Cyanidin glycosides in flowers of genus Corydalis (Fumariaceae)

Nine taxa of Corydalis were surveyed for their floral anthocyanins. Five cyanidin glycosides: cyanidin 3-glucoside, cyanidin 3-sambubioside, cyanidin 3-rutinoside, cyanidin 3-(2G-xylosylrutinoside) and cyanidin 3-(2G-xylosylrutinoside)-7-glucoside were isolated from these taxa and identified by chemical and spectroscopic techniques. A novel anthocyanin was found in the flowers of Corydalis elata and Corydalis flexuosa cultivars, and identified to be cyanidin 3-(2G-xylosylrutinoside)-7-glucoside. Two anthocyanins, cyanidin 3-sambubioside and cyanidin 3-(2G-xylosylrutinoside), were also found for the first time in Corydalis flowers. Furthermore, the major anthocyanin constituent of the flowers was cyanidin 3-sambubioside in the outer petals of Corydalis ambigua and Corydalis lineariloba, and cyanidin 3-rutinoside in those of Corydalis decumbens, Corydalis curvicalcarata and Corydalis speciosa. Similarly, Corydalis incisa contained cyanidin 3-(2G-xylosylrutinoside), and C. flexuosa 'China Blue' and 'Blue Panda', and C. elata contained the most complex structural pigment, cyanidin 3-(2G-xylosylrutinoside)-7-glucoside, as their dominant anthocyanin in their outer petals. According to the results of anthocyanin analyses, these nine plants were classified into four groups: groups A (three taxa), B (two taxa), C (one taxa) and D (three taxa). On the other hand, the anthocyanin constituent of their inner petals was composed of cyanidin 3-rutinoside as only one dominant anthocyanin.