Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.
Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China; Key Laboratory of Organ Transplantation, Ministry of Education, People's Republic of China; NHC Key Laboratory of Organ Transplantation, People's Republic of China; Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, People's Republic of China.
Bioorg Chem. 2020 Jun;99:103816. doi: 10.1016/j.bioorg.2020.103816. Epub 2020 Apr 9.
Three previously undescribed compounds, including a meroterpenoid, guignardone T (1), and two ophiobolin-type sesterterpenoids, maydispenoids A and B (2 and 3), along with four known compounds (4-7), were isolated from the phytopathogenic fungus Bipolaris maydis collected from Anoectochilus roxburghii (Wall.) Lindl leaves. The structures of all undescribed compounds were elucidated by spectroscopic analysis, electronic circular dichroism (ECD) calculations and single-crystal X-ray diffraction. Structurally, maydispenoids A was characterized by a fascinating decahydro-3-oxacycloocta[cd]pentalene fragment. It is notable that the compounds 2 and 3 exhibited potential inhibitory activity in anti-CD3/anti-CD28 monoclonal antibodies (mAbs) stimulated murine splenocytes proliferation, with IC values of 5.28 and 9.38 μM, respectively, and also suppress the murine splenocytes proliferation activated by lipopolysaccharide (LPS), with IC values of 7.25 and 16.82 μM, respectively. This is the first report of ophiobolin-type sesterterpenoids as immunosuppressor, and may provide new chemical templates for the development of new immunosuppressive drugs for autoimmune disease treatment.
从采自 Anoectochilus roxburghii (Wall.) Lindl 叶片的植物病原菌串珠镰刀菌中分离得到三个以前未描述的化合物，包括一个倍半萜类化合物，guignardone T（1），和两个 ophiobolin 型倍半二萜，maydispenoids A 和 B（2 和 3），以及四个已知化合物（4-7）。通过光谱分析、电子圆二色性（ECD）计算和单晶 X 射线衍射解析了所有未描述化合物的结构。在结构上，maydispenoids A 的特征是一个迷人的十氢-3-氧杂环辛[cd]戊并[cd]戊烷片段。值得注意的是，化合物 2 和 3 对抗 CD3/抗 CD28 单克隆抗体（mAbs）刺激的小鼠脾细胞增殖具有潜在的抑制活性，IC 值分别为 5.28 和 9.38 μM，并且还抑制脂多糖（LPS）激活的小鼠脾细胞增殖，IC 值分别为 7.25 和 16.82 μM。这是首次报道 ophiobolin 型倍半二萜作为免疫抑制剂，可为开发用于治疗自身免疫性疾病的新型免疫抑制剂提供新的化学模板。
