Structure of Claudimerin-A, a Novel Dimeric Coumarin from Citrus hassaku.

The chemical structure of claudimerin-A (1), a novel dimeric coumarin from roots of Citrus hassaku (Rutaceae), have been elucidated by spectrometric studies and a single crystal X-ray analysis. The structure of 1 consisted of two clausarin (2) units linked symmetrically with the forming of the pyranopyran ring.