School of Pharmaceutical Sciences , South-Central University for Nationalities , Wuhan , Hubei 430074 , P.R. China.
Kunming Institute of Botany, Chinese Academy of Sciences , Kunming 650204 , P.R. China.
Org Lett. 2019 Feb 15;21(4):1108-1111. doi: 10.1021/acs.orglett.9b00015. Epub 2019 Jan 25.
Curtachalasins C-E (1-3), which have an unprecedent bridged 6/6/6/6 ring system, were identified from the endophytic fungus Xylaria cf. curta. Residual dipolar coupling analyses associating with density functional theory calculations were utilized to determine the relative configuration of noncrystallizable compound 2. The absolute configurations of 1-3 were determined by X-ray diffraction and electronic circular dichroism calculations. Remarkably, curtachalasin C (1) showed significant resistance reversal activity against fluconazole-resistant Candida albicans.
从内生真菌 Xylaria cf. curta 中鉴定出 Curtachalasins C-E（1-3），它们具有前所未有的桥接 6/6/6/6 环系统。利用残基偶极耦合分析结合密度泛函理论计算确定了不可结晶化合物 2 的相对构型。通过 X 射线衍射和电子圆二色性计算确定了 1-3 的绝对构型。值得注意的是，Curtachalasin C（1）对氟康唑耐药白色念珠菌表现出显著的耐药逆转活性。
