摘要
Angucyclinones是一类主要由陆地放线菌产生的芳香聚酮类化合物,其生物合成主要是由Ⅱ型聚酮合酶(PKS)催化完成。为了在海洋放线菌中探索此类芳香聚酮类化合物,我们以167株海洋放线菌基因组DNA为模板,对含有Ⅱ型聚酮合酶的菌株进行了PCR筛选,通过对PCR产物测序验证,确定了12株阳性菌株。通过大规模发酵培养和色谱分离、波谱鉴定,从阳性菌株Streptomyces sp.PKU-MA00218中发现了四个angucyclinone芳香聚酮类化合物,6-deoxy-8-O-methylrabelomycin(1),8-O-methylrabelomycin(2),8-O-methyltetrangulol(3),和angucyclinone C的C环裂解产物(4)。化合物4为首次从海洋放线菌中分离得到。Angucyclinone芳香聚酮1–4的发现展示了基于生物合成的基因组挖掘技术在天然产物探索发现中的重要作用。
Angucyclinones are aromatic polyketides produced by type Ⅱ polyketide synthases（PKS） and are mainly found in terrestrial actinomycetes. To discover more angucyclinones from marine actinomycetes, a genomic DNA-based PCR assay targeting type Ⅱ polyketide synthases was performed. Among the 167 marine actinomycetes strains screened, twelve strains were identified as the ＂positive＂ strains possessing type Ⅱ PKS-encoding genes based on the sequencing of PCR products. One of the 12 ＂positive＂ strains, Streptomyces sp. PKU-MA00218 was selected for the large-scale fermentation based on the HPLC and TLC analysis. Four angucyclinones, 6-deoxy-8-O-methylrabelomycin（1）, 8-O-methylrabelomycin（2）, 8-O-methyltetrangulol（3）, C-ring cleavage product of angucyclinone C（4）, were isolated and their structures were elucidated based on spectroscopic analyses. The isolation of angucyclinones 1–4 highlights the power of genome mining technologies based on biosynthetic knowledge in natural products discovery.
基金
National Natural Science Foundation of China(Grant No.81573326)
