Asterric acid and its analogs belong to diphenyl ethers (DPEs) with multiple substitutions on A/B aromatic rings. This member of DPEs originates from the polyketide pathway and displays a wide range of biological effects. Though the structures of asterric acid analogs are not complex, there were only more than 50 asterric acid analogs found in nature from 1960 to 2023. In this review, the structures, bioactivities, and biosynthesis of asterric acid analogs are summarized. More importantly, the empirical rule about the shielding effect of B-ring on H-6 is suggested, and this provides a convenient and useful way to analyze the NMR spectral data of asterric acid analogs, based on which the chemical shift values of the A-ring in some asterric acid analogs are revised.

中文翻译：

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天然存在的紫苑酸类似物：化学和生物学

紫苑酸及其类似物属于 A/B 芳环上有多个取代基的二苯醚 (DPE)。DPE 的这一成员源自聚酮化合物途径，并表现出广泛的生物效应。虽然星形酸类似物的结构并不复杂，但从1960年到2023年，自然界中仅发现了50多种星形酸类似物。本文对星形酸类似物的结构、生物活性和生物合成进行了综述。更重要的是，提出了B环对H-6屏蔽效应的经验规律，为分析紫星酸类似物的NMR谱数据提供了一种方便有效的方法，并在此基础上确定了A环的化学位移值。一些星形酸类似物中的-环被修改。