9
30
Russ. Chem. Bull., Int. Ed., Vol. 66, No. 5, May, 2017
Zanina et al.
NO release into the solution. The structure of these interꢀ
mediates was confirmed by mass spectrometry.7
(1) dissociation of TNIC according to the previously
reported scheme;
,23
23
The results obtained for the identification of molecuꢀ
lar ions by the mass spectrometry are given in Table 1.
The mass spectrum of PEP contains a molecular ion with
m/z 168. In the mass spectrum of the reaction mixture,
the presence of this molecular ion was being observed
during the entire observation time, 36 min. This evidence
allows us to conclude that the reaction between PEP and
DNICthio is slow. Based on the chemical structure of the
PEP molecule, it was assumed that the PEP molecules in
a solution can exist in the form of dimers, but there was
no observed ions with m/z 336. An anion with m/z 318
is probably referred to the first reaction product,
(2) the reaction between DNICthio and the PEP moleꢀ
cule, i.e., elimination of the NO group leads to the [PEPꢀ
2
–
DNICthio] complex, from which an [O S —Fe—PEP]
3
2
intermediate product with m/z 318 is formed. Then, the
–
[SO ] ion is eliminated to give the [S—Fe—PEP] reacꢀ
3
tion product;
(3) the [O S—S—Fe]– ion, which is a fragment of
3
DNICthio and is formed as a product of the TNIC dissoꢀ
ciation, reacts with PEP to form the same [O S —
3
2
2
–
Fe—PEP] intermediate reaction product, stabilized as
–
[S—Fe—PEP] .
In summary, the new compound was produced in the
reaction between PEP and TNIC via formation of the
iron—oxygen bond. The mass numbers of the reaction
products were determined by the mass spectrometry method.
The scheme of the reaction process and the structures of
formed products were proposed. The additional kinetic
studies are needed to refine the proposed scheme, to deterꢀ
mine the quantitative parameters in the steps of the proꢀ
cess, and the structure of intermediate products.
2
–
2–
compound [O S —Fe—PEP] ([FeC S PO H ] , see
3
2
3
2
8
3
Scheme 1). The characteristic for the reaction product
anion with m/z 318 appeared in the spectrum after 2 min
from mixing of the TNIC and PEP solutions, while an
ion with m/z 228 (DNICthio) with two NO groups was
also present.
An anion with m/z 256 is probably referred to the
–
second reaction product, compound [S—Fe—PEP]
–
(
[FeC SPO H ] , Scheme 1 and Table 1). These ions
3
6
5
The authors are grateful to the Center for Collective
Use of Institute of Problems of Chemical Physics RAS
for providing the opportunity to conduct mass spectroꢀ
metric studies.
appeared in the spectrum 2 min after from the reaction
onset. The peak intensity of this ion was increasing durꢀ
ing the reaction process until the 36th min of observation.
–
Probably, the [S—Fe—PEP] molecular ion with m/z 256
2
–
was formed from compound [O S —Fe—PEP]
.
3
2
After 36 min of observation, the amount of compound
References
–
[
S—Fe—PEP] was almost 2.5 times greater than the
2
–
amount of the [O S —Fe—PEP] compound. Comꢀ
pound [S—Fe—PEP] can be also formed in a different
way, via a parallel reaction of PEP with the [S—Fe] ion
1. Chemical handbook, v. 21, Chemistry and Chemical Engiꢀ
neering, http://chem21.info/info/1765362/ (in Russian,
checked on August 1, 2017).
. M. H. Chambon, O. M. Viratelle, Anal. Biochem., 1998,
63, 198.
. E. A. Saratovskikh, T. A. Kondrat´eva, B. L. Psikha, R. I.
Gvozdev, V. G. Kartsev, Bull. Acad. Sci. USSR, Div. Chem.
Sci., 1988, 37, 2252.
. E. A. Saratovskikh, B. L. Psikha, N. A. Sanina, Russ. Chem.
Bull. (Int. Ed.), 2011, 60, 1177.
3
2
–
–
2
that is a residue of TNIC.
2
It is interesting that after 2 min from mixing the
solutions of the starting materials an ion with m/z 420
appeared in the mass spectrum. Obviously, this is the ion
from the third reaction product, in which the TNIC
residue is coordinated with two molecules of PEP,
3
4
[
S—Fe—2PEP] (see Table 1).
5. D. E. Metzler, Biochemistry. The Chemical Reactions of
Living Cells, Acad. Pres., New York—San Francisco—Lonꢀ
don, 1977.
Apparently, the following processes take place in the
system:
6
. T. Ogawa, H. Mori, M. Tomita, M. Yoshino, Res. Microꢀ
biol., 2007, 158, 159.
Table 1. Mass spectrometry analisys data for products of the
reaction of PEP with TNIC after 2 (I) and 36 min (II) from the
reaction onset
7. S. M. Aldoshin, N. A. Sanina in Fundamental´nye nauki —
meditsine. Biofizicheskie meditsinskie tekhnologii [Fundaꢀ
mental Sciences for Medicine. Biophysical Medicinal Techꢀ
nologies], Vol. 1, Eds A. I. Grigorev, Y. A. Vladimirov,
MAKS Press, Moscow, 2015, p. 72 (in Russian).
Reaction products
m/z
Relative intensity of
ion flow (%)
8
9
. F. Murad, J. Biosci. Rep., 1999, 19, 133.
. E. I. Arutiunova, A. P. Pleten, N. K. Nagradova, V. I.
Muronetz, Biochemistry (Moscow), 2006, 71, 685.
I
II
1
1
0. K. L. Davis, E. Martin, I. V. Turko, F. Murad, Annu. Rev.
Pharmacol. Toxicol., 2001, 41, 203—236.
1. B. L. Psikha, E. A. Saratovskikh, N. A. Sanina, Russ. Chem.
Bull., 2012, 61, 1810.
[
[
[
S—Fe—PEP]–
256
318
420
11.90
33.90
19.25
57.69
16.03
28.21
2
–
O S —Fe—PEP]
3
2
–
S—Fe—2PEP]