Angelic acid

Angelic acid is a monocarboxylic unsaturated organic acid. It is mostly found in the plants of the family Apiaceae. German pharmacist Ludwig Andreas Buchner isolated angelic acid in 1842 from the roots of garden angelica (Angelica archangelica) which gave the acid its name. Angelic acid is a volatile solid with a biting taste and pungent sour odor. It is the trans isomer of 2-methyl-2-butenoic acid, which easily converts to the cis isomer, tiglic acid, upon heating or reaction with inorganic acids. The reverse transformation occurs much less readily. The salts and esters of angelic acid are called angelates. Angelic acid esters are the active components of herbal medicine used against a wide range of various health disturbances including pains, fever, gout, heartburn, etc.