Vitamin b5, pantothenic acid

Vitamin b5, pantothenic acid

1. pantothenic acid. (Vitamin B5) Name : Mahalaxmi R oll no : 53

2. Objectives : Introduction Structure Chemistry & synthesis RDA ( recommended dietary allowance ) Dietary sources Deficiency symptoms.

3. Introduction Vitamin B5 is known as pantothenic acid Roger J. Williams discovered the pantothenic acid. Lipmann discovered CoA in 1946 Pantos (greek ) : every-where Widely distributed in nature Water soluble vitamin Chick anti- dermitis factor or filtrate factor Pantothenic acid is the component of CoA which function in the transfer of acyl group.

4. Structure : Molecular formula : C9H17O5 Structure of CoA consists of pantothenic acid joined to beta- mercaptoethanolamine (thioethanolamine) at one end. Pantothenic acid is held by a phosphate bridge to adenylic acid. The adenylic acid is made up of adenine , and a phosphate linked to corbon-3 of ribose .

5. Chemistry & synthesis of CoA : Consists of 2 components : 1) Pantoic acid 2) ßeta – alanine Held together by a peptide linkage . Synthesis of CoA from pantothenic acid occurs in a series of reactions. Pantathenate is first phosphorylated, to which cysteine is added. Decarboxylation, followed by addition of AMP moiety and a phosphate results in CoA.

6. synthesis of CoA from pantothenic acid :

7. Biochemical functions : Functions of pantothenic acid are exerted through CoA. Plays a unique role in integrating various metabolic pathways. More than 70 enzymes that depend on coenzyme A are known. CoA has a thiol or sulfhydryl (-SH) group which is the reactive site , hence CoA sometimes abbreviated as CoA-SH to denote this active site. Acyl groups (free fatty acids ) are linked to coenzyme A by a thioester bond , to give acyl CoA. When bound to acetyl unit, it is called acetyl CoA. Serves as a carrier of activated acetyl or acyl groups (as thiol esters).

8. A few examples of enzymes involved the participation of coenzyme A are given below.

9. In some of the metabolic reactions , group transfer is important which occurs in a coenzyme A bound form. Acetyl CoA + choline acetyl choline + CoA Acetyl CoA + oxaloacete citrate + CoA Succinyl CoA + acetoacetate acetoacyl CoA + succi nate Coenzyme A may be regarded as a coenzyme of metabolic integration , since acetyl CoA is a central molecule for wide variety of reactions. Succinyl CoA is involved in many reactions , including a synthesis of porphyrins of heme. Pantothenic acid is a component of fatty acid synthase complex and is involved in the formation of fatty acid.

10. Formation and utilisation of acetyl CoA :

11. Recommended dietary allowance (RDA) The requirement of pantothenic acid is not clearly known. A daily intake of about 5 – 10 mg is advised for adults.

12. Dietary sources : Rich sources : milk, mushrooms, yeast, eggs, liver, & meat Good sources : vegetables, avocados, broccoli, & whole grains.

13. Deficiency symptoms : It’s deficiency symptoms have not been reported in humans. Dr. Gopalan, a world renowed nutritionist from india , linked the burning feet syndrome with pantothenic acid deficiency. Pain and numbness in the toes, sleeplessness, fatigue etc… It’s deficiency in experimental animals results in anemia , fatty liver, decreased steroid synthesis etc.

14. Thank you.