Experimental and Theoretical Evidence on the Amoebicidal Activity of Synthesized tRNA-Palmitic Acid Esters

Synthesis of tRNA-palmitic acid esters was carried out in dimethyl sulfoxide (DMSO) and tert-butanol, %20 and %80 (v/v), respectively, for 24h at 55oC. These conditions have been to be optimal in the synthesis of monosaccharide-fatty acid esters in previous studies. The majority of the ester product (89.19%) was “phthalic acid, butyl undecyl ester”, as identified by GC-MS. This finding hinted that the ester bond took place between tRNA ribose unit(s) and carboxyl group of the palmitic acid. NMR (Nuclear Magnetic Resonance) was also used for the characterization of the ester product (data not shown). The ester product (O1) exerted remarkable amoebicidal activity, at 4mg/ml, on the trophozoites and cysts of Acanthamoeba castellanii. No live trophozoites or cysts could be detected after the 24th and 72th of incubation, respectively. The study included all the necessary control experiments. Interactions between the substrate molecules were scrutinized by molecular docking calculations. Activities of the studied molecules against various Acanthamoeba castellanii proteins (PDB ID: 1PRQ and 6UX0), in crystal form, were compared, and finally, ADME/T analyses were carried out.