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

  • Molecules. 2021 Oct 28;26(21):6505. doi: 10.3390/molecules26216505.
Guichon Huang  1 ,  Weiwen Lin  1 ,  Hanpeng Li  1 ,  Qian Tang  1 ,  Zhiyu Hu  1 ,  Huiying Huang  1 ,  Xianming Deng  1  2 ,  Qingyan Xu  1  2
Affiliations
  • 1. State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.
  • 2. State-Province Joint Engineering Laboratory of Targeted Drugs from Natural Products, Xiamen University, Xiamen 361102, China.
PMID: 34770914 DOI: 10.3390/molecules26216505
Abstract

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.

Keywords
antibacterial activity; cytochalasins; octant rule; pentacyclic system.
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