Retinoic acid is a metabolite of vitamin A₁ that is required for embryonic development, male fertility, regulation of bone growth and immune function. All-trans-retinoic acid is required for chordate animal development, which includes all higher animals f + some more technical info; chemically it is a C20 polyene carboxylic acid (molecular formula C20H28O2, molar mass 300.44 g mol-1) that exists primarily as the all-trans isomer under controlled storage and as 9-cis and 13-cis geometric isomers under less-stable conditions. At the molecular level retinoic acid functions as a nuclear signaling ligand for retinoic acid receptors RAR alpha, RAR beta and RAR gamma and forms permissive heterodimers with RXR receptors to regulate transcription of genes involved in patterning, cell differentiation and apoptosis, including Hox family targets. It is a pale yellow crystalline solid with very low aqueous solubility, readily soluble in polar organic solvents such as DMSO, ethanol and isopropanol, and shows characteristic UV absorbance between 350 and 370 nm depending on solvent and isomeric composition. It is photosensitive and oxidation-prone so analytical handling and formulation typically use inert atmosphere, amber glass and low temperature storage to preserve the all-trans form. Common analytical identification and purity determination methods are HPLC-UV with photodiode array detection, LC-MS for related compound profiling and NMR for structural confirmation.
Parent: Retinoic Acid
Parent: Retinoic acid
Parent: Retinoic Acid
Typical high-purity all-trans-retinoic acid specifications for research and pharmaceutical starting material grades state assay by HPLC 98.0 percent minimum; total related compounds and impurities typically limited to not more than 2.0 percent. Representative impurity limits commonly applied are 13-cis-retinoic acid 0.5 percent maximum, 9-cis-retinoic acid 0.5 percent maximum, combined isomeric impurities 1.0 percent maximum, retinol and retinal each typically below 0.2 percent, and oxidative degradants such as 4-oxo-retinoic acid below 0.2 percent. Residual solvent and elemental impurity controls follow ICH guidelines with solvents categorized and limited accordingly, for example methanol and ethanol controlled to their permitted daily exposures and reporting thresholds, total heavy metals commonly specified less than 20 ppm, and water content typically maintained under 1.0 percent by Karl Fischer for stable storage. Exact impurity and related-compound limits vary by supplier grade and intended use; certificates of analysis provide definitive quantitative values for each lot.
Retinoic acid is used as a research reagent to study gene regulation, differentiation and development; clinically the all-trans isomer is used as a therapeutic agent in dermatology for acne and in oncology for acute promyelocytic leukemia where it induces differentiation of malignant promyelocytes; it is also used as an intermediate in the manufacture of vitamin A derivatives and in formulation development for topical and systemic products.
Retinoic acid is a metabolite of vitamin A₁ and represents an active oxidized form that mediates many biological effects of vitamin A through nuclear receptors; it is not a storage form but a biologically active signaling form derived from retinol and retinal.
Another common name is all-trans-retinoic acid for the biologically active all-trans isomer; it is also referred to as ATRA in clinical and research contexts and sometimes as tretinoin when used pharmaceutically.
No, retinoic acid is not the same as retinol; retinol is the alcohol storage form of vitamin A that can be enzymatically oxidized to retinal and then to retinoic acid, which is the terminal oxidation product and the transcriptionally active ligand for retinoic acid receptors.
