硬毛棘豆根的抑菌活性成分研究

为明确硬毛棘豆Oxytropis hirta Bunge根的农用抑菌活性成分,用75％乙醇浸提硬毛棘豆根,得到粗提物;再分别以石油醚、乙酸乙酯与正丁醇为溶剂对粗提物进行萃取,得到不同溶剂萃取相;通过活性追踪法对抑菌活性好的乙酸乙酯相运用现代柱层析与波谱学技术进行了分离与结构鉴定,并对所分离的化合物进行了抑菌活性评价.结...

Studies on the antimicrobial constituents from the roots of Oxytropis hirta Bunge

The antifungal and antibacterial chemical constituents in agriculture were identified from the roots of Oxytropis hirta Bunge. The 75% ethanol extract from the roots of O. hirta was further extracted by petroleum ether, ethy acetate and n-butanol, respectively. The most active ethy acetate phase was isolated and identifed for its chemcial constituents by mordern column chromatography and spectroscopy techniques, and the antimicrobial activity of the isolated compounds was evaluted. The results showed that the ethyl acetate phase had the best antimicrobial activity. It showed antifugal activities against Thanatephorus cucumeris and Botrytis cinerea with inhibitory rates of 57.2% and 55.4% at 1 × 103 mg/L, respectively. It also showed antibacterial activities against Pseudomonas solanacearum and Pseudomonas syringae pv. actinidae with the antibacterial circle diameter of 21.8 mm and 19.0 mm, respectively. Six compounds were isolated and identified from the ethyl acetate phase of O. hirta as β-amyrin ( 1 ), 3-oxo-azukisapogenol ( 2 ), 5α-stigmast-9(11)-en-3β-ol ( 3 ), stigmast-4-ene-3,6-dione ( 4 ), 3β,22β,24-trihydroxy-olean-12-ene ( 5 ) and azukisapogenol ( 6 ). The results of antibacterial activity showed that the minimum inhibitory concentration (MIC) of compound 1 against Staphylococcus aureus was 50 mg/L, and the MIC of compound 1 against P. solanacearum, P. syringae and Bacilus subtilis was 100 mg/L. The EC₅₀ value of compound 6 against T. cucumeris and B. cinerea were 117.4 mg/L and 86.2 mg/L, respectively. The ethyl acetate phase of O. hirta showed better inhibitory activity against pathogenic fungi and bacteria. Triterpenoids are one of the main active constituents and have the potential to be further developed as fungicides.