Two new quinones from the roots of Juglans mandshurica

Two new quinones, 1-hydroxy-5-pentyl-anthraquinone ( 1 ) and 4-(5-hydroxy-1,4-dioxo-1,4-dihydro-naphthalen-2-ylamino)-butyric acid methyl ester ( 2 ), together with two known quinones, 5-hydroxy-2-(2-hydroxy-ethylamino)-(1,4) naphthoquinone ( 3 ) and juglone ( 4 ) were isolated from the roots of Juglans mandshurica (Juglandaceae). Their structures were elucidated on the basis of spectral data. Compound 3 was isolated from the Juglans genus for the first time. Compounds 1 – 4 exhibited significant cytotoxicity towards cultured MDA-MB231, HepG2 and SNU638 cells with IC 50 values ranging from 4.46 to 88.47 μM.