Biotransformacija

Biotransformacija je hemijska modifikacija (ili modifikacije) koju je učinio organizam na hemijskom jedinjenju. Ako se ta modifikacijom dovede do formiranja mineralnih jedinjenja kao što je ${\ce {CO2}}$, ${\ce {NH4+}}$, ili ${\ce {H2O}}$, biotransformacija se naziva mineralizacijom.

Biotransformation means chemical alteration of chemicals such as nutrients, amino acids, toxins, and drugs in the body. It is also needed to render non-polar compounds polar so that they are not reabsorbed in renal tubules and are excreted. Biotransformation of xenobiotics can dominate toxicokinetics and the metabolites may reach higher concentrations in organisms than their parent compounds.

Metabolizam lekova

Главни чланак: 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. There are many different processes that can occur; the pathways of drug metabolism can be divided into:

• phase І
• phase II

Drugs can undergo one of four potential biotransformations: Active Drug to Inactive Metabolite, Active Drug to Active Metabolite, Inactive Drug to Active Metabolite, Active Drug to Toxic Metabolite (biotoxification).

Reakcija faze I

• Includes oxidative, reductive, and hydrolytic reactions.
• In these types of reactions, a polar group is either introduced or unmasked, so the drug molecule becomes more water-soluble and can be excreted.
• Reactions are non-synthetic in nature and in general produce a more water-soluble and less active metabolites.
• The majority of metabolites are generated by a common hydroxylating enzyme system known as Cytochrome P450.

Reakcija faze II

• These reactions involve covalent attachment of small hydrophilic endogenous molecule such as glucuronic acid, sulfate, or glycine to form water-soluble compounds, that are more hydrophilic.
• This is also known as a conjugation reaction.
• The final compounds have a larger molecular weight.

Vidi još

• Biodegradacija
• Mikrobna biodegradacija
• Ksenobiotčki metabolizam

Spoljašnje veze

• Biotransformation of Drugs
• Biodegradation, Bioremediation and Biotransformation
• Microbial Biodegradation
• Biotransformation and Bioaccumulation in freshwater invertebrates
• Ecotoxicology & Models