|
| ||
|
|
||
Biogenetic Pathway (biogenetic + pathway)
Selected AbstractsCampylopin from Delphinium campylocentrum, the First Hetidane C20 -Diterpene, Suggests a New Alkaloid Biogenetic Pathway.CHEMINFORM, Issue 24 2007Feng-Peng Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Xylogranatins F,R: Antifeedants from the Chinese Mangrove, Xylocarpus granatum, A New Biogenetic Pathway to TetranortriterpenoidsCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2008Jun Wu Dr. Abstract Thirteen limonoids with a new carbon skeleton, the xylogranatins,F,R (1,13), have been isolated from the seeds of a Chinese mangrove, Xylocarpus granatum; two recently reported compounds, xylogranatins,C and,D were also isolated. Their structures were elucidated on the basis of spectroscopic data and chemical methods. The absolute configurations of these compounds were determined by using the modified Mosher MTPA ester method and by quantum chemical circular dichroism (CD) calculations. Xylogranatins,F,Q are the first aromatic B-ring limonoids found in nature. They belong to two substructural classes, of which one (1,3) contains a pyridine ring while the other one (4,12) contains a central furan core. Xylogranatins,C and,R can be considered to be key biosynthetic intermediates, while xylogranatin,D, the only limonoid found so far with a carbon skeleton that conatains a C30C9 linkage, is apparently an artifact. The structures of these compounds suggest a new biogenetic pathway to tetranortriterpenoids. Xylogranatins,F, G and R were found to exhibit marked antifeedant activity against the third instar larvae of Mythimna separata (Walker) at a concentration of 1,mg,mL,1. The most potent compound tested was xylogranatin,G. Its AFC50 (concentration for 50,% antifeedant activity) values at the exposure times of 24 and 48,h were 0.31 and 0.30,mg,mL,1, respectively. [source] Trichocarpinine, a Novel Hetidine,Hetisine Type Bisditerpenoid Alkaloid from Aconitum tanguticum var. trichocarpumHELVETICA CHIMICA ACTA, Issue 1 2010Ling Lin Abstract Trichocarpinine (1), the first hetidine,hetisine type bisditerpenoid alkaloid, was isolated from the whole herbs of Aconitum tanguticum var. trichocarpum. Its structure was determined by a combination of spectroscopic techniques, including HR-ESI-MS and 1D- and 2D-NMR experiments. Its plausible biogenetic pathway was proposed as well (Scheme). [source] Two Novel Antioxidative Stilbene Tetramers from Parthenocissus laetevirensHELVETICA CHIMICA ACTA, Issue 7 2009Shan He Abstract Laetevirenols F (1) and G (2), two novel stilbene tetramers with an unprecedented skeleton, were isolated from Parthenocissus laetevirens. Their structures were elucidated by spectroscopic analysis, including 1D- and 2D-NMR experiments, and their possible biogenetic pathway was discussed. In addition, both compounds were determined to be potent singlet-oxygen quenchers by electron paramagnetic resonance (EPR) experiments, which highlights their potential pharmacological applications in singlet oxygen mediated diseases. [source] A Pair of New Nortriterpene Saponin Epimers from the Roots of Gypsophila oldhamianaHELVETICA CHIMICA ACTA, Issue 5 2006Jian-Guang Luo Abstract A pair of new oleanane-type nortriterpene saponin epimers, neogypsoside,A (1) and B (2) (Fig.,1) with neogypsogenin,A (3) and neogypsogenin,B (4) as the two new aglycons, as well as the two known triterpene saponins 5 and 6(Fig.,1), were isolated from the roots of Gypsophila oldhamiana. Their structures were determined by analysis of their NMR data. A possible biogenetic pathway to the nortriterpene saponins 1 and 2 is proposed (Scheme,2). [source] Xylogranatins F,R: Antifeedants from the Chinese Mangrove, Xylocarpus granatum, A New Biogenetic Pathway to TetranortriterpenoidsCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2008Jun Wu Dr. Abstract Thirteen limonoids with a new carbon skeleton, the xylogranatins,F,R (1,13), have been isolated from the seeds of a Chinese mangrove, Xylocarpus granatum; two recently reported compounds, xylogranatins,C and,D were also isolated. Their structures were elucidated on the basis of spectroscopic data and chemical methods. The absolute configurations of these compounds were determined by using the modified Mosher MTPA ester method and by quantum chemical circular dichroism (CD) calculations. Xylogranatins,F,Q are the first aromatic B-ring limonoids found in nature. They belong to two substructural classes, of which one (1,3) contains a pyridine ring while the other one (4,12) contains a central furan core. Xylogranatins,C and,R can be considered to be key biosynthetic intermediates, while xylogranatin,D, the only limonoid found so far with a carbon skeleton that conatains a C30C9 linkage, is apparently an artifact. The structures of these compounds suggest a new biogenetic pathway to tetranortriterpenoids. Xylogranatins,F, G and R were found to exhibit marked antifeedant activity against the third instar larvae of Mythimna separata (Walker) at a concentration of 1,mg,mL,1. The most potent compound tested was xylogranatin,G. Its AFC50 (concentration for 50,% antifeedant activity) values at the exposure times of 24 and 48,h were 0.31 and 0.30,mg,mL,1, respectively. [source] | ||||||||||