A series of methyl esters of N-substituted (Z)- and (E)-maleamic acids
were synthesized and their effect on food intake measured on fifth-in
star nymphs of Triatoma infestans. Suppression of food intake was foun
d only for the (Z)isomers. The initial reaction rate of the synthesize
d compounds with glutathione (GSH) was calculated from the reaction in
vitro of the (Z)-isomers. No reaction was observed with the (E)-isome
rs. Good correlation between the suppression of food intake, measured
by its ED,, (effective dose that inhibited feeding of 50% of the popul
ation) and the initial reaction rate with GSH and the hydrophobic para
meter pi, was found.