采用玻片浸渍法,测定并筛选了25种具有代表性的香豆素类化合物对朱砂叶螨Tetranychus cinnabarinus雌成螨的触杀活性,并构建了一个预测能力较强的定量构效关系(QSAR)模型。结果表明:所有供试化合物对朱砂叶螨均具有触杀活性,且随着处理时间的延长活性升高。处理48 h后,LC50值低于1 000 mg/L的化合物有8个,分别是3-(2-苯并咪唑)-7-(二乙氨基)香豆素(1)、3-(2-苯并噻唑)-7-(二乙氨基)香豆素(2)、3-氨基香豆素(3)、3-乙酰基香豆素(4)、4-甲氧基香豆素(5)、6-硝基香豆素(8)、6,7-二甲氧基香豆素(13)和7,8-二羟基香豆素(21),其中化合物1、2、3、5和13的杀螨活性优于药剂对照螺螨酯或与其活性相当;活性最好的化合物为13,处理48 h和72 h后LC50值分别为284.8和122.2 mg/L,其毒力约为螺螨酯的2倍。通过计算得到25种香豆素类化合物的34种物化参数,以此为描述子,经过SPSS相关性剔除、逐步回归分析和校正,得到一个以扭转力、取向力、总能量和分子半径为自变量的QSAR模型,该模型复相关系数R达到0.987,复判定系数R2也达到0.967,通过F检验证明上述模型具有较高的预测能力。
The acaricidal bioactivities of 25 representative coumarin compounds were evaluated by slide-dip method and a quantitative structure-activity relationship(QSAR) model with strong predictive ability was established. The acaricidal assay results showed that all the tested compounds exhibited high contact activity against Tetranychus cinnabarinus and the contact activity increased with prolongation of treatment time. The 48 h LC50 values of 8 compounds [3-(2-benzimidazolyl)-7-(diethylamino)coumarin(1), 3-(2- benzothiazolyl)-7-(diethylamino)coumarin(2), 3-aminocoumarin(3), 3-acetylcoumarin(4), 4- methoxycoumarin(5), 6-nitrocoumarin(8), 6,7-dimethoxy coumarin(13), 7,8-dihydroxy- coumarin(21)] were less than 1 000 mg/L. The acaricidal activities of compouds 1, 2, 3, 5and 13 were higher or comparable to 98.32% spirodiclofen TC. The 48 h and 72 h LC50 values of the compound with the highest acaricidal activity(13) were 284.8 and 122.2 mg/m L respectively. The acaricidal activity against T. cinnabarinus of compound 13 was two fold higher than that of spirodiclofen. 34 physicochemical parameters of the above mentioned 25 coumarin compounds were calculated and used to build a QSAR model. SPSS Stepwise Regression analysis method was applied,without correlation and correcting. And the Stretch-Bend Dipole, Dipole, Total Energy and Molecular Radius were taken as independent variables in the model. This model has a strong predictive ability with R = 0.987, R2 = 0.967 and F = 155.176.