Description
Water solubility of flupyrazofos is 0.8 mg/L. Log
Kow = 5.24. Flupyrazofos is slowly hydrolyzed in aqueous
media; DT
50 at pH 4, 7, and 9 are 266, 180, and
121 h, respectively. Vp 3.7 mPa (25 ?C). Flupyrazofos is
a nonsystemic insecticide used for the control of caterpillars,
especially diamondblack moth, Plutella xylostella,
larvae.
Uses
Flupyrazofos is a new pyrazole organophosporus insecticide, which has a high activity against the diamond-back moth (Plutella xylostella).
Uses
Flupyrazofos is a new insecticide under development which has
shown good activity against caterpillars, especially Plutella xylostella
larvae.
Metabolic pathway
The principal route of metabolism of flupyrazofos is by oxidative
desulfuration to the oxon which is hydrolysed, principally via base rather
than esterase catalysis, to 1-phenyl-3-trifluoromethyl-5-hydroxypyrazole.
The physico-chemical parameters of flupyrazofos, including water solubility,
hydrolysis rates, vapour pressure and octanol/water partition
coefficients, have been reported by Kim et al. (1997).
Metabolism
The principal
route of metabolism of flupyrazofos is by oxidative
desulfuration to the oxon, followed by hydrolysis to 1-
phenyl-3-trifluoromethyl-5-hydroxypyrazole and diethyl
hydrogen phosphate. Flupyrazofos is degraded in soil with
DT
50 of about 14 d.
Degradation
The hydrolytic half-life at pH values 4, 7 and 9 was 266, 180 and 121
hours, respectively (Kim et al., 1997). Flupyrazofos showed good photostability.
The photodegradation products which were identified were
flupyrazofos oxon (2), 1-phenyl-3-trifluoromethyl-5-hydroxypyrazole
(3) and the thiono-thiolo rearranged isomer O,S-diethyl O-(1-phenyl-3-
trifluoromethyl)pyrazol-5-yl phosphorothioate (4) (Cho et al., 1993) (Scheme 1).
Toxicity evaluation
Acute oral LD
50 for rats is 372–605 mg/kg.
