Two new sterol derivatives isolated from the endophytic fungus Aspergillus tubingensis YP-2

Abstract

Two new sterol derivatives, namely ergosterimide B (1) and demethylincisterol A₅ (2), along with eleven known metabolites (3–13), were isolated from the rice fermentation culture of Aspergillus tubingensis YP-2. The chemical structures were elucidated by detailed NMR and MS spectroscopic data and by comparison with reported data. Newly isolated compound 2 and known compound 3 were evaluated for their cytotoxicities against the A549 and HepG2 cell lines. Compound 2 showed weak activities with IC₅₀ values of 11.05 and 19.15 μM, respectively, while 3 exhibited cytotoxicities with IC₅₀ values of 5.34 and 12.03 μM, respectively, against the tested cell lines.

Graphical Abstract

Keywords:

• Aspergillus tubingensis
• endophytic fungus
• secondary metabolites
• ergosterimide B
• demethylincisterol A₅
• cytotoxicities

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This work was supported by the National Science and Technology Major Project [grant number 2009ZX09301–011] and National Science and Technology Major Project for New Drug Research and Development of MOST (2019ZX09735002-005).