TOLYLFLUANID

Uses

Tolylfluanid is used to control a wide range of fungal diseases on apples, grapes, strawberries and other fruit and storage diseases on many crops.

Uses

Tolylfluanid may be used as a reference standard for the determination of the analyte in nutraceutical formulations using dispersive liquid-liquid microextraction(DLLME) coupled with gas chromatography-mass spectrometry method.

Definition

ChEBI: A member of the class of sulfamides that is dichlofluanid in which the hydrogen at the para position of the phenyl group is replaced by a methyl group. A fungicide first marketed in 1971 and used in the cultivation of fruit and vegetables, as ell as in wood preservatives, it is no longer approved for use in the European Union.

Metabolic pathway

Tolylfluanid contains an unstable dichlorofluoromethylthio (sulfenyl) moiety that has been shown to undergo rapid hydrolytic and metabolic degradation to dimethylaminosulfotoluidide (2). By analogy with captan, presumably the dichlorofluoromethylthio moiety can be transferred to the sulfur atoms of cellular thiols such as cysteine and glutathione. Thus, in the presence of thiols tolylfluanid is probably cleaved at the N-S bond to form thiophosgene or its monofluoro analogue (3) and other gaseous products such as hydrogen sulfide, hydrogen chloride and carbonyl sulfide. Thiophosgene or its monofluoro analogue is rapidly hydrolysed by water. The dichlorofluoromethylthio group and thiophosgene may be intermediates in the formation of addition products, for example addition to cysteine affords thiazolidine-2-thione-4-carboxylica cid (4). A thiazolidine derivative of glutathione may also be formed. The main metabolic reactions in all media were cleavage of the N-S bond to give dimethylaminosulfotoluidide (2) followed by hydroxylation of the phenyl ring and oxidation of the methyl substituent on the phenyl ring. Glucoside conjugates were detected in plants and the cysteine adduct, thiazolidine-2- thione-4-carboxylic acid (4), was formed in rats.

Degradation

Tolylfluanid is hydrolysed rapidly in alkaline conditions. The hydrolytic DT₅₀ is about 12 days, 29 hours and <10 minutes at pH 4,7 and 9, respectively, at 22 °C. In the environment, hydrolysis is faster than photolysis (PM; PSD, 1995). Tolylfluanid does not absorb light of wavelength >295 nm and so photodegradation is unlikely to occur in the absence of photosensitisers.