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

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.