Microbial Strain Collection, Helmholtz-Centre for Infection Research (HZI), Inhoffenstr. 7, 38124 Braunschweig, Germany.
German Centre for Infection Research (DZIF), partner site Hannover-Braunschweig, 38124 Braunschweig, Germany.
Mar Drugs. 2020 May 26;18(6):280. doi: 10.3390/md18060280.
sp. M2 has been isolated from a soil sample collected at the Wadden Sea beach in our ongoing program aimed at the isolation of rare Actinobacteria, ultimately targeting the discovery of new antibiotics. Because crude extracts derived from cultures of this strain showed inhibitory activity against the indicator organism , it was selected for further analysis. HPLC-MS analysis of its culture broth revealed the presence of lipophilic metabolites. The two major metabolites of those were isolated by preparative reversed-phase HPLC and preparative TLC. Their planar structures were elucidated using high-resolution electrospray ionization mass spectrometry (HRESIMS), 1D and 2D NMR data as new thiopeptide antibiotics and named litoralimycin A () and B (). Although rotating frame nuclear Overhauser effect spectroscopy (ROESY) data established a Z configuration of the Δ double bond, the stereochemistry of C-5 and C-15 were assigned as S by Marfey's method after ozonolysis. The biological activity spectrum of and is highly uncommon for thiopeptide antibiotics, since they showed only insignificant antibacterial activity, but showed strong cytotoxic effects.
sp. M2 是从我们正在进行的从瓦登海海滩土壤样本中分离出来的稀有放线菌的项目中分离出来的，该项目的目的是发现新的抗生素。因为从该菌株培养物中提取的粗提取物对指示生物显示出抑制活性，所以选择该菌株进行进一步分析。对其发酵液的 HPLC-MS 分析表明存在亲脂性代谢物。使用高效液相色谱-质谱分析（HPLC-MS）、1D 和 2D NMR 数据从这些代谢物中分离出两种主要的代谢物，并通过高分辨率电喷雾电离质谱（HRESIMS）确定了它们的平面结构，将两种新噻肽抗生素命名为 litoralimycin A（）和 B（）。尽管旋转框架核奥弗豪瑟效应光谱（ROESY）数据确定 Δ双键的 Z 构型，但通过臭氧化后 Marfey 法确定 C-5 和 C-15 的立体化学构型为 S。和 的生物活性谱对于噻肽抗生素来说非常罕见，因为它们仅显示出微不足道的抗菌活性，但 显示出强烈的细胞毒性作用。
