Flavonoids in the leaves of Polish species of the genus Betula L. IV. The flavonoids of Betula pubescens Ehrh., B. carpatica Waldst., B. tortuosa Ledeb., and B. nana L. leaves

Abstract

Besides the flavonoids detected earlier, the leaves of purebred <em>B. pubescens</em> specimens were found to contain quercetin 3-arabinoside, isorhamnetin 3-galactoside, luteolin 4'-glucoside, isoquercitrin, acacetin 7-glucoside, and perhaps scutellarein 7-glycoside, whereas <em>B. nana</em> exhibited a low content of myricetin 3-galactoside and quercetin 3-arabinoside, and also possibly quercetin 7-rhamnoside. The qualitative composition of the flavonoids of desiccated <em>B. tortuosa</em> leaves seems to point to the validity of the assumption that this birch is of hybrid origin. The set of flavonoids in <em>B. carpatica</em> was almost identical with that in <em>B. tortuosa</em>.