Two new gallotannins, pistafolins A (1) and B (2), were isolated from the leaf extract of Pistacia weinmannifolia. Their structures were determined by spectral methods.
A novel gallotannin, crenulatin (1), was isolated from the stem of Rhodiola crenulata, and its structure was determined by means of spectral analyses(including ~1H—~1H COSY, ~1H—^(13)C COSY and ~1H—^(13)C COLOC spe...A novel gallotannin, crenulatin (1), was isolated from the stem of Rhodiola crenulata, and its structure was determined by means of spectral analyses(including ~1H—~1H COSY, ~1H—^(13)C COSY and ~1H—^(13)C COLOC spectral measurements)and chemical evidence.展开更多
Eucaglobulin 1, a new complex of gallotannin and monoterpene, was isolated from the leaves of Eucalyptus globulus. Its structure was determined by spectral methods.
As an exploration of synthesizing gallotannins,the natural products with versatile biological activities 3 o galloyl D glucose (7) was prepared from gallic acid (1) and D glucose (3).The phenol hydroxyl groups of gall...As an exploration of synthesizing gallotannins,the natural products with versatile biological activities 3 o galloyl D glucose (7) was prepared from gallic acid (1) and D glucose (3).The phenol hydroxyl groups of gallic acid were protected by benzylation which was cleaved subsequently by 10% palladised charcoal,and the four hydroxyl groups (1,2,4,6 ) of glucose shielded by isopropylation followed by acid hydrolysis.The structure was elucidated from the data of thin layer chromatography(TLC) and NMR spectrum.展开更多
文摘Two new gallotannins, pistafolins A (1) and B (2), were isolated from the leaf extract of Pistacia weinmannifolia. Their structures were determined by spectral methods.
文摘A novel gallotannin, crenulatin (1), was isolated from the stem of Rhodiola crenulata, and its structure was determined by means of spectral analyses(including ~1H—~1H COSY, ~1H—^(13)C COSY and ~1H—^(13)C COLOC spectral measurements)and chemical evidence.
文摘Eucaglobulin 1, a new complex of gallotannin and monoterpene, was isolated from the leaves of Eucalyptus globulus. Its structure was determined by spectral methods.
文摘As an exploration of synthesizing gallotannins,the natural products with versatile biological activities 3 o galloyl D glucose (7) was prepared from gallic acid (1) and D glucose (3).The phenol hydroxyl groups of gallic acid were protected by benzylation which was cleaved subsequently by 10% palladised charcoal,and the four hydroxyl groups (1,2,4,6 ) of glucose shielded by isopropylation followed by acid hydrolysis.The structure was elucidated from the data of thin layer chromatography(TLC) and NMR spectrum.
