Irbic acid, a dicaffeoylquinic acid derivative from Centella asiatica cell cultures.

3,5-O-dicaffeoyl-4-O-malonilquinic acid (1) (irbic acid) has been isolated for the first time from cell cultures of Centella asiatica and till now it has never been reported to be present in the intact plant. Evidence of its structure was obtained by spectroscopic analyses (MS/NMR). Besides 1, cell cultures produce also the known 3,5-O-dicaffeoylquinic acid, chlorogenic acid, and the triferulic acid 2 (4-O-8'/4'-O-8″-didehydrotriferulic acid). Biological activities were evaluated for compound 1, which showed to have a strong radical scavenging capacity, together with a high inhibitory activity on collagenase. This suggests a possible utilization of this substance as a topical agent to reduce the skin ageing process.