DIFFERENTIATION OF GLYCOSIDASE ACTIVITY IN SOME HEMIPTERA AND LEPIDOPTERA BY MEANS OF CASTANOSPERMINE AND OTHER POLYHYDROXY ALKALOIDS

Inhibition of glycosidase activity by a ranger of polyhydroxy alkaloid s was studied in a number of insect species. Castanosperimine, usually inactive against maltose and sucrose hydrolysis in insects, was an ac tive inhibitor of maltose hydrolysis in aphids and Heliconius melpomon e at pH 5.1 but inactive at pH 6.0. Conversely, 2R,5R-dihydroxymethyl- 3R,4R-dihydroxypyrrolidine, normally a potent inhibitor of insect sucr ose and maltose hydrolysis, was relatively ineffective in the former s pecies at pH 5.1, The data suggest that several separate enzymes or ac tive sites were responsible for maltose and sucrose hydrolysis in aphi ds and H. melpomone.