内生真菌源3-硝基丙酸的分离鉴定及其抗菌作用的研究

Isolation and identification of 3-nitro propionic acid as an antibacterial agent from an endophytic fungus

通过硅胶层析、薄层层析和重结晶技术从一株丹参内生真菌发酵液中分离得到一种抑菌物质,该物质为白色结晶物质,结合核磁共振技术、红外技术、质谱分析鉴定该物质为3-硝基丙酸.经微量肉汤法测定结果表明其具有广谱抗菌作用,其最小抑菌浓度/最小杀菌浓度分别为:对枯草芽孢杆菌1.25mg/mL和2.5mg/mL、大肠杆菌O157:H7为1.25mg/mL和5mg/mL;对金黄色葡萄球菌ATCC 29213、绿脓杆菌、鸡白痢沙门氏菌CVCC 533、肠炎沙门氏菌CVCC 3377为2.5mg/mL和5mg/mL;并且对17-耐沙门氏菌、17-耐金黄色葡萄球菌、14-耐大肠杆菌表现出显著的抑制作用.

An antibacterial substance,a white crystal identified as 3-nitro propionic acid,was isolated from fermentation broth of an endophytic fungus,by silica gel chromatography,thin layer chromatography and recrystallization technology.Its structure was elucidated by spectroscopic methods,mainly 1 H and 13 C nuclear magnetic resonance（NMR）,Infrared Radiation spectrometry,and high-resolution mass spectra.3-nitro propionic acid was displayed a broad inhibition effect on tested pathogenetic bacteria by broth microdilution method.The results showed minimal inhibitory concentration（MIC）and minimum bactericidal concentration（MBC）of 3-nitropropionic acid against Bacillus subtilis were 1.25mg/mL and2.5mg/mL respectively,against Escherichia coli were 1.25mg/mL and 5mg/mL,and against Staphylococcus aureus ATCC 29213,Pseudomonas aeruginosa,Salmonella pullorum CVCC 533,Salmonella enteritidis CVCC 3377 were 2.5mg/mL and 5mg/mL.Moreover it revealed a distinct antibacterial activity against multidrug resistant strains including 17-resistant Salmonella,17-resistant Staphylococcusaureus and 14-resistant Escherichia coli.