几种苯甲酸类化合物对甜菜夜蛾多酚氧化酶活性的影响

为了探讨环境友好杀虫剂的开发途径,以对羟基苯甲酸等5种苯甲酸类化合物为效应物,研究了该类化合物对甜菜夜蛾多酚氧化酶(PPO)活性的影响。结果表明:5种化合物均对该酶表现出一定的抑制作用,其中以对羟基苯甲酸的抑制作用最为显著,I50为0.23 mg/mL,其次为5-甲氧基水杨酸。进一步研究这两种化合物对甜菜夜蛾多酚氧化酶的抑制机理,发现对羟基苯甲酸属于可逆反应的混合型抑制剂,其Ki与Kis分别为0.46 mg/mL和0.02 mg/mL;5-甲氧基水杨酸属于竞争性抑制剂,Ki为0.87 mg/mL。

The Effects of Benzoic Acid Compound Series on PPO of Spodoptera exigua Hübner

The effects of 5 benzoic acid compounds on polyphenol oxidase(PPO) of Spodoptera (exigua) were studied, when they were partially purified by 40% saturated (NH_4)_2SO_4 and Sephadex G-100 gel filtration. The PPO is a key enzyme which takes part in melanin formation, sclerotization, recognition system in the development of insect, The results indicated that (p-hydrobenzoic) acid was the strongest inhibitor with I_(50 ) 0.23 mg/mL, and the second compound was 5-methoxysalicylic. In addition, the results also showed that the PPO activity was inhibited by p-hydrobenzoic acid through mixed-competition with K_i=0.46 mg/mL,K_(is)=0.02 mg/mL,and 5-methoxysalicylic was competitive inhibitor with K_i=0.87 mg/mL.