Nitric oxide release from a photoactive water-soluble ruthenium nitrosyl. Biological effects

Abstract

This research presents the synthesis and characterization of the photochemical nitric oxide (NO) precursor Ru(salenCO2H)(NO)Cl (I, salenCO2H = N,. This water-soluble ruthenium nitrosyl releases NO upon photolysis with a quantum yield that is pH dependent owing to the nitrosyl to nitrite conversion of that axial ligand at higher pH. Also described are the water, oxygen, and thermal stability of I and the cytotoxicity and the vascular relaxivity properties of I in the dark and under photolysis.

The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity

“…Tunability of the structure of MOFs, reviewed by Seabra and Duran, also allows for controlled release of NO for specific biological applications . Finally, many ls-{RuNO} 6 and ls-{MnNO} 6 complexes have shown utility as light-triggered NO delivery platforms for photodynamic therapy. ,,,− …”

Visible-light NO photolysis of ruthenium nitrosyl complexes with N2O2 ligands bearing π-extended rings and their photorelease dynamics

“…Salen (= N , N ′-bis(salicylidene)ethylenediamine dianion) type ligands, which form octahedral metal complexes with square planar N 2 O 2 ligands at equatorial positions, have also been successfully applied to ruthenium nitrosyls. 43–46 In these complexes, the photoactive absorption bands were red-shifted when the ligands contained π-extended systems. 44 The ligands could be easily modified to immobilize the nitrosyl complexes for biological and medicinal applications.…”

Ruthenium-nitrosyl complexes as NO-releasing molecules, potential anticancer drugs, and photoswitches based on linkage isomerism

“…The most common synthetic routes to ruthenium nitrosyl complexes include: (a) the use of specific starting materials, which already contain the ruthenium nitrosyl moiety, via a variety of substitution reactions (NO 2 by Cl, 27 NH 3 , 28,29 pyridines, 29–33 pyrazine; 34 NO 3 by H 2 O, F; 35 OH by F; 22,36,37 Cl by pyridines, 38–40 tetradentate Schiff bases, 41,42 tetradentate 2-hydroxybenzamidobenzene derivatives, 43 bis-phosphine monoxide ligands; 44 H 2 O by Cl, 45 SO 4 ; 46 NH 3 by Cl 46 ) or metathesis reactions of Na + to Ba 2+ , 29 Ba 2+ to NH 4 + , 29 Cl − to ClO 4 − , 47 PF 6 − , 48 in solution and in the solid state; 45,46 (b) conversion of the coordinated nitro ligand into nitrosyl in acidic media (HCl, TFA, HFP 6 , HNO 3 ) reported for ruthenium triammine complex, 45 as well as for compounds with pyridine, bipyridine, terpyridine, phenanthroline, triazine, and indazole ligands (see references in Table 1); (c) direct reaction of ruthenium pyridine, bipyridine, terpyridine, porphyrin, corrole species (see Table 1) or ruthenium azole complexes 49 with NO via substitution reactions of labile monodentate ligands, e.g. , Cl, 50–54 H 2 O, 55,56 DMSO, 57 etc .…”