还原态吡咯喹啉醌清除氮自由基能力研究

The research on scavenging nitrogen radical ability of reduced pyrroloquinoline quinone

探讨了不同质量浓度及不同反应时间条件下还原态吡咯喹啉醌(Reduced pyrroloquinoline quinone,PQQH_(2))对ABTS自由基清除率的变化规律,建立一级和二级反应动力学模型,并以常规抗氧化剂维生素C作为对照,研究了PQQH_(2)对ABTS自由基的清除性能。结果表明:PQQH_(2)浓度越高,时间越长,对ABTS自由基清除率越高,反应25 min,70 mg/L PQQH_(2)对自由基清除率可达到90%以上。准二级动力学模型拟合的线性相关系数为0.959~0.996,更符合PQQH_(2)对ABTS自由基的清除特性。PQQH_(2)清除ABTS自由基的IC 50值为90μmol/L,是维生素C的51.14%,当保温时间一定时,相同质量浓度的维生素C对ABTS自由基清除能力的损失是PQQH_(2)的2~3倍;当加热温度一定时,相同质量浓度的维生素C对ABTS自由基的清除能力损失约为PQQH_(2)的3~7倍。综上,PQQH_(2)的抗氧化能力优于维生素C。

The changes were discussed in the scavenging rate of ABTS free radicals of reduced pyrroloquinoline quinone(PQQH_(2))under different mass concentrations and different reaction time conditions.The primary and secondary reaction kinetic models were established.With conventional antioxidant vitamin C as a control,the scavenging performance of PQQH_(2) on ABTS free radicals was studied.Results:The higher of the concentration of PQQH_(2) and the longer the time were,the higher of the scavenging rate of ABTS free radicals was.After 25 minutes of reaction,the scavenging rate of 70 mg/L PQQH_(2) could reach more than 90%.The linear correlation coefficient fitted by the quasi-second-order kinetic model was 0.959~0.996,which was more in line with the scavenging characteristics of ABTS free radicals by PQQH_(2).The IC 50 value of PQQH_(2) for scavenging ABTS free radicals was 90μmol/L,which was 51.14%of vitamin C,when the holding time was constant,the loss of ABTS free radical scavenging ability of the same concentration of vitamin C was 2 to 3 times that of PQQH_(2).At a certain temperature,the loss of ABTS free radical scavenging ability of the same concentration of vitamin C was about 3 to 7 times that of PQQH_(2).In summary,PQQH_(2) has better antioxidant capacity than vitamin C.