RHODODENDROL GLYCOSIDES AND PHENYL GLUCOSIDE ESTERS FROM INNER BARK OF BETULA-PUBESCENS

A chemical investigation of the inner bark of Betula pubescens has led to the isolation of rhododendrin, epirhododendrin, apiosylrhododendri n and apiosylepirhododendrin. This is the first observation of both ()- and (-)-rhododendrol glycosides in the same species. Also, the new compounds methoxyphenyl-6-O-vanilloyl-beta-D-glucopyranoside and ethox yphenyl-6-O-syringoyl-beta-D-glucopyranoside, and the known 4-O-beta-D -glucoside of p-hydroxybenzoic acid, as well as (+)-catechin, catechin 7-O-beta-D-xylopyranoside and B1 and B3 procyanidins were found.