Search

Mono‐ and binuclear benzimidazole based half‐sandwich organoruthenium(II) compounds; [Run(triazolateCOOCH3,COOCH3)n(η6‐p‐Cym)nL]0/+/2+ (n = 1, L = LCH2CH3 (7) and HLSO3H (8); n = 2, L = LDTP (9)) were synthesized by [3+2] free catalyzed cycloaddition reaction of azide complexes 4–6 with electron‐poor alkyne dimethyl acetylene dicarboxylate. In comparison with the parent [RunCln(η6‐p‐Cym)nL]0/+/2 complexes (1–3), the lysozyme binding affinity of the corresponding triazolate compounds 7–9 was investigated by electrospray ionization mass spectrometry. Complexes bearing benzimidazole ligand with an alkylated sulfonate side chain (2 and 8) are able to bind lysozyme noncovalently, which have not been clearly seen by other investigated Ru(II) complexes. The complexes were assessed for their potential antimicrobial activity against some representative microbes. Complex 9 exhibits antifungal activity against C. albicans (MIC = 24 nm) and C. neoformans (MIC = 12 nm), perfect blood compatibility as well as no toxicity to non‐malignant cell line (human embryonic kidney cells (HEK293). [ABSTRACT FROM AUTHOR]

A series of photoactivatable CO‐releasing molecules (PhotoCORMs) was prepared from manganese pentacarbonyl bromide and 1H‐benzimidazol‐2‐ylmethyl‐(N‐phenyl)amine ligands (L) bearing different electron‐donating and electron‐withdrawing groups R = H, 4‐CH3, 4‐OCH3, 4‐Cl, 4‐NO2, 2‐, 3‐, and 4‐COOCH3 on the phenyl substituent to give octahedral manganese(I) complexes of the general formula [MnBr(CO)3(L)]. Aerated DMSO solutions of the compounds are stable in the dark for 16 h with no CO release. However, the compounds rapidly release CO upon illumination at 412–525 nm, depending on the substitution pattern. Its influence on the photophysical and photochemical properties was systematically explored using UV/Vis spectroscopy and CO release measurements with a commercial gas sensor system. In the nitro‐substituted compound, the electronically excited state switched from benzimidazole‐ to phenyl‐centered, leading to a markedly different photochemical behavior of this visible‐light activated PhotoCORM. [ABSTRACT FROM AUTHOR]

The lysozyme binding affinity of new Au(III) complexes, bearing pyridylbenzimidazole ligands, was investigated by ESI‐MS and UV/Vis. Metalation of lysozyme happened mainly by {Au}n+, {AuCl}0/n+ and {AuCl2}n+/–. The appendage sulfonate group of pyridylbenzimidazole ligand system played a role in determining the products of interaction of HEWL with Au(III) complexes. The hydrophilic sulfonate group inhibited the ligand cleavage via the participation in several coulombic and H‐bond interactions giving several AuLn+ containing adduct peaks (L = 1‐[(pyridin‐2‐yl) benzimidazole]‐propyl‐sulfonic acid). The stability of the complexes in presence of ascorbic acid was examined by UV/Vis and 13C NMR. To recognize if His15 side‐chain is the metalation site of HEWL, the interactions between the complexes and imidazole, as a simple model of histidine, were investigated by 1H and 13C NMR. The DNA binding studies of the complexes were reported. For this class of Au(III) complexes, it is preferred to decorate the pyridylbenzimidazole system with ethyl group rather than sulfonate and phthalimido group to have a complex with interesting antifungal activity against Candida albicans and Cryptococcus neoformans var. grubii. Au(III) complex, having sulfonate group, is noncytotoxic to non‐malignant cells (human embryonic kidney cells (HEK293)), shows negligible hemoglobin release and is safe to the normal cells if applicable. [ABSTRACT FROM AUTHOR]