Reference

Alkaline hydrolysis of some pyrethroid insecticides

Alkaline hydrolysis of some pyrethroid insecticides. Camilleri, Patrick (Sittingbourne Res. Cent., Shell Res. Ltd., Sittingbourne/Kent ME9 8AG, UK). J. Agric. Food Chem., 32(5), 1122-4 (English) 1984. CODEN: JAFCAU. ISSN: 0021-8561. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) The mechanism of hydrolysis of the pyrethroids (S,S-fenvalerate [66230-04-4] and cypermethrin [66290-21-9] under alk. conditions was shown to be similar to that of simple aliph. esters; the rate-detg. step is nucleophilic attack by a hydroxyl group. The final products of reaction were identified as the corresponding acid and 3-phenoxybenzaldehyde [39515-51-0] (the latter derived from the fast decompn. of the cyanohydrin intermediate). This simple mechanism is valid only under low concns. of pyrethroid (￡10-5M). At higher concns. another reaction sets in, between 3-phenoxybenzaldehyde and unreacted pyrethroid, leading to the formation of a benzoin ester deriv.

The metabolism of fenvalerate in plants: the conjugation of the acid moiety

The metabolism of fenvalerate in plants: the conjugation of the acid moiety. Mikami, Nobuyoshi; Wakabayashi, Noriko; Yamada, Hirohiko; Miyamoto, Junshi (Takarazuka Res. Cent., Sumitomo Chem. Co. Ltd., Takarazuka 665, Japan). Pestic. Sci., 16(1), 46-58 (English) 1985. CODEN: PSSCBG. ISSN: 0031-613X. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) The metab. of fenvalerate [51630-58-1] and of its most insecticidal isomer (S)-a-cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)-3-methylbutyrate [66230-04-4], was examd. in cabbage plants grown and treated under lab. conditions with [14C]chlorophenyl- and [ring-14C]benzyl-labeled prepns. of the 2 compds. Both insecticides disappeared from the treated leaves with similar half-lives of approx. 12-14 days; they underwent ester cleavage to a significant extent, together with some hydroxylation at the 2- or 4-position of the phenoxy ring, and hydrolysis of the nitrile group to amide and carboxyl groups. Most of the carboxylic acids and phenols thus produced occurred as glycoside conjugates. In sep. expts., the uptake and metab. of 2-(4-chlorophenyl)-3-methylbutyric acid (I) [2012-74-0], the acidic half of the fenvalerate mol., were examd. in the lab., using abscised leaves of kidney bean, cabbage, cotton, cucumber and tomato plants. I was readily converted, mainly into glucose and 6-O-malonylglucose esters in kidney bean, cabbage and cucumber plants, into glucosylxylose, sophorose, and gentiobiose esters in cotton, and into 2 types of triglucose esters with differing isomerism in tomato. One of the acetyl derivs. of the trisaccharide conjugates was identical with the synthetic deca-acetyl deriv. of the [1?6]-triglucose ester.