A new furostanol saponin from Dendrobium chrysanthum Lindl. with cytotoxic activity

A new furostanol saponin, (25R)-26-O-(α-d-glucopyranosyl)-(1→2)-α-l-rhamnopyranosyl-furost-5-ene-3β, 22α, 26-triol-3-O-α-d-glucopyranoside (1), together with four known compounds 2–5 were isolated from the ethanolic extract of the stems of Dendrobium chrysanthum Lindl. The structures of these new compounds were identified by extensive spectroscopic analysis including 1D and 2D NMR and HR-ESI-MS, as well as chemical methods. Compounds 1–3 were isolated from D. chrysanthum for the first time. Furthermore, the inhibitory effects of the compounds on tumor cells were evaluated, and compounds 1–2 exhibited significant cytotoxic activities potentially against SPC-A1, MCF-7 and HeLa human cancer cell lines. Compounds 3–5 showed inhibitory activity against the SPC-A1 and MCF-7.     

A new caffeic acid tetramer from the Dracocephalum moldavica L.

A new caffeic acid tetramer compound, named (+) methyl rabdosiin (4), together with seven known caffeic acid multimers (1–3, 5–8) and one caffeic acid monomer (9), were isolated from the aerial parts of Dracocephalum moldavica L. The structures of these compounds were assigned on the basis of 1D and 2D NMR spectroscopic and mass spectrometry analyses. The protective effects of compounds 2–4 against hydrogen peroxide (H₂O₂)-induced apoptosis were evaluated in primary cardiomyocytes of SD neonatal rats in vitro by the MTT method. Three compounds exhibited potent protective activities at 12.5 μg/mL.     

Two new benzolactones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities

Two new benzolactones, 5-methyl-6-prenyl-isobenzofuran-1(3H)-one (1), 5-hydroxymethyl-6-prenyl-isobenzofuran-1(3H)-one (2), together with four known phenolic compounds (3–6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1–6 exhibited high anti-TMV activities with inhibition rates in the range of 16.9–26.2%, respectively.     

Xanthones isolated from Gentianella acuta and their protective effects against H2O2-induced myocardial cell injury

In the present study, two new xanthones, (5′S,8′S)-1,3,5,8-tetrahydroxyxanthone(7→2′)-1,3,5,8-tetrahydroxy-5′,6′,7′,8′-tetrahydroxanthone (1), 5-hydroxy-3,4,6-trimethoxyxanthone-1-O-β-D-glucopyranoside (2), and eight known xanthones (3–10) were isolated from the whole plants of Gentianella acuta. Their structures were identified by the spectroscopic analyses (HR-ESI-MS, and 1D and 2D NMR). Meanwhile, cell-protective effects against H₂O₂-induced H9c2 cardiomyocyte injury and cytotoxic activities of compounds 1–10 were also determined.     

New chalcanonol glycoside from the seeds of saw palmetto: antiproliferative and antioxidant effects

A new chalcanonol glycoside dimer, bis-O-[(I-4′) → (II-6′)]-α-hydroxyphloretin-2′-O-β-glucoside (1), in addition to six known compounds, namely ( ? )-epicatechin (2) and ( ? )-epiafzelechin (3), 4-hydroxybenzoic acid (4), protocatechuic acid (5), methylgallate (6), β-sitosterol (7) and β-sitosterol-3-O-glucoside (8), was isolated from the seeds of saw palmetto. The structures of the isolated compounds were established from the analysis of their MS and 1D and 2D NMR spectroscopic data. The antiproliferative activities of the isolated compounds towards PC3, the human prostate cancer cells were investigated. Amongst the isolated compounds, the new compound and the sterolic derivatives showed antiproliferative effects. Screening of the antioxidant effects of the isolated compounds by 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid radical assay revealed that the isolated phenolics were active free radical scavengers.     

A bioactive cycloartane triterpene from Garcinia hombroniana

The dichloromethane bark extract of Garcinia hombroniana yielded one new cycloartane triterpene; (22Z,24E)-3β-hydroxycycloart-14,22,24-trien-26-oic acid (1) together with five known compounds: garcihombronane G (2), garcihombronane J (3), 3β acetoxy-9α-hydroxy-17,14-friedolanostan-14,24-dien-26-oic acid (4), (22Z, 24E)-3β, 9α-dihydroxy-17,14-friedolanostan-14,22,24-trien-26-oic acid (5) and 3β, 23α-dihydroxy-17,14-friedolanostan-8,14,24-trien-26-oic acid (6). Their structures were established by the spectral techniques of NMR and ESI-MS. These compounds together with some previously isolated compounds; garcihombronane B (7), garcihombronane D (8) 2,3’,4,5’-tetrahydroxy-6-methoxybenzophenone (9), volkensiflavone (10), 4’’-O-methyll-volkensiflavone (11), volkensiflavone-7-O-glucopyranoside (12), volkensiflavone-7-O-rhamnopyranoside (13), Morelloflavone (14), 3’’-O-methyl-morelloflavone (15) and morelloflavone-7-O-glucopyranoside (16) were evaluated for cholinesterase enzymes inhibitory activities using acetylcholinesterase and butyrylcholinesterase. In these activities, compounds 1–9 showed good dual inhibition on both the enzymes while compounds 10–16 did not reasonably contribute to both the cholinesterases inhibitory effects.     

New alkylamide from the stems of Zanthoxylum nitidum

A new alkylamide, named (2E,6E,8E)-N-(2-methylpropyl)-10-oxo-2,6,8-decatrienamide (1), together with 22 known compounds (2–23), were isolated from the stems of Zanthoxylum nitidum. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR spectroscopy. The isolated compounds exhibited slightly antioxidant activities through DPPH and ABTS radical scavenging assays but showed no antibacterial activity against Streptococcus mutans ATCC2517, a dental caries causing bacteria.     

A new anthraquinone glycoside from Rhamnus nakaharai and anti-tyrosinase effect of 6-methoxysorigenin

In continual study on the heartwood of Rhamnus nakaharai, a new alaternin-8-O-glucoside, namely 1,2,6,8-tetrahydroxy-3-methylanthraquinone-8-O-β-glucopyranoside (1), together with some known compounds were further isolated and characterised by 1-D, 2-D NMR and other spectral evidences. The free radical scavenging and antityrosinase activities of the isolates, including alaternin (1a), emodin (2a), emodin-8-O-β-glucopyranoside (2), 6-methoxysorigenin-8-O-β-glucopyranoside (3) and 6-methoxysorigenin (3a) were tested. Alaternin (1a) exhibited to be mild DPPH radical scavenger with half as potent as vitamin C, while both alaternin (1a) and emodin-8-O-β-glucopyranoside (2) exhibited stronger SOD-like activity than that of BHA. 6-Methoxysorigenin (3a), a reported potential antioxidant, and its 8-O-glucoside (3) both performed significant inhibitory effect on mushroom tyrosinase with about twice as potent as kojic acid, the positive control.     

Phenolic compounds from the aerial parts of Clematis viticella L. and their in vitro anti-inflammatory activities*

Phytochemical investigations on the EtOH extract of Clematis viticella led to the isolation of six flavonoid glycosides, isoorientin (1), isoorientin 3′-O-methyl ether (2), quercetin 7-O-α-L-rhamnopyranoside (3), quercetin 3,7-di-O-α-L-rhamnopyranoside (4), manghaslin (5) and chrysoeriol 7-O-β-D-glucopyranoside (6), one phenylethanol derivative, hydroxytyrosol (7), along with three phenolic acids, caffeic acid (8), (E)-p-coumaric acid (9) and p-hydroxybenzoic acid (10). The structures of the isolates were elucidated on the basis of NMR and HR-MS data. All compounds were isolated from C. viticella for the first time. Compounds 7 and 8 showed significant anti-inflammatory activity at 100 μM by reducing the release of NO in LPS-stimulated macrophages comparable to positive control indomethacin. Compounds 3 and 7 exhibited anti-inflammatory activity through lowering the levels of TNF-α while 1, 3 and 5 decreased the levels of neopterin better than the positive controls.     

槲树叶中的5种酚性成分

从槲树叶Quercus dentata Thunb中分离纯化得到五种酚性成分. 通过理化性质分析和光谱解析等手段确定其化学结构分别为: 2-新橙皮糖基-2,6-二羟基苯甲酸苯甲酯(1), 龙胆酸5-O-(6-O-没食子酰基)--D-吡喃葡萄糖苷(2), 3,5,7-三羟基色原酮-3-O--D-吡喃葡萄糖苷(3), 没食子酸(4), 儿茶素(5), 其中化合物1和3为新化合物.     

A new epicatechin glucopyranoside derivative from Styrax suberifolius

Abstract

A new derivative of epicatechin glucopyranoside, (2R,3R)-3,7,4'-trihydroxy-5,3'-dimethoxyflavan 7-O-β-d-glucopyranoside (1), together with three mononuclear phenolic acid esters, methyl orsellinate (2), ethyl orsellinate (3) and methyl β-orcinolcarboxylate (4) were isolated from the bark of Styrax suberifolius. The structures of 1–4 were determined on the basis of extensive analysis of NMR and MS spectra combined with chemical hydrolysis. The antifungal activities of the isolated compounds against three plant pathogenic fungi, Alternaria solani, Fusarium oxysporum and Phomopsis cytospore were evaluated using radial growth inhibition assay. Compounds 2, 3 and 4 exerted selective inhibitory activities against the tested fungi. Among of them, methyl β-orcinolcarboxylate (4) exhibited obvious inhibitory effect against P. cytospore, with an inhibition rate of 86.72% at 100?μg/ml.     

Chemical composition and antioxidant activity of aerial parts of Ferula longipes Coss. ex Bonnier and Maury

This is the first study on the phytochemistry and antioxidant activity of Ferula longipes Coss. ex Bonnier and Maury (Apiaceae). A new flavonoid quercetin-3-O-α-L-rhamnopyranoside-7-O-ß-D-[2-O-caffeoyl]-glucopyranoside (1), along with 10 known compounds kaempferol-3-O-α-L-rhamnopyranoside (2), quercetin-3-O-α-L-rhamnopyranoside (3), kaempferol-3-O-ß-D-glucopyranoside-7-O-α-L-rhamnopyranoside (4), isorhamnetin-3-O-α-L-rhamnopyranoside-7-O-ß-D-glucopyranoside (5), quercetin-3-O-α-L-rhamnopyranoside-7-O-ß-D-glucopyranoside (6), isorhamnetin-3,7-di-O-β-D-glucopyranoside (7), apigenin (8), apigenin-7-O-ß-D-glucopyranoside (9), 3,5-dicaffeoylquinic acid (10), deltoin (11) were isolated from the aerial parts of Ferula longipes Coss. Structures elucidation was performed by comprehensive 1D and 2D NMR analyses, mass spectrometry and by comparison with literature data. The compounds 1, 3, 4, 6, 7 and 10 were evaluated for their antioxidant activity, compound 1 exhibited the best antiradical activity potential and showed IC₅₀ and A_0.5 values 5.70, 7.25, 5.00, and 2.63 μg/mL towards DPPH free radical-scavenging, ABTS, CUPRAC, and reducing power assays, respectively compared with BHA, BHT and ascorbic acid which were used as positive controls.     

A new flavanone glycoside isolated from Tournefortia sibirica

A new flavanone glycoside, (2S)-dihydrooroxylin A 7-O-[β-D-apiosyl(1→2)]-β-D-glucoside (1), and four known compounds (2–5) were isolated from Tournefortia sibirica L. The chemical structures of these compounds were determined by 1?D and 2?D NMR and HR-ESI-MS spectra, and results were compared with data from the literature. These five compounds (1–5) were isolated from the family Boraginaceae for the first time. Anti-inflammatory effects of compounds (1–5) were evaluated in terms of inhibition of production of NO, TNF-α, and IL-6 in LPS-induced RAW 264.7 cells.     

Antiangiogenic phenylpropanoid glycosides from Gynura cusimbua

A new phenylpropanoid glycoside, named α-L-rhamnopyranosyl-(1?2)-β-D-[4″-(8E)-7-(3,4-dihydroxyphenyl)-8-propenoate, 1″-O-(7S)-7-(3,4-dihydroxyphenyl)-7-methoxy-ethyl]-glucopyranoside (1), together with nine known compounds (2–10) were isolated from the active fraction (n-Butanol fraction) of Gynura cusimbua for the first time. The known compounds (2–10) were identified as phenylpropanoid glycosides on the basis of extensive spectral data and references. The antiangiogenic activities of compounds (1–10) were evaluated by MTT assay on HUVECs and wild-type zebrafish in vivo model assay. As a result, compounds 1, 6, 7, 8 and 10 exhibited certain antiangiogenic activities.     

Sesquiterpene lactones from Centaurea rhizantha C.A. Meyer

Two new sesquiterpene lactones, rhizantholide A (1) and rhizantholide B (2), together with five known compounds (3-7) have been isolated from the aerial parts of Centaurea rhizantha (Asteraceae). Sesquiterpene lactones belong to guaianolide class, and rhizantholide B is a rare guaianolide characterized by a free primary alcoholic function at C-10 along with a 3β,10β-epoxy function. Their structures have been established on the basis of 1D and 2D NMR experiments, as well as HR-ESIMS. The antimicrobial activity of compounds 1-7 has been evaluated against Gram-positive and Gram-negative strains. Only deacylcynaropicrin 8-O-[3′-hydroxy-2′-methylpropionate] (5) showed moderate antibacterial activity against Staphylococcus aureus with a MIC/MBC value of 500 μg/mL. All isolated compounds have been also evaluated for their cytotoxic activities against cancer cells. Among them, compound 5 showed the highest cytotoxic activity with IC₅₀ values in the range 5.02–16.76 μg/mL.     

Minor antifungal aromatic glycosides from the roots of Gentiana rigescens （Gentianaceae）

Two new phenolic glycosides,2,3-dihydroxybenzoic acid methyl ester 3-O-β-D-glucopyranosyl-(1-6)-β-D-glucopyranoside(1) and 2,5-dihydroxylbenzofuran 5-O-β-D-xylopyranosyl-(1-6)-O-β-D-glucopyranoside(2),were isolated as the minor chemical constituents from the roots of Gentiana rigescens,along with 15 known compounds.Their structures were elucidated by detailed spectroscopic analysis,including 1D,2D NMR and chemical method.All of these compounds were isolated for the first time from the title plant.Moreove...     

Methylenebisnicotiflorin: a rare methylene-bridged bisflavonoid glycoside from ripe Pu-er tea

A new methylene-bridged dimeric flavonol glycoside, methylenebisnicotiflorin (1), was isolated from ripe Pu-er tea, along with 10 known flavonoids (2–11) and seven known phenolic compounds (12–18). The structure elucidation was based on spectroscopic analysis. Among them, 1,3-dihydroxyphenyl-2-O-sulfate (13), 2,3,4-trihydroxybenzoic acid (16) and 3,3′,4,4′-tetrahydroxybiphenyl (18) are reported from tea plants for the first time.     

Dhasingreoside: new flavonoid from the stems and leaves of Gaultheria fragrantissima

A new flavonoid, dhasingreoside (1) and seven known compounds, quercetin 3-O-β-d-galacturonopyranoside (2), quercetin 3-O-β-d-galactopyranoside (3), quercetin 3-O-β-d-glucuronopyranoside (4), quercetin 3-O-α-l-rhamnopyranoside (5), (–)-epicatechin (6), salicylic acid (7) and gaultherin (8), have been isolated from the shade-dried stems and leaves of Gaultheria fragrantissima, commonly known as ‘Dhasingre’ in Nepal. The structures were elucidated on the basis of physical, chemical and spectroscopic methods. Among known compounds, five compounds (3–6 and 8) were isolated for the first time from G. fragrantissima. In vitro antioxidant activity of all the isolated compounds was evaluated by 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging assay. Dhasingreoside (1) and other compounds (2–6) showed significant free radical-scavenging activity.     

A new phenolic glycoside from Saprosma merrillii

A new phenolic glycoside derivative, saproglucoside (1), along with five known phenolic glycoside derivatives (2–6) were isolated from the stems of Saprosma merrillii. The structure of the new compound 1 was determined by 1D and 2D NMR as well as by HRESIMS and hydrolysis. The inhibitory activities of all compounds against seven pathogenic bacteria and two cancer cell lines were evaluated.     

Triterpenoid saponins from the buds of Lonicera similis

Four new lupane triterpenoid saponins, along with one known lupane and eight hederagenin saponins, were isolated from the EtOH extract of the buds of Lonicera similis Hemsl. The structures of the new compounds were established as 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl 23-hydroxybetulinic acid 28-O-β-D-glucopyranosyl ester (lonisimilioside A, 1), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl 23-hydroxybetulinic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (lonisimilioside B, 2), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl betulinic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (lonisimilioside C, 3) and 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl betulinic acid 28-O-β-D-glucopyranosyl ester (lonisimilioside D, 4), respectively. The cytotoxic activities of the isolates against human cancer cell lines HepG2, MCF-7 and A-549 were evaluated. Only the monodesmosidic saponin with a free carboxyl group at C-28 (12) exhibited significant cytotoxicities against HepG2, MCF-7 and A-549 cell lines with the IC₅₀ values of 8.98 ± 0.19, 12.48 ± 0.45 and 11.62 ± 0.54 μM, respectively. Furthermore, Hoechst fluorescence 33342 staining was used to demonstrate that 12 could induce HepG2 and A-549 cells apoptosis significantly.