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From the unsaponifiable fraction of an ethereal extract of the leaves ofBetula lanata, in addition to 3-epiocotillol (I) we have isolated a new triterpene, 20(S), 24(R)-epoxydammarane-3,11,25-triol (V) and also derivatives of it — the monoacetates at C-3 (II) and C-11 (III), and the monoketone at C-3 (IV). The structures of compounds (I-V) have been established on the basis of the results of physicochemical investigations.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center of the Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 513–516, July–August, 1980.  相似文献   

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Summary From the unsaponifiable part of an ethereal extract of the leaves ofBetula costata four triterpenoids of the dammarane series have been isolated. For the previously unknown triterpenoids A and C the structures of dammar-24-ene-3,17,20-triol and of betulafoliene-tetraol oxide, respectively, have been proposed.Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Scientific Center of the Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 757–762, November–December, 1976.  相似文献   

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A polysaccharide has been isolated from the leaves ofPhytolacca americana and has been characterized. It has been established that it contains residues of galactose, arabinose, xylose, and rhamnose, in a ratio of 3:4:1:3 and also D-galacturonic acid (85–90%). The results obtained permit the polysaccharide to be assigned to the class of pectin substances.All-Union Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 166–169, March–April, 1982.  相似文献   

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N.G. Bisset  B.C. Das  J. Parello   《Tetrahedron》1973,29(24):4137-4148
From the leaves ofStrychnos icaja Baill. a further seven alkaloids have been isolated and their structures determined: 16-hydroxystrychnine (1e), 21,22-α-epoxy-4-hydroxy-3-methoxy-N-methyl-sec.-pseudostrychnine (5c), 21,22-α-epoxy-4-hydroxy-N-methyl-sec.-pseudostrychnine5a), 21,22-α-epoxy-2-methoxy-N-methyl-sec.-pseudostrychnine (5b), 21,22-α-epoxy-14-hydroxy-N-methyl-sec.-pseudostrychnine (6a), 21,22-α-epoxy-4,14-dihydroxy-N-methyl-sec.-pseudostrychnine (6b), and 14-hydroxy-N-methyl-sec.-pseudostrychnine (7). Jaminet's alkaloid B' is shown to be impure 21,22-α-epoxy-14-hydroxy-2,3-dimethoxy-N-methyl-sec.-pseudostrychnine (6c).  相似文献   

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A new steroid saponin has been isolated from the air-dry leaves ofYucca aloifolia L., and it has been shown to be (25R)-5-spirostan-3-ol O-D-glucopyranosyl-(1 2)-D-galactopyranoside. The substance melts at 302–303°C []D20 –27.2, (c 1.0; CHCl3).I. G. Kutateladze Institute of Pharmacochemistry, Academy of Sciences of the Georgian SSR, Tbilisi. Translated from Khimiya Prirodnikh Soedinenii, No. 6, pp. 744–747, November–December, 1984.  相似文献   

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Products of the oxidation, polymerization, and esterification of tocopherols and esters of phytol with aliphatic acids have been identified in fractions of an alcoholic extract of shed plane leaves by means of mass-spectrometric analysis.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, FAX (3712) 62 73 48. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 363–371, May–June, 1994.  相似文献   

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Two new megastigmane O-glucopyranosides,named (2R,3R,5R,6S,9R)-3-hydroxy-5,6-epoxy-β-ionol-2-O-β-D-glucopyrano- side(1) and (2R,3R,5R,6S,9R)-3-hydroxyl-5,6-epoxy-acety-β-ionol-2-O-β-D-glucopyranoside(2) together with six known mega- stigmanes,were isolated from the leaves of Broussonetia papyrifera (Linn.) Vent.Their structures were established by chemical methods and spectroscopic techniques including 2D NMR.  相似文献   

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From the unsaponifiable fraction of an ethereal extract of the leaves ofBetula ovalifolia have been isolated the new triterpene 20(S),24(R)-epoxydammarane-3,17,25-triol (V) and the corresponding monoketone at C3 (VI). The leaves ofB. middendorfii have yielded the triterpene (IX) and (X), identified as, respectively, dammar-23-ene-3,12,20(S),25-tetraol and damman-25-ene-3,12,20-(S),24-tetraol, which have been obtained previously from the leaves ofBetula platyphylla Sukatchev var.japonica.The species of birch were determined by V. I. Baranov of the Laboratory of Chemotaxonomy.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 323–329, May–June, 1981.  相似文献   

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Pentacyclic triterpenes (1) and (2) have been isolated from Mimusops elengi and assigned structures 3beta,6beta,19alpha,23-tetrahydroxy-urs-12-ene and 1beta-hydroxy-3beta-hexanoyllup-20 (29)-ene-23, 28-dioic acid, respectively, on the basis of spectroscopic studies including 2D-NMR. The compound 1 showed moderate inhibiting activity against beta-glucuronidase enzyme  相似文献   

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