Flavonol glycosides from Montcalm dark red kidney bean: Implications for the genetics of seed coat color in Phaseolus vulgaris L.

Three flavonol glycosides were isolated and identified from the commercial dark red kidney bean (Phaseolus vulgaris L.) cultivar Montcalm. In order of highest to lowest concentration these compounds were 3',4',5,7-tetrahydrox yflavonol 3-O-beta-D-glucopyranosyl (2-->1) O-beta-D-xylopyranoside (compou nd 1), quercetin 3-O-beta-D-glucopyranoside (compound 2), and kaempferol 3- O-beta-D-glucapyranoside (compound 3). Compound 1 is a flavonol glycoside t hat has not been reported before in P. vulgaris L. These three flavonol gly cosides were yellow compounds that do not contribute to the garnet red colo r of Montcalm seed coats. Red-colored compounds which tested positive for p roanthocyanidins are most likely responsible for the red seed coat color of Montcalm. Previous work on the chemistry of the compounds produced from th e multi-allelic seed coat gene series C-C-r-c(u) indicated that neither ant hocyanins nor flavonol glycosides were detected from seed coat extracts in the presence of the c(u) locus. However, the seed coat color genotype of Mo ntcalm is c(u) J g B v rk(d) and three flavonol glycosides were found. Tech nological advances such as modern HPLC analysis of seed coat extracts may a llow for detection of small amounts of compounds which previously could not be seen using paper chromatography. Alternatively, the change of the Rk al lele to rk(d) may allow for the synthesis of flavonol glycosides in the pre sence of c(u).