Germanium Dioxide and the Antioxidant Properties of Catechols

Germanium Dioxide and the Antioxidant Properties of Catechols Full article

Journal

European Journal of Inorganic Chemistry
ISSN: 1434-1948 , E-ISSN: 1099-0682

Output data

Year: 2019, Volume: 2019, Number: 5, Pages: 676-681 Pages count : 6 DOI: 10.1002/ejic.201801259

Authors

Nikolaevskaya Elena N. ¹ , Kansuzyan Artem V. ^1,3 , Filonova Galina E. ^1,3 , Zelenova Vera A. ^1,3 , Pechennikov Valery M. ³ , Krylova Irina V. ¹ , Egorov Mikhail P. ¹ , Jouikov Viatcheslav V. ² , Syroeshkin Mikhail A. ¹

Affiliations

1	N. D. Zelinsky Institute of Organic Chemistry Leninsky prosp. 47 119991 Moscow Russia
2	UMR CNRS 6226 ISCR, University of Rennes 1, 35042 Rennes, France
3	Pharmaceutical Department I.M. Sechenov First Moscow State Medical University Moscow Russia

Complexes of tetra- and hexa-coordinated germanium AdrCat2Ge (1, AdrCat = adrenaline catecholate), AldCat2Ge (2, AldCat = 4-formylcatecholate), AldCat3Ge(Et3NH)2 (3) were synthesized by the reaction of germanium dioxide with adrenaline and 3,4-dihydroxybenzaldehyde in aqueous solution. The structures of the complexes were confirmed by 1H and 13C NMR and IR spectroscopy, HRMS, and elemental analysis. Cyclic voltammetry in phosphate buffer solutions (pH = 6.86) has shown the oxidation potentials Ep of these complexes to be shifted by ca. 330–360 mV to more positive potentials compared to the parent aromatic diols, which means that their electron-releasing properties were diminished by about 7.6–8.3 kcal mol–1. A study of the kinetics of the reaction of these complexes with 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical in the presence of 5 % acetonitrile reveals a decrease of approximately one order of magnitude in the radical scavenging activity of adrenaline and model 3,4-dihydroxybenzaldehyde upon their complexation with Ge. The corresponding rate constants drop from (3.23 ± 0.07) × 103 L mol–1 s–1 (adrenaline) to (3.80 ± 0.20) × 102 L mol–1 s–1 for 1, and from (4.40 ± 0.20) × 103 L mol–1 s–1 (3,4-dihydroxybenzaldehyde) to (4.45 ± 0.25) × 102 L mol–1 s–1 for 2 and 3 (germanium is equally capable to bind two or three molecules of the diol). Keeping in mind that 1,2-diols are widespread in the living nature and often have important biological functions, these results will contribute to the understanding of role of germanium dioxide in metabolic mechanisms and to alert against unreasonable use of Ge preparations.

Nikolaevskaya E.N. , Kansuzyan A.V. , Filonova G.E. , Zelenova V.A. , Pechennikov V.M. , Krylova I.V. , Egorov M.P. , Jouikov V.V. , Syroeshkin M.A.
Germanium Dioxide and the Antioxidant Properties of Catechols
European Journal of Inorganic Chemistry. 2019. V.2019. N5. P.676-681. DOI: 10.1002/ejic.201801259 WOS Scopus OpenAlex

Web of science:	WOS:000458272500015
Scopus:	2-s2.0-85059965072
OpenAlex:	W2903408078

DB	Citing
OpenAlex	20
Scopus	17
Web of science	16