A CYTOTOXIC PRINCIPLE OF TAMARINDUS-INDICA, DI-N-BUTYL MALATE AND THESTRUCTURE-ACTIVITY RELATIONSHIP OF ITS ANALOGS

Bioassay-guided fractionation of the methanolic extract of Tamarindus indica fruits led to the isolation of L-(-)-di-n-butyl malate which ex hibited a pronounced cytotoxic activity against sea urchin embryo cell s. In order to study structure-activity relationships, close-structure relatives of di-n-butyl malate were synthesized using D-(+)- and L-(- )-malic acid as starting materials, and their cytotoxic activities wer e examined for the sea urchin embryo assay. L-(-)-Di-n-pentyl malate w as the most effective inhibitor to the development of the fertilized e ggs. Significant inhibitory activity was not seen in the esters of D-( -)-isomer.