Key Laboratory of Phytochemistry and Plant Resources in West China , Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650201 , People's Republic of China.
Graduate University of the Chinese Academy of Sciences , Beijing 100049 , People's Republic of China.
J Org Chem. 2018 May 18;83(10):5516-5522. doi: 10.1021/acs.joc.8b00525. Epub 2018 May 4.
A pair of new natural meroterpenoids, (±)-cochlactone A (1) possessing a bicyclo[4.4.0]decane ring system with a γ-lactone fragment, was isolated from Ganoderma cochlear. To further confirm their absolute configurations, a high-yielding, one-step biomimetic synthesis of (±)-cochlactone A (1) from ganomycin C (3) was conducted. In addition, a new compound, (±)-cochlactone B (2), featuring a bicyclo[3.3.1]decane fragment fused to a γ-lactone moiety was synthesized. Their structures were determined using spectroscopic data, X-ray diffraction crystallography, and electronic circular dichroism (ECD) analyses. Furthermore, a plausible reaction mechanism for the formation of 1 and 2 was proposed. Compounds (+)-2 and (±)-2 showed inhibitory effects against Staphylococcus aureus with MIC values of 41.1 ± 0.1 and 64.0 ± 2.6 μg/mL, respectively. Meanwhile, (±)-1, (-)-1, (+)-2, and (±)-2 displayed significant anti-inflammatory activities (IC: 5.9 ± 0.1, 6.1 ± 0.2, 12.1 ± 0.4, and 18.7 ± 1.9 μM, respectively).
一对新的天然倍半萜类化合物（±）-cochlactone A（1），具有双环[4.4.0]癸烷环系统和γ-内酯片段，从 Cochlear Ganoderma 中分离得到。为了进一步确定它们的绝对构型，从 Ganomycin C（3）进行了高产一步仿生合成（±）-cochlactone A（1）。此外，合成了一种新的化合物（±）-cochlactone B（2），其特征是双环[3.3.1]癸烷片段与γ-内酯部分融合。它们的结构通过光谱数据、X 射线衍射晶体学和电子圆二色性（ECD）分析确定。此外，还提出了形成 1 和 2 的可能反应机制。化合物（+）-2 和（±）-2 对金黄色葡萄球菌表现出抑制作用，MIC 值分别为 41.1 ± 0.1 和 64.0 ± 2.6 μg/mL。同时，（±）-1、（-）-1、（+）-2 和（±）-2 表现出显著的抗炎活性（IC：5.9 ± 0.1、6.1 ± 0.2、12.1 ± 0.4 和 18.7 ± 1.9 μM，分别）。
