Retinal, retinol and retinoic acid are the aldehyde, alcohol and acid forms of vitamin A. The retinoids exist as many geometric isomers due to the unsaturated bonds in the aliphatic chain. Retinol is biologically active in a wide range of processes.
Retinol or all-trans-retinol is a 20-carbon molecule with cyclohexenyl ring, a side chain with four double bonds (all in trans configuration) and an alcohol end group.
Retinol has been used as a standard in ultra-performance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS) for the vitamins detection and quantification.
Retinol and its derivatives exhibit anti-aging properties. Retinol is used for treating wrinkles and signs of aging. However, due to its photo instability and skin irritation potency, it is hardly used in cosmetic formulations. Retinol is also used as a therapeutic for dermatoses. Its deficiency leads to xerosis and follicular hyperkeratosis.
根据欧洲药典 II，217 (1983)，1 U 相当于 1 国际 U