Isolation and characterisation of three new anthraquinone secondary metabolites from <i>Symplocos</i><i>racemosa</i>

<div><p>Three new anthraquinone secondary metabolites were isolated from <i>Symplocos racemosa</i>, a small tree of family symplocaceae. The structures of compounds (<b>1</b>–<b>3</b>) were elucidated to be 1,4-dihydroxy-6-(ethoxymethyl)-8-propylanthracene-9,10-dione (<b>1</b>), 1,4-dihydroxy-6-(hydroxymethyl)-8-butylanthracene-9,10-dione (<b>2</b>) and 1,4-dihydroxy-6-(hydroxymethyl)-8-propyl anthracene-9,10-dione (<b>3</b>) using their spectral data, i.e. through IR, UV, ¹H NMR, ¹³C NMR and two-dimensional (2D) NMR techniques including heteronuclear multiple quantum coherence, heteronuclear multiple bond correlation and correlation spectroscopy.</p></div