Absolute configuration determination of asarinin by synchrotron radiation with crystalline sponge method.

The determination of the absolute configuration of natural products still faces many challenges, especially the active pharmaceutical ingredient which is trace, oily and novel structures. Currently, NMR requires chiral reagents in determining the absolute configuration; ECD involves theoretical calculations and requires chromophores. In this study, the absolute configuration of asarinin had successfully identified by using synchrotron radiation with crystalline sponge method and combining MS with NMR. This method could identifying the crystal structure of trace amorphous substances, resolving the problem of absolute configuration of multi-chiral central compounds, and hopefully providing a new idea and approach for structural elucidation of natural products.