Valeric acid, or pentanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula C 5 H 10 O 2.Like other low-molecular-weight carboxylic acids, it has a very unpleasant odor.t is found naturally in the perennial flowering plant valerian (Valeriana officinalis), from which it gets its name. Its primary use is in the synthesis of its esters. Volatile esters of valeric acid tend to have pleasant odors and are used in perfumes and cosmetics.