Two new coumarins from the seeds of Solanum indicum

Abstract

Two new coumarins, (E)-2-(4-hydroxy-3-methoxybenzylidene)-5-methoxy-2H-[1,4]dioxino[2,3-h]chromene-3,9-dione (indicumin E, 1) and 7-hydroxy-6,8-dimethoxy-3-(4′-hydroxy-3′-methoxyphenyl)-coumarin (2), together with two known coumarins isofraxidin (3) and fraxetin (4), were isolated from the Solanum indicum seeds. Their structures were established on the basis of 1D and 2D spectroscopic data. Compound 1 was the rarest coumarinolignoid known to date.

Keywords::

• Solanum indicum
• coumarins
• coumarinolignoid
• indicumin E
• NMR

Acknowledgments

We are grateful to Mrs Yan Xue, Mrs Mei-feng Xu, and Mrs Yu-mei Zhao of the National Center of Biomedical Analysis for the measurements of the MS and NMR spectra.