The 14-membered macrolide, mutolide (1), was discovered by chemical screening of the culture broth of the fungus F-24′707y, obtained after UV mutagenesis of the wild type strain, which normally produces the spirobisnaphthalene cladospirone bisepoxide (2). The structure of 1 was established by detailed spectroscopic analysis, X-ray analysis and derivatisation. The biogenetic origin of the carbon skeleton and the hydroxy groups was verified by feeding sodium [1-13C]acetate and 18O2 to growing cultures of the fungus. Macrolide 1 is generated from acetate/malonate only. The unexpected change of the normal metabolite pattern of this strain is discussed, and proves the value of the OSMAC method.

中文翻译：

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Mutolide 的结构和生物合成，一种来自真菌 F-24'707 紫外线突变体的新型大环内酯

14 元大环内酯，mutolide (1)，是通过对真菌 F-24'707y 的培养液进行化学筛选发现的，该菌是在野生型菌株的紫外线诱变后获得的，通常会产生螺二萘克拉多螺酮双环氧化物 (2)。1的结构是通过详细的光谱分析、X射线分析和衍生化确定的。通过将[1-13C]乙酸钠和 18O2 加入真菌的生长培养物中，证实了碳骨架和羟基的生物起源。大环内酯 1 仅由醋酸盐/丙二酸盐生成。讨论了该菌株正常代谢物模式的意外变化，并证明了 OSMAC 方法的价值。