The radiolysis of aqueous solutions of 3,4-dihydroxyphenylalanine (dopa) using N˙3 as a one-electron oxidant leads to the formation of dopasemiquinone and, successively, dopaquinone and dopachrome. It is now shown that under pH conditions where significant protonation of N–3 to HN3 occurs, dopachrome formation is suppressed, probably due predominantly to addition of HN3 to dopaquinone. The possibility of such nucleophilic reactions occurring needs to be considered in studies of quinone intermediates generated using N–3 as oxidant.
使用 N˙3 作为单电子氧化剂对 3,4-二羟基苯丙
氨酸(多巴)
水溶液进行辐射分解,导致形成多巴半醌,并依次形成多巴醌和多巴色素。现在表明,在 N-3 显着质子化为
HN3 的 pH 条件下,多巴色素的形成受到抑制,这可能主要是由于 添加到多巴醌中。在研究使用 N-3 作为氧化剂生成的醌中间体时,需要考虑发生此类亲核反应的可能性。