Synthesis and characterization of Se-adenosyl-L-selenohomocysteine selenoxide

Abstract

Selenium is an essential micronutrient in humans due to the important roles of the selenocysteine-containing selenoproteins. Organoselenium metabolites are generally found to be substrates for the biochemical pathways of their sulfur analogs, and the redox chemistry of selenomethionine and some other metabolites have been previously reported. We now report the first synthesis and characterization of Se-adenosylselenohomocysteine selenoxide (SeAHO) prepared via hydrogen peroxide oxidation of Se-adenosylselenohomocysteine. The selenoxide SeAHO, in contrast to its corresponding sulfoxide S-adenosylhomocysteine (SAHO), can form hydrate, has an electrostatic interaction between the α-amino acid moiety and the highly polar selenoxide functional group, and readily oxidizes glutathione (GSH) and cysteine thiols.

GRAPHICAL ABSTRACT

Keywords:

• organoselenium
• Se-adenosylselenohomocysteine selenoxide
• Se-adenosylselenohomocysteine
• selenomethionine
• oxidation

Acknowledgements

The authors are grateful to Wanlu Qu, Shanshan Liu, and William Devine for assistance with mass spectrometry, and to Jason Guo and Roger Kautz for assistance with NMR. We gratefully acknowledge the general assistance of Tianzhu “Indi” Zang, Kun Zhang, and Michael Pollastri.

Supplementary data

Supplementary data associated with this article, including characterizations of compounds 2 (X = S), 3 (X = S), and 9 can be found in the online version, at http://dx.doi.org/10.1080/17415993.2014.979173.

Additional information

Funding

This work was supported by NIH NIGMS under grant 1R01GM101396 to Z.S.Z.