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Radioisotopically labelled l-leucine and l-valine were fed to Pisum sativum and incorporated into squalene and β-amyrin. Chemical degradation of the radioactive squalene revealed an equal distribution of the radioactivity in the isopentenyl pyrophosphate(IPP)-derived and the 3,3-dimethylallyl pyrophosphate(DMAPP)-derived moieties of the squalene molecule, unlike the unbalanced distribution in favour of the DMAPP-derived moiety of a monoterpenoid molecule biosynthesized from these amino acids by higher plants. 相似文献
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C. Betancor R. Freire A.G. Gonzalez J.A. Salazar C. Pascard T. Prange 《Phytochemistry》1980,19(9):1989-1993
The investigation of stems and leaves of Catha cassinoides afforded, in addition to sitosterol, β-amyrin, ursolic acid, lup-20(29)-en-3β,30-diol and friedelin, three new pentacyclic triterpenes: 30-hydroxyfriedelan-3-one, 29-hydroxyfriedelan-3-one and 3-oxo-friedelan-29-oic acid. The structures ofthese were determined by spectral studies and correlations, and were confirmed by X-ray analysis of 29-hydroxyfriedelan-3-one acetate. 相似文献
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Parimi Atchuta Ramaiah Parimi Uma Devi Felix Frolow David Lavie 《Phytochemistry》1984,23(10):2251-2255
3-Oxo-friedelan-20α-oic acid, named as maytenonic (polpunonic) acid, has been isolated along with β-amyrin and sitosterol from Gymnosporia emarginata. 1H and 13C NMR signals have been assigned for the structure. X-ray analysis of the single crystal confirmed that the carboxylic acid is α-oriented at C-20 and the D/E rings of this D:A-friedo-oleanane are in chair-chair conformation. 13C NMR data of the present compound also enabled the assignment of the C-20α- and β-methyl carbons in friedelin. 相似文献
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Swapnadip Thakur Prantika Das Toshihiro Itoh Kazunori Imai Taro Matsumoto 《Phytochemistry》1984,23(9):2085-2087
The hexane and methanol soluble extract of the latex coagulum of Calotropis gigantea afforded two new triterpene esters, viz. 3′-methylbutanoates of α-amyrin and ψ-taraxasterol, besides the known 3′-methylbutanoates of three triterpene alcohols. The compositions of the alkane fraction, total triterpene alcohol fraction, and free, acetyl and 3′-methylbutanoyl triterpene alcohol fractions of the extract were determined. 相似文献
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Wickramasinghe M. Bandaranayake 《Phytochemistry》1980,19(2):255-257
The following terpenoids were identified in the oleoresin, bark and timber of Canarium zeylanicum: 3β-hydroxyurs-12-en-11-one, 3β-hydroxyolean-12-en-11-one, olean-12-en-3,11-dione, urs-12-en-3,11-dione, α- and β-amyrin, α- and β-amyrenone, taraxerol, sitosterol, canaric acid, elemene, elemol, α-pinene, α- and β-phellandrene, limonene, terpineol and carvone. 相似文献
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The ethanol extract of Cnidosculus urens yielded β-amyrin cinnamate and germanicol acetate. Also, using 13C NMR spectroscopy, mixtures of β-amyrin, germanicol and lupeol as well as their acetates were identified. 相似文献
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