3',4',5,7-TETRAHYDROXYFLAVONE DERIVATIVES, PROCESS FOR THEIR PREPARATION AND THEIR THERAPEUTICAL USE

摘要

This invention relates to quercetin or fisetin derivatives substituted on the oxygen in the 3 position by groups such as lower alkyl, cycloalkyl, methanesulfonyl or paratoluenesulfonyl. The derivatives substituted by methanesulfonyl or paratoluenesulfonyl are obtained from a 3-O-glycoside whose phenol OH groups are blocked in the form of benzoate, and from which the OH in the 3 position is released by the action of concentrated HCl; this OH is esterified by mesityl chloride or paratoluenesulfonic acid chloride, and the benzoate groups are eliminated by soda treatment. The O derivatives substituted by alkyl or cycloakyl are prepared from a suitably substituted acetonitrile or metadiphenol; the resulting derivative reacts with 3,4-dibenzyloxybenzoic acid and the resulting flavone is debenzylated by hydrogenolysis. The derivatives, object of this invention, are useful in preventive or curative therapy of ocular and nervous complications from diabetes and are also useful as hypolipidemic or hypoglycemic agents.