Structural Modifications of Hybrid O-Alkylsulfonyl-β-(Benzimidazol-1-yl)propioamidoximes as a Pathway to the Antimicrobial, Antifungal and Antidiabetic Drugs

The continuous search for new chemical structures more active and less toxic than those currently in practice is justified on the basis of the use of proven pharmacophoric building blocks (benzimidazole heterocycle, sulfonyl group and amidoxime framework in our case). The aim of the work was to synthesize new O-alkylsulfonyl-β-(benzimidazol-1-yl)propioamidoximes and to test them for in vitro biological activities to identify potentially effective agents. Novel O-alkylsulfonylamidoximes were synthesized in hydrochloride and base forms by the reaction of β-(benzimidazol-1-yl)propioamidoxime with alkylsulfonyl chlorides AlkSO2Cl (Alk = CH3, n-C3H7, i-C3H7, n-C4H9) in a mixture of water:acetone in hydrochloride and base forms. Hydrochlorides and bases of the O-alkylsulfonyl-β-(benzimidazol-1-yl)propioamidoximes were obtained in moderate to high yields. The structures of the synthesized compounds were established by physicochemical and spectral (elemental analysis, FT-IR, NMR and X-ray diffraction) methods. The obtained derivatives were tested for antimicrobial, antifungal and antidiabetic activity. Biological screening found effective samples of amidoximes with antimicrobial and antifungal activities that were near or exceeded the activity of the reference drugs gentamicin and nystatin; in addition, two samples with antidiabetic activity higher than acarbose were found. The results of the present study open new possibilities for the novel β-aminopropioamidoxime class as active antimicrobial and antifungal agents, as well as antidiabetic ones.