What happens during conjugation in Phase 2 of metabolism?
Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine. The substances that result from metabolism may be inactive, or they may be similar to or different from the original drug in therapeutic activity or toxicity.
Is conjugation a Phase 2 reaction?
Phase II reactions consist of adding hydrophilic groups to the original molecule, a toxic intermediate or a nontoxic metabolite formed in phase I, that requires further transformation to increase its polarity. These reactions include conjugation reactions, glucuronidation, acetylation, and sulfation.
Why are drugs conjugated in Phase 2 metabolism?
Conjugation. Glucuronidation, the most common phase II reaction, is the only one that occurs in the liver microsomal enzyme system. Glucuronides are secreted in bile and eliminated in urine. Thus, conjugation makes most drugs more soluble and easily excreted by the kidneys.
What is sulfation in metabolism?
Sulfation is an important pathway of metabolism for a range of endogenous compounds including steroid hormones, bile acids, neurotransmitters, and small peptides. Xenobiotics also undergo conjugation by sulfation, which generally, but not exclusively, leads to reduced biological activity.
What is glutamine conjugation?
It is a glutamine family amino acid, a proteinogenic amino acid, a glutamine and a L-alpha-amino acid. It is a conjugate base of a L-glutaminium. It is a conjugate acid of a L-glutaminate. It is an enantiomer of a D-glutamine.
Is hydroxylation a Phase 2 reaction?
Hydroxylation is the most common reaction type in phase I metabolism and usually produces a chemically stable and more polar hydroxylated metabolite than the drug.
What is conjugation in drug metabolism?
What is glycine conjugation?
Abstract. A number of endogenous and xenobiotic organic acids are conjugated to glycine, in animals ranging from mosquitoes to humans. Glycine conjugation has generally been assumed to be a detoxification mechanism, increasing the water solubility of organic acids in order to facilitate urinary excretion.
What are conjugation reactions?
Conjugation reactions, or phase II reactions, synthesize more water-soluble compounds by combining a substance with an endogenous molecule to enhance excretion of that substance. Glucuronide, sulfate, and glycine are the common endogenous molecules to which drugs are bound.
Is glutathione a Phase 1 or 2?
Abstract. Glutathione (γ-glutamyl-cysteinyl-glycine) is an intracellular thiol molecule and a potent antioxidant that participates in the toxic metabolism phase II biotransformation of xenobiotics.