Hepatoprotective and antioxidant arylbenzofurans and flavonoids from the twigs of Morus mesozygia.

The chemical investigation of the twigs of Morus mesozygia resulted in the isolation of three new prenylated 2-arylbenzofurans, named moracin KM, LM, and SC (1-3), nine known 2-arylbenzofurans (4-12), and two known flavonoids (13-14). The structures of the new compounds were established as [2", 3": 6,7]( 6-(S)-hydroxymethyl-6-methylpyrano)-2-(3,5-dihydroxyphenyl) benzofuran-5-ol (1), [2", 3": 6,7]-(4,7-dihydro-6-methyloxepine)- 2-(3-hydroxy-5-methoxyphenyl) benzofuran-5-ol (2), and [2", 3": 6,7]-(6,6-dimethylpyrano)-2-(3,5-dihydroxyphenyl) benzofuran (3). One of the new compounds, moracin LM (2), displayed modest antioxidant activity, whereas known compounds 4, 13, and 14 showed significant hepatoprotective and antioxidant activities.