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A Water‐Soluble Cyclic Selenide with Enhanced Glutathione Peroxidase‐Like Catalytic Activities
Author(s) -
Kumakura Fumio,
Mishra Beena,
Priyadarsini K. Indira,
Iwaoka Michio
Publication year - 2010
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200901114
Subject(s) - chemistry , selenide , thiol , catalysis , dithiothreitol , hydrogen peroxide , catalytic cycle , peroxidase , selenium , glutathione , medicinal chemistry , photochemistry , organic chemistry , enzyme
Abstract Antioxidative catalytic activities of trans ‐3,4‐dihydroxyselenolane (DHS red ), a water‐soluble cyclic selenide, were investigated in the reaction of hydrogen peroxide with three different thiol substrates, monothiol glutathione (GSH), dithiol dithiothreitol (DTT red ), and polythiol reduced ribonuclease A (RNase A) having eight thiol groups along the polypeptide chain. For all the thiol substrates, DHS red exhibited higher glutathione peroxidase (GPx)‐like antioxidative catalytic activities than the corresponding linear selenide, that is, Se(CH 2 CH 2 OH) 2 . The rate‐determining step of the catalytic cycle was unambiguously assigned to the oxidation process of the selenide rather than the reduction process of the selenoxide intermediate. The enhanced catalytic activities of DHS red can be ascribed to the cyclic structure, which elevates the HOMO energy level and makes the selenium atom more exposed to the surroundings.