Cytotoxic xanthones from the plant endophytic fungus Paecilamyces sp. TE-540

Abstract

One new xanthone, chryxanthone C (1), together with four known analogues (2−5), were isolated from the cultures of Paecilamyces sp. TE-540, an endophytic fungus obtained from the leaves of Nicotiana tabacum L. The structure of 1 was elucidated by comprehensive spectral analysis including HRESIMS and 1D/2D NMR, which were confirmed by Cu Kα X-ray crystallography. Compound 1 featured an unusual dihydropyran ring fused to an aromatic ring, rather than the commonly occurring prenyl moiety. The cytotoxicity of compounds 1−5 were evaluated against five human tumour cell lines and 4 exhibited moderate to strong cytotoxicities with IC₅₀ values ranging from 5.6 to 14.2 µM.

Keywords:

• endophytic fungus
• Paecilamyces sp.
• secondary metabolites
• xanthones
• cytotoxicity

Supplementary material

Supplementary material relating to this article is available online, including HRESIMS, 1D and 2D NMR spectra, and single-crystal X-ray structure of compound 1.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research work was financially supported by the National Natural Science Foundation of China (31700295), and the Agricultural Science and Technology Innovation Program (ASTIP-TRIC05).