Isoprenylated Flavonoids with PTP1B Inhibition from Macaranga denticulata.

Three new C-methylated and isoprenylated chalcone derivatives, dentichalcones A-C (1-3), together with six known compounds (4-9), were isolated from the twigs and leaves of Macaranga denticulata. Their structures were elucidated by spectroscopic analysis, including 1D, 2D NMR, and MS data. The known compounds, (2E)-1-(5,7-dihydroxy-2,2,6-trimethyl-2H-benzopyran-8-yl)-3-(4-methoxyphenyl)-2-propen-1-one (4), (2E)-1-(5,7-dihydroxy-2,2-dimethyl-2H-benzopyran-8-yl)-3-phenyl-2-propen-1-one (5), laxichalcone (6), macarangin (7), bonanniol A (8), and bonannione A (9), showed inhibitory activities against protein tyrosine phosphatase 1B (PTP1B) in vitro. Three new C-methylated and isoprenylated chalcone derivatives, dentichalcones A-C (1-3), together with six known compounds, were isolated from the twigs and leaves of Macaranga denticulata. Some compounds showed inhibitory activities against PTP1B in vitro.