Terephthalic acid Terephthalic acid Terephthalic acid is an organic compound with formula CH(COH). This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tonnes are produced annually. The common name is derived from the turpentine-producing tree "Pistacia terebinthus" and phthalic acid. Terephthalic acid was first isolated (from turpentine) by the French chemist Amédée Cailliot (1805–1884) in 1846. Terephthalic acid became industrially important after World War II. Terephthalic acid was produced by oxidation of "p"-xylene with dilute nitric acid. Air oxidation of "p"-xylene gives "p"-toluic acid, which resists
Petroselinic acid in Garryaceae. In Picramniaceae, petroselinic acid is accompanied by tariric acid. In addition, petroselinic acid has been found in minor amounts in several fats of plant and animal origin, including in human sources. The occurrence of petroselinic acid as the major fatty acid is used in chemosystematics as a proof of a close relationship of several families within the Apiales as well as within the Garryales. Besides petroselinic acid, oleic acid has been shown to be present in all cases examined. Fatty acids mostly occur as their esters, commonly the triglycerides, which are the greasy materials in many natural oils.