Some preformed metal-complexes have shown the capability to
inhibit IN in in vitro enzymatic assays [22e26]. In line with these
studies, here we presented the thermodynamic characterization
and the antiretroviral activity against HIV-infected cells of some
chelating ligands and of their metal complexes, highlighting that
the activity of the complexes is retained or it is even higher in
cellular assays. In a scenario of few available data on the activity of
isolated metal complexes in HIV infection [27e31], we found that
the ligand HL5 with the carboxamidic scaffold and some of its metal
complexes have antiviral activity in the nanomolar range. These
compounds inhibit IN and, even if with minor efficacy, also interfere
with the function of the RNase H component of the RT.
Therefore, chelating ligands could probably exert a multivalent
mode of action during the virus lifecycle, having as a target
different metal-dependent viral enzymes with analogous metalbased
catalysis. This enforces the concept of metal chelation as a
suitable strategy for the development of novel and effective
antivirals.