叠氮水杨酰胺类化合物对呼吸链琥珀酸-细胞色素c还原酶的抑制作用

The Inhibitory Effect of Azidosalic Amides on the SQR and QCR Activities of Purified Succinate Cytochrome c Reductase

合成了３－叠氮基－Ｎ－正癸烷基水杨酰胺和５－叠氮基－Ｎ－正癸烷基水杨酰胺并检测了它们对呼吸链酶系从琥珀酸到细胞色素ｃ段电子传递活性的抑制作用．两种化合物对琥珀酸－泛醌还原酶的抑制能力基本相同，而５位叠氮基取代物对泛醌－细胞色素ｃ还原酶的抑制能力较３位叠氮基取代物为强．它们与泛醌反应抑制剂３－硝基－Ｎ－正癸烷基水杨酰胺相比较，其抑制性质基本相似。

The inhibitory effect of synthetic inhibitors,3 azidosalicyl N ( n decyl)amide and 5 azidosalicyl N ( n decyl)amide,on succinate ubiquinone reductase and QH 2 cytochrome c reductase of purified succinate cytochrome c reductase of the respiratory chain was studied and their inhibitory mechanism was also discussed.The two inhibitors exhibited almost equal inhibitory effect on SQR,but on the activity of QCR,the inhibitory potency of 5 azidosalicyl N ( n decyl)amide was much greater than that of 3 azidosalicyl N ( n decyl)amide.Since the 3 position azido group could form intramolecular hydrogen bond with 2 position hydroxyl,it lowered the ability of the formation of intermolecular hydrogen bond between 3 azidosalicyl N ( n decyl)amide and ubisemiquinone.But,it was difficult for 5 position azido group and 2 position hydroxyl to form intramolecular hydrogen bond due to the distance and orientation.Moreover,the azido group on 5 azidosalicyl N ( n decyl)amide formed intermolecular hydrogen bond with ubisemiquinone,which was much easier than that between 3 azidosalicyl N ( n decyl)amide and ubisemiquinone considering the steric hindrance.Compared with 3 nitrosalicyl N ( n decyl)amide,their inhibitory effects on ubiquinone reactions were almost identical.