The heterocyclic ring fission and dehydroxylation of catechins and relatedcompounds by Eubacterium sp strain SDG-2, a human intestinal bacterium

A human intestinal bacterium, Eubacterium (E.) sp. strain SDG-2, was tested for its ability to metabolize various (3R)- and (3S)-flavan-3-ols and thei r 3-O-gallates. This bacterium cleaved the C-ring of (3R)- and (3S)flavan-3 -ols to give 1,3-diphenylpropan-2-ol derivatives, but not their 3-O-gallate s. Furthermore, E. sp. strain SDG-2 had the ability of p-dehydroxylation in the B-ring of (3R)-flavan-3-ols, such as (-)-catechin, (-)-epicatechin, (- )-gallocatechin and (-)-epigallocatechin, but not of (3S)-flavan-3-ols, suc h as (+)-catechin and (+)-epicatechin.