Synthesis and investigation of antibacterial activities and carbonic anhydrase and acetyl cholinesterase inhibition profiles of novel 4,5-dihydropyrazol and pyrazolyl-thiazole derivatives containing methanoisoindol-1,3-dion unit

ABSTRACT

Novel 4,5-dihydropyrazole derivatives (3a–i), 3-(4-((3aR,4S,7R,7aS)-1,3-dioxo-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindol-2(3H)-yl)phenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothio amide, were obtained by the addition of thiosemicarbazide (2) to the chalcones (1a–i). The addition–cyclization of 2,4′-dibromoacetophenone (4) to pyrazole derivatives (3a–i) gave the new pyrazolyl-thiazole derivatives (5a–i), (3aR,4S,7R,7aS)-2-(4-(1-(4-(4-bromophenyl)thiazol-2-yl)-5-phenyl-4,5-dihydro-1H-pyrazol-3-yl)phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione. Antibacterial and acetylcholinesterase (AChE) enzyme and human carbonic anhydrase (hCA) I, and II isoform inhibitory activities of the compounds 3a–i and 5a–i were investigated. Some of the compounds showed promising antibacterial activity. In addition, the hCA II and I were effectively inhibited by the lately synthesized derivatives, with K_i values in the range of 18.90 ± 2.37 −58.25 ± 13.62 nM for hCA II and 5.72 ± 0.98 −37.67 ± 5.54 nM for hCA I. Also, the K_i parameters of these compounds for AChE were obtained in the range of 25.47 ± 11.11 − 255.74 ± 82.20 nM. Also, acetazolamide, clinical molecule, was used as a CA standard inhibitor that showed K_i value of 70.55 ± 12.30 nM against hCA II, and 67.17 ± 9.1 nM against hCA I, and tacrine inhibited AChE showed K_i value of 263.67 ± 91.95.

GRAPHICAL ABSTRACT

KEYWORDS:

• Acetylcholinesterase
• antibacterial activity
• carbonic anhydrase
• pyrazole
• pyrazolyl-thiazole

Additional information

Funding

The authors are indebted to The Scientific and Technological Research Council of Turkey (TUBİTAK Project No: 111T990) for financial supports.