Novel Type of Tetranitrosyl Iron Salt: Synthesis, Structure and Antibacterial Activity of Complex [FeL'2(NO)2][FeL'L(NO)2] with L'-thiobenzamide and L-thiosulfate

In this work a new donor of nitric oxide (NO) with antibacterial properties, namely nitrosyl iron complex of [Fe(C6H5C-SNH2)(2)(NO)(2)][Fe(C6H5C-SNH2)(S2O3)(NO)(2)] composition (complex I), has been synthesized and studied. Complex I was produced by the reduction of the aqueous solution of [Fe-2(S2O3)(2)(NO)(2)](2-) dianion by the thiosulfate, with the further treatment of the mixture by the acidified alcohol solution of thiobenzamide. Based on the structural study of I (X-ray analysis, quantum chemical calculations by NBO and QTAIM methods in the frame of DFT), the data were obtained on the presence of the NO horizontal ellipsis NO interactions, which stabilize the DNIC dimer in the solid phase. The conformation properties, electronic structure and free energies of complex I hydration were studied using B3LYP functional and the set of 6-31 + G(d,p) basis functions. The effect of an aquatic surrounding was taken into account in the frame of a polarized continuous model (PCM). The NO-donating activity of complex I was studied by the amperometry method using an amiNO-700 sensor electrode of the inNO Nitric Oxide Measuring System. The antibacterial activity of I was studied on gram-negative (Escherichia coli) and gram-positive (Micrococcus luteus) bacteria. Cytotoxicity was studied using Vero cells. Complex I was found to exhibit antibacterial activity comparable to that of antibiotics, and moderate toxicity to Vero cells.

Automated summary

In this work, a new nitric oxide donor with antibacterial properties was synthesized and studied. The compound exhibited antibacterial activity comparable to antibiotics and moderate toxicity to cells.