2,3- and 4,5-Secodopa, the Biosynthetic Intermediates Generated fromL-Dopa by an Enzyme System Extracted from the Fly Agaric,Amanita muscaria L., and Their Spontaneous Conversion to Muscaflavin and Betalamic Acid, Respectively, and Betalains
作者:Fernand Terradas、Hugo Wyler
DOI:10.1002/hlca.19910740115
日期:1991.1.30
An enzyme is extracted from the red peel of Amanita muscaria which cleaves the C(2)–C(3) and the C(4)–C(5) bond of the aromatic ring of L-dopa (1) to form a mixture of 4,5-secodopa (= salt of 6-amino-2-hydroxy-4-(2′-oxoethylidene)hept-2-enedioic acid; 2) and 2,3-secodopa ( = salt of 7-amino-5-formyl-2-hydroxyocta-2,4-dienedioic acid; 3), two hitherto hypothetical biosynthetic intermediates (see Scheme)
从毒蝇伞的红皮中提取一种酶,该酶切割L-多巴(1)芳香环的C(2)–C(3)和C(4)–C(5)键,形成混合物4,5-secodopa(= 6-氨基-2-羟基-4-(2'-氧代亚乙基)庚-2-烯二酸的盐; 2)和2,3-secodopa(= 7-氨基-5的盐-甲酰基-2-羟基辛基-2,4-二烯二酸;3),两个迄今假设的生物合成中间体(参见方案)。尽管不可能分离出这些产物,但与已知化合物相比,可以从反应产物,动力学和光谱特征中推断出结构证据。Secodopas 2和3的特征在于,通过HPLC和UV / VIS光谱稀溶液(阴离子;λ最大。424和414纳米,RESP,ε 420 = 25500;关于酸化,转移到380和372纳米,RESP)。它们可以在没有酶催化的情况下进行环化,最佳的pH值为4.5-5。3产生muscaflavin(5)和2 betalamic acid(4)。通过与HPLC中的真实样品直接比较,1