Schempp H, Ulrich H, Elstner E F
Lehrstuhl für Phytopathologie, Labor für Angewandte Biochemie, Technische Universität München.
Z Naturforsch C J Biosci. 1994 Sep-Oct;49(9-10):691-2. doi: 10.1515/znc-1994-9-1023.
R(+)-thioctic acid is the naturally occurring cofactor in alpha-ketoacid dehydrogenases. We show both photometrically by NADH+H+ oxidation and by HPLC product analysis that this enantiomer is rapidly reduced by NADH+H+ catalyzed by porcine heart lipoamide dehydrogenase/diaphorase. The racemate exhibits approximately 40% activity as compared to the R(+) form while the S(-) enantiomer photometrically shows little activity and yields no detectable reduced lipoic acid.
R(+)-硫辛酸是α-酮酸脱氢酶中的天然辅因子。我们通过NADH + H⁺氧化的光度法以及HPLC产物分析表明，这种对映体在猪心硫辛酰胺脱氢酶/黄递酶催化下被NADH + H⁺迅速还原。与R(+)形式相比，外消旋体表现出约40%的活性，而S(-)对映体在光度法上几乎没有活性，也没有产生可检测到的还原型硫辛酸。
