title: New pyranonaphthoquinone and pyranonaphthohydroquinone from the roots of Pentas longiflora.
abstract: Several quinone type compounds were isolated from the hexane, dichloromethane, and ethyl acetate extracts of the roots of Pentas longiflora. The hexane extract afforded two new compounds, [(3alpha,3'alpha,4beta,4'beta)-3,3']-dimethoxy-cis-[4,4'-bis(3,4,5,10-tetrahydro-1H-naphtho[2,3-c]pyran)]-5,5',10,10'-tetraone (1) and cis-3,4-dihydroxy-3,4-dihydromollugin (2), together with six known compounds, namely, pentalongin, mollugin, trans-3,4-dihydroxy-3,4-dihydromollugin, methyl-2,3-epoxy-3-prenyl-1,4-naphthoquinone-2-carboxylate, tectoquinone, and 3-hydroxymollugin. From the dichloromethane extract were isolated the three known compounds 3-methoxymollugin, methyl-3-prenyl-1,4-naphthoquinone-2-carboxylate, and scopoletin, while the ethyl acetate extract afforded the known 2-methoxy-3-methylanthraquinone.
mesh_terms: D002855:Chromatography, Thin Layer; D007630:Kenya; D013058:Mass Spectrometry; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019666:Rubiaceae / Q000737:chemistry*; D012603:Scopoletin / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: C470807:((3alpha,3'alpha,4beta,4'beta)-3,3')-dimethoxy-cis-(4,4'-bis(3,4,5,10-tetrahydro-1H-naphtho(2,3-)pyran))-5,5',10,10'-tetraone; C470808:3,4-dihydroxy-3,4-dihydromollugin; D009285:Naphthoquinones; D011714:Pyrans; C046245:rubimaillin; D012603:Scopoletin