The skyllamycins are a class of heavily modified, non-ribosomal peptides, first isolated from Streptomyces sp. KY11784. A Streptomyces strain with potent antibiotic activity against Bacillus subtilis was isolated from a sample of the New Zealand lichen Pseudocyphellaria dissimilis. Whole genome sequencing and biosynthetic gene cluster genetic analysis coupled with GNPS LCMS/MS molecular networking revealed that this strain had the capacity to produce skyllamycins, including previously undescribed congeners, and that these were likely the source of the observed biological activity. Guided by the results of the molecular networking, we isolated the previously reported skyllamycins A–C (1–3), along with two new congeners, skyllamycins D (4) and E (5). The structures of these compounds were elucidated using comprehensive 1D and 2D NMR analyses, along with HRESIMS fragmentation experiments. Antibacterial assays revealed that skyllamycin D possessed improved activity against B. subtilis E168 compared to previously reported congeners.

中文翻译：

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Skyllamycins D 和 E，来自地衣来源的环状链霉菌的非核糖体环状缩肽

skyllamycins 是一类经过高度修饰的非核糖体肽，首先从Streptomyces sp. 中分离出来。KY11784。甲链霉菌用针对强效的抗菌活性菌株枯草芽孢杆菌从新西兰地衣的样品中分离Pseudocyphellaria dissimilis。全基因组测序和生物合成基因簇遗传分析与 GNPS LCMS/MS 分子网络相结合，表明该菌株具有产生 Skyllamycins 的能力，包括以前未描述的同源物，并且这些很可能是观察到的生物活性的来源。在分子网络结果的指导下，我们分离了先前报道的skyllamycins A–C ( 1 – 3)，以及两个新的同类物，skyllamycins D ( 4 ) 和 E ( 5 )。这些化合物的结构通过综合 1D 和 2D NMR 分析以及 HRESIMS 碎裂实验进行了阐明。抗菌试验表明，与先前报道的同类物相比，skyllamycin D 对枯草芽孢杆菌E168 的活性有所提高。