4-Aminobenzoic acid
![Skeletal formula of PABA](/Images/godic/202502/04/4-Aminobenzoic_acid.svg1425.png")
![Ball-and-stick model of the PABA molecule](/Images/godic/202502/04/4-Aminobenzoic-acid-3D-balls1425.png")
![Tetrahydrofolate synthesis pathway](/Images/godic/202502/04/THFsynthesispathway1425.png")
4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the number 4 carbon in the benzene ring is also known as the para position) is an organic compound with the formula H2NC6H4CO2H. PABA, a white-grey crystalline substance, is only slightly soluble in water. It consists of a benzene ring substituted with an amino group and a carboxyl group.