COMPARATIVE SAR EVALUATIONS OF ANNONACEOUS ACETOGENINS FOR PESTICIDALACTIVITY

The activities of 44 Annonaceous acetogenins, which were originally is olated by monitoring plant fractionations with the brine shrimp lethal ity test (BST), were evaluated in the yellow fever mosquito larvae mic rotiter plate (YFM) assay. The results clearly demonstrate that most a cetogenins have pesticidal properties, The structure-activity relation ships indicate that the compounds bearing adjacent bis-THF (tetrahydro furan) rings with three hydroxyl groups are the most potent, Bullataci n (1) and trilobin (7) gave the best activities against YFM with LC(50 ) values of 0.10 and 0.67 mg litre(-1), respectively. Compounds showin g LC(50) values below 1.0 mg litre(-1) in this assay are usually consi dered significant as new lead candidates for pesticidal development. I n the BST, the corresponding LC(50) values were 1.6 x 10(-3) (1) and 9 .7 x 10(-3) (7) mg litre(-1). This is the first report of pesticidal s tructure-activity relationships for a series of Annonaceous acetogenin s which are known to act, at least in part, as potent inhibitors of mi tochondrial NADH: ubiquinone oxidoreductase.