TY  - JOUR
A1  - Mansour, Ahmed M.
A1  - Steiger, Christoph
A1  - Nagel, Christoph
A1  - Schatzschneider, Ulrich
T1  - Wavelength‐dependent control of the CO release kinetics of manganese(I) tricarbonyl PhotoCORMs with benzimidazole coligands
JF  - European Journal of Inorganic Chemistry
N2  - 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‐CH\(_3\), 4‐OCH\(_3\), 4‐Cl, 4‐NO\(_2\), 2‐, 3‐, and 4‐COOCH\(_3\) 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.
KW  - CO‐releasing molecules (CORMs)
KW  - Manganese Carbonyl ligands
KW  - Benzimidazole
KW  - TDDFT
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218362
VL  - 2019
IS  - 42
ER  - 
TY  - JOUR
A1  - Tinajero-Trejo, Mariana
A1  - Rana, Namrata
A1  - Nagel, Christoph
A1  - Jesse, Helen E.
A1  - Smith, Thomas W.
A1  - Wareham, Lauren K.
A1  - Hippler, Michael
A1  - Schatzschneider, Ulrich
A1  - Poole, Robert K.
T1  - Antimicrobial Activity of the Manganese Photoactivated Carbon Monoxide-Releasing Molecule [Mn(CO)\(_3\)(tpa-kappa\(^3\)N)]\(^+\) Against a Pathogenic Escherichia coli that Causes Urinary Infections
JF  - Antioxidants & Redox Signaling
N2  - Aims: We set out to investigate the antibacterial activity of a new Mn-based photoactivated carbon monoxide-releasing molecule (PhotoCORM, [Mn(CO)\(_3\)(tpa-kappa\(^3\)N)]\(^+\)) against an antibiotic-resistant uropathogenic strain (EC958) of Escherichia coli. Results: Activated PhotoCORM inhibits growth and decreases viability of E. coli EC958, but non-illuminated carbon monoxide-releasing molecule (CORM) is without effect. NADH-supported respiration rates are significantly decreased by activated PhotoCORM, mimicking the effect of dissolved CO gas. CO from the PhotoCORM binds to intracellular targets, namely respiratory oxidases in strain EC958 and a bacterial globin heterologously expressed in strain K-12. However, unlike previously characterized CORMs, the PhotoCORM is not significantly accumulated in cells, as deduced from the cellular manganese content. Activated PhotoCORM reacts avidly with hydrogen peroxide producing hydroxyl radicals; the observed peroxide-enhanced toxicity of the PhotoCORM is ameliorated by thiourea. The PhotoCORM also potentiates the effect of the antibiotic, doxycycline. Innovation: The present work investigates for the first time the antimicrobial activity of a light-activated PhotoCORM against an antibiotic-resistant pathogen. A comprehensive study of the effects of the PhotoCORM and its derivative molecules upon illumination is performed and mechanisms of toxicity of the activated PhotoCORM are investigated. Conclusion: The PhotoCORM allows a site-specific and time-controlled release of CO in bacterial cultures and has the potential to provide much needed information on the generality of CORM activities in biology. Understanding the mechanism(s) of activated PhotoCORM toxicity will be key in exploring the potential of this and similar compounds as antimicrobial agents, perhaps in combinatorial therapies with other agents.
KW  - intracellular hydrogen-peroxide
KW  - campylobacter-jejuni
KW  - oxygen-metabolism
KW  - deficient mutant
KW  - oxidative stress
KW  - aqueous-solution
KW  - metal caponyls
KW  - RU(CO)(3)CL(GLYCINATE)
KW  - bacteria
KW  - enzyme
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188910
VL  - 24
IS  - 14
ER  -