Metabolism of Hempa Uniformly Labeled with C14 in Male House Flies13

Metabolism of carbon-14-labeled hempa by adult boll weevils

“…From the tentative identifications of the major metabolites, the sequence of the removal of N-methyl substituents appears similar to that described for certain drugs (Gram and Fouts 1968); that is, the methyl groups are apparently removed sequentially, and the first methyl of each N-dimethyl substituent comes off more rapidly than the second. However, the first demethylation reaction is the most important because it inactivates the molecule (Chang et al 1967). Since N-demethylation is extensive, the relatively low level of 14CO 2 expired by weevils during feeding on diet containing 14C_labele d hempa seems unusual but a similar result is reported in the studies with house flies (Chang et al 1967, Chang andBorkovec 1969).…”

“…However, the first demethylation reaction is the most important because it inactivates the molecule (Chang et al 1967). Since N-demethylation is extensive, the relatively low level of 14CO 2 expired by weevils during feeding on diet containing 14C_labele d hempa seems unusual but a similar result is reported in the studies with house flies (Chang et al 1967, Chang andBorkovec 1969). This is explained in part by the evidence that substantial portions of liberated radioactivity are incorporated into the body tissues.…”

“…The primary metabolic pathway involves a series of N-demethylation reactions comparable to but apparently faster than that found for house flies, Musca domestica L., (Chang et al 1967, Chang andBorkovec 1969). As in house flies Borkovec 1968), the N-demethylation is probably a function of the microsomal oxidase enzyme system.…”

“…Commercial hempa was purified by vacuum distillation, and samples of its demethylated homologues (Terry and Borkovec 1967) were provided by P. H. Terry of the Insect Chemosterilants Laboratory, USDA. Hempa, uniformly labeled with carbon-14 (Chang et al 1967), was synthesized by C. W. Woods of the same organization. The specific activity of the 14C-labeled hempa was 9.8 mCi/mmole: it was 93.6 percent pure.…”

Effects of hempa on the gonads of Locusta Migratoria (L.) (Orthoptera, Acrididae)

“…j (Klassen et al, 1968); and two-spotted spider mite, Tetranychus urticae Koch (Redfern, j 1970). Chang et al (1967) argue that the low sterilising activity of hempa is due to the j slow action (as compared with tepa) and its rapid metabolism within the organism. ' The metabolism may be even faster in cases where no sterility is caused by hempa.…”