Buprofezin

Uses

Buprofezin is a contact and ingested insecticide, active against Homoptera (whiteflies, leafhoppers, scale insects, etc.) in and on citrus, cotton, cucumbers, tomatoes, sweet potatoes, rice, etc.

Uses

Insecticide.

Uses

Buprofezin is a insecticide which works as a chitin synthesis inhibitor. Buprofezin is used to control stubborn rice pests and is effective in controlling green leaf hoppers and white back plant hoppe rs for long durations.

Definition

ChEBI: Buprofezin is a 2-(tert-butylimino)-5-phenyl-3-(propan-2-yl)-1,3,5-thiadiazinan-4-one in which the C=N double bond has Z configuration. It has a role as an insecticide and a member of homopteran inhibitor of chitin biosynthesis.

Hazard

Moderately toxic by ingestion. Low toxic- ity by skin contact.

Agricultural Uses

Insecticide, Acaricide, Insect growth regulator: For insect control in food crops and greenhouse ornamentals.

Trade name

APPLAUD®; NNI-750®

Pharmacology

The foregoing indicates that the modes of action of buprofezin and benzoylureas could be similar or identical. However, one differing biochemical effect of buprofezin is inhibition of prostaglandin biosynthesis (33), a mechanism that has been suggested as responsible for its ovicidal activity. Subsequently, the in vitro and in vivo effects of buprofezin were found to be strongly antagonized by 20- hydroxyecdysone (34), which also affected prostaglandin biosynthesis. Thus, inhibition of both prostaglandin and chitin biosynthesis by buprofezin was prevented by 20- hydroxyecdysone, so that both effects of the insecticide are mediated via an effect on the hormone concentration or its receptor. Consequently, buprofezin seems to inhibit the drop in the 20-hydroxyecdysone titer that triggers epidermal cell proliferation, old cuticle digestion, and new cuticle deposition, but the detailed mechanism of this action has yet to be established.

Metabolic pathway

Buprofezin gradually decomposes in soils under flooded and upland conditions, with half-lives of 104 and 80 days, respectively. After 150 days, five degradation products are identified as 2-tert- butylimino-5-(4-hydroxyphenyl)-3-isopropylperhydro- 1,3,5-thiadiazin-4-one, 3-isopropyl-5-phenylperhydro- 1,3,5-thiadiazin-2,4-dione, 1-tert-butyl-3-ispropyl-5- phenylbiuret, 1-isopropyl-3-phenylurea, and phenylurea. As minor products, 2-tert-butylimino-5- phenylperhydro-1,3,5-thiadiazin-4-one or buprofezin sulfoxide are found in the flooded or in the upland soils. Since neither formation of 14CO2 nor hydroxylation is observed in the sterile soils, buprofezin seems to have undergone complete mineralization in soils under both conditions through biological transformation by soil microorganisms.

Degradation

Buprofezin (1) was degraded under acidic conditions with half-lives (DT₅₀) f 6-12 days (pH 4), 34 days (pH 6) and 65 days (pH 10) at 40 °C. Opening of the thiadiazinanone ring appeared to be the primary hydrolytic degradation pathway, to yield 1-tert-butyl-3-isopropyl-5-phenyl-2- thiobiuret (2) and N-isopropyl-N-phenylurea (3) as major products.
Buprofezin is stable to aqueous photolysis. The estimated DT₅₀ of buprofezin in distilled water when exposed to UV light was 39 days. A more complex photodegradation pathway of buprofezin in methanol was reported recently (Datta and Walia, 1997) with DT9 values of 4 hours and 15 days under UV and sunlight irradiation, respectively.