Plant Metabolism of Insecticides, Identification of Metabolites of Zectran Insecticide in Broccoli

Abstract

The metabolism of Zectran in broccoli is reported. In addition to a small amount of Zectran, the following metabolites were found to be present in the broccoli flower: 4-dimethylamino-3,5-xylenol, 2,6-dimethylhydroquinone, 2,6-dimethyl-p-benzoquinone, and 4-dimethylamino-3,5-dimethyl-o-benzoquinone. The xylenol was found in both free and conjugated form, but the hydroquinone derivative was detected only as a watersoluble conjugate. Evidence is presented which suggests that metabolites of this pesticide have been incorporated into lignin.

The comparative metabolism of 2,6-dichlorothiobenzamide (Prefix) and 2,6-dichlorobenzonitrile in the dog and rat

“…(Fig. 1) of strongly anionic substances was tentatively ascribed to strongly acidic sulphate esters; in another context similar assignments have also been made (Williams, Meikle & Redemann, 1964). The relative proportion of strongly anionic substances, when urines were extracted at pH 6*0, was almost the same as that of the free phenols, when the urines were extracted under more acid conditions.…”

Photoxidation of two 4-dimethylaminoaryl methylcarbamate insecticides (Zectran and Matacil) on bean foliage and of alkylaminophenyl methylcarbamates on silica gell chromatoplates

“…A similar irradiation behavior is noted for Zectran when the photodegradation products on the silica gel chromatoplates are detected with ultraviolet-quenching rhodamine B and iodine vapor (6). Within 10 days following the streaking of a Zectran solution onto the stems of broccoli plants immediately below the flower clusters, the compound is degraded to yield 4-dimethylamino-3,5xylenol, 2,6dimethylhydroquinone, 2,6-dimethyl-/?-benzoquinone, and 4-dimethylamino-3,5-dimethyl-obenzoquinone, along with conjugates of some of these compounds and with materials which are incorporated into the lignin fraction (19). It is not known to what extent these degradation reactions take place on the surface of the plant or are the result of enzymatic attack following absorption into the plant.…”

Metabolism and Excretion of Insecticide (6-Chloro-3,4-dimethylphenyl N-Methylcarbamate) in the Rat

“…Metabolic studies with various C14-labeled carbamates using plants, animals, and isolated enzyme systems have recently been reported (Abdel-Waheb et al, 1966;Borough and Casida, 1964; Friedman and Lemin, 1966;Knaak et al, 1965;Krishna and Casida, 1966; Leeling and Casida, 1966;Williams et al, 1964). A comprehensive report on the fate of carbamate pesticides in mammals (Krishna and Casida, 1966) indicated the ease with which these compounds are eliminated.…”