Phenolic Compounds of Commercial Wheat Germ

Abstract

SUMMARY Two related glycoflavones (flavonoids A and B) have been isolated from commercial wheat germ samples, where they occur to the extent of some Q.2–0.3%. Each consists of an apigenin nucleus to which is attached a highly hydroxylated glycosyl‐type side chain. Evidence from ultraviolet spectrophotometric studies and from similarities with known glycoflavones suggests that the side chain is in the & position. Short hydrolysis of flavonoid A splits off a molecule of sinapic acid, leaving flavonoid B, while more prolonged mineral acid treatment of both flavonoids leads to partial formation of a third glycoflavoue. In addition to the glycoflavones, ferulic acid and vanillic acid have been found in wheat germ in the free form. The presence of a methoxy hydroquinone glycoside has also been indicated.