XENOBIOTICS STRUCTURAL COMPONENTS AND ITS TYPES

Xenobiotics is a chemical compound

1. XENOBIOTICS M.S.SWETHA BP231508

2. XENOBIOTICS(definition) xenobiotic is a foreign chemical substance found within an organism that is not normally naturally produced by or expected to present within. it can also cover substances that are present in much higher concentrations than are usual. specifically, Drugs such as antibiotics are xenobiotics in humans because the human body does not produce them itself, nor are they part of a normal food

3. Biological effects: Xenobiotics can produce a variety of biological effects including 1.pharmacalogical responses 2.Toxicity 3.Immunological responses 4.Cancers

4. TYPES OF XENOBIOTICS EXOGENOUS : The foreign molecules which are not normally ingested or utilized by the organism but they gain entry through dietary food stuffs,or in the form of certain medicines/drugs used for a threapeutic cause or inhaled through environment Drugs Food additive Pollutants Insecticides Carcinogens

5. ENDOGENOUS Though they are not foreign substances but have effects similiar to exogenous xenobiotics. these are synthesized in the body or produced as metabolites of various processes in the body Bilirubin Bile acids Steroids Fatty acids

6. METABOLISM OF XENOBIOTICS Metabolism of xenobiotics occurs in two phases Phase-1 The major reaction involved is hydroxylation,In addition to hydroxylation, a wide range of reactions also take place including- Deamination- Removal of amino group from molecule Dehalogenation- Chemical Reactions ivolve in cleavage of carbon-halogen bonds Desulfuration - Removal of sulfur compounds from the molecule. Reduction- Transfer of electrons from one to another Peroxygenation – Replacing nitrogen in the alveolus with oxygen

7. Phase-2 The hydroxylated or other compounds produced in phase-1 are converted by specific enzymes to various polar metabolites by conjugation with- glucuronic acid sulfate acetate glutathione aminoacids by methylation

8. Structural features of xenobiotic compounds: Instead of hydrogen, halogen is present in the molecule which needs additional energy for cleavage. Other groups like sulphonate, nitro, amino, methoxy, etc. are present. Cycloalkanes, aromatic compounds, and heterocyclic compounds are more recalcitrant. Branched linear chains are resistant to biodegradation.

9. 1.Halocarbons: These xenobiotic compounds contain halogens in diverse amounts viz. chlorine, bromine, fluorine or iodine instead of hydrogen atoms. They find their application in various ways such as propellants in spray cans of cosmetics, paints etc., and solvents such as chloroform. They are also used in condenser units of cooling systems (freons, CCl3F, CCl2F2 etc.) and as insecticide (DDT, BHC, lindane etc.)and herbicide such as dalapon Chloroform and freons which are basically volatile in nature and released into the atmosphere where they devastate protective ozone layer that leads to increased UV radiation.

10. 2.Polychlorinated biphenyls (PCBs): They are basically utilized as coolants in transformer or as exchange fluids for heat 3.Synthetic polymers: These are polyethylene, polyvinyl chloride, polystyrene,etc ., and nylons, which are used as article of clothing, enveloping material . 4.Alkylbenzyl Sulphonates: They are surface-active detergents that are superioras compared to soaps. The sulphonate (-SO3-) group at one end opposes microbial degradation, while the other end becomes recalcitrant

11. 5.Oil Mixtures: Oil is recalcitrant basically because it is not soluble in water and due to lethal nature of some of its compounds. Biodegradation is used when there is small oil seepage but when large spill occurs these complexes are recalcitrant in nature 6.Other xenobiotics: Compounds containing aliphatic, cyclic ring arrangements that contains nitro, sulphonates, amino, methoxy, or carbamyl groups other than halogen group. These properties make them recalcitrant

12. EFFECTS OF XENOBIOTICS Metabolism of a xenobiotic can result in cell injury,Immunologic damage or cancer Cell injury (cytotoxicity)can be severe enough to result in cell death These macromolecular targets include DNA,RNA and Protein The reactive species of a xenobiotic may bind to a protein altering its Antigenicity The resulting Antibiotics can then damage the cell by several immunologic mechanisms that grossly perturb normal cellular biochemical processes. Reactions of activated species of chemical carcinogens with DNA are of great importance in Chemical carcinogenesis

13. THANK YOU