The breakdown of [¹⁴C]monocrotophos insecticide on maize, cabbage and apple

Abstract

The breakdown of 14C‐labelled monocrotophos (dimethyl 3‐hydroxy‐N‐methyl‐cis‐crotonamide phosphate) on the foliage of maize, cabbage and apple and on apple fruit has been studied. The breakdown products were mainly hydrophilic compounds such as (II) and probably dimethyl phosphate. Other breakdown products were (III), (IV) (free and conjugated), (VI) and (IX). In maize and apple (IV) was conjugated with sugars other than ß‐D‐glucose and a polar component, possibly a conjugate, was present in cabbage but this may not have been derived from (IV) .

Growth Rate of Ankistrodesmus falcatus and Scenedesmus bijuga in Mixed Culture Exposed to Monocrotophos

“…However, we have not identified any such enzymes or degradation product. P-dimethyl-phosphate, a hydrolytic degradation product of monocrotophos and Nhydroxymethyl and N-dealkylated derivatives were found from cotton plants treated with monocrotophos (Beynon and Wright 1972). The initial metabolism pathways evidenced in the degradation of monocrotophos in plants are (a) cleavage of the O-P-CH 3 linkage (b) hydrolysis of P-O vinyl bond and (c) dehydroxylation of N-methyl group followed by N-dealkylation.…”