Abstract: Through reactions of deacetylation and partial deacetylation with selected opening of epoxide ring, seven derivatives of crotepoxide (futoxide), a known antitumor constituent from Piper futokudzura, were prepared. Preliminary pharmacological tests showed that individual derivative possess significant inhibitory activity at 2×10^-4 mol/L to the PAF—induced platelet aggregation, while crotepoxide has no effect even at fivefold of this concentration.