Study of benzoin 4-phenyl-3-thiosemicarbazone and benzil bis(4-phenyl-3-thiosemicarbazone) : Synthesis and their antiparasitic activity on trypanosome.

Abstract

Thiosemicarbazones represent a large family of molecules with extremely diverse pharmacological properties. Their interest in medicinal chemistry has stimulated the development of new methods of preparing these molecules. In this work, benzoin and benzil were used with 4-phenyl-3-thiosemicarbazide to synthesize benzoin 4-phenyl-3-thiosmicarbazone (Bzn-4PhT) with AAG and benzyl bis(4- phenyl-3-thiosemicarbazone) (Bzl-b4PhT) with NaOH, according to a new approach in the synthesis. Steric aspect and reaction conditions played an important role in the synthesis and yields of 75% and 67% respectively. The products presented physical properties compatible with reasonable pharmacokinetics and drug availability. The molecules were characterized by proton and carbon 13 NMR spectrometric analyzes (1H & 13C). The antiparasitic activity of the products was evaluated on Trypanosoma brucei brucei and their larvae toxicity on Aremia salina Leach It emerges after the test that the compounds have inhibited a moderate trypanocidal activity on the parasite and a toxic activity on the larvae with their inhibitory (and lethal) halfconcentrations IC50 = 15.43 and 26.40 μM an LC50 = 165 and 257 μM respectively). Products turned out selective on the parasite with their selectivity index greater than to unit (SI = 9 and 10). Compounds could be able to have applications in the treatment of parasitic diseases.