Pentacyclic Cytochalasins and Their Derivatives from the Endophytic Fungus Phomopsis sp. xz-18

Molecules

Qingyan Xu¹  Xianming Deng¹  Weiwen Lin¹  Zhiyu Hu¹  Huiying Huang¹  Guichon Huang¹  Hanpeng Li¹  Qian Tang¹ 

[1] State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China;

关键词: cytochalasins;    pentacyclic system;    octant rule;    antibacterial activity;   

DOI  :  10.3390/molecules26216505

来源: DOAJ

【 摘 要 】

Eight new cytochalasins 1–8 and ten known analogs 9–18 were isolated from the endophytic fungus Phomopsis sp. xz-18. The planar structures of the cytochalasins were determined by HR-ESI-MS and NMR analysis. Compounds 1, 2, 9 and 10 were 5/6/6/7/5-fused pentacyclic cytochalasins; compounds 3 and 4 had conjugated diene structures in the macrocycle; and compound 6 had a β,γ-unsaturated ketone. The absolute configuration of 6 was confirmed for the first time by the octant rule. The acid-free purification process proved that the pentacyclic system was a natural biosynthetic product and not an acid-mediated intramolecular cyclized artifact. The new compounds did not exhibit activities against human cancer cell lines in cytotoxicity bioassays or antipathogenic fungal activity, but compounds 1, 3 and 4 showed moderate antibacterial activity in disk diffusion assays.

【 授权许可】

Unknown