Prof. Dr. Hamida Mohamed Abdel-HamidProf. Dr. Doaa Ahmed GhareebProf. Dr. Mohammed Salah AyoupProf. Dr. Mohamed Nabil Abd Al Moaty2026-01-272026-01-27https://dspace.academy.edu.ly/handle/123456789/1898The first part: included 3,5-diaryl-1,2,4-oxadiazole scaffolds 129 and 130 were synthesized and used as ligands to obtain three novel Ag(I) complexes 131-133. The structure of the Ag(I) complexes 131-133 have been confirmed by single crystal X-ray diffraction. Complex 131 has the dinuclear formula [Ag(129)(NO3)]2. 132 and 133 are monomeric complexes having the formula [Ag(130)2(NO3)] and [Ag(130)2]ClO4, respectively. In vitro, trypsin, ALDH2, and iNOS inhibition activities were assessed for the free ligands and their Ag(I) complexes. Interestingly, Ag(I) complexes 131-133 revealed more prominent trypsin inhibitory activity than the ligands 129 and 130. The oxadiazole derivative 130 and its Ag(I) complex 133 showed significant ALDH2 inhibition (45% and 55%, respectively). Complex 133 (IC50 = 35.61 μM) surpassed its 1,2,4-oxadiazole ligand 130 (IC50 = 88 μM) and evidenced the most prominent ALDH2 inhibitory activity.This thesis includes three chapters: The first chapter is the introduction deals with the role of five-membered heterocyclic compounds especially 1,2,4-oxadiazoles ring in assisting organic synthesis and their biological effects. Nitrogen -containing heterocyclic entities exist in many chemotherapeutic agents. Heterocyclic compounds based on 1,2,4-oxadiazoles ring existed in several drugs.Design, synthesis and characterization of a novel five-