抗肿瘤抗生素博安霉素体外产生羟基自由基的自旋捕捉─ESR研究

Spin trapping detection of hydroxyl radicals generated from boanmycin in Vitro

采用电子自旋捕捉技术检测抗肿瘤抗生素博安霉素体外产生羟基自由基（OH）。以5，5’-二甲基吡咯啉-N-氧化物作为羟基自由基捕捉剂．借助电子自旋共振（ESR）波谱仪在室温下检测自由基信号。磷酸缓冲液中单独加入博安霉素或硫酸亚铁，或两者共存．同时在溶液里通入氮气，均无自由基产生；缓冲液中同时加入博安霉素及硫酸亚铁并通入氧气，出现OH信号，信号强弱与博安霉素浓度呈正相关系。博安霉素／硫酸亚铁／氧气系统中加入乙二胺四乙酸二钠或过氧化氢酶，自由基信号明显减弱，上述系统中以硫酸铁胺替换硫酸亚铁，自由基信号消失。

Using DMPO as the trap, the hydroxyl free radical generation byboanmycin/ferrous sulfate/O2 system was detected with spin trapping technique. Neitherboanmycin nor ferrous sulfate alone could produce hydroxyl radicals in phosphate buffersaline (PBS). Adding both boanmycin and ferrous sulfate to PBS and bubbling O2concurrently produced OH, the amplitude of electron spin resonance (ESR ) spectra ofhydroxyl radical increased with boanmycin in a concentration-dependent manner. Thehydroxyl radicals produced by boanmycin were decreased by adding either EDTANa2 orcatalase. With the substitution of ammonium iron(Ⅲ) sulfate for ferrous sulfate(Ⅱ) in PBS-boanmycin system, no ESR spectrum appeared.