含氢化诺卜基的季铵盐化合物的抑菌活性及其机理研究

The Antibacterial Activity and Mechanism of Hydronopyl Quaternary Ammonium Compounds

以松节油主要成分之一的β-蒎烯为原料合成得到含单氢化诺卜基的单季铵盐(1~13)、含双氢化诺卜基的单季铵盐(14~18)及含双氢化诺卜基的对称型双子季铵盐(19~36)共36个季铵盐类化合物,采用96孔板法,以刃天青作显色剂,以硫酸卡那霉素为阳性对照,测试了化合物对大肠杆菌、恶臭假单胞菌、金黄色葡萄球菌和枯草芽孢杆菌等4种有害细菌的最小抑菌浓度(MIC值)。结果表明:36个季铵盐化合物的抑菌活性都明显优于原料β-蒎烯和关键中间体氢化诺卜醇;分子中含有氢化诺卜基与长碳链烷基的单季铵盐(10~11)、含有双氢化诺卜基的单季铵盐(14~18)以及含有双氢化诺卜基的对称型双子季铵盐(19~36)的抑菌活性均较高,但大多数化合物的MIC值都高于硫酸卡那霉素的MIC值(对恶臭假单胞菌的MIC值为10 mg/L,对另3种菌的MIC值为5 mg/L);而双氢化诺卜基二甲基溴化铵(14)对恶臭假单胞菌的MIC值为1.25 mg/L、对金黄色葡萄球菌和枯草芽孢杆菌的MIC值均为2.5 mg/L,双氢化诺卜基二乙基溴化铵(16)对恶臭假单胞菌的MIC值为2.5 mg/L,均低于阳性对照硫酸卡那霉素的MIC值。此外,初步的抗菌机理研究显示:化合物14可以增加恶臭假单胞菌的细胞膜通透性,使相对电导率明显增加;同时抑制其ATP酶活性,这些氢化诺卜基季铵盐类化合物有望作为潜在的抗菌剂。

In this work,we adopted β-pinene,which was one of the main components of turpentine oil,to synthesize 36 quaternary ammonium compounds including hydronopyl monoquaternary ammonium salts(1-13),dihydronopyl monoquaternary ammonium salts(14-18) and symmetric dihydronopyl bis-quaternary ammonium salts(19-36).The minimum inhibitory concentrations(MIC) of these compounds against four harmful bacteria such as Escherichia coli,Pseudomonas putida,Staphylococcus aureus and Bacillus subtilis were tested by 96-well microtiter plates,using resazurin as chromogenic agent and kanamycin sulfate as the positive control.The results showed that the antibacterial activities of the synthesized quaternary ammonium compounds were significantly higher than that of the starting material β-pinene and the critical intermediate hydronol.The monoquaternary ammonium salts with hydronopyl and long carbon chain alkyl(10-11),the monoquaternary ammonium salts with dihydronopyl(14-18),and the symmetric dihydronopyl bis-quaternary ammonium salts(19-36) had high antibacterial activity,while the MIC values of most quaternary ammonium compounds were higher than those of kanamycin sulfate(the MIC values against P.putida and the other three bacteria are 10 mg/L and 5 mg/L,respectively).The MIC values of dihydronobuyl dimethyl ammonium bromide(14) against P.putida,S.aureus and B.subtilis were 1.25 mg/L,2.5 mg/L,2.5 mg/L,respectively,and the MIC value of dihydronobuyl diethyl ammonium bromide(16) against P.putida was 2.5 mg/L,which was lower than the MIC value of the positive control kanamycin sulfate.Furthermore,the preliminary antibacterial mechanism studies revealed that compound 14 increased the permeability of P.putida cell membranes,resulting in a significant increase in relative conductivity,and at the same time,inhibiting its ATP activity.These hydronopyl quaternary ammonium compounds were expected to be used as potential antimicrobial agents.