N-oxidation: a possible route of tinidazole metabolism in man

H A Coker1, E E Essien, E J Edoho

  • 1Department of Pharmaceutical Chemistry, College of Medicine, University of Lagos, Nigeria.

Related Concept Videos

Drug Metabolism: Phase I Reactions01:17

Drug Metabolism: Phase I Reactions

A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs in the liver, facilitated by the cytochrome P450 system of hemoproteins situated in the lipophilic endoplasmic reticulum of cells. The metabolite generated through this process can have varying polarities. If it is sufficiently polar, it can be easily excreted in the urine due to its water compatibility. However, if the metabolite is nonpolar,...
Drug Metabolism: Phase II Reactions01:14

Drug Metabolism: Phase II Reactions

Phase II reactions are essential for the detoxification and elimination of drugs from the body. These reactions involve the conjugation of parent drugs or their phase I metabolites with endogenous molecules, resulting in more hydrophilic drug conjugates. The primary conjugation reactions in this phase are sulfation and glucuronidation. Both sulfation and glucuronidation typically produce biologically inactive metabolites. However, in some cases involving prodrugs, active metabolites may be...
Phase I Oxidative Reactions: Overview01:19

Phase I Oxidative Reactions: Overview

Phase I biotransformation, or functionalization, is a crucial chemical process that converts drugs and other xenobiotics into more water-soluble forms, facilitating expulsion from the body. It involves oxidative, reductive, and hydrolytic reactions that add or unveil polar functional groups on lipophilic substrates. Key players in phase I reactions are the mixed-function oxidases. Situated in liver cell microsomes, these enzymes predominantly carry out drug metabolism. They require molecular...
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems01:19

Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems

Phase I biotransformation reactions are integral to drug metabolism, predominantly involving oxidative, reductive, and hydrolytic transformations. Chief among these are oxidative reactions, which enhance the hydrophilicity of xenobiotics and introduce polar functional groups to facilitate their elimination from the body.
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
Phase II Reactions: Miscellaneous Conjugation Reactions01:19

Phase II Reactions: Miscellaneous Conjugation Reactions

Phase II biotransformations are detoxification mechanisms that conjugate xenobiotics with endogenous substances, neutralizing their toxicity.
A key example involves the conjugation of cyanide ions, which impair cellular respiration and alter hemoglobin into non-oxygen-carrying cyanmethemoglobin. To neutralize this threat, a sulfur atom from thiosulphate is transferred to the cyanide ion, catalyzed by the enzyme rhodanese, resulting in an inactive compound called thiocyanate. The production of...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase01:27

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...