4-Aminobenzoic acid

4-Aminobenzoic acid, or PABA, is an aromatic carboxylic acid with an amino group opposite the carboxyl group on a benzene ring. It is a precursor in bacterial folate synthesis and absorbs ultraviolet radiation.

Connect

Benzoic acid: An aromatic carboxylic acid consisting of a benzene ring bonded to a carboxyl group. PABA is a benzoic acid derivative with an amino substituent.
Dihydropteroate synthase: A bacterial enzyme that joins PABA to a pterin precursor during folate synthesis. This enzyme uses PABA as a substrate to form dihydropteroate.
Sunscreen: A topical product that reduces skin exposure to ultraviolet radiation through absorption, reflection, or scattering. PABA's ultraviolet absorption made it an early sunscreen active ingredient.
2-Aminobenzoic acid: An aromatic carboxylic acid with an amino group adjacent to the carboxyl group, also called anthranilic acid. Its ortho arrangement differs from PABA's para arrangement and changes its chemistry.
Aromaticity: The unusual stability and electronic structure of cyclic, conjugated molecules such as benzene. PABA's benzene ring gives its substituents a shared electronic framework.
Folate biosynthesis: The biochemical pathway by which organisms produce folate from precursor molecules. PABA supplies the aromatic component incorporated into bacterial folate.
Octyl methoxycinnamate: An organic ultraviolet filter, also called octinoxate, used in some sunscreens. Octinoxate is a later UVB-filter alternative to PABA-based sunscreen ingredients.
3-Aminobenzoic acid: An aromatic carboxylic acid with an amino group one carbon removed from the carboxyl group's ring position. Its meta arrangement provides a positional-isomer comparison with PABA.
Carboxylic acid: An organic compound containing a carbonyl and hydroxyl group bonded to the same carbon atom. The carboxyl group makes PABA an acid and participates in its reactions.
Sulfonamide: A class of compounds containing a sulfonamide group, including drugs that inhibit bacterial folate synthesis. Sulfonamides resemble PABA and compete with it at dihydropteroate synthase.