4-Aminobenzoic acid, commonly known as PABA, is an intermediate in the synthesis of tetrahydrofolic acid in many non-mammalian organisms, including bacteria and fungi. Folates, like tetrahydrofolic acid, have critical roles in the metabolism of nucleic acid precursors and several amino acids, as well as in methylation reactions. In mammals, PABA is metabolized by a variety of enzymes, including N-acetyltransferases. It may also be utilized by bacteria or fungi that are living in mammalian organisms, including those resident in the gut.
