“…The Liming Institute of Chemical Industry has intensively investigated various degradation products of 2-ethylanthraquinones, identifying 2-ethyl hydroxyl anthrone, 2-ethyl-anthrone, and tetrahydro-epoxy-2-ethylanthraquinone using standard samples [27]. Other extensive studies have also conducted on the degradation products of alkylanthraquinones and the regeneration principles [28][29][30].…”