Flavonoids from Camptosorus sibiricus Rupr.

Three new flavonol glycosides, kaempferol-3-O-(6-trans-caffeoyl)-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (1), kaempferol-3-O-(6-trans-caffeoyl)-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside-7-O-β-d-glucopyranoside (2), and kaempferol-3-O-(6-trans-p-coumaroyl)-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside-7-O-β-d-glucopyranoside (3), were isolated from the aerial part of Camptosorus sibiricus. Their structures were elucidated by spectroscopic methods, including 2D NMR spectral techniques.     

Three new flavonoid glycosides from Urena lobata

Three new flavonoid glycosides, kaempferol-3-O-β-d-apiofuranosyl(1 → 2)-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside (1), kaempferol-4′-O-β-d-apiofuranosyl-3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside (2), and 5,6,7,4′-tetrahydroxy-flavone-6-O-β-d-arabinopyranosyl-7-O-α-l-rhamnopyranoside (3), were isolated from the aerial parts of Urena lobata L., along with 10 known compounds (4–13). Their structures were determined based on spectroscopic methods including 1D and 2D NMR spectroscopy as well as HR-ESI-MS.     

Four new oleanane type Saponins from Morina nepalensis var. alba

Four new oleanane type saponins, monepalosides G–J (1–4), were isolated from the water-soluble part of the whole plant of Morina nepalensis var. alba Hand-Mazz. On the basis of chemical and spectroscopic evidence, their structures were determined as 3-O-α-L-arabinopyranosyl-(1→3)-α-L-arabinopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (monepaloside G, 1), 3-O-α-L-arabinopyranosyl-(1→3)-β-D-xylopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (monepaloside H, 2), 3-O-α-L-arabinopyranosyl-(1→3)-[β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (monepaloside I, 3), 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosy-(1→3)]-α-L-arabinopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (monepaloside J, 4), respectively. Two-dimensional NMR spectra, including H–H COSY, HMQC, 2D HMQC–TOCSY, HMBC and ROESY were utilized in the structure elucidation and complete assignments of ¹H and ¹³C NMR spectra.     

New furostanol glycosides from the rhizomes of Dioscorea futschauensis R. Kunth

Two new furostanol glycosides, 26-O-β-D-glucopyranosyl-3β,26-dihydroxy-23(S)-methoxyl-25(R)-furosta-5,20(22)-dien-3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranoside (dioscoreside E, 1) and 26-O-β-D-glucopyranosyl-3β,26-dihydroxy-25(R)-furosta-5,20(22)-dien-3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl (1→3)]-β-D-glucopyranoside (prtotogracillin, 2), together with 11 known furostanol glycosides were isolated from the rhizomes of Dioscorea futshauensis R. Kunth. Their structures were elucidated on the basis of spectroscopic analysis (NMR and FABMS). Their anti-fungal activity against the plant pathogenic fungus Pyricularia oryzae and cytotoxic activity on K562 cancer cell line were evaluated in vitro.     

Triterpenoid saponins from the rhizome of Polygonatum sibiricum

Three new triterpenoid saponins, polygonoides C (1), D (2), and E (3), were obtained from the ethanolic extract of the rhizome of Polygonatum sibiricum Redoute. On the basis of NMR and ESI-MS spectra, and chemical evidence, the structures of the three new compounds were elucidated as 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranosyl-3β,7β,22β-trihydroxy-oleanolic acid (1), 3-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranosyl-3β,7β,22β-trihydroxy-oleanolic acid methyl ester (2), and 3-O-β-D-glucopyranosyl-(1 → 3)-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamno-pyranosyl-(1 → 2)]-β-D-glucopyranosyl-3β,21β-dihydroxy-oleanolic acid 28-O-β-D-glucopyranosyl-(1 → 3)-β-D-glucopyranosyl-(1 → 3)-β-D-glucopyranoside (3).     

New acylated flavonoid glycosides from flowers of Aerva javanica

Chromatographic purification of ethyl acetate soluble fraction of the methanolic extract of the flowers of Aerva javanica yielded three new acylated flavone glycosides: kaempferol-3-O-β-d-[4?-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-galactoside (1), kaempferol-3-O-β-d-[4?-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-(3″-E-p-coumaroyl)galactoside (2), and kaempferol-3-O-β-d-[4?-E-p-coumaroyl-α-l-rhamnosyl(1 → 6)]-(4″-E-p-coumaroyl)galactoside (3), along with p-coumaric acid (4), caffeic acid (5), gallic acid (6), eicosanyl-trans-p-coumarate (7), hexadecyl ferulate (8), and hexacosyl ferulate (9). The compounds 1–9 were characterized using 1D (¹H, ¹³C) and 2D NMR (HMQC, HMBC, and COSY) spectroscopy and mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) and in comparison with the reported data in the literature. Compound 1 showed weak inhibitory activity against enzymes, such as acetylcholinesterase, butyrylcholinesterase, and lipoxygenase with IC₅₀ values 205.1, 304.1, and 212.3 μM, respectively, whereas compounds 2 and 3 were only weakly active against the enzyme acetylcholinesterase.     

Two new flavone glycosides from the seeds of Impatiens balsamina L.

Two new flavone glycosides were isolated from the seeds of Impatiens balsamina L. and their structures were determined as quercetin-3-O-[α-l-rhamnose-(1 → 2)-β-d-glucopyranosyl]-5-O-β-d-glucopyranoside (1), and quercetin-3-O-[(6?-O-caffeoyl)-α-l-rhamnose-(1 → 2)-β-d-glucopyranosyl]-5-O-β-d-glucopyranoside (2) on the basis of various spectral and chemical studies.     

Two new lignan glycosides from the seeds of Cuscuta chinensis

Two new lignan glycosides, 2′-hydroxyl asarinin 2′-O-β-D-glucopyranoside (cuscutoside C, 1) and 2′-hydroxyl asarinin 2′-O-β-D-apiofuranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 6)]-β-D-glucopyranoside (cuscutoside D, 2), were isolated from the seeds of Cuscuta chinensis Lam., along with six known compounds, 2′-hydroxyl asarinin 2′-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (3), 2′-hydroxyl asarinin 2′-O-β-D-apiofuranosyl-(1 → 2)-β-D-glucopyranoside (cuscutoside A, 4), kaempferol 3,7-di-O-β-D-glucopyranoside (5), 5-caffeoyl quinic acid (6), 4-caffeoyl quinic acid (7), and cinnamic acid (8). Their structures were elucidated on the basis of spectroscopic analyses including HR-ESI-MS, ESI-MS/MS, ¹H and ¹³C NMR, HSQC, HMBC, and TOCSY.     

A new acylated flavonoid glycoside from the flowers of Camellia nitidissima and its effect on the induction of apoptosis in human lymphoma U937 cells

From the EtOH extract of the flowers of Camellia nitidissima Chi, a new acylated flavonoid glycoside, quercetin 7-O-(6″-O-E-caffeoyl)-β-d-glucopyranoside (1), has been isolated, together with three known flavonoids: quercetin (2), quercetin 3-O-β-d-glucopyranoside (3), and quercetin 7-O-β-d-glucopyranoside (4). Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 was shown to inhibit proliferation and to induce apoptosis of human lymphoma U937 cells.     

Two new anthraquinone glycosides from the roots of Rheum palmatum

Two new anthraquinone glycosides, named 1-methyl-8-hydroxyl-9,10-anthraquinone-3-O-β-d-(6′-O-cinnamoyl)glucopyranoside (1) and rhein-8-O-β-d-[6′-O-(3″-methoxyl malonyl)]glucopyranoside (2), have been isolated from the roots of Rheum palmatum, together with seven known compounds, rhein-8-O-β-d-glucopyranoside (3), physcion-8-O-β-d-glucopyranoside (4), chrysophanol-8-O-β-d-glucopyranoside (5), aleo-emodin-8-O-β-d-glucopyranoside (6), emodin-8-O-β-d-glucopyranoside (7), aleo-emodin-ω-O-β-d-glucopyranoside (8), and emodin-1-O-β-d-glucopyranoside (9). Their structures were elucidated on the basis of chemical and spectral analysis.     

Three new lignans from the seeds of Saussurea involucrata

Three new lignans, arctigenin-4-O-(6″-O-acetyl-β-d-glucoside) (1), arctigenin-4-O-(2″-O-acetyl-β-d-glucoside) (2), and arctigenin-4-O-(3″-O-acetyl-β-d-glucoside) (3), together with two known lignans, were isolated from the seeds of Saussurea involucrata. Their structures were established by spectroscopic methods, mainly 1D and 2D NMR, and mass spectral analysis.     

A new cerebroside from Uvaria tonkinensis var. subglabra

A new cerebroside, subglain A (1), together with five known compounds (2–6) have been isolated from the stems of Uvaria tonkinensis var. subglabra. The structure of 1 has been determined to be 1-O-β-D-glucopyranosyl-(2S,3S,4R,8Z,2′R)-2-[N-(2′-hydroxytetracosanyl)-N-(1″,2″-dihydroxyethyl)-amide]-8-tetradecene-1,3,4-triol by spectroscopic evidence. The known compounds were identified as schisandriside (2), erythritol (3), β-D-glucopyranose (4), kaempferol-3,7-O-α-L-dirhamnoside (5), and (+)-lyoniresinol (6).     

Flavonoids from Pyrrosia petiolosa (Christ) Ching

A new kaempferol glycoside, kaempferol-3-O-β-d-glucopyranoside-7-O-α-l-arabinofuranoside (1), was isolated from the EtOH extract of Pyrrosia petiolosa together with six known flavonoids already reported from the same plant. Structural elucidation was performed by means of physico-chemical methods including MS, and 1D and 2D NMR spectroscopy.     

Two new glycosides from Carduus acanthoides

Two new glycosides, syringic acid-4-O-β-l-arabinopyranoside (1) and kaempferol-3-O-α-l-rhamnopyranosyl-7-O-β-d-glucuronopyranoside (2), were isolated from whole plants of Carduus acanthoides (Asteraceae), and their structures were elucidated on the basis of spectroscopic analysis.     

Three triterpenoid saponins acylated with monoterpenic acid from Gymnocladus chinensis

A new triterpenoid saponin acylated with monoterpenic acid, together with two known triterpenoid saponins, has been isolated from the fruit of Gymnocladus chinensis Baill. Their structures were elucidated as 2β,23-dihydroxy-3-O-α-L-rhamnopyranosyl-21-O-{(6S)-2-trans-2,6-dimethyl-6-O-[3-O-(β-D-glucopyranosyl)-4-O-((6S)-2-trans-2,6-dimethyl-6-hydroxy-2,7-octadienoyl)-β-L-arabinopyranosyl]-2,7-octadienoyl}-acacic acid 28-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-[α-L-rhamnopyranosyl-(1 → 6)]-β-D-glucopyranosyl ester (1), gymnocladus saponin E (2), and gymnocladus saponin F₂ (3).     

Evaluation of cytotoxic activity of patriscabratine,tetracosane and various flavonoids isolated from the Bangladeshi medicinal plant Acrostichum aureum

Context: Acrostichum aureumL. (Pteridaceae), a mangrove fern, has been used as a Bangladeshi traditional medicine for a variety of diseases including peptic ulcer.

Objective: Isolation and structural elucidation of cytotoxic secondary metabolites from the methanol extract of the aerial parts of A. aureum.

Materials and methods: Compounds were isolated using HPLC. The compound structures were elucidated by 1D and 2D NMR, MS and other spectroscopic methods using published data. The compounds were tested for their cytotoxic activity against healthy and cancer cells using the MTT assay. Active compounds were further evaluated for apoptosis–and necrosis-inducing potential against gastric cancer cells (AGS) using the FITC Annexin V apoptosis assay.

Results and discussion:Seven known compounds, patriscabratine, tetracosane and 5 flavonoids (quercetin-3-O-β-d-glucoside, quercetin-3-O-β-d-glucosyl-(6→1)-α-l-rhamnoside, quercetin-3-O-α-l-rhamnoside, quercetin-3-O-α-l-rhamnosyl-7-O-β-d-glucoside and kaempferol) were isolated. Patriscabratine was found moderately cytotoxic against AGS, MDA-MB-231 and MCF-7 cells with IC₅₀ values ranging from 69.8 to 197.3 μM. Tetracosane showed some cytotoxic activity against AGS, MDA-MB-231, HT-29 and NIH 3T3 cells with IC₅₀ values ranging from 128.7 to >250 μM. Patriscabratine and tetracosane displayed an apoptotic effect (10%) on AGS cells within 24 h which was increased (20%) after 48 h, and was comparable to, if not greater, than the positive control, cycloheximide.

Conclusion:Except for quercetin-3-O-β-d-glucoside and kaempferol; compounds were isolated for the first time from this plant and evaluated for their cytotoxic activity. The results highlight the potential of this plant as a source of bioactive compounds and provide a rationale for its traditional use in peptic ulcer treatment.     

Flavonoids from the leaves of Pleioblastus argenteastriatus

A new flavonoid, 5,7,3′-trihydroxy-6-C-β-d-digitoxopyranosyl-4′-O-β-d-glucopyranosyl flavonoside (1), along with four known flavonoids 5,7,4′-trihydroxy-3′,5′-dimethoxy flavone (2), 5,3′,4′-trihydroxy-7-O-β-d-glucopyranosyl flavonoside (3), 5,4′-dihydroxy-3′,5′-dimethoxy-7-O-β-d-glucopyranosyl flavonoside (4), 5,3′,4′-trihydroxy-6-C-[β-d-glucopyranosyl-(1 → 6)]-β-d-glucopyranosyl flavonoside (5) were isolated from 95% EtOH extract of the leaves of Pleioblastus argenteastriatus. Their structures were determined on the basis of spectroscopic techniques and chemical methods.     

Two new isoflavone triglycosides from the small branches of Sophora japonica

Two new isoflavone triglycosides, genistein 4′-O-(6″-O-α-l-rhamnopyranosyl)-β-sophoroside (1), and genistein 4′-O-(6?-O-α-l-rhamnopyranosyl)-β-sophoroside (2), together with five known compounds, namely, sophorabioside, genistin, rutin, quercetin 3-O-β-d-glucopyranoside, and kaempferol 3-O-β-d-glucopyranoside, were isolated from the small branches of Sophora japonica L. Their structures were elucidated on the basis of spectroscopic analyses and chemical evidence.     

New flavonol glycosides and new xanthone from Polygala japonica

Three new flavonol glycosides and a new xanthone were isolated from Polygala japonica HOUTT. with eight known compounds. Their structures were identified as 1,7-dihydroxy-3,4-dimethoxy-xanthone (1), kaempferol-7,4′-dimethyl ether (2), physcion (3), guazijinxanthone (4), rhamnetin (5), polygalin A (6), 3,5,7-trihydroxy-4′-methoxy-flavone-3-O-β-d-galactopyranoside (7), 3,5,3′-trihydoxy-7,4′-dimethoxy-flavone-3-O-β-d-galactopyranoside (8), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-galactopyranoside (9), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-glucopyranoside (10), polygalin B (11), polygalin C (12). Among them, compound 4 is a new xanthone, and 6, 11 and 12 are new flavonol glycosides. Compounds 1, 4, 7 and 8 were tested for cytotoxic activity with MTT assays on five human tumor cell lines, K562, A549, PC-3M, HCT-8 and SHG-44. Compound 4 showed cytotoxic activity against all the five cell lines.     

Compounds from the pods of Astragalus armatus with antioxidant,anticholinesterase, antibacterial and phagocytic activities

Context: The phytochemical study and biological activities of Astragalus armatus Willd. subsp. numidicus (Fabaceae) pods, an endemic shrub of Maghreb, are reported.

Objective: This study isolates the secondary metabolites and determines the bioactivities of Astragalus armatus pods.

Materials and methods: The chloroform, ethyl acetate and n-butanol extracts of hydro-ethanolic extracts were studied. Antioxidant activity was investigated using DPPH and ABTS radical scavenging, CUPRAC and ferrous chelating assays at concentrations ranging from 3 to 200?μg/mL. Anticholinesterase activity was determined against acetylcholinesterase and butyrylcholinesterase enzymes at 50, 100 and 200?μg/mL. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) method. Carbon clearance method in albino mice was used for the phagocytic activity at concentrations 50, 70 and 100?mg/kg body weight. Spectroscopic techniques were used to elucidate the compounds.

Results: Ethyl acetate extract afforded a flavonoid (1) while the n-butanol extract gave four flavonoids (2–5), a cyclitol (6) and a cycloartane-type saponin (7). The ethyl acetate extract exhibited highest antioxidant activity in DPPH (IC₅₀: 67.90?±?0.57?μg/mL), ABTS (IC₅₀: 11.30?±?0.09?μg/mL) and CUPRAC (A_0.50: 50.60?±?0.9?μg/mL) assays. The chloroform extract exhibited the best antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, each with 80?μg/mL MIC values. The n-butanol extract enhanced phagocytic activity.

Discussion and conclusion: Isorhamnetin (1), isorhamnetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-galactopyranoside (2), isorhamnetin-3-O-β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-galactopyranoside (3), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-β-d-galactopyranoside (4), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside (5), pinitol (6) and cyclomacroside D (7) were isolated whereas 1, 2, 6 and 7 are reported for the first time from A. armatus.