Two novel Ag(I) complexes of N-nicotinyl phosphoric triamide derivatives: Synthesis, X-ray crystal structure and in vitro antibacterial and cytotoxicity studies

•Synthesis of two Ag(I) complexes with N-nicotinyl phosphoramides are reported.•Crystal structures showed N–Ag–N coordination pattern.•Complexes showed good antibacterial activity.•C1 and C2 exhibited strong cytotoxic activity against HeLa, MCF-7 and MG-63.

New Ag(I) complexes of N-nicotinyl, N′,N″-bis(cyclohexyl) phosphoric triamide, 3-NC5H4C(O)NHP(O)[NH(C6H11)]2 (L1), and N-nicotinyl, N′,N″-bis(tert-butyl) phosphoric triamide, 3-NC5H4C(O)NHP(O)[NHC(CH3)3]2 (L2), with formula Ag(L1)2NO3 (C1) and Ag(L2)2NO3 (C2) were synthesized and characterized by NMR, IR, UV–Vis spectroscopy and elemental analysis. Molecular structures of C1 and C2 were determined by X-ray crystallography and revealed that coordination of ligands to Ag(I) has been occurred from the nitrogen atom of the pyridine ring. Also, compound C1 exists as two conformers in crystalline structure which are weakly connected to each other through intermolecular Ag…OC electrostatic interaction. Ag(I) complexes and the corresponding ligands were screened for their antibacterial activity against selected Gram-positive and Gram-negative bacteria, showing bactericidal activity for complexes. In vitro cytotoxicity of compounds was studied against human carcinoma cell lines, HeLa (cervical cancer), MCF-7 (breast cancer) and MG-63 (osteosarcoma). Results indicated that C1 and C2 possess strong cytotoxic activity against cancer cells with IC50 values ranging from 3.3 to 15.3 μM for two exposure time (24 and 48 h). The cytotoxicity of complexes against non-tumorigenic breast cell, MCF-10A was further evaluated. Structure–activity relationships have been also discussed.

Graphical abstractTwo new N-nicotinyl phosphoramides and their Ag(I) complexes (C1 and C2) have been synthesized and characterized. The complexes showed N–Ag–N coordination pattern. In vitro antibacterial and cytotoxic activities of compounds are reported.Figure optionsDownload full-size imageDownload as PowerPoint slide