Synthesis, crystal structures, fluorescence and xanthine oxidase inhibitory activity of pyrazole-based 1,3,4-oxadiazole derivatives

• Published in: Journal of molecular structure 2015-11, Vol.1100, p.421-428
• Main Authors: Qi, De-Qiang, Yu, Chuan-Ming, You, Jin-Zong, Yang, Guang-Hui, Wang, Xue-Jie, Zhang, Yi-Ping
• Format: Article
• Language: English
• Subjects: 1,3,4-Oxadiazole; Activity; Fluorescence; Pyrazole; Xanthine oxidase
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2015.07.067

A series of pyrazole-based 1,3,4-oxadiazole derivatives were rationally designed and synthesized in good yields by following a convenient route. All the newly synthesized molecules were fully characterized by IR, 1H NMR and elemental analysis. Eight compounds were structurally determined by single crystal X-ray diffraction analysis. The fluorescence properties of all the compounds were investigated in dimethyl sulfoxide media. In addition, these newly synthesized compounds were evaluated for in vitro inhibitory activity against commercial enzyme xanthine oxidase (XO) by measuring the formation of uric acid from xanthine. Among the compounds synthesized and tested, 3d and 3e were found to be moderate inhibitory activity against commercial XO with IC50 = 72.4 μM and 75.6 μM. The studies gave a new insight in further optimization of pyrazole-based 1,3,4-oxadiazole derivatives with excellent fluorescence properties and XO inhibitory activity. Several novel 1,3,4-oxadiazole derivatives containing pyrazole were synthesized and evaluated for in vitro xanthine oxidase inhibitory activity. [Display omitted] •Novel pyrazole-based 1,3,4-oxadiazole derivatives were synthesized and characterized.•Eight crystal structures were determined by single crystal x-ray diffraction.•The fluorescence properties in DMSO were investigated.•The in vitro xanthine oxidase (XO) inhibitory activity were evaluated.