Synthesis and Biological Activities of Halogenated Chalcone-Based Pyra

Twenty new 1,3,5-trisubstituted pyrazoline derivatives have been synthesized from chalcones and acylhydrazides in two steps. In the first step, chalcones were prepared by treatment of various acetophenones with different substituted benzaldehydes by Claisen-Schmidt condensation. In the second step, pyrazoline derivatives were synthesized by conducting the reaction of chalcones with acylhydrazides in acetonitrile at 67 °C in the presence of triazabicyclodecene as a catalyst. The synthesized compounds were identified by 1H, 13C NMR and HRMS spectral data and were evaluated for their antibacterial, anticancer and tyrosinase inhibitory activities. In antibacterial and tyrosinase inhibitory activities, most of pyrazoline derivatives showed inactive properties. Further investigation in anticancer activity, in vitro assay against colon cancer cell line (HCT-116) indicated that several compounds exhibited cytotoxicity in micromolar range, depending on substitution patterns of either 3,5-diaryl rings or aromatic ring of 4,5-dihydropyrazole core. Among compounds screened against HCT-116 and A549 cell lines, 4b showed the most potent activity against HCT-116 but inactive toward A549.