Chlorogenic acid

Chlorogenic acid (CGA) is a natural chemical compound which is the ester of caffeic acid and (−)-quinic acid. It is an important biosynthetic intermediate. Chlorogenic acid is an important intermediate in lignin biosynthesis. This compound, known as an antioxidant, may also slow the release of glucose into the bloodstream after a meal.

The term chlorogenic acids can also refer to a related family of esters of hydroxycinnamic acids (caffeic acid, ferulic acid and p-coumaric acid) with quinic acid.

Despite the "chloro" of the name, chlorogenic acids contain no chlorine. Instead, the name comes from the Greek χλωρός (light green) and -γένος (a suffix meaning "giving rise to"), because of the green color produced when chlorogenic acids are oxidized.

Chemical properties

Structurally, chlorogenic acid is the ester formed between caffeic acid and L-quinic acid.

Isomers of chlorogenic acid include 4-O-caffeoylquinic acid (cryptochlorogenic acid or 4-CQA), 5-O-caffeoylquinic acid (neochlorogenic acid or 5-CQA). The epimer at position 1 has not yet been reported.