120068-36-2Relevant articles and documents
Chiral resolution of the insecticide fipronil enantiomers and the simultaneous determination of its major transformation products by high-performance liquid chromatography interfaced with mass spectrometry
Paolini, Léa,Hausser, Nicolas,Zhang, Tong
supporting information, p. 473 - 483 (2022/01/22)
A high-performance liquid chromatography–mass spectrometry (HPLC-MS) method was developed using a chiral column based on amylose tris(3-chloro-5-methylphenylcarbamate) for analysis of fipronil (a popular insecticidal nerve agent) and the related transformation products. The optimized method reached the goal of the simultaneous and complete separation of the multiple fiproles in a single run, including the chiral separation of fipronil enantiomers, fipronil metabolites, and photoproducts. The efficacy of such a method was demonstrated by its application in analyzing a series of fipronil samples exposed to sunlight conditions. In general terms, our study provided experimental approaches and an efficient analytical tool for monitoring the environmental fate of fipronil as well as its multitransformation products upon its applications either in agricultural or any other areas.
A convenient conversion of pyrazolyl disulfide to sulfides by sodium dithionite and synthesis of sulfoxides
Tang, Ri-Yuan,Zhong, Ping,Lin, Qiu-Lian
, p. 948 - 953 (2008/02/10)
Indirectly introduce trifluoromethylthio-, alkylthio-, and trifluoromethylsulfinyl to pyrazole ring by a convenient reaction of a pyrazolyl disulfide with F3CBr and alkyl halides in the presence of sodium dithionite at room temperature. Followed by selective oxidation with H2O2 or trichloroisocyanuric acid (TCCA) to give trifluoromethylsulfenyl phenylpyrazole, alkylsulfenyl phenylpyazole, trifluoromethylsulfinyl phenylpyrazole 4a (a highly efficient insecticide named fipronil) and ethylsulfinyl phenylpyrazole 4c derivatives, respectively.
Mechanisms for selective toxicity of fipronil insecticide and its sulfone metabolite and desulfinyl photoproduct
Hainzl, Dominik,Cole, Loretta M.,Casida, John E.
, p. 1529 - 1535 (2007/10/03)
Fipronil, an N-phenylpyrazole with a trifluoromethylsulfinyl substituent, initiated the second generation of insecticides acting at the γ-aminobutyric acid (GABA) receptor to block the chloride channel. The first generation includes the polychlorocycloalkanes α-endosulfan and lindane. In this study, we examine the mechanisms for selective toxicity of the sulfoxide fipronil and its sulfone metabolite and desulfinyl photoproduct relative to their target site interactions in vitro and ex vivo and the importance in fipronil action of biooxidation to the sulfone. Differences in GABA receptor sensitivity, assayed by displacement of 4'-ethynyl-4-n-[2,3-3H2]- propylbicycloorthobenzoate ([3H]EBOB) from the noncompetitive blocker site, appear to be a major factor in fipronil being much more toxic to the insects (housefly and fruit fly) than to the vertebrates (humans, dogs, mice, chickens, quail, and salmon) examined; in insects, the IC50s range from 3 to 12 nM for fipronil and its sulfone and desulfinyl derivatives, while in vertebrates, the IC50 average values are 1103, 175, and 129 nM for fipronil, fipronil sulfone, and desulfinyl fipronil, respectively. The insect relative to the vertebrate specificity decreases in the following order: fipronil > lindane > desulfinyl fipronil > fipronil sulfone > α-endosulfan. Ex vivo inhibition of [3H]EBOB binding in mouse brain is similar for fipronil and its sulfone and desulfinyl derivatives at the LD50 dose, but surprisingly, at higher doses fipronil can be lethal without detectably blocking the [3H]EBOB site. The P45 inhibitor piperonyl butoxide, acting in houseflies, increases the metabolic stability and effectiveness of fipronil and the sulfone but not those of the desulfinyl compound, and in mice it completely blocks the sulfoxide to sulfone conversion without altering the poisoning. Thus, the selective toxicity of fipronil and fipronil-derived residues is due in part to the higher potency of the parent compound at the insect versus the mammalian GABA receptor but is also dependent on the relative rates of conversion to the more persistent and less selective sulfone metabolite and desulfinyl photoproduct.
