title: Naphthoquinone esters from the root of Rhinacanthus nasutus.
abstract: Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.
authors.affiliation: Department of Chemistry, National Cheng Kung University, Tainan, Taiwan, R.O.C.
authors.forename: T S
authors.initials: TS
authors.lastname: Wu
authors.forename: H C
authors.initials: HC
authors.lastname: Hsu
authors.forename: P L
authors.initials: PL
authors.lastname: Wu
authors.forename: Y L
authors.initials: YL
authors.lastname: Leu
authors.forename: Y Y
authors.initials: YY
authors.lastname: Chan
authors.forename: C Y
authors.initials: CY
authors.lastname: Chern
authors.forename: M Y
authors.initials: MY
authors.lastname: Yeh
authors.forename: H J
authors.initials: HJ
authors.lastname: Tien
mesh_terms: D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification; D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification*; D004952:Esters / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification*; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000959:Antihypertensive Agents; D000998:Antiviral Agents; D004952:Esters; D009285:Naphthoquinones