Ko Sugama

Two iridoid glycosides from Rehmannia glutinosa

Two new iridoid glycosides named jioglutosides A and B, together with 11 known iridoid glycosides, have been isolated from the fresh roots of Rehmannia glutinosa var. hueichingensis. On the basis of chemical and spectral analyses, the structures of jioglutosides A and B have been elucidated.

Two xanthones from Polygala tenuifolia

Abstract Two new xanthones, onjixanthones I and II, and four known xanthones, 1,6-dihydroxy-3,7-dimethoxyxanthone, 1,7-dihydroxy-3-methoxyxanthone, 1,6-dihydroxy-3,5,7-trimethoxyxanthone and 1-hydroxy-3,6,7-trimethoxyxanthone were isolated from roots of Polygala tenuifolia. The structures of these xanthones were established on the basis of chemical studies and spectral evidence including 2D NMR and NOE studies.

Eremophilenolides from petasites japonicus

Abstract Chemical investigation of the young flower stalks of Petasites japonicus afforded some eremophilenolides, including a mixture of the two new compounds 6β-angeloyloxy-3β,8α-dihydroxyeremophil-7(11)-en-12,8β- olide and 6β-angeloyloxy-3β,8β-dihydroxyeremophil-7(11)-en-12,8α- olide. Their structures were elucidated by chemical and spectroscopic methods. The 13 C NMR signals for the carbon atoms of the eremophilenolides were assigned with the help of Beierbecks parameters. The CD spectra of the compounds are briefly discussed.

Five cyclopentanoid monoterpenes from Rehmannia glutinosa

Abstract Five new cyclopentanoid monoterpenes named jioglutins A, B, C, jioglutolide and jiofuran, along with other known compounds, have been isolated from the steamed roots of Rehmannia glutinosa var. hueichingensis and their structures elucidated on the basis of chemical and spectroscopic methods.

Eudistomidins E and F, new β-carboline alkaloids from the okinawan marine tunicate Eudistoma glaucus

Abstract Two new β-carboline alkaloids, eudistomidins E ( 1 ) and F ( 2 ), have been isolated from the Okinawan marine tunicate Eudistoma glaucus and the structures elucidated on the basis of spectroscopic data.

Triterpenes from Tripterigium wilfordii

Abstract The acetone extract of dried root bark of Tripterigium wilfordii afforded two novel oleanane and D:B-friedooleanane triterpenes: wilforol C and D. Their structures were established on the basis of chemical and spectroscopic studies.

Norcarotenoids of Rehmannia glutinosa var. Hueichingensis

Abstract Two new norcarotenoids named trihydroxy-β-ionone and sec -hydroxyaeginetic acid, together with three known compounds, have been isolated from the steamed roots of Rehmannia glutinosa var. hueichingensis . Their structures were determined by chemical and spectral studies, and confirmed by X-ray analysis of trihydroxy-β- ionone acetate.

Sesquiterpenoids from petasites fragrans

Abstract Chemical analysis of Petasites fragrans yielded the eremophilane type of sesquiterpenes: petasol, isopetasol, S-petasin, neo-S-petasin, and a mixture of petasol derivatives, with caffeic acid methyl ester and a mixture of phytosterols. Their structures were elucidated by chemical and spectroscopic methods.

Two lignans from Schisandra sphenanthera

Abstract Two new dibenzocyclooctadiene lignans, benzoylgomisin U and tigloylgomisin O were isolated from the fruits of Schisandra sphenanthera together with known lignans, gomisin U and epigomisin O. Their structures were determined by chemical and spectral studies. The structure of isoschizandrin was also revised by advanced chemical and spectral studies.

Dibenzocyclooctadiene lignans from Kadsura japonica

Two new dibenzocyclooctadiene lignans, angeloylbinankadsurin B, acetylbinankadsurin B, and a known lignan, deangeloylschisantherin F, were isolated from the fruits of Kadsura japonica. Their structures were determined on the basis of chemical and spectral studies.