PRESENTED BY NUZHAT NAZIR(TOPPER OF

BATCH 14-15)NAVEED UL MUSHTAQ

DEPT OF BIORESOURCES KU

BIOSYNTHESIS OF VITAMIN C

Vitamins

Vitamins are essential organic nutrients required in very small amounts for normal metabolism, growth and physical well-being.

Most vitamins are not made in the body, or only in insufficient amounts, and are mainly obtained through food. When their intake is inadequate, vitamin deficiency disorders are the consequence.

VITAMINS

No single food contains all of the vitamins and, therefore, a balanced and varied diet is necessary for an adequate intake. Each of the 13 vitamins known today has specific functions in the body, which makes every one of them unique and irreplaceable.

Of the 13 vitamins, 4 are fat-soluble, namely vitamins A, D, E and K. The other vitamins are water-soluble: vitamin C and the B-complex, consisting of vitamins B1, B2, B6, B12, folic acid, biotin, pantothenic acid and niacin

VITAMINS

While plants and micro organism have the capability to produce the vitamins necessary for the metabolism themselves, humans and animals have unfortunately lost this ability during evolution.

Because of the lack of specific enzymes for synthesis, vitamins became essential nutrients for them.

VITAMIN A

SynonymsRetinolChemistryRetinol and its related

compounds consist of four isoprenoid units joined head to tail and contain five conjugated double bonds. They naturally occur as alcohol (retinol), as aldehyde (retinal) or as acid (retinoic acid).

VITAMIN A

Vitamin D

Synonyms Calciferol; antirachitic factor;

“sunshine” vitamin Chemistry Vitamin D is a generic term and

indicates a molecule of the general structure shown for rings A, B, C, and D with differing side chain structures. The A, B, C, and D ring structure is derived from the cyclopentano perhydro phenanthrene ring structure for steroids.

Technically, vitamin D is classified as a seco-steroid. Seco-steroids are those in which one of the rings has been broken; in vitamin D, the 9,10 carbon-carbon bond of ring B is broken.

Vitamin D

Vitamin E

SynonymsTocopherolChemistryA group of compounds

composed of a substituted chromanol ring with a C16 side chain saturated in tocopherols, with 3 double bonds in tocotrienols.

Vitamin E

Vitamin K

Synonyms Phylloquinone, menaquinone Chemistry Compounds with vitamin K

activity are 3-substituted 2-methyl-1,4-naphthoquinones.

Phylloquinone contains a phytyl group, whereas menaquinones contain a polyisoprenyl side chain with 6 to 13 isoprenyl units at the 3-position.

Vitamin K

Vitamin C

VITAMIN C

SynonymsAscorbic acid, hexuronic acid, anti-scorbutic

vitaminChemistryL-ascorbic acid , dehydro-L-ascorbic acid (2-

oxo-L-gulonic acid- g-lactone).

Industrial production

The synthesis of ascorbic acid was achieved by Reichstein in 1933

Today synthetic vitamin C, identical to that occurring in nature, is produced from glucose on an industrial scale by chemical and biotechnological synthesis

Biosynthesis of vit C

Although the pathways responsible for L-ascorbate accumulation in plants are not completely understood, a major component of plant ascorbate synthesis is through the L-galactose pathway , in which GDP-D-mannose is converted to L-ascorbate by four successive intermediates, as summarized in Fig.

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