Structural and antitrypanosomal data of different carbasones of piperitone

Abstract This article reports data on four carbazones of piperitone: semicarbazone 1 , thiosemicarbazone 2 , 4-phenyl semicarbazone 3 and 4-phenyl thiosemicarbazone 4 prepared directly in situ from essential oil of Cymbopogon schoenantus, whose GC-FID and GC–MS analysis revealed piperitone as major component (68.20%). The structures of hemi-synthesized compounds were confirmed by high throughput IR, MS, 1 H and 13 C NMR based spectrometric analysis. Their antiparasitic activities were evaluated in vitro on Trypanosoma brucei brucei ( Tbb ). The compound 3 (IC 50 =8.63±0.81 µM) and 4 (IC 50 =10.90±2.52 µM) exhibited antitrypanosomal activity, 2 had a moderate activity (IC 50 =74.58±4.44 µM) but 1 was void of significant activity (IC 50 =478.47 µM). The in vitro tests showed that all compounds were less cytotoxic against the human non cancer fibroblast cell line (WI38) (IC 50 >80 µM) while only 2 (IC 50 =21.16±1.37 μM) and 4 (IC 50 =32.22±1.66 µM) were cytotoxic against the Chinese Hamster Ovary (CHO) cells and toxic on Artemia salina (Leach) larvae. Piperitone 4-phenyl semicarbazone 3 , the best antitrypanosomal compound, showed also a selectivity index (SI) higher than 7 on the larvae and the tested cells and therefore might be further studied as antitrypanosomal agent. Also, all compounds except 3 showed selectivity between the two tested cell lines (SI>2). This data reveals for the first time the antitrypinosomal properties of thiosemicarbazones, their cytotoxicity on mammalian cells as well as their activities against Tbb and A. salina Leach.