Synthesis and cytotoxicity studies of 3,5-diaryl N-acetyl pyrazoline - Isatin hybrids

Numerous reports highlighting the cytotoxic effects of 3,5-diaryl N-acetyl-pyrazolines and isatin tempted us to synthesise conjugates of the functionalities via alkyl armed triazole tetheration. The hybrids were synthesized by click chemistry approach and were evaluated against a panel of cell lines i.e. viz HeLa (cervix cancer), CAKI-I (Renal cancer), PC-3 (Prostate cancer) and Mia-paca-2 (pancreatic cancer). The hybrids were classified into right-handed and left-handed conjugates on the basis of the placement of the isatin ring. The length of the alkyl armed triazole linker was varied from 2 to 6. Structure activity relationship has also been presented. A preliminary cytotoxic assay was performed on the series of 3,5-diaryl N-acetyl-pyrazolines and only the potent 3,5-diaryl N-acetylpyrazolines were selected for their inclusion in the hybrid scaffold. Among the cell lines employed, HeLa cell line was the most sensitive towards the exposure of test compounds. Out of all the compounds evaluated, two right-handed conjugates MI-7b and MI-8b and two left-handed conjugates MI-4b, MI-6b displayed significant cytotoxic potential and exhibited an IC₅₀ range from 1.3 to 3.5 μM against HeLa Cell line.