Cytotoxic Chaetoglobosins from the Endophyte Chaetomium globosum

Abstract

Two new alkaloids chaetoglobosins V (1) and W (2), together with the six known congeners 3–8, were isolated through bioassay-guided fractionations from the EtOAc extract of a solid culture of Chaetomium globosum IFB-E041. The structures were elucidated by spectroscopic methods including mainly 1D and 2D NMR techniques. Chaetoglobosin W (2) was unique in its possession of an oxolane ring formed via an oxygen bridge between C-3 and C-6. The isolated fungal metabolites exhibited moderate cytotoxic activities against four human cancer cell lines (KB, K562, MCF-7, and HepG2) with their IC₅₀ values in a range of 18–30 µg/mL.

Key words

Chaetomium globosum - Chaetomiaceae - chaetoglobosin - cytotoxicity - structure elucidation

References

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