Electrochemistry of 6-methyl-5,6,7,8-tetrahydropterin |
| |
Authors: | Lionel G Karber Glenn Dryhurst |
| |
Institution: | Department of Chemistry, University of Oklahoma, Norman, OK 73019 U.S.A. |
| |
Abstract: | The electrochemical oxidation of 6-methyl-5,6,7,8-tetrahydropterin (6-MTHP), the most effective of the synthetic aromatic amino acid hydroxylase pseudo cofactors, has been studied in aqueous solution over a wide pH range at a pyrolytic graphite electrode. The first electrooxidation of 6-WTHP occurs by a quasi-reversible 2e-2H+ reaction giving an unstable quinonoid-dihydropterin. The latter undergoes a first order chemical follow-up reaction yielding 6-methyl-7,8-dihydropterin (6-MDHP). At pH values ?5.6 6-MDHP forms an equilibrium mixture of a covalently hydrated species and non-hydrated species. The covalently hydrated form of 6-MDHP is electrooxidized in a 2e-2H+ quasi-reversible reaction to another unstable quinonoid that appears to undergo a two-step rearrangement to 6-methylpterin. Non-hydrated 6-MDHP is electrooxidized at the most positive potential in an irreversible 2e-2H+ reaction giving 6-methylpterin. |
| |
Keywords: | To whom correspondence and reprint requests should be addressed |
本文献已被 ScienceDirect 等数据库收录! |
|