2-Acetylpyridine thiosemicarbazones: Cytotoxic activity in nanomolar doses against malignant gliomas

Abstract

2-Acetylpyridine N(4)-phenyl thiosemicarbazone (H2Ac4Ph), and its N(4)- ortho-tolyl (H2Ac4 oT), N(4)- meta-tolyl (H2Ac4 mT), N(4)- para-tolyl (H2Ac4 pT), N(4)- ortho-chlorophenyl (H2Ac4 oClPh), N(4)- meta-chlorophenyl (H2Ac4 mClPh) and N(4)- para-chlorophenyl (H2Ac4 pClPh) derivatives were assayed for their cytotoxicity against RT2 (expressing p53 protein) and against T98 (expressing mutant p53 protein) glioma cells. The compounds were highly cytotoxic against RT2 (IC 50 = 24–1.4 nM) and T98 cells (IC 50 = 50–1.0 nM). IC 50 for cisplatin = 5 (RT2) and 17 μM (T98). The thiosemicarbazones presented haemolytic activity with IC 50 > 10 −3M, indicating a very good therapeutic index. SAR studies suggested that stereo properties are critical to define the potential activity of the studied compounds against the RT2 cell line, while electronic properties seem to be important for interaction with the biological target in T98 cells.