本实验将大蒜切片后于室温下浸泡于10%乙醇水溶液或者蒸馏水一段时间，得到老蒜提取物样品一和样品二；依次用石油醚、乙酸乙酯、正丁醇对样品一和样品二进行萃取，得到不同极性的萃取部位，以多种细菌、霉菌、放线菌为供试菌进行抑菌圈实验，研究各个萃取部位的抑菌活性。实验结果表明石油醚层和乙酸乙酯层表现出了较强的抑菌活性，正丁醇层抑菌活性较弱，水层没有抑菌活性。选取抑菌活性较强的石油醚层和乙酸乙酯层进行了气质联用分析，样品一石油醚层中含有的多种具有二硫键的化合物可能使其具有较强的抑菌活性，而且样品一和样品二的石油醚层和乙酸乙酯层均鉴定出多种酚类物质和有机酸，对其抑菌活性可能有一定的贡献。老蒜提取物样品一、样品二的功能成分存在的差异导致了其抑菌活性的不同。

Two kinds of aged garlic extracts (AGEs) namely AGE-1 and AGE-2 were prepared by soaking fresh garlic slices in a solution of 10% ethanol and distilled water, respectively, for a certain period, at room temperature. Subsequently, AGE-1 and AGE-2 were sequentially extracted with petroleum ether, ethyl acetate, and n-butanol to yield fractions with different polarities. Inhibition zone tests were employed to study the antimicrobial activities of these fractions against multiple bacteria, mold fungi, and actinomycetes. The results showed that the petroleum ether and ethyl acetate fractions exhibited high antimicrobial activities, the n-butanol fraction showed low antimicrobial activity, and the water fraction exhibited no antimicrobial activity. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the petroleum ether and ethyl acetate fractions with high antimicrobial activities. In AGE-1, various compounds containing -S (O) -S- groups in the petroleum ether fraction might have led to the strong antimicrobial activity. In addition, multiple phenols and organic acids were found in the petroleum ether and ethyl acetate fractions from AGE-1 and AGE-2, and they might have contributed to the antimicrobial activities of AGE. The differences in the functional components between AGE-1 and AGE-2 might have caused the difference in their antimicrobial activities.

天津科学技术委员会（14JCZDJC34800）