VANICOSIDE-A AND VANICOSIDE-B, PROTEIN-KINASE-C INHIBITORS FROM POLYGONUM-PENSYLVANICUM

Two new protein kinase C inhibitory glycosides, vanicosides A [1] and B [2] were isolated from Polygonum pensylvanicum (Polygonaceae) by chr omatographic techniques guided by bioassays for PKC inhibition. The st ructures of these glycosides were established primarily by analysis of H-1- and homonuclear correlated nmr and high-resolution fab mass spec tra of 1 and 2 and the derived octaacetate, 3. Both glycosides were fo und to have p-coumaryl esters at the 1, 3, and G carbons of sucrose an d a feruloyl ester at the 6' carbon. Vanicoside A [1] also had an acet ate group at the 2' carbon.