What is xenobiotic biotransformation?

Point 1 Xenobiotic biotransformation or drug metabolism is the process of converting lipophilic (fat-soluble) chemicals, which are readily absorbed from the gastrointestinal tract and other sites, into hydrophilic (water-soluble) chemicals, which are readily excreted in urine or bile.

What is the main function of biotransformation of xenobiotics in the body?

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 xenobiotics PPT?

These are synthesized in the body or are produced as metabolites of various processes in the body. Examples-Bilirubin, Bile acids, Steroids, Eicosanoids and certain fatty acids. Metabolism of Xenobiotics Metabolism of xenobiotics occurs in two phases- Phase 1, the major reaction involved is hydroxylation.

How are xenobiotics metabolized?

Lipophilic xenobiotics are often first metabolized by phase I enzymes, which function to make xenobiotics more polar and provide sites for conjugation reactions. Phase II enzymes are conjugating enzymes and can directly interact with xenobiotics but more commonly interact with metabolites produced by phase I enzymes.

What are the four types of biotransformation process?

Hydroxylation with reduction; Hydroxylation with oxidation; hydroxylation with side chain degradation; rupture of C-C linkages with oxidation of side chain.

• Methods of Biotransformation:
• Range of Biotransformation:
• Applications of Biotransformation:

What is the process of biotransformation?

Biotransformation is the process by which substances that enter the body are changed from hydrophobic to hydrophilic molecules to facilitate elimination from the body. This process usually generates products with few or no toxicological effects.

What are the types of biotransformation?

Biotransformation is of two types: Enzymatic and Non-enzymatic. Enzymatic are further divided into Microsomal and Non-microsomal. Enzymatic Elimination is the biotransformation occurring due to various enzymes present in the body.

What are xenobiotics and its types?

1 Types of Xenobiotics. Environmental pollutants, hydrocarbons, food additives, oil mixtures, pesticides, otherxenobiotics, synthetic polymers, carcinogens, drugs, and antioxidants are the major groups of xenobiotics.

What does biotransformation mean?

Biotransformation is a metabolic process that takes place mainly in the liver and helps to facilitate the excretion of both exogenous and endogenous substances. A series of reactions alter the chemical structures of these substances.

How many phases of xenobiotic metabolism do we have?

The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion. These reactions act in concert to detoxify xenobiotics and remove them from cells.

What is the four step reaction to xenobiotics in the human body?

Drug Metabolism It comprises Phases 0 (entry into cells), I (introduction of a reactive group), II (conjugation with polar moieties), and III (export). Xenobiotic-metabolizing enzymes usually mediate detoxification but can form reactive intermediates causing toxicity.

What is the principle of biotransformation?

What are the phases of biotransformation?

Reactions classify as Phase I, Phase II, or Phase III. It is important to note that these reactions do not have to take place sequentially and can even take place in reverse, Phase II, and then Phase I, or as a single reaction. Phase I metabolism consists of reduction, oxidation, or hydrolysis reactions.

How xenobiotics are formed?

Natural compounds can also become xenobiotics if they are taken up by another organism, such as the uptake of natural human hormones by fish found downstream of sewage treatment plant outfalls, or the chemical defenses produced by some organisms as protection against predators.

What are the characteristics of xenobiotics?

Xenobiotics have been defined as chemicals to which an organism is exposed that are extrinsic to the normal metabolism of that organism. Without metabolism, many xenobiotics would reach toxic concentrations. Most metabolic activity inside the cell requires energy, cofactors, and enzymes in order to occur.

What are the stages of biotransformation?

How are xenobiotics metabolized and detoxified?

In the first step of xenobiotic metabolisms, foreign compounds are processed by phase I detoxification enzymes. In the phase I reaction, multiple cytochrome P450 enzymes are employed,2 and xenobiotics are modified mainly by oxidation reactions to increase electrophilicity.

What are examples of biotransformation?

Wine and beer making are examples of biotransformations that have been practiced since ancient times. Vinegar has long been produced by fermentation, involving the oxidation of ethanol to acetic acid. Cheesemaking traditionally relies on microbes to convert dairy precursors.

What are the types of xenobiotics?

What is the importance of xenobiotics?

The xenobiotic metabolizing enzymes 2 have a primary role in protection against harmful insult from the environment. Playing a key role in the metabolism and elimination of potentially toxic compounds, any change in their regulation, expression and/or their activity may have harmful effects on the body.

What is the biotransformation of xenobiotics?

Biotransformation of Xenobiotics… Cytochrome P450 reactions • Expoxidation of double bonds – Carbamazepine to 10,11-epoxide • Heteroatom oxygenation, N-hydroxylation – Amines to hydroxylamines – Omeprazole to sulfone (CYP3A4) 18 19. Biotransformation of Xenobiotics…

Which microorganisms are involved in the aerobic transformation of xenobiotics?

Microorganisms for the aerobic transformations of xenobiotics • The diversity of microorganisms participating in the aerobic transformations of xenobiotics is vast. • The majority of those microorganisms include the following species: Pseudomonas, Acinetobacter, Alcaligenes, Bacillus, Rhodoccocus, Micrococcus orStreptomyces

What is the biodegradation of xenobiotics?

Biodegradation of Xenobiotics • General features: • Since xenobiotics consist of a wide variety of compounds their degradation occurs via many metabolic pathways. • Biodegradation involves conversion of complex molecules to simpler molecules or if possible to CO2 and H2O. • This is carried out via aerobic metabolism or anaerobic metabolism 15.

What is biotransformation?

DEFINITION :BIOTRANSFORMATION •Enzyme catalysed •Biochemical transformation of drug •Within living organism •Lipid soluble drug/metabolite → water soluble form •Excreted through the kidney •Mainly Liver •Also kidney,intestine,adrenal cortex,lungs,placenta,skin Dr. Jerin James 4 5.