Methanol addition to the trimethyl ester of cofactor PQQ (PQQTME) was investigated in detail to obtain information on the action of quinoprotein methanol dehydrogenase. The hemiacetal-type adduct was easily isolated from a methanol solution of PQQTME. The crystalstructure of the adduct was determined by X-ray diffraction for the first time, showing that methanol addition occurred at the S-position
对辅因子 PQQ (PQQTME) 的三甲酯中添加甲醇进行了详细研究,以获得有关喹蛋白甲醇脱氢酶作用的信息。半缩醛型加合物很容易从 PQQTME 的甲醇溶液中分离出来。加合物的晶体结构首次通过 X 射线衍射确定,表明与丙酮加合物形成的情况一样,甲醇加成发生在醌的 S 位 (CS)。另一方面,在酸性条件下在甲醇中处理 PQQTME 得到二甲基缩醛衍生物作为主要产物,通过 X 射线晶体学分析确定甲醇的加成位置为 C-4
Synthesis and characterization of the 6-deaza derivative of coenzyme PQQ, methyl 4,5-dihydro-4,5-dioxobenz[g]indole-2-carboxylate
The synthesis of the 6-deaza derivative of coenzyme PQQ, methyl 4,5-dihydro-4,5-dioxobenz[g]indole-2-carboxylate (4), is described, and its physical and chemical properties are compared to those of the trimethyl ester of PQQ (2) and the methyl ester of 7,9-didecarboxy PQQ (3). The synthesis of 4 was achieved by starting with 1-aminonaphthalene and constructing 2-carbomethoxybenz[g]indole (7) by a Japp-Klingemann reaction with methyl alpha-methylacetoacetate and a subsequent Fischer indolization reaction. The quinone function was introduced by a Fremy's salt oxidation of 5-aminoindole 9 which was prepared from 7 by regioselective nitration and catalytic hydrogenation. From the physical properties, it can be recognized that the peri pyridine nitrogen and the ester groups at the 7- and 9-positions considerably affect the electronic nature of the molecules. This is reflected on the reactivities of the quinones in the acetone-adduct formation, the reaction with phenylhydrazine, and the aerobic autorecycling oxidation of benzylamine. The significant roles of the pyridine nitrogen and the ester groups in these reactions are discussed.
Synthesis of 7,9-didecarboxymethoxatin (4,5-dihydro-4,5-dioxo-1H-pyrrolo[2,3-f]quinoline-2-carboxylic acid) and comparison of its chemical properties with those of methoxatin and analogous o-quinones. Model studies directed toward the action of PQQ requiring bacterial oxidoreductases and mammalian plasma amine oxidase
作者:Paul R. Sleath、J. Barry Noar、Gert A. Eberlein、Thomas C. Bruice
DOI:10.1021/ja00297a044
日期:1985.5
ITOH, SHINOBU;INOUE, TERUHISA;FUKUI, YOSHIFUMI;HUANG, XIN;KOMATSU, MITSUO+, CHEM. LETT.,(1990) N, C. 1675-1678