Ghisla S, Kenney W C, Knappe W R, McIntire W, Singer T P
Biochemistry. 1980 Jun 10;19(12):2537-44. doi: 10.1021/bi00553a001.
A number of derivatives of riboflavin and of 3-methyllumiflavin substituted in the 6 position have been synthesized starting with 6-nitro flavins, reduction to the 6-amino flavin, and diazotization, followed by reaction with the appropriate nucleophile. The absorption spectra, oxidation-reduction potentials, and the electron spin resonance spectra of the radical cationic forms of several of these synthetic compounds have been determined, including 6-S-cysteinyl-3-methyllumiflavin and 6-S-cysteinylriboflavin. The latter has been shown to be identical with the dephosphorylated form of the aminoacyl flavin isolated from trimethylamine dehydrogenase [Steenkamp, D. J., Kenney, W. C. & Singer, T. P. (1978) J. Biol. Chem. 253, 2812-2817; Steenkamp, D. J., McIntire, W., & Kenney, W. C. (1978) J. Biol. Chem. 253, 2818-2824] in regard to absorption specturm, photochemical properties, and mobility in high-voltage electrophoresis and in thin-layer chromatography. An unusually pronounced interaction between the amino group and the isoalloxazine ring system was deduced from the absorption spectra of 6-amino-3-methyllumiflavin and 6-aminoriboflavin.
以6-硝基黄素为起始原料，经还原得到6-氨基黄素，再进行重氮化，然后与适当的亲核试剂反应，合成了一系列在6位被取代的核黄素和3-甲基黄素的衍生物。已测定了其中几种合成化合物的自由基阳离子形式的吸收光谱、氧化还原电位和电子自旋共振光谱，包括6-S-半胱氨酰基-3-甲基黄素和6-S-半胱氨酰基核黄素。后者已被证明在吸收光谱、光化学性质以及在高压电泳和薄层色谱中的迁移率方面，与从三甲胺脱氢酶中分离出的氨酰基黄素的去磷酸化形式相同[Steenkamp, D. J., Kenney, W. C. & Singer, T. P. (1978) J. Biol. Chem. 253, 2812 - 2817; Steenkamp, D. J., McIntire, W., & Kenney, W. C. (1978) J. Biol. Chem. 253, 2818 - 2824]。从6-氨基-3-甲基黄素和6-氨基核黄素的吸收光谱中推断出氨基与异咯嗪环系统之间存在异常明显的相互作用。
