Laboratory of Applied Microbiology, Faculty of Nature Science and Life, University of Bejaia, Targa Ouzemmour 06000, Algeria.
Mar Drugs. 2013 Jan 10;11(1):124-35. doi: 10.3390/md11010124.
Polyketide 13 [=2-hydroxy-5-((6-hydroxy-4-oxo-4H-pyran-2-yl)methyl)-2- propylchroman-4-one] and three related known compounds 7, 9 and 11 were obtained and structurally characterized from Streptomyces sundarbansensis strain, an endophytic actinomycete isolated from the Algerian marine brown algae Fucus sp. Compound 13 was obtained as the major metabolite from optimized culture conditions, by using Agar state fermentation. Due to tautomeric equilibrium, 13 in CD(3)OD solution was able to incorporate five deuterium atoms, as deduced by NMR and ESI-MS/MS analysis. The 2-hydroxy-γ-pyrone form was established for these metabolites based on the comparison of their experimental IR spectra with the DFT calculated ones, for both the corresponding 4-hydroxy-α-pyrone and 2-hydroxy-γ-pyrone forms. During antibacterial evaluation, compound 13 stood out as the most active of the series, showing a selective activity against the gram positive pathogenic methicillin-resistant S. aureus (MRSA, MIC = 6 μΜ), with a bacteriostatic effect.
聚酮化合物 13 [=2-羟基-5-((6-羟基-4-氧代-4H-吡喃-2-基)甲基)-2-丙基色满-4-酮]和三种相关的已知化合物 7、9 和 11 从海洋来源的放线菌 Streptomyces sundarbansensis 中获得，该放线菌是从阿尔及利亚海洋褐藻 Fucus sp. 中分离得到的内生放线菌。化合物 13 是从优化的培养条件中获得的主要代谢产物，采用琼脂状态发酵。由于互变异构平衡，13 在 CD(3)OD 溶液中能够掺入五个氘原子，这可以通过 NMR 和 ESI-MS/MS 分析来推断。基于对相应的 4-羟基-α-吡喃酮和 2-羟基-γ-吡喃酮形式的实验 IR 光谱与 DFT 计算的光谱进行比较，确定了这些代谢物的 2-羟基-γ-吡喃酮形式。在抗菌评估过程中，化合物 13 是该系列中最具活性的化合物，对革兰氏阳性致病耐甲氧西林金黄色葡萄球菌 (MRSA，MIC = 6 μΜ) 具有选择性活性，表现出抑菌作用。
