ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 5, pp. 904!905. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + D.S. Ruzanov, A.I. Fisher, A.V. Eremin, V.G. Antonov, O.S. Fedorova, M.A. Stepanova, A.N. Belyaev, and S.A. Simanova,
2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 5, pp. 867!868.
Catalytic Properties of Oligonuclear Cobalt Acetate Complexes
in Oxidation of Glutathione with Hydrogen Peroxide
D. S. Ruzanov, A. I. Fisher, A. V. Eremin, V. G. Antonov, O. S. Fedorova,
M. A. Stepanova, A. N. Belyaev, andS. A. Simanova
St. Petersburg State Institute of Technology (Technical University), St. Petersburg, Russia
Kirov Military Medical Academy, St. Petersburg, Russia
Institute of Human Brain, Russian Academy of Sciences, St. Petersburg, Russia
Received April 8, 2008
Abstract-Catalytic activity of oligonuclear cobalt(III) and cobalt(II,III) oxoacetate complexes in homo-
geneous oxidation of glutathione with hydrogen peroxide was studied.
Commercial preparations based on oxidized gluta-
thione (g-glutamylcysteinylglycine, GSH), GSSG,
are produced by GSH oxidation catalyzed by ?EI-
][1, 2]. High cost and potential renal
toxicity of platinum compounds make urgent re-
placement of ?EI-[Pt(NH
]by another catalyst.
In addition, peptides with thiol groups can be oxi-
dized not only to disulfides but also to sulfenic (R3
SOH), sulfinic (R3SO
H), and sulfonic (R3SO
acids . Therefore, a search for selective catalysts of
mild oxidation of thiols to disulfides is of interest.
In this study we examined catalytic oxidation of
GSH with hydrogen peroxide by high-performance
liquid chromatography (HPLC). Oligonuclear
cobalt(III) and cobalt(II, III) oxoacetate complexes
(1) and [Co
O(11) in trace amounts (10
were examined as catalysts of mild selective oxida-
tion to compounds containing the 3S3S group
The choice of these catalysts is governed by the
fact that polynuclear cobalt oxoacetate complexes
can effectively transfer electron and hydroperoxy
radicals in oxidation of organic compounds .
Complexes 1 and 11 were prepared by treatment
of [cobalt(III) acetate] with glacial acetic acid in
the presence of nitrate ion (complex 1) or with
acetone3methanol mixture in the presence of fluor-
ide ions (complex 11) .
The reaction course was monitored by high-per-
formance liquid chromatography (HPLC) on a
Gilson chromatograph (France). We used a 4.6 0
250-mm Lichrospher 100-rp-18 column (Taiwan,
China), a UV-220 detector, and 0.1% trifluoroacetic
acid + 2% acetonitrile as the mobile phase. The flow
rate was 1.5032.50 ml min
; the injected sample
volume was 10 ml.
A model system containing 2 mg ml
GSH (1.3 0
M), equimolar amount of sodium hydroxide,
and half amount of hydrogen peroxide was used to
study the oxidation kinetics. The total volume of the
system was brought to 20 ml with double-distilled
water. The resulting solutions contained 1.7 0
M catalyst (DSH/catalyst molar ratio 1000).
The time reading started after adding an aliquot
of the oxidizing agent (H
solution) to the system.
Then, the samples of the solution were taken and
analyzed by HPLC. The content of oxidized GSH
was determined from the chromatogram of a stan-
dard GSSG solution. The reaction systems were
thermostatically controlled at 22+1oC with stirring.
GSH was oxidized at pH 5.035.1.
According to HPLC data, the only product of
catalytic oxidation of GSH is the hexapeptide with
the 3S3S3 bridge (GSSG), with the catalytic activity
of complexes 1 and 11 being similar.
Since complexes 1 and 11 are highly active cata-
lysts of selective oxidation of GSH, these com-