.beta.-D-Glucopyranose, cyclic 4,6-(4,4',5,5',6,6'-hexahydroxy(1,1'-biphenyl)-2,2'-dicarboxylate)-1-(3,4,5-trihydroxybenzoate), stereoisomer 517-46-4 AIDS-089542 AIDS089542 Shepherdia argentea leaf isolate Strictinin