The thermophilic bacterium Thermoactinomyces vulgaris strain ISCAR 2354, isolated from a coastal hydrothermal vent in Iceland, was shown to contain thermoactinoamide A (1), a new cyclic hexapeptide composed of mixed d and l amino acids, along with five minor analogues (2–6). The structure of 1 was determined by one- and two-dimensional NMR spectroscopy, high-resolution tandem mass spectrometry, and advanced Marfey’s analysis of 1 and of the products of its partial hydrolysis. Thermoactinoamide A inhibited the growth of Staphylococcus aureus ATCC 6538 with an MIC value of 35 μM. On the basis of literature data and this work, cyclic hexapeptides with mixed d/l configurations, one aromatic amino acid residue, and a prevalence of lipophilic residues can be seen as a starting point to define a new, easily accessible scaffold in the search for new antibiotic agents.

中文翻译：

---

Thermoactinoamide A，一种来自冰岛嗜热细菌的嗜热放线菌抗生素亲脂性环肽。

嗜热菌嗜热寻常应变ISCAR 2354，从在冰岛沿海热液喷口分离，显示出含有thermoactinoamide A（1），混合组成的新的环六肽d和升氨基酸，具有五个次要类似物（沿2 - 6）。1的结构通过一维和二维NMR光谱，高分辨率串联质谱法以及先进的Marfey对1及其部分水解产物的分析来确定。嗜热肌动蛋白A抑制金黄色葡萄球菌的生长ATCC 6538的MIC值为35μM。根据文献数据和这项工作，可以将具有混合的d / l构型，一个芳香族氨基酸残基和大量亲脂性残基的环状六肽视为寻找新的，易于接近的支架的起点。新的抗生素制剂。