CYP3A4,5 hydroxylates AFB1 to AFQ1

Stable Identifier
Reaction [transition]
Homo sapiens
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Metabolites that are formed from aflatoxin B1 (AFB1) include AFQ1, AFM1 and AFP1 (Gallagher et al. 1996). These metabolites and other naturally occurring aflatoxins (G1, B2 and G2) are poorer substrates for epoxidation and, consequently, are less mutagenic, carcinogenic and toxic than AFB1. AFB1 metabolites can be useful biomarkers of human exposure to aflatoxins and AFM1, AFQ1 and AFP1 have all been detected in human urine samples (Groopman et al. 1985). Cytochrome P450 3A4 and 3A5 are the predominant enzymes involved in AFQ1 (3-hydroxy aflatoxin) production (Raney et al. 1992).
Literature References
PubMed ID Title Journal Year
8975785 The kinetics of aflatoxin B1 oxidation by human cDNA-expressed and human liver microsomal cytochromes P450 1A2 and 3A4

Eaton, DL, Stapleton, PL, Kunze, KL, Gallagher, EP

Toxicol. Appl. Pharmacol. 1996
3931076 Aflatoxin metabolism in humans: detection of metabolites and nucleic acid adducts in urine by affinity chromatography

Chen, JS, Groopman, JD, Zhu, JQ, Wogan, GN, Donahue, PR

Proc. Natl. Acad. Sci. U.S.A. 1985
1643250 Oxidation of aflatoxins and sterigmatocystin by human liver microsomes: significance of aflatoxin Q1 as a detoxication product of aflatoxin B1

Guengerich, FP, Groopman, JD, Raney, KD, Kim, DH, Harris, TM, Shimada, T

Chem. Res. Toxicol. 1992
Catalyst Activity

monooxygenase activity of CYP3A4,5 [endoplasmic reticulum membrane]

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