dicaffeoyl

Dicaffeoyl denotes a chemical motif in which two caffeic acid units are linked by ester bonds to a single core molecule. The most common context is dicaffeoylquinic acids (DCQAs), where two caffeoyl groups are esterified to quinic acid. Depending on which hydroxyl groups of quinic acid are esterified, several regioisomers arise, notably 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid.

DCQAs are widespread in the plant kingdom and are particularly abundant in coffee beans, artichokes, and many herbs. They are part of the larger family of chlorogenic acids. Biosynthesis proceeds via hydroxycinnamoyltransferases that transfer caffeoyl units from caffeoyl-CoA to quinic acid, forming mono- and di-caffeoyl derivatives as part of plant defense and phenylpropanoid metabolism.

Chemical properties reflect their polyphenolic structure, with multiple hydroxyl groups contributing to antioxidant activity and radical scavenging. In vitro studies report anti-inflammatory, antimicrobial, and potential neuroprotective effects, though activity varies by isomer and context. DCQAs also influence food quality and flavor and can contribute to astringency and browning reactions in processed foods.

Analytical methods for dicaffeoylquinic acids include high-performance liquid chromatography and mass spectrometry, enabling isomer separation and quantification in plant extracts and foods. In nutrition science, they are considered among the major chlorogenic acid–related polyphenols, contributing to the health effects attributed to coffee and other plant-derived foods.