抄録
Degradation of 3H-epinephrine during incubation for 14 h at 37°C in a phosphate buffer, pH 7.0, containing ascorbic acid was observed in a study on the radioimmunoassay of epinephrine. Chromatographic separations of the products were carried out on a large scale. They were identified as 1, 2, 3, 4-tetrahydro-4, 6, 7-trihydroxy-2-methylisoquinoline (1) and 1, 2, 3, 4-tetrahydro-4, 7, 8-trihydroxy-2-methylisoquinoline (2). These products were synthesized from epinephrine and formaldehyde for the first time. Our results suggested that 3H-epinephrine reacted with formaldehyde generated through the oxidation of ascorbic acid by oxygen from air under the incubation conditions used above to yield 1 or 2. Care is clearly required in using ascorbic acid as an antioxidant in catecholamine studies.
