Abstract：
Bipoladiens A-E (1-5), five new ophiobolin-derived sesterterpenoids, and a known compound 6 (bipolaricin R) were isolated from the cultures of the phytopathogenic fungus Bipolaris maydis. Their structures and absolute configurations were elucidated based on comprehensive spectroscopic analyses, HRESIMS, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction analyses. Notably, compound 1 has an undescribed tetracyclic 5/8/5/7 fused carbon skeleton, and compound 2 possesses a rare multicyclic caged ring system. The biosynthetic pathway of 1 was proposed starting from 6 via a series of oxidation and cyclization reactions. Compound 6 showed excellent antiproliferation and apoptosis induction effects against A549 cell line. Additionally, compounds 5 and 6 exhibited noticeable antimicrobial ability against Bacillus cereus, Staphylococcus aureus, and Staphylococcus epidermidis. These findings not only developed the chemical and bioactivities diversities of ophiobolin-sesterterpenoid but also provided an idea to boost the application of natural products in the control of food pathogens.
摘要：
BipoladiensA-E（1-5），五种新的ophiobolin衍生的酯萜类化合物，和已知的化合物6（双极霉素R）从植物病原真菌BiParlismaydis的培养物中分离出来。根据全面的光谱分析阐明了它们的结构和绝对构型，HRESIMS,电子圆二色性(ECD)计算，和单晶X射线衍射分析。值得注意的是,化合物1具有未描述的四环5/8/5/7稠合碳骨架，化合物2具有罕见的多环笼环体系。通过一系列氧化和环化反应，从6开始提出了1的生物合成途径。化合物6对A549细胞系显示出优异的抗增殖和凋亡诱导作用。此外,化合物5和6对蜡样芽孢杆菌表现出明显的抗菌能力，金黄色葡萄球菌,和表皮葡萄球菌.这些发现不仅发展了ophiobolin-sisterterpenoid的化学和生物活性多样性，而且为促进天然产物在食品病原体控制中的应用提供了思路。
