Structure of a New Flavonoid in the Blue Complex Molecule of Commelinin Studies on Anthocyanins, LIV

Abstract

A pale yellow pigment, one of the substantial components of the blue metalloanthocyanin previously isolated from Commelina flowers, was also found in a free state in the cell sap of the same flowers. This was isolated in a crystalline state, and shown to be a glucoside belonging to the group of C-glucosylflavone, which has been found less frequently in plant world. The name “flavocommelin” was proposed for the original glucoside, and “flavocommelitin” for its partially hydrolyzed moiety. The total structure of this new pigment was determined by a series of standard chemical analyses. As a consequence, flavocommelitin is defined as 6-C-glucopyranosylgenkwanin (genkwanin=7-O-methylapigenin), and flavocommelin as 4'-O-glucoside of flavocommelitin.