Synthesis and structure confirmation of the complex flavonoids in Pityrogramma calomelanos.

Abstract

By unambiguous synthesis, the structures of two complex flavonoids in the farinose exudate of Pityrogramma calomelanos were established to be 8-(3-phenylpropionyl)-5, 7-dihydroxyneoflavanone [8-(3-phenylpropionyl)-5, 7-dihydroxy-4-phenylchroman-2-one] (1) and 8-(2-carboxy-1-phenylethyl)-5, 7-dihydroxyflavone δ-lactone (3).