Tannins and Related Polyphenols of Melastomataceous Plants. I. Hydrolyzable Tannins from Tibouchina semidecandra COGN.
نویسندگان
چکیده
منابع مشابه
Tannins and related polyphenols of melastomataceous plants. VIII. Nobotanins L, M and N, trimeric hydrolyzable tannins from Tibouchina semidecandra.
Three hydrolyzable tannins, nobotannins L, M and N, were isolated from the water-soluble portion of the leaf extract of Tibouchina semidecandra, and their trimeric structures were elucidated from spectral and chemical evidence. Nobotanins L and N exist as equilibrium mixtures of four anomers due to the presence of two unacylated anomeric centers.
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Until now, the recommended procedure for measuring hydrolyzable tannins has been to mix the reagent and sample, subject the mixture to a certain amount of chill, allow the reaction to continue for some time at a higher temperature and then measure the absorbance of the colored solution. The effect of different chill conditions has been studied by many workers but the effect of conditions after ...
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ژورنال
عنوان ژورنال: Chemical and Pharmaceutical Bulletin
سال: 1991
ISSN: 0009-2363,1347-5223
DOI: 10.1248/cpb.39.2233