(Delphinidin 3-gentiobiosyl) (apigenin 7-glucosyl) malonate from the flowers of Eichhornia crassipes.

A novel acylated delphinidin glycoside was isolated from the blue-purple flowers of Eichhornia crassipes as a major pigment, and was identified as (6'''-O-(delphinidin 3-O-(6''-O-(beta-D-glucopyranosyl)-beta-D-glucopyranosyl))) (6''-O-(apigenin 7-O-(beta-D-glucopyranosyl)))malonate by spectral methods. The three dimensional structure of this pigment was suggested from the observation of the negative Cotton effect at lambda max 535 nm that delphinidin (chromophore) and apigenin (co-pigment) occupy a folding conformation as a binary complex.