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Ranunculin, a potent cytotoxic component of P.koreana, was synthesized by reacting (5)-(-)-5-(hydroxymethyl)-2(5H)-furanone with 2,3,4,6-tetra-0- acetyl-α -D-glucopyrano sal bromide and successive removal of the acetyl protecting group by 0.5M HCl/MeOH. A new deacetylation process of the intermediate tetraacetylranunculin was devised giving a yield of 83% of ranunculin. Protoanemonin, the cytotoxic structural moiety of ranunculin, was synthesized by dehydration of (s)- (-)-5-hydroxymethyl-2(5H)-furanone. Ranunculin showed a moderate cytototoxic activity against A-549 (ED50) = 7.53 ㎍/ml), NIH3T (ED50 = 13.6 ㎍/ml), and SK-OV-3 (ED50 = 17.5 ㎍/ml). Meanwhile, protoanemonin also exhibited moderate cytotoxicity against A-549 (ED50 = 9.38 ㎍/ml), NIH3T (ED50 = 13.8 ㎍/ml), and SK-OV-3 (ED50 = 15.1 ㎍/ml). It was found that both of the synthetic products showed a potenter cytotoxicity against A- 549.
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