TY - CHAP M1 - Book, Section TI - Biotransformation of Xenobiotics A1 - Parkinson, Andrew A1 - Ogilvie, Brian W. A1 - Buckley, David B. A1 - Kazmi, Faraz A1 - Parkinson, Oliver A2 - Klaassen, Curtis D. A2 - Watkins, John B. PY - 2021 T2 - Casarett & Doull’s Essentials of Toxicology, 4e AB - KEY POINTSBiotransformation is the metabolic conversion of endogenous and xenobiotic chemicals to more water-soluble compounds.Xenobiotic biotransformation is accomplished by a limited number of enzymes with broad substrate specificities.Phase I reactions involve hydrolysis, reduction, and oxidation. These reactions expose or introduce a functional group (—OH, —NH2, —SH, or —COOH), and usually result in only a small increase in hydrophilicity.Phase II biotransformation reactions include glucuronidation, sulfonation (more commonly called sulfation), acetylation, methylation, and conjugation with glutathione (mercapturic acid synthesis), which usually result in increased hydrophilicity and elimination. SN - PB - McGraw Hill CY - New York, NY Y2 - 2024/03/29 UR - accesspharmacy.mhmedical.com/content.aspx?aid=1178013502 ER -