阿维菌素包合物的红外光谱研究

依据β-环糊精的分子空腔容纳性质，利用饱和水溶液法制备出阿维菌素-β-环糊精包合物，利用高效液相色谱法测定其包封率。 结合红外光谱谱图说明了阿维菌素-β-环糊精包合物的形成;分析了阿维菌素光解所产生的化学结构变化;研究了所形成的包合物增强阿维菌素化学结构光稳定性的效应。 结果表明：阿维菌素-β-环糊精包合物的包封率为40.5%;从红外光谱谱图分析，说明阿维菌素-β-环糊精包合物形成了分子间氢键，组合效应与其物理混合物有区别。 阿维菌素B1a分子大环内酯结构可以被光分解破坏，分解后大环内酯结构中的C—O—C结构红外伸缩振动峰消失，内酯键发生明显断裂。 形成阿维菌素-β-环糊精包合物后，β-环糊精起包合作用的分子位点覆盖了阿维菌素B1a分子大环内酯结构，为阿维菌素B1a分子大环内酯结构中的C—O—C结构提供良好的避光保护作用，提高了阿维菌素B1a分子的光稳定性。 本实验的创新之处在于对所制备的阿维菌素-β-环糊精包合物的结构和特性从红外光谱角度进行了分析，此类包合物可望作为理想的阿维菌素保护型控释制剂中间体。

Study on the Inclusion Compound of Avermectin by Infrared Spectroscopy

This study was designed to investigate the formation and effect of inclusion complex of Avermectin-β-cyclodextrin based on the accommodation property of β-cyclodextrins molecular cavity. The inclusion complex of Avermectin-β-cyclodextrin was prepared using saturated solution method and high performance liquid chromatography (HPLC) was employed to determine its entraping efficiency. The formation of Avermectin-β-cyclodextrin inclusion complex was also demonstrated by infrared spectroscopy(IR). The change of chemical structure produced by photocatalysis of Abamectin was analyzed and the effect of inclusion complex to strengthen the photolysis stability of Abamectins chemical structure was studied. The results show that the entraping efficiency of the inclusion complex was 40.5%. The IR analysis presents that the intermolecular hydrogen bond was formed in the Avermectin-β-cyclodextrin inclusion complex, indicating the composition effect was different from physical mixture. The lactones structure of Avermectin B1a can be photodecomposed and disrupted. After decomposition, the infrared stretching vibration peak of C—O—C structure disappeared and the lactone bond was significantly broken. The lactones structure of avermectin B1a was covered by the inclusion molecular loci in β-cyclodextrin after the formation of avermectin-β-cyclodextrin inclusion complex, providing a good photophobic protection for C—O—C structure in the macrocyclic lactone structure of avermectin B1a and improving the photostability of avermectin B1a molecule. The innovation of this study is that the structure and the characters of the prepared avermectin-β-cyclodextrin inclusion complex were analyzed using spectrum methods. This inclusion complex is expected to be the ideal intermediate in the construction of protective controlled release formulation of avermectin.