紫茎泽兰甲醇提取物对石膏样小孢子菌的抑制作用及其机制

通过硅胶柱层析、薄层层析和气相色谱-质谱联用方法,从紫茎泽兰(Ageratina adenophorais)甲醇提取物中分离、鉴定出3类化合物,分别为9-羰基-10,11-去氢泽兰酮(euptox A)、3-烯-2,7-二酮-杜松萜烯(CED)和烯烃类化合物。使用含毒介质法分别检测125、62.5、31.25、15.6、7.8、3.9、1.95和0.98 μg·mL^-1的euptox A和CED在48、72、96、120、144 h时对石膏样小孢子菌(Microsporidium gypsum)的抑制率。对euptox A处理过的石膏样小孢子菌开展碘化丙啶(PI)染色试验,并测定其细胞膜麦角固醇含量,以及细胞外液中总蛋白质和总磷的含量。结果显示,紫茎泽兰甲醇提取物中euptox A和CED具有一定的抗真菌活性,且以euptox A的效果更好。经euptox A作用后,石膏样小孢子菌的菌丝在荧光显微镜下呈现出强红色荧光,细胞外液中总蛋白质和总磷含量显著(P<0.05)增加,麦角固醇的含量显著(P<0.05)降低。据此推测, euptox A作用于石膏样小孢子菌后,可通过抑制其麦角固醇合成,使细胞膜完整性受到破坏,导致细胞内外物质交换紊乱,从而最终引起真菌细胞死亡。

Inhibition effect of Ageratina adenophorais methanol extracts against Microsporidium gypsum and its mechanism

In the present study, 9-oxo-10,11-dehydroagerophorone (euptox A), cadinan-3-ene-2,7-dione (CED) and olefin compounds were separated and identified from Ageratina adenophorais methanol extract by silica gel column chromatography, thin-layer-chromatography and gas chromatography-mass spectrometer. The inhibition effects of 125, 62.5, 31.25, 15.6, 7.8, 3.9, 1.95 and 0.98 μg·mL^-1 euptox A and CED against Microsporidium gypsum were determined at 48, 72, 96, 120, 144 h, respectively. The Microsporidium gypsum samples treated with euptox A were selected as test materials, dye penetration test with propidium iodide (PI) was carried out, and the content of total protein and total phosphorus in extra-cellular fluid, and ergo-sterol content in mycelium were determined. It was shown that the separated euptox A and CED from Ageratina adenophorais methanol extract could inhibit the growth of Microsporidium gypsum, and euptox A possessed stronger inhibition effect. After the treatment with euptox A, the hyphae of Microsporidium gypsum showed strong red fluorescence under fluorescence microscope. The contents of total protein and total phosphorus in extracellular fluid of Microsporidium gypsum were significantly (P<0.05) increased, yet the ergo-sterol content in mycelium was significantly (P<0.05) decreased. It was inferred that euptox A could inhibit the synthesis of ergo-sterol, cause membrane damage, and lead to cellular disorder and cell death.