Synthesis of aminophenylhydroxamate and aminobenzylhydroxamate derivatives and in vitro screening for antiparasitic and histone deacetylase inhibitory activity

A series of aminophenylhydroxamates and aminobenzylhydroxamates were synthesized and screened for their antiparasitic activity against Leishmania, Trypanosoma, and Toxoplasma. Their anti-histone deacetylase (HDAC) potency was determined. Moderate to no antileishmanial or antitrypanosomal activity was found (IC50 > 10 mu M) that contrast with the highly efficient anti-Toxoplasma activity (IC50 < 1.0 mu M) of these compounds. The antiparasitic activity of the synthetized compounds correlates well with their HDAC inhibitory activity. The best-performing compound (named 363) express a high anti-HDAC6 inhibitory activity (IC50 of 0.045 +/- 0.015 mu M) a moderate cytotoxicity and a high anti-Toxoplasma activity in the range of known anti-Toxoplasma compounds (IC50 of 0.35-2.25 mu M). The calculated selectivity index (10-300 using different human cell lines) of the compound 363 makes it a lead compound for the future development of anti-Toxoplasma molecules.