芫菁体内斑蝥素的含量及存在形式

Contents and existing forms of cantharidin in Meloidae (Coleoptera)

目的测定芫菁体内斑蝥素的含量及其存在形式。方法利用气相色谱法测定了8种芫菁和作为对照的黑翅红蝉体内总斑蝥素和游离斑蝥素的含量,总斑蝥素含量是通过酸水解法测得的,游离斑蝥素含量是通过直接浸提法测得的,以总斑蝥素与游离斑蝥素含量之差作为结合斑蝥素含量;并比较了结合斑蝥素与钙、镁含量之间的相关性。结果芫菁体内总斑蝥素的含量为游离斑蝥素含量的1~9倍,总斑蝥素的含量一般多于虫体干重的2.0%,而游离斑蝥素的含量均低于虫体干重的1.7%。黑翅红蝉体内不含任何形式的斑蝥素。斑芫菁属和豆芫菁属昆虫中的结合斑蝥素含量与钙元素呈正相关,斑芫菁属中结合斑蝥素含量与镁元素呈正相关,而豆芫菁属中结合斑蝥素含量与镁元素呈负相关。斑芫菁属昆虫体内钙元素的摩尔量要低于结合斑蝥素的摩尔量。结论芫菁体内总斑蝥素含量远高于游离斑蝥素的含量;结合斑蝥素可能是以斑蝥素酸钙和斑蝥素酸镁形式存在。

[Objective] To determine the contents and the existing form of cantharidin in Meloidae. [Methods]The total cantharidin obtained with acidolysis method and the free cantharidin obtained with direct extraction method were determined in eight species of Meloidae and the control species Huechys sanguinea （De Geer） （Homoptera： Cicadidae） by gas chromatography, and the content of the bound cantharidin in each species was calculated with the content difference between the total cantharidin and the free cantharidin. The relationship between the contents of the bound cantharidin and the contents of Ca and Mg elements in Meloidae were assessed. [Results] The results showed that the total cantharidin contents in the samples of Meloidae were 1 to 9 times the free cantharidin contents. The total cantharidin contents were generally higher than 2.0% of dry body weight and the free cantharidin contents were all less than 1.7% of dry body weight in Meloidae. No cantharidin in any form was found in H. sanguinea. Positive relationship was found between the bound cantharidin and Ca element in Mylabris and Epicauta, and between the bound cantharidin and Mg element in Mylabris, but negative relationship was found between the bound cantharidin and Mg element in Epicauta. And the mol of Ca element in Mylabris was lower than that of the bound cantharidin. [Conclusion] The contents of the total cantharidin were higher than the contents of the free cantharidin in Meloidae. The bound cantharidin may exist in the forms of magnesium cantharidate and calcium cantharidate.