Notiz über Ellagitannine und Flavonol-glycoside aus Rosenblüten

Note on Ellagitannins and Flavonol Glycosides from Rose Petals Petals from two garden roses proved to be very rich in ellagitannins and flavonol glycosides. Rutin ( 1 ), spiraeoside ( 2 ), quercitrin ( 3 ), isoquercitrin ( 4 ), nicotiflorin ( 5 ), eugeniin ( 6 ), rugosin A (7), rugosin D ( 10 ), casuarictin ( 8 ), and tellimagrandin I (9) were isolated. Spiraeoside, at physiological pH, exerts a pronounced stabilisation of the anthocyanin colour with enhancement of extinction and bathochromic shift of the absorption maximum in the visible range. The abundance of gallic-acid derivatives 6–10 is in contrast to the apparent inability of rose flowers to produce anthocyanins with a trihydroxylated ring B , a prerequisite in breeding true blue-coloured roses.