Bioactivity-guided chromatographic methods are of great significance for the isolation of the active compounds in complex samples. In this study, four anti-fungal compounds were located by activity screening and successfully isolated from a microbial fermentation sample by preparative high-performance liquid chromatography. Separation performance of columns including C18, positively charged C18, negatively charged C18 and C8 were firstly investigated. And it showed a better capacity of mixed-mode stationary phases for retention and separation. Therefore, the positively charged C18 column was used to separate the sample into several fractions, among which the active one was identified by the antifungal test. And then the active fraction was enriched and separated again by successively using the negatively charged C18 and C8 columns to obtain four compounds, which were identified as polyoxins A, K, F and H. With activity verification, four polyoxins were found to have good inhibitory effects against the three fungal plant diseases including rice sheath blight, tomato grey mould disease, and apple spot leaf disease.

中文翻译：

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通过制备型高效液相色谱法在生物活性引导下分离抗真菌化合物

生物活性引导的色谱方法对于复杂样品中活性化合物的分离具有重要意义。在本研究中，四种抗真菌化合物通过活性筛选被定位，并通过制备型高效液相色谱从微生物发酵样品中成功分离。首先考察了包括C18、带正电的C18、带负电的C18和C8在内的色谱柱的分离性能。它显示出更好的混合模式固定相的保留和分离能力。因此，使用带正电荷的 C18 柱将样品分成几个部分，其中活性部分通过抗真菌试验鉴定。