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( Retinol)
nona-2,4,6,8-tetraen-1-ol In 1913, Elmer McCollum, a biochemist at the University of Wisconsin-Madison, and colleague Marguerite Davis identified a fat-soluble nutrient in butterfat and cod liver oil. Their work confirmed that of Thomas Osborne and Lafayette Mendel, at Yale, which suggested a fat-soluble nutrient in butterfat, also in 1913.[1] Vitamin A was first synthesized in 1947 by two Dutch chemists, David Adriaan van Dorp and Jozef Ferdinand Arens. Many different geometric isomers of retinol, retinal and retinoic acid are possible as a result of either a trans or cis configuration of four of the five double bonds found in the polyene chain. The cis isomers are less stable and can readily convert to the all-trans configuration (as seen in the structure of all-trans-retinol shown here). Nevertheless, some cis isomers are found naturally and carry out essential functions. For example, the 11-cis-retinal isomer is the chromophore of rhodopsin, the vertebrate photoreceptor molecule. Rhodopsin is comprised of the 11-cis-retinal covalently linked via a Schiff base to the opsin protein (either rod opsin or blue, red or green cone opsins). The process of vision relies on the light-induced isomerisation of the chromophore from 11-cis to all-trans resulting in a change of the conformation and activation of the photoreceptor molecule. One of the earliest signs of vitamin A deficiency is night-blindness followed by decreased visual acuity. Many of the non-visual functions of vitamin A are mediated by retinoic acid, which regulates gene expression by activating intracellular retinoic acid receptors. The non-visual functions of vitamin A are essential in the immunological function, reproduction and embryonic development of vertebrates as evidenced by the impaired growth, susceptibility to infection and birth defects observed in populations receiving suboptimal vitamin A in their diet.
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Retinol Subcategories
Retinol Articles
Clinical Study on Retinol Cream by Skin Couture Adorage by Francis Adam
As we get older, our skin undergoes changes that make it feel, act and look different from younger skin. Its outer cells don’t slough off as easily as before, it doesn’t retain moisture as it was in youth and its support of fibers, collagen and elast...
Acne- Proven Cure For Your Acne With Vitamin A Derivatives by cd mohatta
Acne and Vitamin A
Vitamin A is considered a very important anti oxidant vitamin. Use of Vitamin A in the form of Beta-carotene kills free radicals and keeps us young for a long time. How vitamin A is used for treating Acne? Let...
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