Live-fibroblast IR imaging of a cytoprotective PhotoCORM Activated with Visible Light

Carbon monoxide releasing molecules (CORMs) are an emerging class of pharmaceutical compounds currently evaluated in several preclinical disease models. There is general consensus that the therapeutic effects elicited by the molecules may be directly ascribed to the biological function of the released CO. It remains unclear, however, if cellular internalization of CORMs is a critical event in their therapeutic action. To address the problem of cellular delivery, we have devised a general strategy which entails conjugation of a CO-releasing molecule (here a photoactivated CORM) to the 5'-OH ribose group of vitamin B12. Cyanocobalamin (B12) functions as the biocompatible water-soluble scaffold which actively transports the CORM against a concentration gradient into the cells. The uptake and cellular distribution of this B12-photoCORM conjugate is demonstrated via synchrotron FTIR spectromicroscopy measurements on living cells. Intracellular photoinduced CO release prevents fibroblasts from dying under conditions of hypoxia and metabolic depletion, conditions that may occur in vivo during insufficient blood supply to oxygen-sensitive tissues such as the heart or brain

The dithiolate-bridged diiron hexacarbonyl complex Na2[(μ- SCH2CH2COO)Fe(CO)3]2 as a water-soluble photoCORM

10.1021/om401013aOrganometallics334959-963ORGN

Binding Interaction of [Re(H2O)3(CO)3]+ with the DNA Fragment d(CpGpG)

Insights into the interaction of the [Re(H2O)3(CO)3]+ complex (1) with the DNA fragment d(CpGpG) have been obtained by one- (1D) and two-dimensional (2D) NMR spectroscopy. The H8 resonances of the single major [Re(H2O)d(CpGpG)(CO)3]– adduct (2) exhibit pH-independent chemical shift changes attributable to metal N7 binding. The structure of this adduct has been characterized by molecular modeling studies based on 1D and 2D NMR data. In solution, 2 shows the presence of two N7-coordinated guanine moieties in a head-to-head (HH) orientation as evidenced by G2H8/G3H8 cross peaks in the [1H-1H]-NOESY spectrum. The presence of the 5'-bridging phosphodiester appears to stabilize the HH1 L conformer as previously described for related Pt and Rh complexes

Synthesis and reactivities of the 17 e- complex [ReIIBr4(CO)2]2-: A convenient entry into Rhenium(II) chemistry

The reduction of (Et4N)[ReIIIBr4(CO)2] (1) by 0.5 equiv of tetrakis-dimethylaminoethylene in acetonitrile yields directly the air-stable, 17-electron ReII synthon (Et4N)2[ReIIBr4(CO)2] (2) in nearly quantitative yield. The versatility of 2 as a synthon for ReII chemistry was demonstrated by substitution reactions of [ReIIBr4(CO)2]2− with different mono-, bi-, and tridentate ligands. The resulting ReII complexes form highly crystalline compounds, and the solid state structures of the neutral trans−cis-[ReIIBr2(CO)2(X)n] species (where X = imidazole, pyridine, or phenanthroline) could be determined. All complexes are stable under aerobic conditions, both as solids and in solution, and showed fully reversible one-electron ReII → ReI reductions between ca. −70 and −120 mV. Carbonyl stretching frequencies (νCO) of this new family of ReII complexes are observed in the 1990 cm−1 (A1) and 1830 (Eg) cm−1 regions. With complex 2, a wide variety of fundamental but so far unknown ReII complexes become accessible via facile substitution reactions