A new coumarin from the fruits of Coutarea hexandra

Abstract

A new 5-O-β-D-glucopyranosyl-4-(4-hydroxyphenyl)-7-methoxy-2H-chromen-2-one (1), together with four known compounds, one coumarin, 5-O-β-D-galactopyranosyl-4-(4-hydroxyphenyl)-7-methoxy-2H-chromen-2-one (2) and three cucurbitacins, 23,24-dihydrocucurbitacin F (3), 23,24-dihydro-25-acetylcucurbitacin F (4) and 2-O-β-D-glucopyranosyl-23,24-dihydrocucurbitacin F (5) have been isolated and characterised from the ethanol extract of Coutarea hexandra fruits. Their structures have been established by spectroscopic analysis (NMR and MS). Interpretation of the HMQC, HMBC, COSY-45 and NOESY experiments permitted us to establish stereochemistry of the natural products. All compounds were tested in cytotoxicity assays against the breast (MCF-7), lung (H-460), and central nervous system (SF-268) human cancer cell lines.

Keywords:

• Coumarins
• Cucurbitacins
• Triterpenoids
• Cytotoxicity
• Coutarea hexandra
• Rubiaceae

Acknowledgments

This investigation was funded by the Organisation of American States (OAS). Thanks are due to Alex Espinosa for assistance in plant collection and to Prof. Mireya D. Correa A., Director of the Herbarium of the University of Panama for taxonomic identification of the plant.