[Phenolic inhibitor of a proteinase from buckwheat seeds].

An inhibitor of a proteolytic enzyme (BAPAse), hydrolyzing N, alpha-benzoyl-DL-arginine-p-nitroanilide (BAPA), has been found in the buckwheat seeds. The inhibitor is located in the seed coat. The inhibitor is shown to have a phenolic nature and, probably, is a proantocyanidine.