| abstract |
PURPOSE: To produce the title inhibitor as a natural product, which is composed of tea polyphenol and used in treatment for hypertension without side-effects, from tea leaves. n CONSTITUTION: Raw tea leaves or leaves of unfermented tea, half-fermented tea, roasted tea or instant tea are rinsed with a mixture of a hydrophilic solvent and a hydrophobic solvent where they are miscible with each other to remove caffeine and pigments, then, the solvents are evaporated off. An adequate amount of water is added to make the leaves wet and the leaves are brought into contact with an organic solvent such as methyl isobutyl ketone to extract a component containing catechin. The solvent is evaporated off from the extract and the concentrate is subjected to high-speed liquid chromatography of a reversed phase column using acetone-tetrahydrofuran-water = 0W25:0W35:65W85(vol.%) mixed solvent as an eluent to obtain tea polyphenols of formulas IWIII (R 1W2 is H, group of formula IV). n COPYRIGHT: (C)1988,JPO&Japio |