Studies of the Thymelaeaceae II. Antineoplastic principles of Gnidia kraussiana.

The acetone and methanol extracts of Gnidia kraussiana roots displayed activity against the P-388 lymphocytic leukemia. Bioactivity-directed fractionation led to the isolation of five daphnane orthoesters , all possessing potent antineoplastic activity. Four of these isolates, gnidilatin (1), gnidilatidin (2), Excoecaria toxin (3), and Pimelea factor P2 (4) have been isolated previously from plants in the Thymelaeaceae and Euphorbiaceae. The fifth compound, kraussianin (5), is a new member of the macrocyclic daphnane orthoester series of compounds.