Constituents of the cultivated mulberry tree.

In addition to mulberrofuran C, a new 2-arylbenzofuran derivative, six flavonoid derivatives, cyclomorusin, morusin, kuwanon C, E, G and H, as well as a known 2-arylbenzofuran derivative, chalcomoracin, were isolated from extracts of root bark of the cultivated mulberry tree (a variety of Morus bombycis K OIDZUMI). The structure of mulberrofuran C was shown to be VIII on the basis of spectral data. It is regarded biogenetically as a Diels-Alder adduct of a chalcone derivative and a dehydroprenyl 2-arylbenzofuran derivative. Intravenous injection of mulberrofuran C produced significant hypotension in rabbit.