Arylidine extensions of 3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-benzenesulfonamide derivatives: Synthesis, computational simulations and biological evaluation as tumor-associated carbonic anhydrase inhibitors.

Several pyrazole-benzene sulfonamides were reported as human carbonic anhydrase inhibitors. In this research work, a design of Arylidine-extented 5-oxo-pyrazole benzenesulfonamides (4a-i), (8a-d) and (10a-e) were reported based on tail-approach design. Beside the reported synthetic procedures and confirmation by different analytical procedures, a DFT study was employed to confirm the Z- conformer of the synthesized compounds. In vitro biological assay against four different human carbonic anhydrases took place and based on the results, SAR study was illustrated and selectivity indexes were discussed. Compounds 4g and 8a exhibited the best inhibitory activity among the target compounds with values (hCAIX: KI = 71.2 nM, hCAXII: KI = 22.5 nM), (hCAIX: KI = 34.3 nM, hCAXII: KI = 74.3 nM); respectively. Both of them were subjected to cellular assay against two different cancer cell lines with expressing nature to hCA isoforms under both normoxic and hypoxic conditions. Compound 4g showed the highest cytotoxic activity against MCF-7 cancer cell line (IC50 = 4.15 µM under hypoxic conditions and IC50 = 8.59 µM under normoxic conditions) compared to the reference drug doxorubicin under normoxic, (IC50 = 4.34 µM), and hypoxic, (IC50 = 2.23 µM), conditions. Further cellular investigations were employed to study the effect of this compound on the cell cycle of the affected cell line. Finally, molecular docking supported by molecular dynamic simulation was utilized to understand the mechanism of the inhibitory activity of two of these compounds - as representative examples- based on the designed rational.

Synthesis and in vitro investigation of novel cytotoxic pyrimidine and pyrazolopyrimidne derivatives showing apoptotic effect.

A series of novel derivatives of hydrazinylpyrimidines, pyrazolylpyrimidines and 3-amino[3,4-d]pyrazolopyrimidines have been synthesized and tested for their in vitro cytotoxic activity against 60 tumor cell lines by NCI. The in vitro cytotoxic IC50 values for the most active compounds were determined against the colon-KM12 cell line (5d, 7c and 7d), breast-MCF-7 (6a) and melanoma-MDA-MB-435 (6h) using 5-fluorouracil (5-FU) as a positive control. Derivatives 5d and 7c were found to be the most potent derivatives against KM12 cell line (IC50 = 1.73 and 1.21 µM, respectively) with a high selectivity index (SI) (18.82 and 35.49, respectively) compared to 5-FU (IC50 = 12.26 µM, SI = 1.93). Compounds 5d and 7c were further investigated for their apoptotic behavior in KM12 cell line. The investigations showed the up-regulation of caspase 3/9 and the pro-apoptotic factor Bax. On the other hand, the expression of the anti-apoptotic factor Bcl-2, was down-regulated, as well as its inhibition at a nanomolar concentration. Furthermore, the apoptotic effect for derivatives 5d and 7c in KM12 cells was detected using annexin V-FITC staining method.