Thiosemicarbazones have become one of the promising compounds as new clinical candidates due to their wide spectrum of
pharmaceutical activities. The wide range of their
biological activities depends generally on their related
aldehyde or
ketone groups. Here, we report the pharmacological activities of some
thiosemicarbazones synthesized in this work.
Benzophenone and derivatives were used with N(4)-phenyl-3-thiosemicarbazide to synthesize corresponding five
thiosemicarbazones (1-5). Their structures were characterized by spectrometrical methods analysis IR, NMR (1)H & (13)C and MS. The compounds were then screened in vitro for their
antiparasitic activity and toxicity on Trypanosoma brucei brucei and Artemia salina Leach respectively. The selectivity index of each compound was also determined. Four
thiosemicarbazones such as 4, 2, 3 and 1 reveal interesting trypanocidal activities with their half inhibitory concentration (IC50) equal to 2.76, 2.83, 3.86 and 8.48 μM respectively, while compound 5 (IC50 = 12.16 μM) showed a moderate anti-trypanosomal activity on parasite. In toxicity test, except compound 1, which showed a half lethal concentration LC50 >281 μM, the others exerted toxic effect on larvae with LC50 of 5.56, 13.62, 14.55 and 42.50 μM respectively for
thiosemicarbazones 4, 5, 3 and 2. In agreement to their selectivity index, which is greater than 1 (SI >1), these compounds clearly displayed significant selective
pharmaceutical activities on the parasite tested. The
thiosemicarbazones 2-5 that displayed significant anti-trypanosomal and cytoxicity activities are suggested to have anti-neoplastic and anti-
cancer activities.