{"entity": "publication", "iuid": "6be2c429bb0046c6925861734bae9e0f", "timestamp": "2026-08-09T03:54:12.855Z", "links": {"self": {"href": "https://publications.scilifelab.se/publication/6be2c429bb0046c6925861734bae9e0f.json"}, "display": {"href": "https://publications.scilifelab.se/publication/6be2c429bb0046c6925861734bae9e0f"}}, "title": "Effect of a Bromo Substituent on the Glutathione Peroxidase Activity of a Pyridoxine-like Diselenide.", "authors": [{"family": "Singh", "given": "Vijay P", "initials": "VP"}, {"family": "Poon", "given": "Jia-Fei", "initials": "JF"}, {"family": "Butcher", "given": "Ray J", "initials": "RJ"}, {"family": "Lu", "given": "Xi", "initials": "X"}, {"family": "Mestres", "given": "Gemma", "initials": "G"}, {"family": "Ott", "given": "Marjam Karlsson", "initials": "MK"}, {"family": "Engman", "given": "Lars", "initials": "L"}], "type": "journal article", "published": "2015-08-07", "journal": {"volume": "80", "issn": "1520-6904", "issue": "15", "pages": "7385-7395", "title": "J. Org. Chem.", "issn-l": "0022-3263"}, "abstract": "In search for better mimics of the glutathione peroxidase enzymes, pyridoxine-like diselenides 6 and 11, carrying a 6-bromo substituent, were prepared. Reaction of 2,6-dibromo-3-pyridinol 5 with sodium diselenide provided 6 via aromatic nucleophilic substitution of the 2-bromo substituent. LiAlH4 caused reduction of all four ester groups and returned 11 after acidic workup. The X-ray structure of 6 showed that the dipyridyl diselenide moiety was kept in an almost planar, transoid conformation. According to NBO-analysis, this was due to weak intramolecular Se\u00b7\u00b7\u00b7O (1.1 kcal/mol) and Se\u00b7\u00b7\u00b7N-interactions (2.5 kcal/mol). That the 6-bromo substituent increased the positive charge on selenium was confirmed by NPA-analysis and seen in calculated and observed (77)Se NMR-shifts. Diselenide 6 showed a more than 3-fold higher reactivity than the corresponding des-bromo compound 3a and ebselen when evaluated in the coupled reductase assay. Experiments followed for longer time (2 h) confirmed that diselenide 6 is a better GPx-catalyst than 11. On the basis of (77)Se-NMR experiments, a catalytic mechanism for diselenide 6 was proposed involving selenol, selenosulfide and seleninic acid intermediates. At low concentration (10 \u03bcM) where it showed only minimal toxicity, it could scavenge ROS produced by MNC- and PMNC-cells more efficiently than Trolox.", "doi": "10.1021/acs.joc.5b00797", "pmid": "26133764", "labels": {"BioMaterial Interactions (BioMat)": null}, "xrefs": [], "notes": [], "created": "2017-05-02T12:58:50.287Z", "modified": "2017-05-30T13:23:06.256Z"}