地木耳中脂溶性物质抑菌活性研究

Study on Antibacterial Effects of Fat-soluble Compositions in Nostoc commune

采用索氏提取法从地木耳中提取脂溶性物质,经硅胶柱层析将脂溶性物质分离成石油醚洗脱组分(非极性脂)、苯洗脱组分(弱极性脂)和乙醇洗脱组分(强极性脂),并对脂溶性物质和3种洗脱组分进行抑菌活性研究,以促进地木耳的综合应用。结果表明,地木耳中脂溶性物质含量为2.62%。其中,非极性石油醚洗脱组分含量最高,占总脂的54%,但无抑菌活性;强极性的乙醇洗脱组分含量其次,占总脂的32%,其抑菌活性最强;弱极性苯洗脱组分含量最低,占总脂的14%,有弱抑菌活性。地木耳脂溶性物质对6种菌有较好的抑制作用,其抑制能力大小为:大肠杆菌>金黄色葡萄球菌>枯草芽孢杆菌>黑曲霉>酿酒酵母>假单胞杆菌。

The antibacterial effects of fat-soluble compositions from Nostoc commune Vauch. were studied in order to contribute to diverse nutritional and medicinal values of N. commune. Soxhlet extraction method was used to extract crude fats from N. commune, and antimicrobial activities of the liposoluble compounds and fractions isolated by column chromatography were assayed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas stutzeri, Asparagillus niger and Saccharomyces cerevisiae. The results showed fat-soluble compositions were about 2.62%in N. commune. Ethanol elution fractions showed most greatly antimicrobial activities against six bacterial stains while its contents was 32%of crube fats, the benzene fraction with the yeild of 14%in crube fats had worse antimicrobial activities than ethanol elution fractions, and the petroleum ether extract was not inhibitory to six bacterial stains with the yeild of 54%in crube fats. Fat-soluble compositions had most strongly inhibitory effect on E.coli with IC50 38.75 mg/mL and MIC 64.0 mg/mL and they had least inhibitory effect on Pseudomonas stutzeri with IC50 89.58 mg/mL and MIC 106.5 mg/mL. Fat-soluble compositions showed antibacterial effects against six bacterial stains：Escherichia coli〉Staphylococcus aureus〉Bacillus subtilis〉Asparagillus niger〉Saccharomyces cerevisiae〉Pseudomonas stutzeri.