The oligostilbenoids isolated from members of the Dipterocarpaceae, Gnetaceae, Vitaceae, and Leguminosae are of interest because they exhibit antimicrobial and cytotoxic activity. 1,2 Prenylated stilbenes, Diels-Alder adducts, and prenylated 2-arylbenzofurans also occur in members of the Moraceae. [3][4][5] Recently, andalasin A(1), 6 a stilbene dimer, and macrourin B (2), 7 a benzofuran-stilbene derivative, were isolated from the heartwood and tree bark, respectively, of Morus macroura Miq. In addition, another stilbene dimer, artogomezianol, was characterised from a member of the allied genus, Artocarpus gomezianus. 8 In our search for further oligostilbenes from moraceaous plants, we have examined the root trunk of M. macroura. We now report the isolation of a new stilbene dimer, which we have named andalasin B (3), along with the known phenolic compounds 1, lunularin, oxyresveratrol, and β-resorcylaldehyde.The dried powdered root trunk of M. macroura was macerated with MeOH, and the MeOH-extract was partitioned into hexane, CH 2 Cl 2 , and EtOAc soluble fractions. The EtOAc fraction was fractionated using silica gel chromatography and the fraction rich in phenolic compounds and more polar than oxyresveratrol, was repeatedly purified by radial chromatography to give compounds 1 and 3. Using the same methodology, lunularin and β-resorcylaldehyde were isolated from the CH 2 Cl 2 fraction. Compound 3, obtained as brownishyellow solid, had a molecular formula C 28 H 22 O 8 [[M] + ion at m/z 486.1332 (calcd. 486.1315)]. The UV spectrum of 3 (see Experimental) showed absorption maxima characteristic of a stilbene chromophore. The IR spectrum of 3 exhibited absorptions for hydroxyl and aromatic functionalities. A dimeric stilbenoid structure was suggested by this data for compound 3. The 1 H NMR spectrum of 3 resembles those of ε-viniferin 9 and the resveratrol (E)-dehydrodimer (4), 10 and revealed signals assignable to two 3,5-dihydroxyphenyl (δ