The 2,3-epoxy naphthoquinol produced by endophyte Arthrinium marii M-211

Abstract

A novel 2,3-epoxy naphthoquinol, named (6R,7R,8R)-theissenone A (1), possessing an oxatricyclo[5.4.0.0^3,5]undeca-trien-2-one skeleton, together with two known compounds, (6S,7R,8R)-theissenone (2) and arthrinone (3), were produced by an endophytic fungus, Arthrinium marii M-211, which was isolated from mangrove plants. The structure of 1, including the absolute stereochemistry, was elucidated by analysis of nuclear magnetic resonance (NMR) and mass spectrometry (MS) data and time-dependent density functional theory (TDDFT) calculations of electronic circular dichroism (ECD) spectra. Additionally, the absolute structure of 2 was deduced as a diastereomer of 1 using ECD spectral data analysis. Compounds 1, 2 and 3 exhibited cytotoxic activity against the H4IIE rat hepatoma cells, with IC₅₀ values of 67.5, 46.6 and 13.4 µM, respectively.

Graphical Abstract

Keywords:

• Theissenone A
• OSMAC
• cytotoxicity
• H4IIE hepatoma cell line

Acknowledgements

The authors thank Prof. Hiroyuki Konno and Prof. Takako Aboshi in Yamagata University for CD and MS experimental supports, respectively.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was partly supported by MEXT KAKENHI Grant Number 19K05709 (Y. S) and the author (U. S) was also supported by World Class Professor Grant Number T/83/D2.3/KK.04.05/2019, Indonesia.