Oxidation of the neurotoxin 6-aminodopamine (1) is known to proceed through the o-quinone 3, which undergoes intramolecular cyclisation to give 5,6-dihydroxyindole (6). In a re-examination of the reaction, we have found that at concentrations of 1 higher than 5 x 10(-3) M a quite different course prevails, leading to the formation of the novel 7-amino-8-(2-aminoethyl)-3-hydroxy-2-oxo-2,3,4,10-tetrahydro [3,4a] iminoethanophenoxazine (7). Product 7 was formed by aerobic, chemical (persulphate, periodate) or enzymatic (tyrosinase, peroxidase/H2O2) oxidation of 1. on acetylation, 7 afforded the tetraacetate 8. Oxidation of the model compound 5-amino-4-methylcatechol (9) proceeded similarly as that of 1, to give the tetrahydrophenoxazinedione 11
A new oxidation pathway of the neurotoxin 6-aminodopamine. Isolation and characterisation of a dimer with a tetrahydro(3, 4a)iminoethanophenoxazine ring system / Napolitano, Alessandra; D'Ischia, Marco; C., Costantini; G. P. R. O. T., A.. - In: TETRAHEDRON. - ISSN 0040-4020. - STAMPA. - 39:(1992), pp. 8515-8522. [10.1016/S0040-4020(01)86599-6]
A new oxidation pathway of the neurotoxin 6-aminodopamine. Isolation and characterisation of a dimer with a tetrahydro(3, 4a)iminoethanophenoxazine ring system.
NAPOLITANO, ALESSANDRA;D'ISCHIA, MARCO;
1992
Abstract
Oxidation of the neurotoxin 6-aminodopamine (1) is known to proceed through the o-quinone 3, which undergoes intramolecular cyclisation to give 5,6-dihydroxyindole (6). In a re-examination of the reaction, we have found that at concentrations of 1 higher than 5 x 10(-3) M a quite different course prevails, leading to the formation of the novel 7-amino-8-(2-aminoethyl)-3-hydroxy-2-oxo-2,3,4,10-tetrahydro [3,4a] iminoethanophenoxazine (7). Product 7 was formed by aerobic, chemical (persulphate, periodate) or enzymatic (tyrosinase, peroxidase/H2O2) oxidation of 1. on acetylation, 7 afforded the tetraacetate 8. Oxidation of the model compound 5-amino-4-methylcatechol (9) proceeded similarly as that of 1, to give the tetrahydrophenoxazinedione 11I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
