Design, synthesis, and antifungal activity of novel cinnamon-pyrazole carboxamide derivatives.

Hit, Lead & Candidate Discovery To discover succinate dehydrogenase inhibitors with a novel structure, we introduced cinnamic acid structure to optimize the lead structure 1 and synthesized four series of cinnamon-pyrazole carboxamide derivatives. The bioassay data showed that compounds (E)-N-(1-[4-chlorophenyl]-4-cyano-1H-pyrazol-5-yl)-3-(2-fluorophenyl) acrylamide (5III-d) and (E)-3-(2-chlorophenyl)-N-(1-[4-chlorophenyl]-4-cyano-1H-pyrazol-5-yl) acrylamide (5III-f) showed the significant antifungal activity against three fungi. In addition, 5III-d and 5III-f exhibited the excellent inhibitory effect against succinate dehydrogenase (SDH) enzymes with IC50 values ranging from 19.4 to 28.7 µM. The study demonstrates that the chlorine substituent group is present on both the phenyl and pyrazole rings that have a very good effect on the antifungal effect, and the compounds 5III-d and 5III-f can act as potential SDH inhibitors (SDHI) and throw a sprat for a new generation of SDHI.

Novel coumarin-pyrazole carboxamide derivatives as potential topoisomerase II inhibitors: Design, synthesis and antibacterial activity.

The identification of novel Topoisomerase II (Topo II) inhibitors is one of the most attractive directions in the field of bactericide research and development. In our ongoing efforts to pursue the class of inhibitors, six series of 70 novel coumarin-pyrazole carboxamide derivatives were designed and synthesized. As a result of the evaluation against four destructive bacteria, including Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Salmonella. Compound 8III-k (MIC = 0.25 mg/L) showed considerable inhibitory activity than ciprofloxacin (MIC = 0.5 mg/L) against Escherichia coli and 8V-c (MIC = 0.05 mg/L) exhibited excellent antibacterial activity than ciprofloxacin (MIC = 0.25 mg/L) against Salmonella. The selected compounds (8III-k, 8V-c and 8V-k) exhibit potent inhibition against Topo II and Topo IV with IC50 values (9.4-25 mg/L). Molecular docking model showed that the compounds 8V-c and 8V-k can bind well to the target by interacting with amino acid residues. It will provide some valuable information for the commercial Topo II inhibiting bactericides.