(+)-Procyanidin B2 (-)-Epicatechin-(4.beta.-8)-(-)-epicatechin 29106-49-8 AIDS-013365 AIDS013365 NSC623097 Proanthocyanidin B2 Procyanidin B2 Procyanidol B2 [4,8'-Bi-2H-1-benzopyran]-3,3',5,5',7,7'-hexol, 2,2'-bis(3,4-dihydroxyphenyl)-3,3',4,4'-tetrahydro-, (2R,2'R,3R,3'R,4R)-