Three new tetronate-class polyketides, nomimicins B, C, and D, along with nomimicin, hereafter named nomimicin A, were isolated from the culture extract of Actinomadura sp. AKA43 collected from floating particles in the deep-sea water of Sagami Bay, Japan. The structures of nomimicins B, C, and D were elucidated through the interpretation of NMR and MS analytical data, and the absolute configuration was determined by combination of NOESY/ROESY and ECD analyses. Nomimicins B, C, and D showed antimicrobial activity against Gram-positive bacteria, Kocuria rhizophila and Bacillus subtilis, with MIC values in the range of 6.5 to 12.5 μg/mL. Nomimicins B and C also displayed cytotoxicity against P388 murine leukemia cells with IC₅₀ values of 33 and 89 μM, respectively.

中文翻译：

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Nomimicins B-D，来自海洋放线菌属放线菌的新型四氢呋喃类聚酮化合物

从Actinomadura sp的培养物提取物中分离出三种新的 tetronate 类聚酮化合物，即拟菌素 B、C 和 D，以及拟菌素（以下称为拟菌素 A）。从日本相模湾深海水中的漂浮颗粒中收集到的 AKA43。通过对 NMR 和 MS 分析数据的解释阐明了拟菌素 B、C 和 D 的结构，并通过 NOESY/ROESY 和 ECD 分析的组合确定了绝对构型。Nomimicins B、C 和 D 显示出对革兰氏阳性菌、Kocuria rhizophila和枯草芽孢杆菌的抗菌活性，MIC 值在 6.5 至 12.5 μg/mL 的范围内。Nomimicins B 和 C 还显示出对 P388 鼠白血病细胞的细胞毒性，IC ₅₀值分别为 33 和 89 μM。