PABA is the acronym for p-amino benzoic acid. It is used as an anti-bacterial agent, as a sun screen, and as a chemical intermediate in the synthesis of other compounds. You can find out the details from citations in the Merck Index. The compound p-amino benzaldehyde has the empirical formula. Otherwise, it would be a handful in addition to aromatic aldehydes react with aromatic amines to form a class of compounds called "aldimines" that have the structure.
PABA has been reported to enhance the effects of cortisone. It may also prevent or even reverse accumulation of abnormal fibrous tissue. Researchers have attempted to discover whether large amounts of PABA would be helpful in various connective tissue disorders. Although preliminary studies have reported that PABA (12 grams per day) was helpful to people with scleroderma, a double-blind trial found that supplementation with PABA did not lead to improvement. PABA is also occasionally used in pill form by sufferers of Irritable bowel syndrome to treat its associated gastrointestinal symptoms, and in nutritional epidemiological studies to assess the completeness of 24-hour urine collection for the determination of urinary sodium, potassium, or nitrogen levels.
PABA is used to improve the protein used in the body, it relates to red blood cell formation as well as assisting the manufacture of folic acid in the intestines. Para-aminobenzoic acid is used in sunscreen preparations since it can help protect the skin against ultra-violet radiation. It has been linked to hair growth as well as reversing the graying of hair, but these results are disappointing. People suffering from vitiligo, over-pigmentation of skin, or without pigment in some spots, have reported an improvement of the skin after more PABA was ingested.