The Experts below are selected from a list of 13041 Experts worldwide ranked by ideXlab platform
Mondher El Jaziri - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis of active constituents in centella asiatica samples from madagascar application for ex situ conservation and clonal propagation
Fitoterapia, 2007Co-Authors: Denis Randriamampionona, Billo Diallo, Francisco Rakotoniriana, Christian Rabemanantsoa, Kiban Cheuk, Annemarie Corbisier, Jacques Mahillon, Suzanne Ratsimamanga, Mondher El JaziriAbstract:A comparative quantitative analysis of the active Triterpenoids in Centella asiatica samples collected in different locations in Madagascar was carried out to evaluate the natural variability in Triterpenoid content and to select elite samples for further ex situ germplasm conservation and clonal propagation. The highest asiaticoside content (6.42%) was measured in samples collected in Mangoro region. In vitro propagation of C. asiatica was successfully achieved in hormone-free medium. Although lower asiaticoside content was detected in 8-week-old vitro plants, the Mangoro sample still showed the highest content in this Triterpenoid constituent (1.78%). Acetoxycentellynol, a C(15)-polyacetylene, was found to be accumulated up to 18 times more in in vitro plants as compared to plant material collected in situ.
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comparative analysis of active constituents in centella asiatica samples from madagascar application for ex situ conservation and clonal propagation
Fitoterapia, 2007Co-Authors: Denis Randriamampionona, Billo Diallo, Francisco Rakotoniriana, Christian Rabemanantsoa, Kiban Cheuk, Annemarie Corbisier, Jacques Mahillon, Suzanne Ratsimamanga, Mondher El JaziriAbstract:A comparative quantitative analysis of the active Triterpenoids in Centella asiatica samples collected in different locations in Madagascar was carried out to evaluate the natural variability in Triterpenoid content and to select elite samples for further ex situ germplasm conservation and clonal propagation. The highest asiaticoside content (6.42%) was measured in samples collected in Mangoro region. In vitro propagation of C asiatica was successfully achieved in hormone-tree medium. Although lower asiaticoside content was detected in 8-week-old vitro plants, the Mangoro sample still showed the highest content in this Triterpenoid constituent (1.78%). Acetoxycentellynol, a C-15-polyacetylene, was found to be accumulated up to 18 times more in in vitro plants as compared to plant material collected in situ. (c) 2007 Elsevier B.V All rights reserved.
Toshiya Muranaka - One of the best experts on this subject based on the ideXlab platform.
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p450s and ugts key players in the structural diversity of Triterpenoid saponins
Plant and Cell Physiology, 2015Co-Authors: Hikaru Seki, Keita Tamura, Toshiya MuranakaAbstract:: The recent spread of next-generation sequencing techniques has facilitated transcriptome analyses of non-model plants. As a result, many of the genes encoding enzymes related to the production of specialized metabolites have been identified. Compounds derived from 2,3-oxidosqualene (the common precursor of sterols, steroids and Triterpenoids), a linear compound of 30 carbon atoms produced through the mevalonate pathway, are called triterpenes. These include essential sterols, which are structural components of biomembranes; steroids such as the plant hormones, brassinolides and the toxin in potatoes, solanine; as well as the structurally diverse Triterpenoids. Triterpenoids containing one or more sugar moieties attached to Triterpenoid aglycones are called Triterpenoid saponins. Triterpenoid saponins have been shown to have various medicinal properties, such as anti-inflammatory, anticancerogenic and antiviral effects. This review summarizes the recent progress in gene discovery and elucidates the biochemical functions of biosynthetic enzymes in Triterpenoid saponin biosynthesis. Special focus is placed on key players in generating the structural diversity of Triterpenoid saponins, cytochrome P450 monooxygenases (P450s) and the UDP-dependent glycosyltransferases (UGTs). Perspectives on further gene discovery and the use of biosynthetic genes for the microbial production of plant-derived Triterpenoid saponins are also discussed.
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Plant Cytochrome P450s in Triterpenoid Biosynthesis: Diversity and Application to Combinatorial Biosynthesis
Fifty Years of Cytochrome P450 Research, 2014Co-Authors: Ery Odette Fukushima, Hikaru Seki, Toshiya MuranakaAbstract:Plants produce a wide variety of specialized (secondary) metabolites, with which they interact in various environmental conditions for survival. Plant cytochrome P450s have a central function to enhance the diversity of the chemicals. Here we focus on the diversity of P450s in (tri)terpenoid biosynthesis and their application to combinatorial biosynthesis. A strategy combining a homology-based approach, gene coexpression analysis, and combinatorial biosynthesis with heterologous expression in yeast was successful in identifying enzymes involved in Triterpenoid biosynthesis and also in generating natural and rare Triterpenoids that do not accumulate in planta. Using this strategy is possible to construct a natural-unnatural Triterpenoid library. The next steps are then to increase product yields as well as to diversify Triterpenoids into novel synthetic entities with improved biological activities by combining enzymes from different sources.
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cyp716a subfamily members are multifunctional oxidases in Triterpenoid biosynthesis
Plant and Cell Physiology, 2011Co-Authors: Ery Odette Fukushima, Hikaru Seki, Toshiya Muranaka, Kazuki Saito, Kiyoshi Ohyama, Eiichiro Ono, Naoyuki Umemoto, Masaharu MizutaniAbstract:Triterpenoids are a diverse group of secondary metabolites that are associated with a variety of biological activities. Oleanolic acid, ursolic acid and betulinic acid are common Triterpenoids in plants with diverse biological activities, including antifungal, antibacterial, anti-human immunodeficiency virus (HIV) and/or antitumor activities. In the present study, using the gene co-expression analysis tool of Medicago truncatula, we found a strong correlation between CYP716A12 and β-amyrin synthase (bAS), which encodes the enzyme responsible for the initial cyclization of 2,3-oxidosqualene to β-amyrin (the basic structural backbone of most Triterpenoid saponins). Through an in vitro assay, we identified CYP716A12 as a β-amyrin 28-oxidase able to modify β-amyrin to oleanolic acid (through erythrodiol and, possibly, oleanolic aldehyde). We also confirmed its activity in vivo, by expressing CYP716A12 in transgenic yeast that endogenously produce β-amyrin. In addition, CYP716A12 was evaluated for its potential α-amyrin- and lupeol-oxidizing activities. Interestingly, CYP716A12 was able to generate ursolic acid (through uvaol and, possibly, ursolic aldehyde) and betulinic acid (through betulin). Hence, CYP716A12 was characterized as a multifunctional enzyme with β-amyrin 28-oxidase, α-amyrin 28-oxidase and lupeol 28-oxidase activities. We also identified homologs of CYP716A12 in grape (CYP716A15 and CYP716A17) that are involved in Triterpenoid biosynthesis, which indicates the highly conserved functionality of the CYP716A subfamily among plants. These findings will be useful in the heterologous production of pharmacologically and industrially important Triterpenoids, including oleanolic acid, ursolic acid and betulinic acid.
Reinhard Jetter - One of the best experts on this subject based on the ideXlab platform.
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oxidosqualene cyclases involved in the biosynthesis of Triterpenoids in quercus suber cork
Scientific Reports, 2020Co-Authors: Lucas Busta, Olga Serra, Ok Tae Kim, Marisa Molinas, Irene Perefossoul, Merce Figueras, Reinhard JetterAbstract:Cork is a water-impermeable, suberin-based material harboring lignin, (hemi)cellulose, and extractable small molecules (primarily Triterpenoids). Extractables strongly influence the properties of suberin-based materials. Though these previous findings suggest a key role for Triterpenoids in cork material quality, directly testing this idea is hindered in part because it is not known which genes control cork Triterpenoid biosynthesis. Here, we used gas chromatography and mass spectrometry to determine that the majority (>85%) of non-polar extractables from cork were pentacyclic Triterpenoids, primarily betulinic acid, friedelin, and hydroxy-friedelin. In other plants, Triterpenoids are generated by oxidosqualene cyclases (OSCs). Accordingly, we mined Quercus suber EST libraries for OSC fragments to use in a RACE PCR-based approach and cloned three full-length OSC transcripts from cork (QsOSC1-3). Heterologous expression in Saccharomyces cerevisiae revealed that QsOSC1-3 respectively encoded enzymes with lupeol synthase, mixed α- and β-amyrin synthase, and mixed β-amyrin and friedelin synthase activities. These activities together account for the backbone structures of the major cork Triterpenoids. Finally, we analyzed the sequences of QsOSC1-3 and other plant OSCs to identify residues associated with specific OSC activities, then combined this with analyses of Q. suber transcriptomic and genomic data to evaluate potential redundancies in cork Triterpenoid biosynthesis.
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composition of the epicuticular and intracuticular wax layers on kalanchoe daigremontiana hamet et perr de la bathie leaves
Phytochemistry, 2009Co-Authors: Clare Van Maarseveen, Reinhard JetterAbstract:Abstract Epicuticular and intracuticular waxes from both adaxial and abaxial surfaces of the leaves of Kalanchoe daigremontiana were analyzed. All wax mixtures were found to contain approximately equal amounts of Triterpenoids and very long chain fatty acid (VLCFA) derivatives. The Triterpenoid fraction consisted of glutinol (8–19% of the total wax) and friedelin (4–9%), together with smaller amounts of glutanol, glutinol acetate, epifriedelanol, germanicol and β-amyrin. The VLCFA derivatives comprised C 27 –C 35 alkanes (19–37% of the total wax), C 32 –C 34 aldehydes (3–7%), C 32 and C 34 fatty acids (0.2–3%), C 26 –C 36 primary alcohols (4–8%), and C 42 –C 52 alkyl esters (2–9%). The wax layers were found to differ in Triterpenoid amounts, with the intracuticular wax containing higher percentages of most Triterpenoids than the epicuticular wax. Friedelin, the only Triterpenoid ketone present, showed the opposite distribution with higher proportions in the epicuticular wax. VLCFA derivatives also accumulated to higher percentages in the epicuticular than in the intracuticular wax layer. Epicuticular wax crystals were observed on both the adaxial and abaxial leaf surfaces.
Dingcheng Xiang - One of the best experts on this subject based on the ideXlab platform.
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Triterpenoids from the bark of dysoxylum hainanense and their anti inflammatory and radical scavenging activity
Fitoterapia, 2017Co-Authors: Yuhai Zou, Wenting Liu, Jinxia Zhang, Dingcheng XiangAbstract:Abstract A phytochemical investigation on the 70% EtOH extract of the bark of Dysoxylum hainanense resulted in the isolation of four new Triterpenoids, dysoxyhaines A–D (1–4). Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D (1H 1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated components were evaluated in vitro for anti-inflammatory activities for Cox-1 and Cox-2, and radical scavenging potential using ABTS·+ and DPPH test. As a result, nor seco-olean type Triterpenoid 1 exhibited significant anti-inflammatory potential, while tirucallane Triterpenoids 3 and 4 showed radical scavenging activities.
Denis Randriamampionona - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis of active constituents in centella asiatica samples from madagascar application for ex situ conservation and clonal propagation
Fitoterapia, 2007Co-Authors: Denis Randriamampionona, Billo Diallo, Francisco Rakotoniriana, Christian Rabemanantsoa, Kiban Cheuk, Annemarie Corbisier, Jacques Mahillon, Suzanne Ratsimamanga, Mondher El JaziriAbstract:A comparative quantitative analysis of the active Triterpenoids in Centella asiatica samples collected in different locations in Madagascar was carried out to evaluate the natural variability in Triterpenoid content and to select elite samples for further ex situ germplasm conservation and clonal propagation. The highest asiaticoside content (6.42%) was measured in samples collected in Mangoro region. In vitro propagation of C. asiatica was successfully achieved in hormone-free medium. Although lower asiaticoside content was detected in 8-week-old vitro plants, the Mangoro sample still showed the highest content in this Triterpenoid constituent (1.78%). Acetoxycentellynol, a C(15)-polyacetylene, was found to be accumulated up to 18 times more in in vitro plants as compared to plant material collected in situ.
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comparative analysis of active constituents in centella asiatica samples from madagascar application for ex situ conservation and clonal propagation
Fitoterapia, 2007Co-Authors: Denis Randriamampionona, Billo Diallo, Francisco Rakotoniriana, Christian Rabemanantsoa, Kiban Cheuk, Annemarie Corbisier, Jacques Mahillon, Suzanne Ratsimamanga, Mondher El JaziriAbstract:A comparative quantitative analysis of the active Triterpenoids in Centella asiatica samples collected in different locations in Madagascar was carried out to evaluate the natural variability in Triterpenoid content and to select elite samples for further ex situ germplasm conservation and clonal propagation. The highest asiaticoside content (6.42%) was measured in samples collected in Mangoro region. In vitro propagation of C asiatica was successfully achieved in hormone-tree medium. Although lower asiaticoside content was detected in 8-week-old vitro plants, the Mangoro sample still showed the highest content in this Triterpenoid constituent (1.78%). Acetoxycentellynol, a C-15-polyacetylene, was found to be accumulated up to 18 times more in in vitro plants as compared to plant material collected in situ. (c) 2007 Elsevier B.V All rights reserved.
