Para-Aminobenzoic acid (PABA) is a chemical used in sunscreen that is an essential nutrient for some bacteria. It is sometimes called Vitamin B-x, although PABA is not essential for humans and it varies in its activity from other B vitamins. The chemical formula is (COOH)-Ph-NH₂ / (C₇H₇NO₂) also known as 4-Amino-benzoic acid and has the chemical structure:

PABA is a white crystalline substance that is only slightly soluble in water.

Although humans lack the ability to synthesize folate from PABA, it is often still sold by some vitamin websites as an essential nutrient. Sulfonamides (sulfa drugs) are chemically similar to PABA, and their antibacterial activity is due to their ability to interfere with PABA utilization by bacteria.

External link

• PABA structure http://www.chemicalland21.com/arokorhi/specialtychem/finechem/p-AMINOBENZOIC%20A
  CID.htm