A new azaphilone from the entomopathogenic fungus Hypocrella sp.

Abstract

This report describes the isolation of a new azaphilone, designated hypocrellone A (2), together with five known compounds (1, 3–6) from a submerged culture of the entomopathogenic fungus Hypocrella sp. (isolate WYTY-21). The absolute stereostructures of the two compounds (1 and 2) were elucidated based on 1D and 2D NMR spectroscopic and mass spectrometric data combined with the data from various chemical transformations. Hypocrellone A (2) and three (3–6) of the five known compounds were cytotoxic to hepatoma cells (cell line BEL-7404); IC₅₀ values ranged from 6.2 to 17.4 μM. At 200 μM, none of the six compounds was toxic to normal human liver cells (cell line HL-7702) or to normal human kidney epithelial cells (cell line HEK-293T).

Keywords::

• entomopathogenic fungus
• Hypocrella
• metabolite
• cytotoxic activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

^1. These authors contributed equally to this work.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under [grant number 31070026]; [grant number 31170025]; [grant number 31470156], the Key Project of Chinese Ministry of Education under [grant number 212088], the Fujian Agriculture and Forestry University Foundation for Distinguished Young Scholars under [grant number xjq201406], the Chinese National Programs for High Technology Research and Development under [grant number 2011AA10A203], and the China National Engineering Research Center of Juncao Technology under [grant number JCJJ13013].