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131.
V. V. Grishko M. M. Shakirov I. Yu. Bagryanskaya Yu. V. Gatilov V. A. Raldugin 《Russian Chemical Bulletin》1996,45(3):709-712
The structure of the molecule of a new trinorlanostane hydroxyketone obtained by alkali treatment of total triterpenoid acids from the ether extract of Siberian fir needles was established using NMR spectra and X-ray analysis.For Part 15 see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 748–751. March, 1996. 相似文献
132.
I. A. Tolmacheva L. N. Shelepen’kina A. S. Shashkov V. V. Grishko V. A. Glushkov A. G. Tolstikov 《Chemistry of Natural Compounds》2007,43(2):153-158
A mixture of diastereomeric 3-acetoxy-(2,3),(19β,28)-diepoxyoleananes was prepared via reaction of 3-acetoxy-19β,28-epoxyolean-2-ene
with m-chloroperbenzoic acid. Directed rearrangement of these formed 2β-acetoxy-19β,28-epoxyolean-3-one whereas heating of
them in amines produced oleanane-type enamines.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 127–131, March–April, 2007. 相似文献
133.
Hui Fang Pi Peng Zhang Tian Zhu Han Li Ruan Yong Hui Zhang Han Dong Sun Ji Zhou Wu 《中国化学快报》2007,18(4):418-420
A new triterpenoid has been isolated from the leaves and stems of Fritillaria hupehensis Hsiao et K.C.Hsia.Its structure wasestablished as(23Z)-9,19-cycloart-23-ene-3α,25-diol 1 through chemical and spectroscopic studies including 2D NMR.Anotherknown triterpenoid 9,19-cycloart-25-ene-3β,24ξ-diol 2 was also isolated. 相似文献
134.
Two new naturally occurring flavonoids, 3,4′,5,7-tetramethoxyflavone and 3,3′,4′,5,7-pentamethoxyflavone, along with known compounds, 5-hydroxy-3,4′,7-trimethoxyflavone, 5-hydroxy-3,3′,4,7-tetramethoxyflavone, ursolic acid, 2α,3α-dihydroxyurs-12-en-28-oic acid, phytosterols, and phytosteryl glucosides, have been isolated and characterized from the fresh leaves of Callicarpa formosana Rolfe. 相似文献
135.
The absolute configurations of the secondary alcohols at C-3 position in betulinic acid and 3-epibetulinic acid have been unambiguously determined as S- and R-configurations, respectively, based on the fucofuranoside method. The absolute stereochemistry of 3α, 27-dihydroxylupen-20(29)-en-28-oic acid methyl ester, a potent topoisomerase II inhibitor, was determined to be 3R, 5R, 8R, 9R, 10R, 13R, 14S, 17S, 18R, and 19R by NMR and ORD spectroscopic studies. 相似文献
136.
Xiao‐Li Li Yu Zhao Xiao Cheng Lin Tu Li‐Yan Peng Gang Xu Qin‐Shi Zhao 《Helvetica chimica acta》2006,89(7):1467-1473
Three new serratane‐type triterpenoids, japonicumins A–C ( 1 – 3 ), as well as a unique, new C13 terpenoid, japonicumin D ( 4 ), were isolated from the dried whole plants of Lycopodium japonicum, together with the known compound lycoclavanol ( 5 ). Their structures were identified by extensive mass‐spectrometric and spectroscopic (especially 2D‐NMR) experiments. Compounds 1 – 5 exhibited no activity against human‐tumor A 549 cells. 相似文献
137.
The new lanostane methylsteroid orbigenin, the structure of which is 23,24-lanost-9(11)-en-3,7,16,19,23,24,25-heptaol, was isolated from Astragalus orbiculatus Ledeb. (Leguminosae). The structure of the new triterpenoid, the first lanostanoid from plants of the Astragalus genus, was determined using electron-impact mass spectrometry and PMR and 13C NMR spectroscopies interpreted using J-modulation, DEPT, and the 2D NMR methods: 1H-1H COSY, HSQC, and HMBC. 相似文献
138.
Chaves DC Assunção JC Braz-Filho R Lemos TL Monte FJ 《Magnetic resonance in chemistry : MRC》2007,45(5):389-392
Two new cucurbitane-type triterpenoids, 2beta,3beta,16alpha,20(R),25-pentahydroxy-9-methyl-19-norlanost-5-en-7,22-dione and 2beta,3beta,16alpha,20(R),25-pentahydroxy-9-methyl-19-norlanost-5-en-7,11,22-trione, were isolated from fruits of Cayaponia racemosa. The total (1)H and (13)C chemical shift assignment of these two closely related compounds is described, making use of one- and two-dimensional NMR techniques. 相似文献
139.
Three new cucurbitane-type triterpenoid saponins, 23-O-beta-D-allopyranosyl-5beta,19-epoxycucurbita-6,24-diene-3beta,22(S),23(S)-triol-3-O-beta-D-glucopyranoside (1), 23-O-beta-D-allopyranosyl-5beta,19-epoxycucurbita-6,24-diene-3beta,22(S),23(S)-triol-3-O-beta-D-allopyranoside (2), and 23-O-beta-D-allopyranosyl-5beta,19-epoxycucurbita-6,24-diene-3beta,19(R), 22(S),23(S)-tetraol-3-O-beta-D-allopyranoside (3), named momordicoside M, N, and O, respectively, along with one known saponin momordicoside L (4), were isolated from the fresh fruits of Momordica charantia. The structures of these saponins were elucidated on the basis of chemical properties and spectral data. 相似文献
140.
Three new triterpenoids with the rarely occurring nigrum skeleton, namely (20E)‐22‐hydroxynigrum‐20‐en‐3‐one ( 1 ), 21β‐hydroxynigrum‐22(29)‐en‐3‐one ( 2 ), and 21α‐hydroxynigrum‐22(29)‐en‐3‐one ( 3 ), were isolated from the mangrove plant Hibiscus tiliaceus. Additionally, five known triterpenoids including friedelin ( 4 ), 12‐oleanen‐3β‐ol ( 5 ), 3β‐hydroxy‐12‐oleanen‐28‐oic acid ( 6 ), 20(29)‐lupen‐3β,28‐diol ( 7 ), and cucurbita‐5,23‐dien‐3β,25‐diol ( 8 ) were also isolated and identified. The latter structures were elucidated by a detailed NMR and MS analyses, as well as by comparison with reported literature data. 相似文献