of headspace solid phase microextraction coupled with gas-chromatography and mass spectrometry (HS-SPME-GC/MS). The VOC composition analysis revealed the production of overall 386 different compounds, with terpenes being the most represented compound class. Statistical data processing allowed the identification of the indicator compounds that differentiate the single populations, revealing the influence of the geographical provenance area in determining the volatile profiles. These results suggested the potential use of VOCs as valuable diacritical characters in discriminating the Helichrysum populations. In addition, the cross-validation analysis hinted the potentiality of this volatolomic study in the discrimination of the Helichrysum species and subspecies, highlighting a general congruence with the current taxonomic treatment of the genus. The consistency between this phytochemical approach and the traditional morphometrical analysis in studying the Helichrysum populations supports the validity of the VOC profile in solving taxonomic problems.

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Datum: 25.08.2016


Identification of a secretory phospholipase A2 from Papaver somniferum L. that transforms membrane phospholipids

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Veronika Jablonická, Johanna Mansfeld, Ingo Heilmann, Marek Obložinský, Mareike Heilmann

The full-length sequence of a new secretory phospholipase A2 was identified in opium poppy seedlings (Papaver somniferum L.). The cDNA of poppy phospholipase A2, denoted as pspla 2 , encodes a protein of 159 amino acids with a 31 amino acid long signal peptide at the N-terminus. PsPLA2 contains a PLA2 signature domain (PA2c), including the Ca2+-binding loop (YGKYCGxxxxGC) and the catalytic site motif (DACCxxHDxC) with the conserved catalytic histidine and the calcium-coordinating aspartate residues. The aspartate of the His/Asp dyad playing an important role in animal sPLA2 catalysis is substituted by a serine residue. Furthermore, the PsPLA2 sequence contains 12 conserved cysteine residues to form 6 structural disulfide bonds. The calculated molecular weight of the mature PsPLA2 is 14.0 kDa. Based on the primary structure PsPLA2 belongs to the XIB group of PLA2s. Untagged recombinant PsPLA2 obtained by expression in Escherichia coli, renaturation from inclusion bodies and purification by cation-exchange chromatography was characterized in vitro. The pH optimum for activity of PsPLA2 was found to be pH 7, when using mixed micelles of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and Triton X-100. PsPLA2 specifically cleaves fatty acids from the sn-2 position of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and shows a pronounced preference for PC over phosphatidyl ethanolamine, -glycerol and -inositol. The active recombinant enzyme was tested in vitro against natural phospholipids isolated from poppy plants and preferably released the unsaturated fatty acids, linoleic acid and linolenic acid, from the naturally occurring mixture of substrate lipids.

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Datum: 25.08.2016


Graphical Contents List

Publication date: August 2016
Source:Phytochemistry, Volume 128










Datum: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


Stress tolerance of transgenic barley accumulating the alfalfa aldose reductase in the cytoplasm and the chloroplast

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Bettina Nagy, Petra Majer, Róbert Mihály, János Pauk, Gábor V. Horváth

Barley represents one of the major crops grown worldwide; its genetic transformation provides an important tool for the improvement of crop quality and tolerance to environmental stress factors. Biotic and abiotic stresses produce reactive oxygen species in the plant cells that can directly oxidize the cellular components including lipid membranes; resulting in lipid peroxidation and subsequently the accumulation of reactive carbonyl compounds. In order to protect barley plants from the effects of stress-produced reactive carbonyls, an Agrobacterium-mediated transformation was carried out using the Medicago sativa aldose reductase (MsALR) gene. In certain transgenic lines the produced MsALR enzyme was targeted to the chloroplasts to evaluate its protective effect in these organelles. The dual fluorescent protein-based method was used for the evaluation of tolerance of young seedlings to diverse stresses; our results demonstrated that this technique could be reliably applied for the detection of cellular stress in a variety of conditions. The chlorophyll and carotenoid content measurements also supported the results of the fluorescent protein-based method and the stress-protective effect of the MsALR enzyme. Targeting of MsALR into the chloroplast has also resulted in increased stress tolerance, similarly to the observed effect of the cytosolic MsALR accumulation. The results of the DsRed/GFP fluorescent protein-based method indicated that both the cytosol and chloroplast accumulation of MsALR can increase the abiotic stress tolerance of transgenic barley lines.

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Datum: 25.08.2016


Metabolic changes in Euphorbia palusrtis latex after fungal infection

Publication date: Available online 20 August 2016
Source:Phytochemistry

Author(s): Gordana Krstić, Boban Anđelković, Young Hae Choi, Vlatka Vajs, Tatjana Stević, Vele Tešević, Dejan Gođevac

The variations of metabolic profile of the latex of wild-growing Euphorbia palustris was carried out using multivariate analysis of 1H NMR spectral data. One population was infected with fungi Fusarium sporotrichioides, Fusarium proliferatum and Alternaria alternata, while the other consisted of healthy plant species. The non-polar metabolites of latex extracts such as benzoyl ingenol-laurate, amyrin decadienoate esters, cis-1,4-polyisoprene, and 24-methylenecycloartanol were identified using 1H and 2D NMR spectra. Principal component analysis of 1H NMR data provided a clear discrimination between the latex of infected and healthy plants. Minimum inhibitory concentration and minimum fungicidal concentration values of the latex extracts of healthy and infected plants were determined. The latex of infected plants was found to contain higher levels of benzoyl ingenol-laurate and 24-methylenecycloartanol, of which concentrations were strongly correlated with the antifungal activities of the latex.

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Datum: 25.08.2016


Induced defenses change the chemical composition of pine seedlings and influence meal properties of the pine weevil Hylobius abietis

Publication date: Available online 11 July 2016
Source:Phytochemistry

Author(s): Lina Lundborg, Frauke Fedderwitz, Niklas Björklund, Göran Nordlander, Anna-Karin Borg-Karlson

The defense of conifers against phytophagous insects relies to a large extent on induced chemical defenses. However, it is not clear how induced changes in chemical composition influence the meal properties of phytophagous insects (and thus damage rates). The defense can be induced experimentally with methyl jasmonate (MeJA), which is a substance that is produced naturally when a plant is attacked. Here we used MeJA to investigate how the volatile contents of Scots pine (Pinus sylvestris L.) tissues influence the meal properties of the pine weevil (Hylobius abietis (L.)). Phloem and needles (both weevil target tissues) from MeJA-treated and control seedlings were extracted by n-hexane and analyzed by two-dimensional gas chromatography-mass spectrometry (2D GC-MS). The feeding of pine weevils on MeJA-treated and control seedlings were video-recorded to determine meal properties. Multivariate statistical analyses showed that phloem and needle contents of MeJA-treated seedlings had different volatile compositions compared to control seedlings. Levels of the pine weevil attractant (+)-α-pinene were particularly high in phloem of control seedlings with feeding damage. The antifeedant substance 2-phenylethanol occurred at higher levels in the phloem of MeJA-treated than in control seedlings. Accordingly, pine weevils fed slower and had shorter meals on MeJA-seedlings. The chemical compositions of phloem and needle tissues were clearly different in control seedlings but not in the MeJA-treated seedlings. Consequently, meal durations of mixed meals, i.e. both needles and phloem, were longer than phloem meals on control seedlings, while meal durations on MeJA seedlings did not differ between these meal contents. The meal duration influences the risk of girdling and plant death. Thus our results suggest a mechanism by which MeJA treatment may protect conifer seedlings against pine weevils.

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Datum: 25.08.2016


Eudesmane-type sesquiterpenoids from Salvia plebeia inhibit IL-6-induced STAT3 activation

Publication date: Available online 6 August 2016
Source:Phytochemistry

Author(s): Hyun-Jae Jang, Hyun-Mee Oh, Joo Tae Hwang, Mi-Hwa Kim, Soyoung Lee, Kyungsook Jung, Young-Ho Kim, Seung Woong Lee, Mun-Chual Rho

Seven eudesmane-type sesquiterpenoid lactones and the known plebeiolide C were isolated from an ethanol-soluble extract of the aerial parts of Salvia plebeia R. Br. Their structures were determined via NMR and MS, and their absolute configurations were elucidated using ECD, and X-ray crystallographic analysis, as well as the modified Mosher ester method. All isolates were evaluated for their inhibitory effects on IL6-induced STAT3 promoter activation in stably transfected Hep3B cells. Of these isolates, eudebeiolide D exhibited an inhibitory effect with the IC50 value of 1.1 μM.

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Datum: 25.08.2016


A potent bidirectional promoter from the monocot cereal Eleusine coracana

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Saswati Sen, Samir Kr. Dutta

Ragi bifunctional α-amylase-trypsin inhibitor (RBI) of Eleusine coracana (L.) Gaertn. (finger millet) simultaneously inhibits α-amylase and trypsin. In continuation of previous work on the cloning, expression and characterization of RBI, a bidirectional promoter from finger millet was explored on the basis of experimental observations. Two trypsin inhibitors were identified while purifying RBI from a trypsin-Sepharose column eluent. Using an FPLC gel filtration column, these three inhibitors were purified to homogeneity and subjected to MALDI-TOF-TOF-MS/MS analysis and N-terminal sequencing. Both ragi trypsin inhibitors (RTIs) showed the same N-terminal sequence and considerable sequence similarity to RBI, indicating the presence of a multigene protease inhibitor family in finger millet. To gain insight into the evolution of these genes, the upstream region of RBI was explored by Genome Walking. Interestingly, on sequencing, a genome walking product of ∼1 Kb showed presence of an N-terminal RBI specific primer sequence twice but in opposite directions and leaving an intervening region of ∼0.9 Kb. The intervening region was presumed to represent an E. coracana bidirectional promoter (EcBDP), intuitively having a divergent RBI-RTI gene pair at two sides. For assaying the bidirectionality of promoter activity, a dual reporter GUS-GFP vector construct was made for plant expression containing the reporter genes at two ends of EcBDP, which was used to transform Agrobacterium tumefaciens LBA 4404. Transient plant transformation by recombinant Agrobacterium cells was carried out in onion scale epidermal cells and finger millet seedling leaves. Simultaneous expression of GUS and GFP under EcBDP established it as a potent natural bidirectional promoter from monocot origin, thereby potentially having vast application in cereal gene manipulations. In addition, inducibility of the EcBDP by either abscisic acid or cold treatment, as determined by transient transformation in onion, would substantiate more precise control of gene expression to mitigate the effects of adverse environmental conditions.

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Datum: 25.08.2016


Withanolides from leaves of cultivated Acnistus arborescens

Publication date: Available online 4 August 2016
Source:Phytochemistry

Author(s): Pedro Henrique J. Batista, Karísia Sousa B. de Lima, Francisco das Chagas L. Pinto, Juliane L. Tavares, Daniel E. de A. Uchoa, Letícia V. Costa-Lotufo, Danilo D. Rocha, Edilberto R. Silveira, Antonio Marcos E. Bezerra, Kirley M. Canuto, Otília Deusdenia L. Pessoa

Seven withanolides, including four previously unknown, were isolated from the acetone and ethanol extracts of cultivated specimens of Acnistus arborescens. These four compounds were identified as rel-(18R,22R)-5β,6β:18β,20-diepoxy-3β,18α-dimethoxy-4β-hydroxy-1-oxowith-24-enolide, rel-(20R,22R)-5β,6β-epoxy-4β,16α,20-trihydroxy-1-oxowitha-2,24dienolide, rel-(20R,22R)-16α-acetoxy-6α-chloro-4β,5β,20-trihydroxy-1-oxowitha-2,24-dienolide and rel-(20R,22R)-16α-acetoxy-20-hydroxy-1-oxowitha-2,5,24-trienolide. Their structures were elucidated by interpretation of spectroscopic data (1D and 2D NMR), HRESIMS experiments and comparison with published data for similar compounds. Cytotoxicity of the isolated compounds was evaluated against a panel of four tumor cell lines (HL-60, HCT-116, SF-268 and PANC-1). Withanolide D was the most active, with an IC50 value in the range of 0.3–1.7 μM, rel-(18R,22R)-5β,6β:18β,20-diepoxy-3β,18α-dimethoxy-4β-hydroxy-1-oxowith-24-enolide and rel-(20R,22R)-5β,6β-epoxy-4β,16α,20-trihydroxy-1-oxowitha-2,24dienolide were moderately active, while all the others were non-cytotoxic.

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Datum: 25.08.2016


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: 25.08.2016


Editorial Board/Publication Information

Publication date: August 2016
Source:Phytochemistry, Volume 128










Datum: 25.08.2016


Amides and neolignans from the aerial parts of Piper bonii

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Duo-Duo Ding, Yue-Hu Wang, Ya-Hui Chen, Ren-Qiang Mei, Jun Yang, Ji-Feng Luo, Yan Li, Chun-Lin Long, Yi Kong

Six amides, piperbonamides A–F, three neolignans piperbonins A–C, and 11 known compounds were isolated from the aerial parts of Piper bonii (Piperaceae). The structures of piperbonamides A–F and piperbonins A–C were elucidated based on the analysis of 1D and 2D NMR and MS data. Piperbonin A, (+)-trans-acuminatin, (+)-cis-acuminatin, (+)-kadsurenone, and pipernonaline showed weak activity against platelet aggregation with IC50 values of 118.2, 108.5, 90.02, 107.3, and 116.3 μM, respectively, as compared with the positive control, tirofiban, with an IC50 value of 5.24 μM. Piperbonamides A–F were inactive against five tumor cell lines at concentrations up to 40 μM.

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Datum: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


Editorial Board/Publication Information

Publication date: September 2016
Source:Phytochemistry, Volume 129










Datum: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


Triterpenoids from the leaves of Alphitonia xerocarpus Baill and their biological activity

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Dima Muhammad, Nathalie Lalun, Hélène Bobichon, Elisabeth Le Magrex Debar, Sophie C. Gangloff, Mohammed Nour, Laurence Voutquenne-Nazabadioko

Ten previously undescribed triterpenoid saponins and a previously undescribed norlupane triterpenoid were isolated, with three known saponins, four known flavonoids, two known lupane derivatives, sitosterol and 6′-heptadecanoyl-3-O-β- d-glucopyranosylsitosterol from the leaves of Alphitonia xerocarpus (Rhamnaceae), an endemic tree of New Caledonia. The chemical structures of the purified compounds were identified by nuclear magnetic resonance and mass spectrometry. The isolated compounds were tested for their antioxidant, antityrosinase, antibacterial and cytotoxic activity. The aqueous methanol extract showed antioxidant activity (DPPH assay) due to the presence of rutin. Ceanothenic acid showed good cytotoxic activity against a KB cell line (IC50 = 2.6 μM) and antibacterial activity against Staphylococcus aureus and Enterococcus faecalis with MIC values of 8 and 16 μg/mL, respectively. The previously undescribed 29-hydroxyceanothenic acid exhibited moderate cytotoxic activity (IC50 = 10 μM), good antibacterial activity against S. aureus (MIC = 4 μg/mL) and moderate antibacterial activity against E. faecalis (MIC = 16 μg/mL).

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Datum: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


A new view on the codonocarpine type alkaloids of Capparis decidua

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


Polyoxygenated ursane and oleanane triterpenes from Siphonodon celastrineus

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Wirongrong Kaweetripob, Chulabhorn Mahidol, Sanit Thongnest, Hunsa Prawat, Somsak Ruchirawat

Twenty polyoxygenated triterpenes, including nineteen ursanes and one oleanane, were characterized from the stem material of Siphonodon celastrineus (Celastraceae) through the application of spectroscopic techniques and chemical transformation. Three of the ursane-type triterpenoids possessed the rare 13,27-cyclopropane ring skeleton.

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Datum: 25.08.2016


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

Publication date: August 2016
Source:Phytochemistry, Volume 128

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. Léonard (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: 25.08.2016


Triterpenoids from the branch and leaf of Abies fargesii

Publication date: Available online 22 July 2016
Source:Phytochemistry

Author(s): Wenming Wu, Xu Chen, Ye Liu, Yanmei Wang, Tian Tian, Xiaoya Zhao, Juan Li, Hanli Ruan

Eighteen triterpenoids, abifarines A-R, including fourteen previously unknown and four artifacts, together with six known ones, were isolated from the branch and leaf of Abies fargesii. Their structures were elucidated by spectroscopic data analysis. The relative configurations of abifarines A and F were further confirmed by single-crystal X-ray diffraction analysis with Mo Kα irradiation. All compounds were evaluated for their in vitro cytotoxicity against the mouse cancer B16 cell line, and human cancer HepG2 and MCF7 cell lines. (24R)-cycloartane-3β,24,25-triol and (24R)-cycloartane-3β,24,25,28-tetrol showed moderate anti-proliferative effect for B16 and HepG2 cell lines with IC50 values of 32.9, 19.5 μM and 26.4, 21.5 μM, respectively.

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Datum: 25.08.2016


Phenylbenzoisoquinolindione alkaloids accumulate in stamens of Xiphidium caeruleum Aubl. flowers

Publication date: August 2016
Source:Phytochemistry, Volume 128

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: 25.08.2016


Bioactive sesquiterpenoids from the flowers of Inula japonica

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Xing-De Wu, Lin-Fen Ding, Wen-Chao Tu, Hui Yang, Jia Su, Li-Yan Peng, Yan Li, Qin-Shi Zhao

Phytochemical investigation of the flowers of Inula japonica led to isolation of nine sesquiterpenoids, inujaponins A-I, as well as eighteen known ones. These sesquiterpenoids belong to six skeletal-types, including eudesmane, 1,10-seco-eudesmane, germacrane, guaiane, 4,5-seco-guaiane, and pseudoguaiane sesquiterpenoids. Their structures were established by extensive spectroscopic analysis. The absolute configurations of inujaponin A, eupatolide, and deacetylovatifolin were determined by Cu-Kα X-ray crystallographic analysis. Most of the isolated compounds exhibited potent cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW-480 cancer cell lines, with IC50 values ranging from 1.57 to 22.58 μM. Some selected compounds also possessed significant inhibitory activity against LPS-induced NO production in RAW264.7 macrophages with IC50 values ranging from 1.42 to 8.99 μM.

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Datum: 25.08.2016


Structural characterization of allomelanin from black oat

Publication date: Available online 14 July 2016
Source:Phytochemistry

Author(s): Mónika Varga, Ottó Berkesi, Zsuzsanna Darula, Nóra Veronika May, András Palágyi

The brown to black coloration found in plants is due to the melanins, which have been relatively poorly investigated among the plant pigments. The aim of this work was to study the dark pigment extracted from the black oat hull with respect to composition and structure. Ultraviolet–visible (UV–Vis) spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared (FT-IR) spectroscopy were applied for the characterization of the pigment. UV–Vis spectroscopy revealed that the extracted material displays a broadband, structureless absorption profile a common feature of melanins. MALDI-TOF MS measurements demonstrated that oat melanin is a homopolymer built up from p-coumaric acid and consists mainly of low molecular weight (527–1499 Da) oligomers of 3–9 monomer units. The tetramer oligomer proved to be dominant. The results of the FT-IR analysis indicated that oat melanin is a fully conjugated aromatic system containing tetrasubstituted aromatic rings linked by CC coupling. The in vitro preparation of melanin from p-coumaric acid by horseradish peroxidase was performed for comparison. The resulting polymer consisted of oligomers of 4–9 monomer units similarly to those in oat melanin. However, the building blocks proved to be connected to each other via COC linkages in contrast with the CC linkages in oat melanin.

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Datum: 25.08.2016


Direct evidence of specific localization of sesquiterpenes and marchantin A in oil body cells of Marchantia polymorpha L.

Publication date: Available online 9 July 2016
Source:Phytochemistry

Author(s): M. Tanaka, T. Esaki, H. Kenmoku, T. Koeduka, Y. Kiyoyama, T. Masujima, Y. Asakawa, K. Matsui

Liverworts are a rich source of a diverse array of specialized metabolites, such as terpenoids and benzenoids, which are potentially useful for pharmaceutical or agrochemical applications, and also provide clues to elucidate the strategy by which liverworts adapt to the terrestrial environment. Liverworts, belonging to orders Marchantiales and Jungermanniales, possess oil bodies. In Marchantia polymorpha L., oil bodies are confined to scattered idioblastic oil body cells. It has been assumed that the specialized metabolites in M. polymorpha specifically accumulate in the oil bodies in oil body cells; however, no direct evidence was previously available for this specific accumulation. In this study, direct evidence was obtained using micromanipulation techniques coupled with MS analysis that demonstrated the specific accumulation of sesquiterpenoids and marchantin A in the oil body cells of M. polymorpha thalli. It was also observed that the number of oil body cells increased in thalli grown in low-mineral conditions. The amounts of sesquiterpenoids and marchantin A detected in crude extract prepared from the whole thallus were roughly proportional to the number of oil body cells found in a given volume of thallus, suggesting that oil body cell differentiation and sesquiterpenoid and marchantin A biosynthetic pathways are coordinated with each other.

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Datum: 25.08.2016


Composition of the epicuticular waxes coating the adaxial side of Phyllostachys aurea leaves: Identification of very-long-chain primary amides

Publication date: Available online 9 July 2016
Source:Phytochemistry

Author(s): Radu C. Racovita, Reinhard Jetter

The present study presents comprehensive chemical analyses of cuticular wax mixtures of the bamboo Phyllostachys aurea. The epicuticular and intracuticular waxes were sampled selectively from the adaxial side of leaves on young and old plants and investigated by gas chromatography-mass spectrometry and flame ionization detection. The epi- and intracuticular layers on young and old leaves had wax loads ranging from 1.7 μg/cm2 to 1.9 μg/cm2. Typical very-long-chain aliphatic wax constituents were found with characteristic chain length patterns, including alkyl esters (primarily C48), alkanes (primarily C29), fatty acids (primarily C28 and C16), primary alcohols (primarily C28) and aldehydes (primarily C30). Alicyclic wax components were identified as tocopherols and triterpenoids, including substantial amounts of triterpenoid esters. Alkyl esters, alkanes, fatty acids and aldehydes were found in greater amounts in the epicuticular layer, while primary alcohols and most terpenoids accumulated more in the intracuticular wax. Alkyl esters occurred as mixtures of metamers, combining C20 alcohol with various acids into shorter ester homologs (C36 C40), and a wide range of alcohols with C22 and C24 acids into longer esters (C42 C52). Primary amides were identified, with a characteristic chain length profile peaking at C30. The amides were present exclusively in the epicuticular layer and thus at or near the surface, where they may affect plant-herbivore or plant-pathogen interactions.

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Datum: 25.08.2016


Oleanane-type triterpenoid saponins from Silene armeria

Publication date: September 2016
Source:Phytochemistry, Volume 129

Author(s): Nobuyuki Takahashi, Wei Li, Kazuo Koike

Twelve triterpenoid saponins, including seven compounds (i.e., armerosides A–G) hitherto unknown, were isolated from whole plants of Silene armeria. Their structures were established based on extensive spectroscopic analyses and chemical methods. From a biosynthetic perspective, C-23 oxidation of the sapogenin appears to be a key factor in the glycosylation pathway.

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Datum: 25.08.2016


Cytotoxic cardenolides and sesquiterpenoids from the fruits of Reevesia formosana

Publication date: Available online 4 July 2016
Source:Phytochemistry

Author(s): Pei-Yu Hsiao, Shiow-Ju Lee, Ih-Sheng Chen, Hsing-Yu Hsu, Hsun-Shuo Chang

Bioassay-guided fractionation of the fruits of Reevesia formosana led to isolation of three cardenolides (reevesioside J, reevesioside K, and epi-reevesioside K), three sesquiterpenoids (reevesiterpenol C, reevesiterpenol D, and reevesiterpenol E), and two glycosides (reevesianin A and reevesianin B), along with 46 known compounds. Their structures were determined using spectroscopic techniques. In addition to the reported cytotoxic cardenolides, reevesioside J and strophanthidin exhibited moderate cytotoxicity against the cell lines MCF-7, NCI-H460, and HepG2, with IC50 values of 0.39 ± 0.06 μM and 1.06 ± 0.12 μM for MCF-7, 0.12 ± 0.01 μM and 0.29 ± 0.01 μM for NCI-H460, and 1.09 ± 0.02 μM and 1.72 ± 0.02 μM for HepG2, respectively. Reevesiterpenol E also exhibited the best selective cytotoxicity to the NCI-H460 cell line, with an IC50 value of 3.15 ± 0.22 μM.

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Datum: 25.08.2016


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: 25.08.2016


Graphical Contents List

Publication date: July 2016
Source:Phytochemistry, Volume 127










Datum: 25.08.2016


Diterpenes from Grangea maderaspatana

Publication date: Available online 23 August 2016
Source:Phytochemistry

Author(s): Fang-Rong Chang, Shih-Ting Huang, Chih-Chuang Liaw, Ming-Hong Yen, Tsong-Long Hwang, Ching-Yeu Chen, Ming-Feng Hou, Shyng-Shiou Yuan, Yuan-Bin Cheng, Yang-Chang Wu

Phytochemical investigation of the ethanolic extract of Grangea maderaspatana led to isolation of gramaderins A–D, together with thirteen known compounds. All isolates were assayed for their anti-inflammatory activities. Consequently, 5,7-dihydroxy-3,6,3′,4′,5′-pentamethoxyflavone and 5,3′-dihydroxy-3,6,7,4′,5′-pentamethoxyflavone showed significant bioactivities by inhibiting superoxide anion generation. 8-Acetoxy-pentadeca-1,9Z,14-trien-4,6-diyne-3-ol also demonstrated potent inhibition on elastase release. The gramaderins A/C (β-alkyl linked γ-lactone) and gramaderins B/D (α-alkyl linked γ-lactone) co-exist in this plant material, of which the latter derivatives are few in nature. Gramaderins C/D possess a special linear dilactone diterpene skeleton, which never been reported.

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Datum: 25.08.2016


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: 25.08.2016


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: 25.08.2016


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: 25.08.2016


Discrimination of wild types and hybrids of Duboisia myoporoides and Duboisia leichhardtii at different growth stages using 1H NMR-based metabolite profiling and tropane alkaloids-targeted HPLC-MS analysis

Publication date: Available online 23 August 2016
Source:Phytochemistry

Author(s): Sophie Friederike Ullrich, Nils J.H. Averesch, Leonardo Castellanos, Young Hae Choi, Andreas Rothauer, Oliver Kayser

Duboisia species, which belong to the family of Solanaceae, are commercially cultivated in large scale, as they are main source of the pharmaceutically-used active compound scopolamine. In this study, 1H NMR-based metabolite profiling linking primary with secondary metabolism and additional quantification via HPCL-MS with special focus on the tropane alkaloids were applied to compare leaf and root extracts of three wild types and two hybrids of Duboisia myoporoides and D. leichhardtii at different developmental stages grown under controlled conditions in climate chambers and under agricultural field plantation. Based on the leaf extracts, a clear distinction between the Duboisia hybrids and the wild types Duboisia myoporoides and D. leichhardtii using principal component analysis of 1H NMR data was observed. The average content in scopolamine in the hybrids of Duboisia cultivated in climate chambers increased significantly from month 3–6 after potting of the rooted cuttings, however not so for the examined wild types. The Duboisia hybrids grown in climate chambers showed higher growth and contained more sugars and amino acids than Duboisia hybrids grown in the field, which in contrast showed an enhanced flux towards tropane alkaloids as well as flavonoids. For a more detailed analysis of tropane alkaloids, an appropriate HPLC-MS method was developed and validated. The measurements revealed large differences in the alkaloid pattern within the different genotypes under investigation, especially regarding the last enzymatic step, the conversion from hyoscamine to scopolamine by the hyoscyamine 6β–hydroxylase. Scopolamine was found in highest concentrations in Duboisia hybrids (20.04 ± 4.05 and 17.82 ± 3.52 mg/g dry wt) followed by Duboisia myoporoides (12.71 ± 2.55 mg/g dry wt), both showing a high selectivity for scopolamine in contrast to Duboisia leichhardtii (3.38 ± 0.59 and 5.09 ± 1.24 mg/g dry wt) with hyoscyamine being the predominant alkaloid.

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Datum: 25.08.2016


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: 25.08.2016


Saponins of Agave: Chemistry and bioactivity

Publication date: Available online 30 June 2016
Source:Phytochemistry

Author(s): Jasmeen Sidana, Bikram Singh, Om P. Sharma

The genus Agave comprises more than 400 species with geographical presence in the tropical and sub-tropical regions of the world. These plants have a rich history of folkloric use and are known for a wide spectrum of applications. Secondary metabolites of diverse chemical classes have been reported from Agave species. Owing to their pharmacological significance, the steroidal saponins of Agave have caught the attention of phytochemists, biologists and drug discovery scientists. The present review describes 141 steroidal saponins and sapogenins and covers the literature published from 1970 to 2015. It is a comprehensive and coherent presentation of the structures, methods of chemical profiling, structure elucidation and biological activities of the saponins and sapogenins reported from Agave. The article provides a perspective of the research on steroidal compounds of Agave.

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Datum: 25.08.2016


Chemical constituents from Melicope pteleifolia leaves

Publication date: Available online 30 June 2016
Source:Phytochemistry

Author(s): Ngoc Hieu Nguyen, Thi Kim Quy Ha, Sangho Choi, Sangmi Eum, Chul Ho Lee, Tran The Bach, Vu Tien Chinh, Won Keun Oh

Five acetophenones bearing spiroketal-hexofuranoside rings, one di-C-glycosidic acetophenone and two benzopyrans, along with 16 known compounds were isolated from the leaves of Melicope pteleifolia. Structures of all the isolates were elucidated using extensive spectroscopic methods, including 1D, 2D-NMR and HRESIMS. All the isolates were also evaluated for their neuraminidase inhibitory activities against H1N1, H9N2, wild-type H1N1 and oseltamivir-resistant H1N1 (H274Y mutation) virus strains. Of the isolates, tamarixetin 3-robinobioside was found to exhibit the strongest enzymatic inhibition (IC50 24.93 ± 3.46, 23.19 ± 5.41, 26.67 ± 5.16 and 40.16 ± 4.50 μM, respectively). Selected candidates, kaempferol 3-robinobioside, kaempferol 3-O-β-d-glucopyranosyl (1 → 2)-α-d-xylopyranoside and tamarixetin 3-robinobioside, also showed moderate reductions in H1N1-induced cytopathic effects on MDCK cells.






Datum: 25.08.2016


Homologous and heterologous expression of grapevine E-(β)-caryophyllene synthase (VvGwECar2)

Publication date: Available online 22 August 2016
Source:Phytochemistry

Author(s): Umberto Salvagnin, Silvia Carlin, Sergio Angeli, Urska Vrhovsek, Gianfranco Anfora, Mickael Malnoy, Stefan Martens

E-(β)-caryophyllene is a sesquiterpene volatile emitted by plants and involved in many ecological interactions within and among trophic levels and it has a kairomonal activity for many insect species. In grapevine it is a key compound for host-plant recognition by the European grapevine moth, Lobesia botrana, together with other two sesquiterpenes. In grapevine E-(β)-caryophyllene synthase is coded by the VvGwECar2 gene, although complete characterization of the corresponding protein has not yet been achieved. Here we performed the characterization of the enzyme after heterologous expression in E. coli, which resulted to produce in vitro also minor amounts of the isomer α-humulene and of germacrene D. The pH optimum was estimated to be 7.8, and the Km and Kcat values for farnesyl pyrophosphate were 31.4 μM and 0.19 s−1 respectively. Then, we overexpressed the gene in the cytoplasm of two plant species, Arabidopsis thaliana and the native host Vitis vinifera. In Arabidopsis the enzyme changed the plant head space release, showing a higher selectivity for E-(β)-caryophyllene, but also the production of thujopsene instead of germacrene D. Overall plants increased the E-(β)-caryophyllene emission in the headspace collection by 8-fold compared to Col-0 control plants. In grapevine VvGwECar2 overexpression resulted in higher E-(β)-caryophyllene emissions, although there was no clear correlation between gene activity and sesquiterpene quantity, suggesting a key role by the plant regulation machinery.

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Datum: 25.08.2016


Quali-quantitative analysis of the phenolic fraction of the flowers of Corylus avellana, source of the Italian PGI product “Nocciola di Giffoni”: Isolation of antioxidant diarylheptanoids

Publication date: Available online 29 June 2016
Source:Phytochemistry

Author(s): Milena Masullo, Angela Mari, Antonietta Cerulli, Alfredo Bottone, Bogdan Kontek, Beata Olas, Cosimo Pizza, Sonia Piacente

There is only limited information available on the chemical composition of the non-edible parts of Corylus avellana, source of the Italian PGI product “Nocciola di Giffoni” (hazelnut). An initial LC-MS profile of the methanolic extract of the male flowers of C. avellana, cultivar ‘Tonda di Giffoni’ led to the isolation of 12 compounds, of which the structures were elucidated by NMR spectroscopy. These were identified as three previously undescribed diarylheptanoids, named giffonins Q-S, along with nine known compounds. Furthermore, the quantitative determination of the main compounds occurring in the methanolic extract of C. avellana flowers was carried out by an analytical approach based on LC-ESI(QqQ)MS, using the Multiple Reaction Monitoring (MRM) experiment. In order to explore the antioxidant ability of C. avellana flowers, the methanolic extract and the isolated compounds were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H2O2 and H2O2/Fe2+, by measuring the concentration of TBARS.

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Datum: 25.08.2016






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