An Antimalarial Alkaloid from Hydrangea

Abstract

Summary Data are given regarding the antimalarial effects against Plasmodium lophurae of a naturally occurring alkaloid isolated from Hydrangea sp., and 54 synthetic quinazolones related to the alkaloid. Sixteen of the synthetic quinazolones were as effective or nearly as effective against Plasmodium lophurae in ducks as the naturally occurring Hydrangea alkaloid. Seven had chemotherapeutic indices (mouse/duck) of at least twice that of the naturally occurring alkaloid. The naturally occurring alkaloid was found to be approximately 100 times more effective than quinine against Plasmodium lophurae in ducks.