桑树防卫素体外抗菌作用的初步研究

Primary studies on the antibacterial activities of mulberry phytoalexin in vitro

人工诱导产生桑防卫素 ,经过有机溶剂的提取、进一步柱层析、制备性 TL C及生物显影检查 ,得到 San- 1、M1 、M2 、M3、M4等 5个组分 ,经化学研究已确证 San- 1是多酚类化合物 ,M2 、M3、M4分别为 MoracinG、C、N。采用微量液体稀释法测定最低抑菌浓度 (MIC) ,结果显示 :(1) San- 1、M2 、M3、M4等 4个样品对革兰氏阳性菌都有抑制作用 ,其中 Moracin N(M4)的抗菌作用最强 ,其 MICs为 3.12 5～ 6 .2 5 mg/ L;(2 )对解脲脲原体 (Uu)、人型枝原体 (Mh)、蜜蜂螺原体 (CH- 1、CR- 1)有较好的抑制作用 ,其中 Uu的 MICs为 12 .5～5 0 mg/ L,Mh的 MICs为 2 5～ 10 0 mg/ L,CH- 1、CR- 1的 MIC为 2 5～ 2 0 0 mg/ L,其中 Moracin C(M3)的抗枝原体作用最强。

The mulberry shoots which were induced were extracted with organic solvents. The active fraction was further purified through column and preparative thin layer chromatography, and five phytoalexins such as M 1, M 2, M 3, M 4 and San 1 were obtained. Among them, M 2~4 were identified as moracin G, C and N respectively, San 1 was a phenolic compound. By using the microdilution method, it was discovered that phytoalexin isolated from their cortices showed a potent antibiotic activity and had broad antibiotic spectrum. Moracin N (M 4) was the strongest one. Its MIC range was 3.125~6.25 mg/L against Gram positive bacteria. Results showed that phytoalexin exhibited moderate activities against Mycoplasma. The MIC of phytoalexins against Ureaplasma urealyticum (Uu), Mycoplasma hominis (Mh), Spiroplasma melliferum (Sm CH 1, CR 1) were 12.5~50, 25~100 and 25~200mg/L respectively.