犁头草抗菌活性及其有效部位研究

本实验将犁头草全草作为研究对象，采用不同方法对犁头草全草的有效成分进行提取，评价并比较各提取物的抗菌活性。并将粗提物按照极性高低分布在石油醚、乙酸乙酯和水相中，评价不同萃取相的抗菌活性。结果显示，乙醇回流法和甲醇冷浸法获得的提取物抗菌活性明显，而水煎煮得到的提取物几乎未见抗菌活性。此外，乙酸乙酯萃取相的抗菌作用要优于石油醚相，而水萃取相抗菌活性最小。甲醇冷浸法和乙醇回流法获得的乙酸乙酯萃取组对金葡菌ATCC 33591和金葡菌ATCC 43300的抗菌活性最佳，最小抑菌浓度（MIC）值达到0.3125 mg/mL，对其他细菌的MIC值在0.3125~1.25 mg/mL之间；而其他萃取组分对金葡菌、枯草芽孢杆菌、铜绿假单胞菌以及耐药菌的MIC值大约在1.25~5 mg/mL之间。本研究确定了犁头草具有广谱的抗菌活性，尤其对耐甲氧西林金葡菌效果较好。研究发现乙醇回流与甲醇冷浸法可用于犁头草的抗菌物质提取，且它的抗菌有效部位为乙酸乙酯萃取相。

ANTIBACTERIALACTIVITY AND EFFECTIVE PARTS OF VIOLA JAPONICA

In this experiment, different methods were used to extract the effective components from the dried whole grass of Viola japonica, and the antibacterial activity of each extract was evaluated and compared. The crude extracts were distributed in petroleum ether, ethyl acetate and aqueous phase according to their polarity. The antibacterial activity of different extraction phases were also evaluated. The results showed that the extracts obtained by ethanol reflux and methanol cold soak showed obvious antibacterial activity, while the extracts obtained from water boiling had no obvious antibacterial activity. The antibacterial effect of ethyl acetate extraction phase was better than that of petroleum ether extraction phase, and the least for water extraction phase. The ethyl acetate extraction obtained from methanol cold immersion method and ethanol reflux method had the best antibacterial activity against Staphylococcus aureus ATCC 33591 and ATCC 43300, with the minimum inhibitory concentration (MIC) value of 0.3125 mg/mL. And the MIC values against the other bacteria fell between 0.3125 and 1.25 mg/mL. The MIC value of other extracts to S. aureus, Bacillus subtilis, Pseudomonas aeruginosa and drug-resistant bacteria is about 1.25~5 mg/mL. This study preliminarily confirmed that V. japonica has broad-spectrum antibacterial activity, especially for methicillin-resistant S. aureus. Ethanol reflux and methanol cold soak methods can be used for the extraction of antibacterial substances from V. japonica, and its antibacterial active part is the ethyl acetate extraction phase.