木霉菌素的光稳定性及其降解产物分析

Studies on photostability of trichodermin and its degradation products

为明确木霉菌素的光稳定性及其主要降解产物,分别采用可见光、紫外光、纳米氧化钛(TiO2)、纳米氧化钛加紫外光(TiO2-UV)催化降解等技术,测试了木霉菌素的光稳定性;并采用高效液相色谱-质谱(HPLC-MS)分析方法,通过与所合成的木霉菌素衍生物进行对照分析,确定了其主要降解产物,同时分析了其降解后活性降低甚至失活的原因。结果表明:可见光、紫外光和纳米TiO2单独作用时对木霉菌素的降解效果均较差,而TiO2-UV的催化降解效果较好;TiO2-UV催化降解24 h后的主要降解产物为木霉菌素衍生物木霉菌醇、12,13-二羟基木霉菌素(M-1)、(12-H,13-OH)-木霉菌素(M-2)及(12-H,13-OH)-木霉菌醇(M-3)。研究表明,木霉菌素具有很强的光稳定性,而采用TiO2-UV的方式可催化降解木霉菌素,其降解产物活性降低甚至失活可能是由于木霉菌素抑制蛋白质合成的关键基团被降解破坏所致。

In order to determine the photo-stability of trichodermin and its major degradation products, a series of photocatalytic degradation methods were used, including visible light, ultraviolet light, nano-titanium dioxide and ultraviolet plus nano-titanium dioxide. The major degradation products were confirmed using high performance liquid chromatography-mass spectrometry method, compared with some synthesized trichodermin derivatives. The possible reasons that the activity of degradation products decreased or inactivated were investigated. The results showed that when used alone, thevisible light, ultraviolet or nano titanium dioxide had little effects on the degradation of trichodermin. However, ultraviolet plus nano-titanium dioxide was efficient in the degradation of trichodermin. It＇s found that the primary products of degradation were the trichodermin derivatives of trichomermol, 12,13-dyhydroxyl trichodermin （ M-1 ）, （ 12-H, 13-OH） -trichodennin （ M-2 ） and （ 12-H, 13-OH） - trichodermol（M-3）. In conclusion, trichodermin has high photostability, and ultraviolet plus nano- titanium dioxide were efective in degrading the trichodermin. Disruption of the key groups of inhibition protein synthesis in trichodermin may result in decreasing even inactivating the activity of the degradation products.