Many metabolites of imidacloprid (IMI) have been identified, but the enzymatic basis for their formation has not been reported. This study with individual recombinant cytochrome P450 (CYP450) isozymes from human liver shows that the principal organoextractable NADPH-dependent metabolites are the 5-hydroxy (major) and olefin (minor) derivatives from hydroxylation and desaturation of the imidazolidine moiety and the nitrosoimine (major), guanidine (minor) and urea (trace) derivatives from reduction and cleavage of the nitroimine substituent. Isozymes selective for imidazolidine oxidation in order of decreasing overall activity are CYP3A4>CYP2C19 or CYP2A6>CYP2C9, while those selective for nitroimine reduction are CYP1A2, CYP2B6, CYP2D6 and CYP2E1. Three flavin monooxygenase isozymes (FMO1, FMO3, and FMO5) with NADPH are not active as assayed. These observations establish site specificity in IMI metabolism by CYP450 isozymes and that a single enzyme (CYP3A4) both oxidizes and reduces IMI at the imidazolidine and nitroimine moieties, respectively.
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http://dx.doi.org/10.1016/s0378-4274(02)00068-1 | DOI Listing |
Dev Reprod
December 2024
Department of Biochemistry and Molecular Biology, College of Medicine, Eulji University, Daejeon 34824, Korea.
The epididymal fat is required for the maintenance of normal spermatogenesis, and the lipectomy of epididymal fat at different postnatal age results in disrupted expression patterns of several testicular steroidogenic enzymes. The current research examined the effect of epididymal fat lipectomy at different postnatal ages on expression of cytochrome 5α-reductase I, cytochrome P450 aromatase, androgen receptor (AR), and estrogen receptors (ER) α and β in the mouse testis after 2 weeks of the lipectomy. The lipectomy of epididymal fat at 2 months of postnatal age resulted in significant increases of expression levels of cytochrome 5α-reductase I, cytochrome P450 aromatase, AR, and ER α and β.
View Article and Find Full Text PDFFront Cell Infect Microbiol
January 2025
Laboratório de Imunidade Natural (LIN), Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
Background: The vitamin D pathway contributes to the microbicidal activity of macrophages against infection. In addition to induction of this pathway, interferon-gamma (IFNγ), interleukin (IL)-15, and IL32γ are part of a network of pro-inflammatory cytokines. The aim of this study was to evaluate single-nucleotide polymorphisms (SNPs) in the components of the vitamin D pathway and associated cytokine genes that could be related to resistance or susceptibility to American tegumentary leishmaniasis (ATL).
View Article and Find Full Text PDFJ Pharm Health Care Sci
January 2025
Department of Pharmacy, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan.
Background: Ensitrelvir is a novel SARS-CoV-2 3-chymotrypsin-like protease inhibitor, similar to nirmatrelvir/ritonavir. Several case reports have demonstrated the efficacy of 3-chymotrypsin-like protease inhibitors in treating prolonged coronavirus disease 2019 (COVID-19) in immunocompromised patients. Tacrolimus (TAC) is a widely used immunosuppressive agent whose blood level can increase significantly due to the inhibition of cytochrome P450 3A (CYP3A) and P-glycoprotein by nirmatrelvir/ritonavir.
View Article and Find Full Text PDFNat Commun
January 2025
Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.
Fatty acid peroxygenases have emerged as promising biocatalysts for hydrocarbon biosynthesis due to their ability to perform C-C scission, producing olefins - key building blocks for sustainable materials and fuels. These enzymes operate through non-canonical and complex mechanisms that yield a bifurcated chemoselectivity between hydroxylation and decarboxylation. In this study, we elucidate structural features in P450 decarboxylases that enable the catalysis of unsaturated substrates, expanding the mechanistic pathways for decarboxylation reaction.
View Article and Find Full Text PDFInsect Biochem Mol Biol
January 2025
College of Life and Environmental Sciences, Biosciences, University of Exeter, Penryn Campus, Penryn, Cornwall, UK. Electronic address:
The brown planthopper Nilaparvata lugens is one of the most economically important pests of cultivated rice in Southeast Asia. Extensive use of insecticide treatments, such as imidacloprid, fipronil and ethiprole, has resulted in the emergence of multiple resistant strains of N. lugens.
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