title: [Structure correction and synthesis of subspinosin].
abstract: "Subspinosin" isolated from the root of Damnacanthus subspinosus Hand-Mazz (Rubiaceae) and deduced as 3-ethoxymethyl-2-hydroxy-1-methoxyan-thraquinone 1 by Li et al in 1981, should be corrected as 2-ethoxymethyl-3-hydroxy-1-methoxyanthraquinone 5 by comparison with the synthetic compound. Since 5 is already known as damnacanthol-omega-ethyl ether, the name "Subspinosin" for 1 (not yet a natural isolate) should be abandoned in order to acknowledge this priority, and, what is more, to avoid confusion. The anthraquinones 1 and 5 were synthesized by condensation of phthalic anhydride with 3-methylcatechol or 2-methylresorcinol in fused AlCl3/NaCl (5:1), followed sequentially by selective acetylation, methylation, bromination and condensation with sodium ethoxide.
authors.affiliation: Shanghai Institute of Materia Medica, Academia Sinica.
authors.forename: J R
authors.initials: JR
authors.lastname: Yu
authors.forename: J C
authors.initials: JC
authors.lastname: Cai
authors.forename: Y S
authors.initials: YS
authors.lastname: Gao
mesh_terms: D000880:Anthraquinones / Q000138:chemical synthesis*; D000972:Antineoplastic Agents, Phytogenic; D055598:Chemical Phenomena; D002621:Chemistry
chemical_list: D000880:Anthraquinones; D000972:Antineoplastic Agents, Phytogenic; C033348:subspinosin