Anthocyanins and Flavonols of Chimonanthus praecox (Calycanthaceae) as Flower Pigments

Abstract

Three anthocyanins and five flavonols in the flowers of Chimonanthus praecox var. praecox and C. praecox var. grandiflorus f. concolor were isolated. Anthocyanins were characterized as cyanidin 3-O-glucoside (chrysanthemin), acylated cyanidin 3-O-glucoside and cyanidin glycoside. Flavonols were identified as quercetin 3-O-rutinoside (rutin), quercetin 3-O-glucoside (isoquercitrin), kaempferol 3-O-rutinoside (nicotiflorin), quercetin 3-O-rutinoside-7-O-glucoside and quercetin itself, by comparisons of PC and HPLC data with authentic specimens, NMR and UV spectra, and characterization of the complete and partial acid hydrolysates. Though the major flavonoid of the species was named "meratin" and regarded as quercetin 3-O-diglucoside, this has been revealed to be quercetin 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside, namely "rutin" based on ¹H- and ¹³C-NMR spectra.