用乙醇浸提链霉菌702菌株发酵液,滤液真空浓缩成油状物,再用乙酸乙酯萃取,萃取液真空浓缩成浸膏,浸膏通过硅胶柱层析,以氯仿与甲醇不同配比进行梯度洗脱,收集含抗真菌活性物质馏分洗脱液,进行真空浓缩至干燥为抗真菌活性物质粗品。粗品通过制备型HPLC仪进一步分离纯化,用乙腈∶水∶TFA不同浓度进行梯度洗脱,按单组分保留时间收集不同馏分洗脱液,将洗脱液冻干成抗真菌活性单体组分样品。抗菌活性和单组分样品纯度检测分别用管碟法检测对黑曲霉的抑菌活性和分析型HPLC。结果表明,含抗真菌活性单位10 000 mg/L发酵液200 L经乙醇浸提液浓缩后得到含抗真菌活性单位22 500 mg/L的油状物80 L,浸提率为90%;80 L油状物经乙酸乙酯萃取浓缩得含抗真菌活性单位120 000 mg/L的12 L浸膏,萃提率为80%。500 g浸膏经硅胶柱层析,获得含抗真菌活性单位达750 mg/g的粗品48.0802 g。粗品经制备型HPLC仪获得纯度分别达到99.47%和90.28%的抗真菌单组分DZP-8和DZP-9。
From a large-scale fermentation of Streptomyces spp.702,mycelium was extracted from the culture filtrate.Filtration was concentrated under reduced pressure to a brown gum.The brown gum was partitioned in AcOEt.The combined extracts were concentrated under reduced pressure.The AcOEt extract was mixed on silica gel and fractionated through flash chromatography eluting with a gradient mixture of chloroform-methanol giving some fractions of antifungal activity.The crude extract was further separated on preparing high pressure liquid chromatography system with mobile phase acetonitrile,water and TFA gradient elution.Two antifungal compounds,which had inhibitory activity against various fungal pathogens were purified.The antimicrobial activity of the fractions was analyzed by cup-plate method on Aspergillusniger,which determined purity of compound by analyzing HPLC.From a large-scale fermentation(200 L,antifungal activity unit 10 000 mg/L),mycelium was extracted.Combined two filtrate to give 80 L of concentrated liquid(antifungal activity unit 22 500 mg/L).The extraction rates were 90%.After the ethanol extraction extrated by AcOEt and concentrated,a brown gum(12 L,antifungal activity unit 120 000 mg/L) was gained.The extraction rates were 80%.The combined extracts were concentrated under reduced pressure to yield 48.0802 g of a crude extract(antifungal activity unit 750 mg/g).Bioactivity-guided isolation by preparing HPLC provided two macrolactone DZP-8 and DZP-9.