Structure of Vitamin A1 H3C CH3 CH- CH3 OH Vitamin A, has four double bounds (all trans )at positions 2, 4, 6, 8 on unsaturated side chain containing 9 carbon atoms There are three methyl groups at positions 2 6,6 of Cyclohexenyl ring attached to position 9 on the side chain
Structure of Vitamin A1 • Vitamin A1 has four double bounds (all trans ) at positions 2,4,6,8 on unsaturated side chain containing 9 carbon atoms. • There are three methyl groups at positions 2´ , 6´ , 6´ of Cyclohexenyl ring attached to position 9 on the side chain. H3C CH3 CH3 OH CH3 CH3
Vitamin a deficiency(VAD) VaD is the leading cause of preventable blindness in children and raises the risk of disease and death from severe infections. In pregnant women VAD may increase the risk of maternal mortality VAD is a public health problem in 118 countries especially in Africa and South-east asia Vitamin a is used for treatment of vad
Vitamin A deficiency (VAD) • VAD is the leading cause of preventable blindness in children and raises the risk of disease and death from severe infections. In pregnant women VAD may increase the risk of maternal mortality. • VAD is a public health problem in 118 countries, especially in Africa and South-east Asia. • Vitamin A is used for treatment of VAD
History In 1913, vitamin a was found in fish liver oil or yolk In 1931, retinol was isolated in mammal and salt water fish, which was called vitamin A Afterward 3-dehydroretinol was isolated in fresh water fish, which was called vitamin A2 、CH3 CH3 CH3 H3C CH OH CH3 CH3 Vitamin a2 Vitamin al
History • In 1913, vitamin A was found in fish liver oil or yolk. • In 1931, retinol was isolated in mammal and salt water fish, which was called vitamin A1 . • Afterward, 3-dehydroretinol was isolated in fresh water fish, which was called vitamin A2 . H3C CH3 CH3 OH CH3 CH3 Vitamin A1 H3C CH3 CH3 OH CH3 CH3 Vitamin A2
Beta carotene is called provitamin a, which can be converted to retinol by the body n the liver, one molecule of beta carotene can be cleaved by an intestinal enzyme into two molecules of retinol so beta carotene can also be good sources of retinol
• Beta carotene is called provitamin A, which can be converted to retinol by the body. • In the liver, one molecule of beta carotene can be cleaved by an intestinal enzyme into two molecules of retinol, so beta carotene can also be good sources of retinol
Stability Vitamin a is sensitive to ultraviolet or oxidation by the air so the compound should be stored in an aluminium container or vitamin e oil Vitamin a is not stable to acid and dehydration of vitamin a results in a dehydrate of vitamin a that is only 0.4%potency of vitamin A
Stability • Vitamin A is sensitive to ultraviolet or oxidation by the air. So the compound should be stored in an aluminium container or vitamin E oil. • Vitamin A is not stable to acid and dehydration of vitamin A results in a dehydrate of vitamin A that is only 0.4% potency of vitamin A