Synthesis and anti-human immunodeficiency virus type 1 integrase activity of hydroxybenzoic and hydroxycinnamic acid flavon-3-yl esters

A series of new hydroxybenzoic and hydroxycinnamic acid flavon-3-yl esters were synthesized in order to obtain compounds targeting the human immunodef iciency virus (HIV) type 1 integrase (IN). The esters were tested for anti- IN and anti-reverse transcriptase (RT) activity in enzyme assays and for an ti-HIV-l, anti-proliferative and anti-topoisomerase activity in cell-based assays. In enzyme assays, the two gallic acid flavon-3-yl esters showed a n otable IN inhibition (IC50 values were 8.3 and 9.1 mu M, respectively), whi le the two caffeic acid flavon-3-yl esters exhibited a modest activity (IC5 0 75 and 60 mu M, respectively). Replacement of hydroxyl groups resulted in loss of potency. Caffeic acid 3',4'-dichloroflavon-3-yl ester also inhibit ed the RT activity whereas it was not active on human topoisomerases. It th erefore represents an interesting example of a compound specifically target ing more than one step of the virus replication cycle.