5.bileacid
Download as PPTX, PDF32 likes13,355 views
Bile is produced in the liver and stored in the gallbladder. It consists of bile acids, bile pigments, and other organic and inorganic compounds. Bile acids are conjugated with either glycine or taurine and act to facilitate fat digestion by emulsifying lipids. More than 20 natural bile acids have been characterized that differ in their hydroxyl group positions. Bile acids are synthesized from cholesterol in the liver through a series of modifications including removal of the side chain and introduction of hydroxyl groups. They play an important role in fat digestion by emulsifying lipids to increase their surface area for pancreatic enzymes to act upon.
![• Liver secrete a clear golden
yellow viscous fluid known as
bile.
• It is stored in gall bladder and
mainly used in digestion.
• Bile consist of inorganic ions as
well as organic compound.[ bile
acids, bile pigments, liquids,
fatty acids and cholesterol]](https://image.slidesharecdn.com/5-180305101727/85/5-bileacid-2-320.jpg)
![• Cholic acid [ 3 α,7 α,12α trihydroxy ]
is extracted from ethereal solution
by 15% HCl.
• Dihydroxy acids [ deoxy and cheno
deoxy cholic acid] are extracted
from ethereal solution by 25% HCl.
• Mono hydroxy acid [ litho cholic acid
] is extracted by concentrated HCl.](https://image.slidesharecdn.com/5-180305101727/85/5-bileacid-9-320.jpg)
5.bileacid
- 1. Bile Acid Prepared by Dr. N.GOPINATHAN ASSISTANT PROFESSOR DEPARTMENT OF PHARMACEUTICAL CHEMISTRY FACULTY OF PHARMACY SRI RAMACHANDRA UNIVERSITY CHENNAI-116 TAMILNADU INDIA
- 2. • Liver secrete a clear golden yellow viscous fluid known as bile. • It is stored in gall bladder and mainly used in digestion. • Bile consist of inorganic ions as well as organic compound.[ bile acids, bile pigments, liquids, fatty acids and cholesterol]
- 3. • Bile acids present as sodium salts of amide with glycine or taurine. • Glycocholate – Glycine + Cholic acid • Taurocholate – Taurine + Cholicacid • It is hydroxy derivative of either 5 beta or alpha cholanic acid. • Its main function is to facilitate digestion of fat.
- 4. More than 20 natural bile acids have been characterised eg. Cholic acid, deoxy cholic acid, chenodeoxy cholic acid and lithocholic acid. The position of hydroxyl group may be 3,6, 7,11,12 and 23.
- 5. • Almost all the natural bile acids, the configuration of the hydroxyl group have been found to be alpha. • 5 alpha cholanic acid mp is 164 C • 5 beta cholanic acid mp is 173 C • It contains steroidal nucleus, COOH at C-24, 1,2,or 3 hydroxyl group in the nucleus. • A/B rings are cis fused result in Beta series
- 6. Bile acid structure Cholic acid Deoxy cholic acid
- 7. Biogenesis • Bile acids are the end product of cholesterol metabolism. • Ring skeleton remains intact, while the isopropyl group of the side chain is removed. • C-12 hydroxylation of ring precedes degradation of the side chain. • Once the side chain is oxidised, no hydroxyl group can be introduced into the 12 alpha position.
- 8. Isolation of bile acid • The peptide linkage is hydrolysed with alkali from the above solution free bile acids have been isolated either by crystallisation from organic solvents or by treating with ethereal solution of acids with various concentration of HCl
- 9. • Cholic acid [ 3 α,7 α,12α trihydroxy ] is extracted from ethereal solution by 15% HCl. • Dihydroxy acids [ deoxy and cheno deoxy cholic acid] are extracted from ethereal solution by 25% HCl. • Mono hydroxy acid [ litho cholic acid ] is extracted by concentrated HCl.
- 10. Colour reaction – Mylius reaction for cholic acid • Substance dissolved in ethanol • Few drops of iodine is added • On warming gives blue colour in transmitted light. • It appears as yellow in reflected light.
- 11. Hammersten test • Cholic acid with 25% HCl • Violet colour • Changes to yellow on heating
- 12. Pettenkofer reaction • A solution of sucrose or fructose is added to solution of bile acid • Concentrated sulphuric acid is added. • Red colour changes on warming to bluish red
- 13. Chemistry • COOH group • soluble in alkali • Esterification • Reduction acid to aldehyde by Rosen mund reduction , Lithium Aluminium hydride and tributoxy aluminium hydride.
- 14. OH Group • For acylation , hydrolysis, reduction and hydrogenation the order of reactivity is C-3> >C-7 > C-12. • 3 alpha group is more easily esterified than the other two.
- 15. Constitution of bile acid
- 16. Conclusion • Cholesterol and bile acid are structurally related because they yield same product cholanic acid. • Bile acid has same degradative reactions as that of cholesterol thus the bile acid have same nucleus as cholesterol • They differ only in one respect that the double bond of cholesterol is absent in bile acid. • On selenum dehydrogenation yield diel,s hydrocarbon
- 17. Side chain of bile acid • Barbier-wieland degradation is used to elucidate the nature of side chain in bile acid.
- 18. Biological role • This facilitate fat digestion by emulsifying them and thereby increase the surface area of the material for pancreatic enzyme. • Emulsification – converts insoluble into water soluble compound which can be easily absorbed in intestine
- 19. Biological role • They activate the enzyme cholesterol esterase and pancreatic lipase. • They cholesterol in solution if the ratio of the bile acid is to cholesterol falls than the normal level the cholesterol precipitates out and form gall stone in liver and gall bladder
- 20. Thank you