Synthesis and characterization of new benzimidazole-containing azide derivatives catalyzed by CdO nanoparticles and their inhibitory effect on alkaline phosphatase

Abstract

 In this study, the co-precipitation approach for synthesizing cadmium oxide nanoparticles (CdO NPs) from cadmium nitrate was used. The size and morphology of CdONP_S were confirmed using AFM and SEM techniques. Subsequently, two new heterocyclic compounds were synthesized as benzimidazole derivatives containing azide groups. The synthesis involved cyclizing 3,4-diaminotoluene with aryl aldehydes using CdO nanoparticles as a catalyst, followed by reactions with chloroacetyl chloride and sodium azide to yield the target compounds. The final products were identified as: Compound N5: 2-azido-1-(2-(4-hydroxyphenyl)-6-methyl-1H-benzo[d]imidazol-1-yl) ethan-1-one, and compound N6: 2-azido-1-(6-methyl-2-(3-nitrophenyl)-1H-benzo[d]imidazol-1-yl) ethan-1-one. The produced compounds were evaluated utilizing spectroscopic methods such as FT-IR, ¹H-NMR, ¹³C-NMR, DEPT-135, DEPT-90 -90 and UV-Vis spectroscopy. The FT-IR spectra displayed characteristic absorption bands, such as the azide group (N₃) at 2140 cm⁻¹. NMR analysis confirmed the molecular structures, revealing distinct signals for aromatic protons, methyl, and methylene groups. The biological activity of compound N6 was evaluated for its inhibitory effect on alkaline phosphatase (ALP) activity. Results showed that N6 exhibited a concentration-dependent inhibition of ALP activity. Enzyme kinetics indicated that N6 acts as a competitive inhibitor. These findings suggest that the compound N6 may have potential therapeutic applications in conditions involving ALP dysregulation.

KEY WORDS: Benzimidazole, Azide, Cadmium oxide nanoparticles, Alkaline phosphatase, Enzyme inhibition

Bull. Chem. Soc. Ethiop. 2026, 40(1), 51-64.                                                               

DOI: https://dx.doi.org/10.4314/bcse.v40i1.5