Further flavonol and iridoid glycosides from Ajuga remota aerial parts

Five new iridoid glycosides characterised as 6-keto-8-acetylharpagide (1), 6,7-dehydro-8-acetylharpagide (2), 7,8-dehydroharpagide (3), 8-acetylharpagide-6-O-β-glucoside (4), harpagide-6-O-β-glucoside (5) together with three flavonol glycosides, myricetin 3-O-rutinoside-4'-O-rutinoside (6), myricetin 3-O-rutinoside-3'-O-rutinoside (7) and isorhamnetin 3-O-rutinoside-7-O-rutinoside-4'-O-β-glucoside (8) have been isolated from the aerial parts of Ajuga remota. Also isolated were two known compounds ajugarin IV and ajugarin V. Their structures were established using spectroscopic methods including UV, IR, FAB-MS, HR-MS, 1D and 2D NMR techniques.     

Stilbene C-glucosides from Cissus repens

Four new stilbene C-glucosides, namely trans-3-O-methyl-resveratrol-2-C-β-glucoside (1), cis-3-O-methyl-resveratrol-2-C-β-glucoside (2), trans-3-O-methyl-resveratrol-2-(2-p-coumaric)-C-β-glucoside (cissuside A) (3), and trans-3-O-methyl-resveratrol-2-(3-p-coumaric)-C-β-glucoside (cissuside B) (4), were isolated from the aerial parts of Cissus repens, along with known trans-resveratrol (5), trans-resveratrol-2-C-β-glucoside (6) and cis-resveratrol-2-C-β-glucoside (7). Their structures were established by spectroscopic methods. Stilbene C-glucosides were found in the genus Cissus for the first time.     

Antioxidant phenolic glucosides from Gentiana piasezkii

An extract of Gentiana piasezkii afforded a new arbutin derivative 6'-O-vanilloylarbutin (1) and a new flavone-C-glucoside 7-O-feruloylorientin (2), together with four known flavonoids lutonarin (3), saponarin (4), isoorient (5) and luteolin (6). Their structures were established based on spectroscopic methods including 2D NMR (COSY and gHMBC) techniques. Compounds 1, 2, 5 and 6 were evaluated for the antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay system.     

Pyrrolizidine alkaloids from Cynoglossum furcatum

Two new pyrrolizidine alkaloids have been isolated from the roots of Cynoglossum furcatum. On the basis of chemical and spectroscopic evidence, structures of the compounds have been elucidated. They are lactodine (3), a monoster alkaloid and viridinatine (4), a pyrrolizidine diester alkaloid. The structure of lactodine is elucidated as 9-O-(-)lactyl heliotridine and viridinatine as 7-O-(-)viridifloryl echinatine.     

Arylglycerol glucosides from Dracocephalum forrestii

Three new arylglycerol glucosides, threo-guaiacylglycerol 3-O-(6-O-p-hydroxybenzoyl)-β-D-glucopyranoside (1), threo-guaiacylglycerol 3-O-[6-O-(E)-p-coumaroyl]-β-D-glucopyranoside (2) and threo-guaiacylglycerol 3-O-[6-O-(Z)-p-coumaroyl]-β-D-glucopyranoside (3), together with seven known compounds were isolated from the whole plants of Dracocephalum forrestii and their structures were determined on the basis of spectroscopic evidences.     

Absolute configuration determination of angular dihydrocoumarins from Peucedanum praeruptorum

From Peucedanum praeruptorum, one new khellactone ester (3'R)-O-acetyl-(4'S)-O-angeloylkhellactone (3), as well as four known angular dihydropyranocoumarins (1, 2, 4, 5) have been isolated. On the basis of NMR spectra and X-ray crystallography, their structures were determined. We have elucidated their absolute configuration by either chiral separation of their alkaline hydrolysis products with Rp-18 HPLC eluted with 5% hydroxypropyl-β-cyclodextrin (β-HCD) or by measurement of their CD spectra. A general rule relating the position and absolute stereochemistry of the khellactone esters to the sign of their Cotton effects in CD curves is proposed.     

Sesquiterpene glucosides from anti-leukotriene B4 release fraction of Taraxacum officinale

Chemical examination of the MeOH extract of the root of Taraxacum officinale, which exhibited inhibitory activity on the formation of leukotriene B₄ from activated human neutrophils, has resulted in the isolation of 14-O-β-D-glucosyl-11,13-dihydro-taraxinic acid (1) and 14-O-β-D-glucosyl-taraxinic acid (2). The absolute stereostructure of 1 has been established by X-ray chrystallographic examination.     

Studies on chemical constituents from Ilex pubescens

Two new phenolic glycosides, ilexpubsides A and B, along with four known lignan glycosides were isolated from the roots of Ilex pubescens. By spectral evidence, the structures of the new compounds were elucidated as 4-O-β-D-[6'-O-(4'-O-β-D-glucopyranosylvanilloyl)glucopyranosyl] vanillic acid (1) and syringinic 6'-O-β-D-xylopyranoside (2). The known compounds were identified to be liriodendrin (3), (-)-olivil (4), tortoside A (5) and (+)-cyclo-olivil (6). All compounds were first isolated from Ilex pubescens.     

A new dicoumarinoid glycoside from Daphne giraldii

A new dicoumarinoid glycoside, named giraldoid A (1), has been isolated from Daphne giraldii Nitsche. The structure of 1 was determined as 7-O-β-glucosyl-8-(7-hydroxy-2H-1-benzopyran-2-one-8-)yl-2H-1-benzopyran-2-one on the basis of chemical reactions and spectroscopic methods.     

Isolation and identification of a novel flavonoid from Penthorum chinense P

A novel flavonoid, pinocembrin-7-O-[3'-O-galloyl-4',6'-hexahydroxydiphenoyl]-β-glucose (1) was isolated from the whole plant of Penthorum chinense P., along with four known compounds, pinocembrin-7-O-β-glucoside, quercitrin, quercetin-3-O-rhamnoside and gallic acid. The structures were established by spectroscopic analysis.     

A new sesquiterpene lactone glucoside with inhibitory effect on K562 cells from Ixeris sonchifolia (Bge) Hance

A new minor sesquiterpene lactone glucoside, ixerin Z_A (1), together with 16 known compounds, were isolated from the whole plants of Ixeris sonchifolia (Bge) Hance. The structure of 1 was elucidated as 1(10),3,11(13)-guaiatriene-12,6-olide-2-one-3-O-[6'-(p-metheoxyphenylacetyl)]-β-glucopyranoside on the basis of spectroscopic and chemical evidence. Compound 1 exhibited an inhibitory effect on K₅₆₂ cells.     

Annonaceous Acetogenins of the Seeds from Annona Muricata

Muricatenol (1) is a new C₃₇ non-THF ring acetogenin with four hydroxyls and one isolated double bond in the long aliphatic chain. 2,4-cis-Gigantetrocinone (2) and 2,4-trans-gigantetrocinone (3) have been isolated as their acetates by preparative TLC. 2,4-trans-Isoannonacin-10-one (4) and 2,4-trans-isoannonacin (5) have been isolated as only 2,4-trans-form for the first time (no cis-form). Also four known acetogenins, gigantetrocin-A (6), gigantetrocin-B (7), annomontacin (8), gigantetronenin (9) and a mixture of N-fatty acyl tryptamines have been isolated (10). Their structures have been established on the basis of spectral analyses. The CHCl₃ fraction of the seeds showed strong antitumor activities.     

A New Bicoumarin from Stellera Chamaejasme L

Thirteen compounds were isolated from roots of Stellera chamaejasme L. (Thymelaeaceae). They are β-sitosterol (2), simplexin (3), pimelea factor P2 (4), daucosterol (5), (+)-3-hydroxy-1,5-diphenyl-1-pentanone (6), 4-ethoxy-benzoic acid (7), 2,4,6-Trimethoxy-benzoic acid (8), (+)-afzelechin (9), fumaric acid (10), N,N-dimethyl-L-aspartic acid (11), umbelliferone (12), daphniretin (13) and a novel bicoumarin named bicoumastechamin (1). Among the known compounds, 7, 8, 9, 10 and 11 were first isolated from this plant, and 6 was first isolated from the natural resources. Their structures have been elucidated on the basis of spectral data. In vitro bioassays showed that 4 inhibited cancer cell growth, 13 exhibited immunomodulatory activity, and 6 exhibited both immunomodulatory and anti-tumor activity.     

Triterpene saponins from Lysimachia christinae

Seven triterpene saponins were isolated from Lysimachia christinae and identified as lysichriside A (1), lysichriside B (2), primulanin (3), lysikokianoside 1 (4), anagallisin C (5), ardisiacrispin A (6), and ardisicrenoside B (7). Compounds 1 and 2 are new triterpene saponins, compounds 3, 5, and 7 were isolated from this genus, and compounds 4 and 6 were isolated from this species for the first time. Their structures were elucidated by means of 1D and 2D NMR experiments.     

Heteroclitin H, a new lignan from Kadsura heteroclita

A new dibenzocyclooctadiene lignan, heteroclitin H (1), was isolated together with seven known compounds, heteroclitin D (2), interiorin B (3), interiorin (4), neokasuranin (5), interiotherin C (6), gomisin J (7) and (+)-anwulignan (8), from the stems of Kadsura heteroclita. Their structures were elucidated by spectroscopic methods. This is the first report of the isolation of compounds 3, 5, 6, 7 and 8 from K. heteroclita.     

Triterpenes from Tripterygium wilfordii Hook

Two new friedelane-type triterpenes, tripterfrielanons A (1) and B (2), along with six known triterpenoids, friedelin (3), canophyllal (4), canophyllalic acid (5), 3-oxo-29-hydroxyfriedelane (6), wilforlide A (7), wilforlide B (8), have been isolated from the EtOH extract of the roots of Tripterygium wilfordii Hook.f. Compounds 4, 5, 6 were isolated for the first time from this plant. The new triterpenes 1 and 2 exhibited mild cytotoxic activity against human Hela cell lines in vitro. The assay showed the IC₅₀ of 1 and 2 were 8.5 and 25 μg/mL, respectively.     

Anthraquinones from Gladiolus gandavensis

Five new anthraquinones have been obtained from the ethanolic extracts of the subterranean corms of Gladiolus gandavensis Van Houtt. Their structures were elucidated as 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone (gandavensin D, 1), methyl 3,8-dihydroxy-6,7-methylenedioxy-1-methyl-anthraquinone- 2-carboxylate (gandavensin E, 2), 2,3,8-trihydroxy-6-methoxy-1-methoxymethyl-anthraquinone (gandavensin F, 3), 8-hydroxy-3,6-dimethoxy-1-methyl-anthraquinone-2-carboxylic acid (gandavensin G, 4) and 1,7-dihydroxy-3,6-dimethoxy-anthraquinone (gandavensin H, 5) on the basis of spectral data. The known compounds isolated for the first time from this plant have been determined to be methyl 3,6,8-trihydroxy-7-methoxy-1-methyl-anthraquinone-2-carboxylate (6), methyl 3,6,8-trihydroxy-1-methyl-anthraquinone-2-carboxylate (7), 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone-2-carboxylic acid (8), 3,6,8-trihydroxy-1-methyl-anthraquinone-2-carboxylic acid (9), 6,8-dihydroxy-3-methoxy-1-methyl-anthraquinone-2-carboxylic acid (10), methyl 3,8-dihydroxy-6-methoxy-1-methyl-anthraquinone-2-carboxylate (11) and methyl 3,7,8-trihydroxy-1-methyl-anthraquinone-2-carboxylate (12).     

Five new norditerpenoid alkaloids from Aconitum sinomontanum

From the roots of Aconitum sinomontanum, five new norditerpenoid alkaloids, sinomontanitines A (1) and B (2), sinomontanines A (3), B (4) and C (5), were isolated together with the known alkaloids lappaconitine (6) and ranaconitine (7), The structures of the new alkaloids were determined by spectral analysis.     

Cytotoxic ent-kauranoids from Isodon leucophyllus

Two new compounds, baiyecrystals D and E (1, 2), together with eight known analogues, xerophilusin B (4), macrocalin B (5), oridonin (6), rosthorin A (7), lasiocarpanin (8), rabdoternin A (9) and phyllostachysin A (10) and B (11), were isolated from the aerial parts of Isodon leucophyllus. The structures of 1 and 2 and 4-11 were elucidated on the basis of spectroscopic methods, especially the 2D NMR spectral analysis. Compounds 2, 6-8 and 10 were evaluated for their antineoplastic activities in vitro. Among them, lasiocarpanin (8) showed significant inhibitory activities against K562 and Bcap37 cells, with the IC₅₀ values of 0.13 and 1.26 μg mL_-1, respectively, which were lower than those of the positive control.     

A new diterpene from the processed roots of Euphorbia Kansui

A new diterpene has been isolated from the processed roots of Euphorbia Kansui. By means of physico-chemical evidences and spectral analysis, the structure was identified as 4-O-acetyl-5-O-benzoyl-3β-hydroxy-20-deoxyingenol (1).