Biotransformation of (-)-epicatechin, (+)-epicatechin, (-)-catechin, and (+)-catechin by intestinal bacteria involved in isoflavone metabolism.

Isoflavone-metabolizing bacteria, Adlercreutzia equolifaciens, Asaccharobacter celatus, Slackia equolifaciens, and Slackia isoflavoniconvertens catalyzed C-ring cleavage of (-)-epicatechin and (+)-catechin, (+)-epicatechin, and (-)-catechin in varying degrees. The cleaving abilities of (-)-epicatechin and (+)-catechin were enhanced by hydrogen, except (+)-catechin cleavage by S. equolifaciens, which was not accelerated. (-)-Catechin cleavage by Ad. equolifaciens was remarkably accelerated by hydrogen.