Previous chemical investigations of plants in the sub-tribe Dianellinae revealed naphthols and naphthoquinones. Further fractionation of benzene extracts from Dianella revoluta yielded a new pigment, trianellinone—an orange-yellow solid decomposing above 300°C, with λmax (EtOH) at 228, 280, 410 mp. Its ¹H NMR (CF₃COOH) showed three singlets at 2.25, 7.10, 7.43 τ (relative intensity 1:3:5). Mass spectrometry gave a molecular weight of 684.130 (C₃₉H₂₄O₁₂), indicating three units of type (IV). The pigment’s trimethyl ether (MW 726) and NMR data (e.g., methoxyl peaks at 5.76/5.78 τ in CF₃COOH with 1:2 intensity, hydroxyl peaks in CDCl₃ at -1.74/-1.64 τ) supported the irregular structure (VI). Trianellinone was synthesized from stypandrone and dianellinone under nitrogen, with the synthetic product identical to the natural one. It was not an artefact, as evidenced by plant component distributions and no formation upon refluxing the two quinones in benzene.