Anthraquinone and Naphthoquinone Derivatives from the Pericarps of Juglans sigillata

Four new anthraquinones ( 1–4 ), along with four known ones ( 5–8 ) and five known naphthoquinones ( 9–13 ), were isolated from the green pericarps of Juglans sigillata. The structures of the new compounds were elucidated as 1,3-diethoxycarbonyl-8-hydroxy-9,10-anthraquinone ( 1 ), 1,3-diethoxycarbonyl-5-hydroxy-9,10-anthraquinone ( 2 ), 1-ethoxycarbonyl-8-hydroxy-9,10-anthraquinone ( 3 ), and 1-ethoxycarbonyl-5-hydroxy-9,10-anthraquinone ( 4 ), based on extensive spectroscopic methods including HR-ESI-MS and 1D and 2D NMR spectra. Compounds 1–12 were evaluated for their in vitro cytotoxicities against MCF-7 and HT-29 cancer cell lines by MTT assay. Compounds 3 and 7 showed weak cytotoxicities against HT-29 with IC 50 of 91.7 and 60.6 μM, respectively. Compounds 9–12 exhibited moderate cytotoxicities against MCF-7 and HT-29 with IC 50 ranging from 7.2 to 23.9 μM.