(+)-Catechin (2R,3S)-(+)-Catechin (2R,3S)-Catechin (2R-trans)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-1-Benzopyran-3,5,7-triol 154-23-4 C06562 Cianidanol Cyanidanol D-Catechin