| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a xanthine oxidase inhibitor comprising highly safe extracts of plants as active ingredients. <P>SOLUTION: The extracts of Lagerstroemia speciosa (banaba) has most strong activity estimated by comparing the xanthine oxidase inhibiting actions of 10 kinds of plant materials. The banaba is extracted with a hot water, or the like, the obtained "crude extract" is treated by adsorption with a styrene-divinylbenzene-based synthetic resin or a dextran-based synthetic resin, the obtained "resin adsorbed ingredient" is treated by partition operation using water and an organic solvent such as chloroform to obtain an "organic solvent-soluble ingredient", the obtained "organic solvent-soluble ingredient" is fractionated by high performance liquid chromatography and the fraction of the second peak in five peaks i.e. a mixture ingredient of 2,5-bis-(4-hydroxy-3,5-dimethoxyphenyl)-3,4-bis-(hydroxymethyl)-(2,3,4,5)-tetrahydrofuran of formula (1) with valoneic acid dilactone of formula (2) is provided as the active ingredient of the xanthine oxidase inhibitor. <P>COPYRIGHT: (C)2004,JPO |
