Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States.
Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States.
J Org Chem. 2021 Aug 20;86(16):11140-11148. doi: 10.1021/acs.joc.1c00262. Epub 2021 Apr 12.
The chemical examination of two undescribed marine actinobacteria has yielded three rare merosesterterpenoids, marinoterpins A-C (-, respectively). These compounds were isolated from the culture broth extracts of two marine-derived actinomycetes associated with the family Streptomycetaceae, (our strains were CNQ-253 and AJS-327). The structures of the new compounds were determined by extensive interpretation of 1D and 2D NMR, MS, and combined spectroscopic data. These compounds represent new chemical motifs, combining quinoline--oxides with a linear sesterterpenoid side chain. Additionally, consistent in all three metabolites is the rare occurrence of two five-ring ethers, which were derived from an apparent cyclization of methyl group carbons to adjacent hydroxy-bearing methylene groups in the sesterterpenoid side chain. Genome scanning of AJS-327 allowed for the identification of the marinoterpin () biosynthetic cluster, which consists of 16 open-reading frames that code for a sesterterpene pyrophosphate synthase, prenyltransferase, type II polyketide synthase, anthranilate:CoA-ligase, and several tailoring enzymes apparently responsible for installing the -oxide and bis-tetrahydrofuran ring motifs.
对两种未描述的海洋放线菌的化学研究产生了三种罕见的单酯二萜类化合物，分别为 marinoterpins A-C（-）。这些化合物是从与链霉菌科相关的两种海洋来源放线菌的培养肉汤提取物中分离出来的（我们的菌株为 CNQ-253 和 AJS-327）。新化合物的结构通过广泛的 1D 和 2D NMR、MS 和组合光谱数据的解释来确定。这些化合物代表了新的化学主题，将喹啉氧化物与线性甾体侧链结合在一起。此外，在所有三种代谢物中都存在两个罕见的五元环醚，这是甾体侧链中甲基碳原子与相邻带羟甲基的亚甲基发生明显环化的结果。对 AJS-327 的基因组扫描允许鉴定 marinoterpin（）生物合成簇，该簇由 16 个开放阅读框组成，编码甾体焦磷酸合酶、 prenyltransferase、II 型聚酮合酶、邻氨基苯甲酸：CoA-连接酶和几个修饰酶，这些酶显然负责安装 -氧化物和双四氢呋喃环结构。
