What is Phase 2 drug metabolism?

What is Phase 2 drug metabolism?

Phase I reactions of drug metabolism involve oxidation, reduction, or hydrolysis of the parent drug, resulting in its conversion to a more polar molecule. Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine.

What is 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.

What do phase 2 enzymes do?

Phase 2 enzymes are major detoxification enzymes and an important part of cellular defense against carcinogens, oxidants, and other toxic chemicals. Moreover, it has also been reported that catalysis of certain substrates by a phase 2 enzyme may actually result in bioactivation of the compounds.

What are the 2 phases of metabolism?

Metabolism is often divided into two phases of biochemical reaction – phase 1 and phase 2. Some drugs may undergo just phase 1 or just phase 2 metabolism, but more often, the drug will undergo phase 1 and then phase 2 sequentially.

Where does Phase 2 metabolism occur?

Phase II metabolism involves the introduction of a hydrophilic endogenous species, such as glucuronic acid or sulfate, to the drug molecule. Enzymes involved in phase II reactions are mainly located in the cytosol, except glucuronidation enzyme, which is also a microsomal enzyme.

Where do Phase 2 reactions occur?

Which enzyme is imp in Phase 2 reaction?

Which enzyme is important in the Phase II reactions? Explanation: Phase II reactions involve the transfer of a suitable moiety such as glucuronic acid sulfate, glycine, etc. to the phase I reaction. This transfer is mediated by the presence of the enzyme Transferase. 2.

Which enzyme is important in the phase 2 reaction?

Which is the most common phase 2 reaction?

Glucuronidation
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 biotransformation phase1?

Phase I biotransformation reactions introduce or expose functional groups on the drug with the goal of increasing the polarity of the compound. Typically, oxidation is the most common phase I reaction. The hepatic cytochrome P450 system is the most important of the phase I oxidation systems (Figure 1).

What is the difference between Phase 1 and Phase 2 reactions?

The key difference between phase I and phase II metabolism is that the phase I reactions convert a parent drug to polar active metabolites through unmasking or insertion of polar functional groups whilst phase II reactions convert a parent drug to polar inactive metabolites through conjugation of subgroups to -SH, -OH …