One new 1,4-napthoquinone derivative from the roots of <italic>Juglans mandshurica</italic>.

A new 1,4-napthoquinone derivative, namely (<italic>S</italic>)-(-)-3-(8-hydroxy-1,4-dioxo-1,4-dihydro-naphthalen-2-yl)-3-(4-hydroxy-3-methoxyphenyl)-propionic acid methyl ester (<bold>1</bold>), was isolated from the roots of <italic>Juglans mandshurica</italic> Maxim. The structure was identified based on HR-ESI-MS, 1D and 2D NMR spectroscopic methods. [ABSTRACT FROM AUTHOR]