(+)- and (-)-cochlearols A (1) and B (2), two meroterpenoids with novel polycyclic skeletons, were isolated from the fruiting bodies of the fungus Ganoderma cochlear. Their structures and stereochemistry were determined by using spectroscopic, computational and single-crystal X-ray diffraction methods. Cochlearol A is a new normeroterpenoid containing a naturally unusual dioxaspiro[4.5]decane motif. Biological studies showed that (-)-2 is a strong inhibitor of p-Smads, exhibiting renoprotective activities in TGF-beta 1 induced rat renal proximal tubular cells.
(+)和(-)-cochlearol A (1)和B (2)是从真菌Ganoderma cochlear的子实体中分离得到的两种具有新颖多环骨架的倍半萜类化合物。它们的结构和立体化学通过光谱分析、计算和单晶X射线衍射方法确定。Cochlearol A是一种新型的倍半萜类化合物,含有一个在自然界中罕见的dioxaspiro[4.5]decane骨架。生物研究表明,(-)-2是p-Smads的强抑制剂,在TGF-beta 1诱导的肾小管上皮细胞模型中显示出保护肾脏的作用。
Total Synthesis of Cochlearol B via Intramolecular [2+2] Photocycloaddition
The first total synthesis of cochlearol B is reported. Utilization of Nozaki–Hiyama–Kishi reaction, oxidative cyclization and intramolecular [2+2] photocycloaddition, resulted in the completion of the total synthesis with 16 steps, and in 9 % overall yield. X-ray crystallographic analyses of synthesized intermediate and cochlearol B clearly confirmed the stereochemistry.
报道了首次全合成耳蜗酚 B。利用 Nozaki-Hiyama-Kishi 反应、氧化环化和分子内 [2+2] 光环加成,共完成 16 步全合成,总产率为 9%。合成的中间体和耳蜗酚 B 的 X 射线晶体学分析清楚地证实了立体化学。
Bioinspired synthesis of cochlearol B and ganocin A
作者:Zhenhao Wang、Yuliang Tang、Ruyu Li、Shuai Tian、Yu Tang、Dehai Li
DOI:10.1016/j.cclet.2023.109247
日期:2024.7
the chromene unit construction through a biomimetic acid-catalyzed [4 + 2] ring cyclization. A photochemical [2 + 2] cycloaddition was featured to construct the cyclobutane core of cochlearol B. Different skeletal rearrangements of cochlearol B afforded ganocin A, that one of them was Lewis acid mediated epoxide rearrangement and another was DDQ induced cyclobutane formed tetrahydrofuran ring. The
这里描述的是一种不同的、受生物合成启发的耳蜗醇 B 和甘诺辛 A 的合成。合成的关键步骤包括通过仿生酸催化的 [4 + 2] 环环化构建色烯单元。通过光化学[2+2]环加成反应构建了cochlearol B的环丁烷核心。cochlearol B的不同骨架重排得到了ganocin A,其中一种是Lewis酸介导的环氧化物重排,另一种是DDQ诱导环丁烷形成四氢呋喃环。所描述的合成不仅以有效的方式获得了这些天然产物,而且还提供了对两种不同骨架之间的生物合成关系的深入了解。