Phase 1 biotransformation includes ?
Ans. is 'a' i.e., Reduction Types of biotransformation reactions Biotransformation reactions (metabolism) of drugs can be classified : A. Non-synthetic (phase I) reactions Metabolism brings about a change in the drug molecule by : Oxidation Hydrolysis Decyclization Reduction Cyclization The new metabolite may retain biological activity or it may be an inactive metabolite. Oxidation is the most impoant metabolizing reaction. The most impoant enzyme for oxidation reaction is cytochrome P450. B. Synthetic (phase H or conjugation) reaction Metabolism involves union of the drug with one of several polar (water-soluble) endogenous molecules that are products of intermediary metabolism, to form a water-soluble conjugate which is readily eliminated by kidney or, if the molecular weight exceeds 300, in the bile. Phase II metabolism almost invariably terminates biological activity, i.e. metabolites are usually inactive. o Reactions are Acetylation Glutathione conjugation Neucleotide synthesis Glucuronide conjugation Sulfate conjugation Glycine conjugation Methylation
Reduction
Acetylation
Sufate conjugation
Methylation