Nitric oxide and nitroxyl formation in the reduction of trans-tetraamminenitrosyltriethylphosphiteruthenium(II) ion

Nitric Oxide and Nitroxyl Products from the Reaction of L‐Cysteine with trans‐[RuNO(NH3)4P(OEt)3](PF6)3

“…[19,21] Because N 2 O can be a product of HNO dimerization (k d = 8.0 ϫ 10 6 m -1 s -1 ) and because of the high concentration of the reagents, this observation strongly suggests that nitroxyl could be formed from this reaction. [12,21] According to the chronoamperometric data, which were corroborated by nitric oxide analyzer (NOA) measurements ( Figure S1, Supporting Information), the formation of NO from the above reactions is pH dependent (Figure 2). The concentration of liberated NO increased when the pH was increased from 2.0 to 4.0 and decreased when the pH was increased beyond 4.0.…”

“…The k 2 values calculated from these spectroscopic changes (Figure 4, B) were pH dependent, as show in Equations (11) and (12) (11) (12) According to the literature, [18] this step of the reaction between nitrosyl ruthenium complexes and a thiol can be expressed as shown in Equations (13) and (14). ( (Figure 4, B), as suggested by Rocaroli.…”

“…[12,13] The reaction between trans-[RuNO(NH 3 ) 4 {P(III)} 3 ](PF 6 ) 3 and europium(II), which is a one-electron reductant, quantitatively yields NO. [12] In addition, the reaction between the trans-[RuNO(NH 3 ) 4 {P(III)} 3 ](PF 6 ) 3 complex and Zn(Hg) (a twoelectron reductant) quantitatively yields HNO.…”

“…[12] In addition, the reaction between the trans-[RuNO(NH 3 ) 4 {P(III)} 3 ](PF 6 ) 3 complex and Zn(Hg) (a twoelectron reductant) quantitatively yields HNO. [12,13] The antileishmanial and antitrypanosomal effects of the following complexes were ascribed to their nitric oxide and nitroxyl release capacities when activated by one or two electron reductions, respectively: trans-[Ru(NO)(NH 3 ) 4 L]-X 3 , where X = BF 4 -, PF 6 -or Cl -and L = imidazole (imN), 4-picoline (4-pic), pyrazine (pz), pyridine (py), triethylphosphite [P(OEt) 3 ], l-histidine (l-hist), isonicotinamide (isn), sulfite (SO 3 -2 ) or nicotinamide (nic), see Equations (1) and (2). [10,[12][13][14][15] (1) (2) Thiols are abundant in biological media and their redox potentials are adequate for reactions with the nitrosonium ligand.…”

“…+ ion according to Equation (11) and Equation (12). This species is suggested to lead the reduction of the NO + ligand by two electrons producing HNO as shown in Equation (16).…”