a saturated dicarboxylic acid, HOOC-(CH₂)₅COOH. Colorless crystals with limited solubility in water. Melting point, 105.5°C. It is formed upon oxidation of fats (hence its name, from Greek pimele, “fat”) and occurs in the urine of herbivores. It is commercially obtained from acryloni-trile and butadiene and by the oxidation of castor oil. Pimelic acid is used in the manufacture of polyamides such as nylon.