The trunk wood of Emmutum nitens (Icacinaceae) contains the aromatic sesquiterpenes (2R,3S)-2-hydroxy-3-(2'-hydroxyisopropyl)-5,8-dimethyl-l-oxo-1,2,3,4-tetrahydronaphthale (emmotin-F), 2-hydroxy-3-(2' hydroxyisopropyl)-5,8-dimethylnaphthalene (emmotin-G) and 3-(2'-hydroxyisopropyl)-5,8-dimethyl-l,2-naphthoquinone (emmotin-H). The identity of the carbon skeletons of these emmotins was proved by conversion of all three into an identical quinoxaline derivative. The nature of this skeleton and the absolute configuration of emmotin-F, as well as of the previously described emmotins A and B, was established by conversion of emmotin-F into (+)-occidol.