海洋链霉菌Streptomyces parvus SCSIO Mla-L010中大环内酰胺类抗生素vicenistatin的糖基定向改造

目的 利用海洋链霉菌Streptomyces parvus SCSIO Mla-L010中糖基转移酶的底物宽泛性对vicenistatin进行糖基定向化改造。方法 采用组合生物合成技术分别将其它糖苷类天然产物生物合成途径中的糖基合成基因导入到SCSIO Mla-L010菌株中，构建糖基合成基因异源表达重组菌株；以有机溶剂萃取重组菌株发酵产物并利用现代色谱分离技术进行化合物纯化，进一步使用质谱、核磁共振光谱技术鉴定所获化合物的结构。结果 将streptolydigin、grincamycin和lobophorin生物合成途径中合成D-olivose、L-rhodinose和L-digitoxose糖基的基因导入到SCSIO Mla-L010菌株中，构建了3株异源糖基合成基因重组菌株，并从中分离得到4个含有不同糖基的新vicenistatin类天然产物。结论 不仅丰富了糖苷类天然产物结构库，为海洋药物的研发提供化学实体，还为利用糖基转移酶的底物宽泛性对其它天然产物进行糖基定向改造提供参考和借鉴。

Engineered glycosylation of macrolactam antibiotic vicenistatin in marine Streptomyces parvus SCSIO Mla-L010

Objective To obtain vicenistatin analogues with different sugar moieties by applying the broad substrate specificity of glycosyltransferase in a potential vicenistatin producing strain Streptomyces parvus SCSIO Mla-L010. Methods The recombinant strains were constructed by introducing the sugar biosynthetic genes of other glycoside natural products into the SCSIO Mla-L010 strain. The fermentation broths were extracted by solvent extraction and the targeted vicenistatin analogues were isolated and purified by a combination of chromatographic separation technologies. The structures of the purified compounds were elucidated by HRMS and intensive NMR analyses Results The biosynthetic genes responsible for the formation of D-olivose, L-rhodinose and L-digitoxose in the biosynthetic pathway of streptolydigin, grincamycin and lobophorin, respectively, were transferred into S. parvus SCSIO Mla-L010 to generate three recombinant strains. Four new vicenistatin analogues containing diverse sugar moieties were isolated from the fermentation broth of these recombinant strains. Conclusion This study not only provides chemical substance for the research and development of marine drugs, but also provides reference for the glycodiversification of other natural products by utilizing the broad substrate of glycosyltransferase.