Chemotaxonomic studies in the Saxifragaceae s.l. 4. The flavonoids of Heuchera micrantha var. diversifolia

Abstract

Sixty flavonoids were isolated from aerial parts of Heuchera micrantha var. diversifolia and identified. The flavonoid aglycones represented were kaempferol, quercetin, isorhamnetin, myricetin, laricytrin (myricetin-3′-O-methyl ether), syringetin (myricetin-3′,5′-di-O-methyl ether), and luteolin. Flavonol glycosylation patterns included 3-O-monoglycosides, 3-O-diglycosides, 3-O-triglycosides, 3,7-di-O-monoglycosides, and 3-O-diglycoside-7-O-monoglycosides. Quercetin- and myricetin-3-O-glucoside-6″-gallates were also found. The sole luteolin derivative was the 7-O-glucoside. Also identified were the 3,5-di-O-glucosides of malvidin and either petunidin or delphinidin and (−)-epigallocatechin gallate. A brief discussion of the flavonoids of the Saxifragaceae is presented. Methods combining column and thin-layer chromatography are described which are generally useful for analysis of complex mixtures of polyphenolic compounds.