FLAVONOL AND DIHYDROFLAVONOL GLYCOSIDES OF ECHINOCEREUS-TRIGLOCHIDIATUS VAR GURNEYI

Perianth parts, in particular, tepals of E. triglochidiatus var. gurneyi yielded a complex mixture of dihydroflavonols and dihydroflavonol 7-O-glucosides. Dihydroquercetin and its 7-O-glucoside were the predominant compounds while dihydrokaempferol and dihydromyricetin and their 7-O-glycosides were present in lesser amounts. Quercetin 7-O-glucoside was the principal flavonol glycoside: others present were quercetin and kaempferol 3-O-glucosides and 3-O-rhamnosylglucosides. The epidermis and spines yielded only traces of presumed flavonols as determined by 2-dimensional TLC. No flavonoids were detected in the cortex tissue. This is the 1st report of dihydroflavonol derivatives from the Cactaceae and constitutes the 1st record of flavonoids from Echinocereus. [Chemotaxonomy is discussed.].