New pyrazolopyridine analogs: Synthesis, antimicrobial, antiquorum-sensing and antitumor screening.

New pyrazolopyridine analogs were prepared and tested for antimicrobial efficacy toward Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Aspergillus fumigatus and Aspergillus flavus. Results revealed that compound 6 has prominent and broad spectrum antimicrobial activity. Compound 8 showed good antibacterial efficacy over the four tested bacterial strains. In addition, compounds 2-4 displayed interesting efficacy over S. aureus, B. cereus and P. aeruginosa as well as moderate efficacy toward E. coli, C. albicans, A. fumigatus and A. flavus. Furthermore, compounds 9 and 10 exhibited interesting efficacy over P. aeruginosa. Antiquorum-sensing efficacy of the same analogs toward Chromobacterium violaceum was also examined, whereas compounds 3, 4 and 6 displayed acceptable activity. In vitro antitumor assay of the new pyrazolopyridines toward liver (HepG2), breast (MCF-7) and cervix (Hela) cancer cells illustrated that compounds 2 and 5 have the highest antitumor activity over the three cell lines. Moreover, compound 4 exhibited interesting efficacy on all tested cell lines, whereas compound 7 showed good activity on MCF-7 cells. The most active in vitro antitumor analogs, 2, 4, 5 and 7 were assessed for in vivo antitumor efficacy on Ehrlich ascites carcinoma (EAC) cells, whereas compound 5 displayed the highest efficacy. In addition, cytotoxicity testing toward W138 and WISH normal cells revealed that all tested analogs are less cytotoxic than doxorubicin. The new analogs were evaluated for DNA-binding affinity, whereas compounds 2, 4 and 5 displayed the highest affinity. In silico studies concluded that all the new pyrazolopyridines are foreseen to have excellent oral absorption.