Sterically modulated silver(I) complexes of coumarin substituted benzimidazol–2–ylidenes: Synthesis, crystal structures and evaluation of their antimicrobial and antilung cancer potentials
Journal
Journal of Inorganic Biochemistry
Journal Volume
183
Pages
43
Date Issued
2018
Author(s)
Abstract
© 2018 Elsevier Inc. In this contribution, a series of sterically–encumbered coumarin substituted benzimidazole–based N–heterocyclic carbene (NHC) precursors (1−12) and their silver(I)–NHC complexes (13–24) are reported. Molecular structure of NHC precursors 8 and 12 and cationic complexes 15 and 16 was established by single crystal X–ray diffraction method. The silver(I) complexes demonstrated various significant intramolecular agostic–like interactions operating between the metal center and the hydrogen atoms of the substituents alongside a variety of feeble π–π stacking interactions. A distorted linear coordination geometry is documented at the silver(I) center with the anti–arrangement of the ligands. Further, the complexes demonstrated promising antibacterial properties against Gram positive and Gram negative bacterial strains, especially complex 18 displayed a minimum inhibitory concentration (MIC) of 2 and 4 μg/mL against S. aureus and E. coli, and P. aeruginosa, respectively. Furthermore, complexes 14, 15, 16 and 18 were found cytotoxic against the human lung cancer cell lines A549 and H1975 with the IC 50 (concentration of the test sample required to kill 50% of the cell population) value under 10 μM, while mono–NHC complex 20 displayed a potential drug window with the IC 50 of 13.7 ± 2.70 and 14.5 ± 1.20 μM against the cancer cell lines H1975 and A549, respectively. Notably, these complexes displayed relatively lesser cytotoxic behaviour against the normal skin fibroblast cell line, Hs68. All the NHC precursors displayed significantly lower biological activities compared with their respective complexes, indicating the utility of silver(I) ions in antimicrobial and antilung cancer applications.
Subjects
4–Bromomethylcoumarin | Antilung–cancer activity | E. coli | N–heterocyclic carbene | Silver(I) complex | X–ray diffraction
4–Bromomethylcoumarin; Antilung–cancer activity; E. coli; N–heterocyclic carbene; Silver(I) complex; X–ray diffraction
SDGs
Other Subjects
1 benzyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) acetate; 1 benzyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazolium hexafluorophosphate; 1 butyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) acetate; 1 butyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazolium hexafluorophosphate; 1 ethyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) acetate; 1 ethyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazolium bromide; 1 hexyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) acetate; 1 hexyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazolium hexafluorophosphate; 1 pentyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) acetate; 1 pentyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazolium hexafluorophosphate; 1 propyl 3 [(6 methyl 2 oxo 2h chromen 4 yl) methyl] benzimidazol 2 ylidenesilver(i) acetate; 1 propyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazolium hexafluorophosphate; antibiotic agent; antineoplastic agent; benzimidazole derivative; bis [1 benzyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) hexafluorophosphate; bis[1 butyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) hexafluorophosphate; bis[1 ethyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) hexafluorophosphate; bis[1 hexyl 3 [(6 methyl 2 oxo 2h chromen 4 yl) methyl] benzimidazol 2 ylidenesilver(i) hexafluorophosphate; bis[1 pentyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver(i) hexafluorophosphate; bis[1 propyl 3 [(6 methyl 2 oxo 2h chromen 4 yl)methyl] benzimidazol 2 ylidenesilver hexafluorophosphate; coumarin derivative; silver derivative; unclassified drug; antiinfective agent; antineoplastic agent; benzimidazole; benzimidazole derivative; coumarin; coumarin derivative; A-549 cell line; antibacterial activity; antineoplastic activity; Article; bromination; carbon nuclear magnetic resonance; comparative study; crystal structure; drug cytotoxicity; drug potency; drug screening; drug synthesis; Escherichia coli; Hs 683 cell line; human; human cell; IC50; minimum inhibitory concentration; NCI-H1975 cell line; proton nuclear magnetic resonance; Pseudomonas aeruginosa; Staphylococcus aureus; structure activity relation; X ray diffraction; cell survival; chemical structure; chemistry; drug effect; Gram negative bacterium; Gram positive bacterium; microbial sensitivity test; tumor cell line; A549 Cells; Anti-Bacterial Agents; Anti-Infective Agents; Antineoplastic Agents; Benzimidazoles; Cell Line, Tumor; Cell Survival; Coumarins; Escherichia coli; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Microbial Sensitivity Tests; Molecular Structure; Staphylococcus aureus
Publisher
ELSEVIER SCIENCE INC
Type
journal article