Biotransformations sometimes yield toxic metabolites, through a process known as bioactivation. The chemical reactions responsible for changing a lipophilic toxicant into a chemical form are known as Phase I and Phase II biotransformations.

What does Bioactivation mean?

Formation of harmful or highly reactive metabolic from relatively inert/nontoxic chemical compounds is called bioactivation or toxication. The bioactive metabolites often interact with the body tissues to precipitate one or more forms of toxicities such as carcinogenesis, teratogenesis, and tissue necrosis.

Are metabolism and biotransformation the same thing?

The key difference between biotransformation and metabolism is that biotransformation is a part of metabolism in which the biochemical transformation occurs in a particular drug or compound while metabolism refers to all biochemical reactions taking place in a living organism.

What phase of biotransformation is hydrolysis?

Phase I metabolism consists of reduction, oxidation, or hydrolysis reactions.

What is biotechnology biotransformation?

Biotransformation is a process by which organic compounds are transformed from one form to another, aided by organisms such as bacteria, fungi and enzymes. ... Microbial biotransformations or microbial biotechnology are extensively used to generate metabolites in bulk amounts.

Gastrointestinal | Biotransformation of Drugs and Toxins

What is another name for biotransformation?

bi·o·trans·for·ma·tion

The conversion of molecules from one form to another within an organism, often associated with change in pharmacologic activity; refers especially to drugs and other xenobiotics. Synonym(s): biodegradation.

What are examples of biotransformation?

Drug metabolism

The metabolism of a drug or toxin in a body is an example of a biotransformation. The body typically deals with a foreign compound by making it more water-soluble, to increase the rate of its excretion through the urine.

What are the two phases of biotransformation?

Biotransformation of organic xenobiotics normally proceed in a first step of oxidation (phase I) that introduces a reactive group in the xenobiotic, and a second step of conjugation (phase II) with a nontoxic endogenous metabolite that yields an excretable product.

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 a hydrolysis reaction?

Thus, a hydrolysis reaction is the cleavage of chemical bonds by the addition of water or a base that supplies the hydroxyl ion ( OH⁻). A chemical bond is cleaved, and two new bonds are formed, each one having either the hydrogen component (H) or the hydroxyl component (OH) of the water molecule.

What is biotransformation in toxicology?

Biotransformation is the metabolic conversion of endogenous and xenobiotic chemicals to more water-soluble compounds. ... Chemical modification of a xenobiotic by biotransformation may alter its biological effects. Some drugs undergo biotransformation to active metabolites that exert their pharmacodynamic or toxic effect.

What is metabolism conjugation?

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 conjugation in drug 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.

Which of the following statement rightly states Bioactivation?

1. Which of the following statement rightly states “bioactivation”? Explanation: Formation of highly reactive metabolites which can interact with the tissues and precipitate out various toxic compounds such as carcinogens, teratogens, etc. is known as bioactivation or toxicological activation.

What are conjugation reactions?

Conjugation reactions usually involve metabolite activation by a high–energy intermediate and have been classified into two general types: type I (e.g., glucuronidation and sulfonation), in which an activated conjugating agent combines with substrate to yield the conjugated product, and type II (e.g., amino acid ...

What is xenobiotic chemical?

Xenobiotic is a term used to describe chemical substances that are foreign to animal life and thus includes such examples as plant constituents, drugs, pesticides, cosmetics, flavorings, fragrances, food additives, industrial chemicals and environmental pollutants.

How many phases of biotransformation are there?

It appears that the metabolism of most foreign compounds occurs in two phases.

How many phases are there in biotransformation?

Generally, biotransformation occurs in two phases. into various components. Catabolic reactions include oxidation, reduction, and hydrolysis.

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 ...

What is the difference between biotransformation and biodegradation?

The process by which organic chemicals are degraded by microorganisms is called Biodegradation. The term "biotransformation" is commonly used interchangeably with "biodegradation" in contemporary literature.

What is biotransformation Slideshare?

INTRODUCTION  Biotransformation is a chemical reaction catalysed by cells ,organs or enzymes.  It is defined as a process through which the functional groups of organic compounds are modified by living cells to a chemically different product. ...  The substrate must not be toxic to the cell culture.

What is the meaning of pharmacodynamic?

Pharmacodynamics is the study of a drug's molecular, biochemical, and physiologic effects or actions. It comes from the Greek words "pharmakon" meaning "drug" and "dynamikos" meaning "power."

What is the purpose of biotransformation?

The major purpose of biotransformation is to chemically modify (metabolize) poorly excretable lipophilic compounds to more hydrophilic chemicals that are readily excreted in urine and/or bile. Without metabolism, lipophilic xenobiotics accumulate in biota, increasing the potential for toxicity.

What are metabolites made of?

Primary metabolites are synthesized by the cell because they are indispensable for their growth. Significant representatives are amino acids, alcohols, vitamins (B2 and B12), polyols, organic acids, as well as nucleotides (e.g. inosine-5'-monophosphate and guanosine-5'-monophosphate).

Which tissue has the greatest capacity to Biotransform drugs?

Liver is the tissue which can do transformation and biotransformation of synthetic and non-synthetic drugs, organic and non-organic nutrients and micro molecules and macro molecules.