Curvulin and spirostaphylotrichins R and U from extracts produced by two endophytic Bipolaris sp. associated to aquatic macrophytes with antileishmanial activity

Abstract

In the present study, biological activity and chemical composition of two crude extracts of endophytic fungal strains of Bipolaris genera isolated from two species of aquatic macrophytes: Eichhornia azurea (Kunth) and Eichhornia crassipes (Mart.) were investigated. The nuclear magnetic resonance and mass spectrometry data provided the identification of three main compounds: curvulin (1), spirostaphylotrichin R (2) and U (3). The fragmentation mechanism of the precursor ions towards collision induced dissociation (CID) tandem mass spectrometry experiment (MS/MS) is also proposed. Furthermore, biological screening of the crude extracts displayed antileishmanial activity with IC₅₀ values ranging from 70–84.2 μg.mL⁻¹.

Keywords:

• Eichhornia azurea
• Eichhornia crassipes
• endophytes
• MS/MS fragmentation mechanism;

Acknowledgements

The authors wish to thank Complexo Central de Apoio à Pesquisa (COMCAP/UEM), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for granting the scholarship and CNPq and Fundação Araucária (FA) for financial support.