New and facile method of preparation of the anti-HIV-1 agent, 1,3-dicaffeoylquinic acid

A facile and inexpensive preparation of 1,3-dicaffeoylquinic acid (cynarin) from the leaves Cynara cardunculus L. (Asteraceae) without the use of any chromatographic steps is described. The procedure is based on separation of the fraction rich in 1,5-dicaffeoylquinic acid, isomerisation of 1,5-dicaffeoylquinic acid to cynarin and, owing to its higher polarity, the simple isolation of cynarin from the reaction mixture. Cynarin inhibited HIV-1 replication in MT-2 cell culture at non-toxic concentrations similar to other previously tested dicaffeoylquinic acids, which have been recently established as a potent and highly selective class of HIV-1 integrase inhibitors.