Study of the collision-induced radical cleavage of flavonoid glycosides using negative electrospray ionization tandem quadrupole mass spectrometry

Negative electrospray ionization tandem quadrupole mass spectrometry was used to study the collision-induced dissociation (CID) of the O-glycosidic bond from different commercially available flavonoid glycosides. Depending on the structure, flavonoid glycosides can undergo both a collision-induced homolytic and heterolytic cleavage of the O-glycosidic bond producing deprotonated radical aglycone ((Y(0) - H)(-*)) and aglycone (Y(0) (-)) product ions. The relative abundance of the radical aglycone to the aglycone fragment from flavonol-3-O-glycosides increased with increasing number of hydroxyl substituents in the B ring and in the order kaempferol - 相似文献   

Simultaneous determination of seven compounds in snow lotus herb using high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method is developed for the quantitative determination of seven components of Snow Lotus Herb (Saussurea tridactyla Sch.-Bip.ex Hook.f.): umbelliferonglucoside, luteolin-7-O-beta-D-glucoside, rutin, apigenin-7-O-beta-D-glucoside, kaempferol-3-O-beta-D-glucoside, apigenin-7-O-beta-D-rutinoside, and luteolin. Samples are analyzed by means of a reverse-phase column (Diamonsil C(18)) using methanol and water under gradient conditions as the mobile phase for 60 min. This method offers selectivity, accuracy, precision, linearity, and ruggedness, as well as efficiency and ease.     

RP-HPLC analysis of Jirakadyarishta and chemical changes during fermentation

Jirakadyarishta, an Ayurvedic formulation prepared by the fermentation of a decoction of Cuminum cyminum (seeds) is traditionally used for intestinal disorders. RP-HPLC analysis of the decoction and the final processed formulation revealed that apigenin-7-O-[galacturonide (1 --> 4)-O-glucoside] and luteolin-4'-O-glucoside-7-O-galacturonide) were the two major constituents of the decoction of C. cyminum. Selective hydrolysis of 7-O-glucosides of luteolin and apigenin during fermentation resulted in an increase in the amount of luteolin and apigenin. The 4'-O-glucoside-7-O-galacturonide of luteolin and galacturonide derivative of apigenin were not hydrolyzed during fermentation. Monomeric phenolics, together with 5-hydroxymethyl furfural (5-HMF), were also introduced into the formulation through the jaggery and other plant materials during fermentation. This communication highlights the importance of the ancient processing methods used in Ayurveda.     

FLAVONOIDS OF THE AERIAL PART OF Scutellaria immaculate

Chrysin-7-O-glucuronide, scutellarein-7-O-glucoside, apigenin-7-O-glucoside, baicalein-7-O-glucoside, norwogonin-7-O-glucoside, oroxyloside, wogonoside, and the new glycoside immaculoside-5,8-dimethoxy-7-O--D-glucopyranosylflavone were isolated for the first time from the aerial part of white skullcap (Scutellaria immaculateNevski). The structure of the last was established using chemical transformations and spectral data.     

Identification of phenolic compounds from pollen extracts using capillary electrophoresis–electrospray time-of-flight mass spectrometry

In this work, a new, easy and rapid method of analyzing phenolic compounds in pollen extract, based on capillary electrophoresis coupled with electrospray ionization time-of-flight-mass spectrometry (CE–ESI–TOF–MS), has been developed. A systematic investigation of separation parameters has been performed with respect to resolution, sensitivity, analysis time and peak shape. The electrophoretic parameters and electrospray conditions must be optimized to obtain reproducible analyses. Using this method, several important phenolic compounds such as acetin-glucoside, 7-O-methylherbacetin-3-sophoroside, galloyl-glucose, quercetin-3-sophoroside, apigenin-6,8-di-C-glycoside, quercetin-3-rutinoside, genistein-7-O-β-D-glucoside, luteolin-7-O-glucoside, apigenin-7-O-glucoside and 2′,4′,6′-trihydroxy-3′-formyldihydrochalcone have been determined directly from pollen extract. The efficiency, the rapidity, the small amounts of sample required, and the high resolution of CE coupled with the sensitivity, the selectivity, the accurate masses and the true isotopic patterns obtained using TOF-MS point to the potential of this approach for identifying the phenolic compounds present in pollen.     

Reactive oxygen species scavenging activity of flavone glycosides from Melilotus neapolitana

One new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-beta-D-glucopyranosyloxy-4',5-dihydroxy-3-[O-alpha-L-rhamnopyranosyl-(1-->6)-3-O-beta-D-glucopyranosyloxy]flavone (1) by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2), kaempferol-3-O-glucoside (3), rutin (4), quercetin-3-O-glucoside (5), isorhamnetin-3-O-rutinoside (6), and isorhamnetin-3-O-glucoside (7). The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated. The organic extract can inhibit MDA marker's synthesis by 57%. All the metabolites displayed good reducing power, with the kaempferol (2,3) and isorhamnetin derivatives (6,7) being less active than the corresponding quercetin derivatives 4,5.     

Separation of patuletin-3-O-glucoside, astragalin, quercetin, kaempferol and isorhamnetin from Flaveria bidentis (L.) Kuntze by elution-pump-out high-performance counter-current chromatography

Flaveria bidentis (L.) Kuntze is an annual alien weed of Flaveria Juss. (Asteraceae) in China. Bioactive compounds, mainly flavonol glycosides and flavones from F. bidentis (L.) Kuntze, have been studied in order to utilize this invasive weed, Analytical high-performance counter-current chromatography (HPCCC) was successfully used to separate patuletin-3-O-glucoside, a mixture of hyperoside (quercetin-3-O-galactoside) and 6-methoxykaempferol-3-O-galactoside, astragalin, quercetin, kaempferol and isorhamnetin using two runs with different solvent system. Ethyl acetate-methanol-water (10:1:10, v/v) was selected by analytical HPCCC as the optimum phase system for the separation of patuletin-3-O-glucoside, a mixture of hyperoside and 6-methoxykaempferol-3-O-galactoside, and astragalin. A Dichloromethane-methanol-water (5:3:2, v/v) was used for the separation of quercetin, kaempferol and isorhamnetin. The separation was then scaled up: the crude extract (ca 1.5 g) was separated by preparative HPCCC, yielding 12 mg of patuletin-3-O-glucoside at a purity of 98.3%, yielding 9 mg of a mixture of hyperoside and 6-methoxykaempferol-3-O-galactoside constituting over 98% of the fraction, and 16 mg of astragalin (kaempferol-3-O-glucoside) at a purity of over 99%. The pump-out peaks are isorhanetin (98% purity), kaemferol (93% purity) and quercitin (99% purity). The chemical structure of patuletin-3-O-glucoside and astragalin were confirmed by MS and 1H, 13C NMR.     

Identification of compounds in wine by HPLC-tandem mass spectrometry

In this work several compounds were detected in wines by HPLC-tandem mass spectrometry. In particular cinnamic and benzoic acids, tyrosol, apigenin-7-glucoside and luteolin-7-glucoside were identified and quantified in Italian wines. Red wines show bigger amount of cinnamic and benzoic acids than white wines. tyrosol is in bigger amount with respect to two flavones: luteolin-7-glucoside and apigenin-7-glucoside. These last two flavones are only in some wine, but it can be important to detect the presence of different substances in small amount to be able to characterize a wine.     

狗枣猕猴桃叶化学成分研究

从狗枣猕猴桃叶中分离得到7个黄酮类化合物, 经1D NMR, 2D NMR和MS等波谱分析, 鉴定它们的化学结构分别为山柰甲黄素-3-O-芸香糖苷(Ⅰ)、 山柰甲黄素-7-O-(4"-O-乙酰基鼠李糖基)-3-O-β-D-吡喃葡萄糖苷(Ⅱ)、山柰甲黄素-7-O-(4"-O-乙酰基鼠李糖基)-3-O-芸香糖苷(Ⅲ)、山柰酚-3-O-β-D-葡萄糖苷(Ⅳ)、山柰酚-3-O-芸香糖苷(Ⅴ)、山柰甲黄素-3-O-β-D-葡萄糖苷(Ⅵ)和山柰甲黄素-7-O-鼠李糖基-3-O-芸香糖苷(Ⅶ). 其中化合物Ⅰ, Ⅱ和Ⅲ为新化合物, Ⅳ, Ⅴ和Ⅵ为首次从该植物中分离得到.     

Systemic chemical characterization of Lemna minor by UHPLC-Q-Exactive Orbitrap MS coupled with parallel reaction monitoring

Lemna minor L. (LM) has been used for measles opacity, rubella itching, edema, and oliguria, and the main active ingredients were flavonoids, namely, apigenin, apigenin-7-O-glucoside, and luteolin-7-O-glucoside. However, few systematic analyses of their constituents have been performed; thus, it was necessary to establish a fast and efficient method to identify the chemical composition of LM. In this study, the UHPLC-Q-Exactive Orbitrap mass spectrometry coupled with parallel reaction monitoring was established. Finally, a total of 112 constituents, including 30 dipeptides, 28 nucleosides, 11 amino acids, 10 organic acids, 10 flavonoids, and 23 other compounds, were identified by MS, diagnostic fragment ions, and retention time. One hundred one of those chemicals were first found in LM, which was very beneficial for the further development and utilization of nutriments and the medicinal use of LM.     

Phenolic chemical composition of Petroselinum crispum extract and its effect on haemostasis

From the aqueous extract (Pc) of Petroselinum crispum (Mill) flat leaves specimens were isolated and identified the flavonoids apigenin (1), apigenin-7-O-glucoside or cosmosiin (2), apigenin-7-O-apiosyl-(1 --> 2)-O-glucoside or apiin (3) and the coumarin 2",3"-dihydroxyfuranocoumarin or oxypeucedanin hydrate (4). The inhibitory activity toward clotting formation and platelet aggregation was assessed for Pc flavonoids (1) and (2), and the coumarin (4). Pc showed no inhibition on clotting activity when compared with the control. On the other hand, a strong antiplatelet aggregation activity was observed for Pc (IC50 = 1.81 mg/mL), apigenin (IC50 = 0.036 mg/mL) and cosmosiin (IC50 = 0.18 mg/mL). In all cases ADP was used as inductor of platelet aggregation. Our results showed that Pc, apigenin and cosmosiin interfere on haemostasis inhibiting platelet aggregation. To the best of our knowledge this is the first report for the cosmosiin antiplatelet aggregation in vitro activity.     

Isolation and purification of flavonoid glycosides from Trollius ledebouri using high-speed counter-current chromatography by stepwise increasing the flow-rate of the mobile phase

Three flavonoid glycosides including orientin, vitexin, quercetin-3-O-neohesperidoside and one unknown compound were isolated and purified by high-speed counter-current chromatography (HSCCC) and semi-preparative HPLC from Trollius ledebouri Reichb., a traditional Chinese medicine. Preparative HSCCC with a two-phase solvent system composed of ethyl acetate-n-butanol-water (2:1:3, v/v/v) was successfully performed by increasing the flow-rate of the mobile phase from 1.5 to 2.5 ml/min after 190 min. Consequently, 95.8 mg orientin, 11.6 mg vitexin, 9.3 mg unknown compound with purities of over 97% and one partially purified peak fraction (contained quercetin-3-O-neohesperidoside at 85.1% purity) were obtained from 500 mg of the crude extract. Then the partially purified fraction was further purified by reversed-phase semi-preparative high-performance liquid chromatography. The structure identification of all pure fractions was carried out by UV, MS, 1H NMR and 13C NMR.     

Isolation and identification of four flavonoid constituents from the seeds of Oroxylum indicum by high-speed counter-current chromatography

Four flavonoids, chrysin, baicalein, baicalein-7-O-glucoside, baicalein-7-O-diglucoside (Oroxylin B) and one unknown flavonoid have been isolated and purified for the first time in the seeds of Oroxylum indicum by high-speed counter-current chromatography with a two-phase solvent system composed of chloroform-methanol-water (8:10:5, v/v). Then, 50 mg baicalein-7-O-glucoside, 10.5 mg baicalein-7-O-diglucoside, 4.5 mg chrysin-7-O-diglucoside, 25 mg baicalein and 45 mg chrysin could be obtained after injecting 20 mg/ml sample extract ten times and their purities were 96, 90, 85, 95 and 98%, respectively. All these constituents were identified by high-performance liquid chromatography-mass spectrometry and nuclear magnetic resonance.     

Fast chromatographic separation for the quantitation of the main flavone dyes in Reseda luteola (weld)

In the past decades, there has been a renewed interest in the use of natural dye plants for textile dyeing, e.g. Reseda luteola (weld). Its main yellow dye constituents are the flavones luteolin-7,3'-O-diglucoside, luteolin-7-O-glucoside and luteolin. The aim of this work was to develop a simple validated industrially usable quantitative method to assess the flavone content of R. luteola samples. The flavones were overnight extracted from the dried and ground aerial parts of the plant at room temperature via maceration with methanol-water 8:2. Afterwards, they were quantified through internal standardisation against chrysin by RP-HPLC-UV at 345 nm. The efficiency of the one-step extraction was 95%. The limits of detection (LOD) and quantitation (LOQ) were ≤ 1 ng and ≤ 3 ng, respectively, providing ample sensitivity for the purpose. The precision expressed as relative standard deviation of the entire method was <6.5% for the combined content of luteolin-7,3'-O-diglucoside, luteolin-7-O-glucoside and luteolin. The average absolute recovery (accuracy) at three spiking levels was 102% (range: 98-107%) and the relative recovery ranged from 99 to 102%. The separation was initially carried out on a traditional 250 mm × 4.6 mm 5 μm HPLC column (80 min run time, 35.9 mL MeOH). It was then speeded up by the use of a 50 mm × 3.0mm 1.8 μm UHPLC column (5 min run time, 1.4 mL MeCN), while still using a conventional HPLC system. Whereas, the retention times on the UHPLC column were relatively less reproducible, cross-validation showed that the quantitation of luteolin-7,3'-O-diglucoside, luteolin-7-O-glucoside and luteolin was not statistically significantly different, with comparable precision. The method using the UHPLC column is more sensitive. The analytical method described meets the demand for a very small manpower input per sample and uses standard laboratory equipment. Usage of short UHPLC columns opens up interesting possibilities for modernising HPLC-based phytochemical analyses.     

Capillary electrochromatography of selected phenolic compounds of Chamomilla recutita

This article explores the use of capillary electrochromatography for the analysis of chamomile (Chamomilla recutita L.) extracts. After a thorough study of analytical parameters such as mobile and stationary phase composition, applied voltage, and temperature, a methodology to determine 11 bioactive phenolic compounds (coumarins: herniarin, umbelliferone; phenylpropanoids: chlorogenic acid, caffeic acid; flavones: apigenin, apigenin-7-O-glucoside, luteolin, luteolin-7-O-glucoside; flavonols: quercetin, rutin and flavanone: naringenin) in chamomile extracts was proposed. The method was performed in a Hypersil SCX/C18 column with pH 2.8 phosphate buffer at 50 mmol L(-1) containing 50% acetonitrile (pH adjusted before the addition of the organic solvent). All compounds were separated in less than 7.5 min under isocratic conditions. Figures of merit include linearity (peak area versus apigenin concentration) from 50.0-1000 microg/mL (r2=0.995), and intra-day precision of retention time and peak area better than 1.3% CV and 15%, respectively. The limits of detection and quantification for apigenin were 35.0 microg/mL and 150.0 microg/mL, respectively. This article also describes an NMR 1H study, carried out to monitor a new clean-up procedure for extracts containing propyleneglycol, whose components are poorly retained in conventional octadecyl silica cartridges.     

Screening and mechanism study of components targeting DNA from the Chinese herb Lonicera japonica by liquid chromatography/mass spectrometry and fluorescence spectroscopy

A method which involves combination of centrifugal ultrafiltration sampling with high-performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC-DAD-MS) analysis was established for screening bioactive compounds binding to calf thymus deoxyribonucleic acid (ct-DNA) from the extracts of Lonicera japonica. Four compounds were screened out and identified as rutin, quercetin-3-O-glucoside, luteolin-7-O-glucoside and lonicerin, based on the comparison of retention time, UV spectra and MS data with those of standards. The DNA-binding capabilities of the latter three flavonoids were found for the first time. The binding mechanisms of rutin, quercetin-3-O-glucoside and luteolin-7-O-glucoside with ct-DNA at the molecular level were explored using acridine orange (AO) as a fluorescence probe. Groove binding is the most appropriate binding mode of these three flavonoids to DNA, according to ultraviolet absorption and fluorescence spectra, as well as melting temperature (T(m)) curves and viscosity measurements. The binding constants of rutin, quercetin-3-O-glucoside and luteolin-7-O-glucoside with DNA-AO complex were 3.81 x 10(3), 3.37 x 10(3) and 5.50 x 10(3) L/mol, respectively.     

High-speed counter-current chromatography assisted preparative isolation of phenolic compounds from the flowers of Chrysanthemum morifolium cv. Fubaiju

Chrysanthemum morifolium cv. Fubaiju is rich in phenolic compounds with various benefits such as anti-inflammatory, antioxidant, and cardiovascular protection. In this study, 12 phenolic compounds, including five flavonoid glycosides and seven quinic acid derivatives, were successfully separated from the flowers of Chrysanthemum morifolium cv. Fubaiju by high-speed counter-current chromatography and preparative high-performance liquid chromatography. Ethyl acetate-n-butanol–acetonitrile–water–acetic acid (5:0.5:2.5:5:0.25, v/v/v/v/v) was selected as solvent system to separate six fractions from the flowers of Chrysanthemum morifolium cv. Fubaiju, and 20% aqueous acetonitrile (containing 0.1% formic acid) was chosen to be the elution solvent in preparative high-performance liquid chromatography for purifying the fractions above. Luteolin-7-O-β-D-glucoside ( 1 ), luteolin-7-O-β-D-glucuronide ( 2 ), apigenin-7-O-β-D-glucoside ( 3 ), luteolin-7-O-β-D-rutinoside ( 4 ), diosmetin-7-O-β-D-glucoside ( 5 ), chlorogenic acid ( 6 ), 1,5-dicaffeoylquinic acid ( 7 ), 1,4-dicaffeoylquinic acid ( 8 ), 3,4-dicaffeoylquinic acid ( 9 ), 3,4-dicaffeoyl-epi-quinic acid ( 10 ), 3,5-dicaffeoylquinic acid ( 11 ), and 4,5-dicaffeoylquinic acid ( 12 ) were isolated with purities all above 95%, respectively. In addition, all isolates were evaluated for their protective effects on H₂O₂-induced oxidative damage in adult retinal pigment epithelial cells.     

Variation of bioactive substances in Hypericum montbretii during plant growth

The present study was conducted to determine phenologic and morphogenetic variation of chlorogenic acid and flavonoids, as rutin, hyperoside, apigenin-7-O-glucoside, quercitrin, quercetin and viteksin content of Hypericum montbretii growing in Turkey. Wild growing plants were harvested at vegetative, floral budding, full flowering, fresh fruiting and mature fruiting stages and dissected into stem, leaf and reproductive tissues and assayed for bioactive compounds by HPLC method. Accumulation of rutin and quercetin was not detected in plant parts of H. montbretii during plant growth. Chlorogenic acid and hyperoside content in whole plant was decreased linearly with advancing of development stages and reached their highest level at vegetative stage. On the contrary, apigenin-7-O-glucoside, quercitrin and viteksin content in whole plant increased during the course of seasonal development and the highest level of those compounds was observed at the stage of full flowering. Leaves did not produce apigenin-7-O-glucoside, while viteksin was not detectable in stem and reproductive tissues. Depending on development stages, reproductive parts had the highest level of apigenin-7-O-glucoside and leaves produced major amount of chlorogenic acid, hyperoside and viteksin whereas accumulation of quercitrin was prevailed in stem tissue. Such kind of data could be useful for elucidation of the chemotaxonomical significance of these compounds and medicinal evaluation of this species.     

Preparative isolation and purification of flavone compounds from sophora japonica L. by high-speed counter-current chromatography combined with macroporous resin column separation

High-speed counter-current chromatography combined with macroporous resin column separation was applied to the isolation and purification of genistein-7,4'-di-O-beta-D-glucoside (I), genistein-7-O-beta-D-glucopyranoside-4'-O-[(alpha-L-rhamnopyransoyl)-(1-2)-beta-D-glucopyranoside] (II), kaempferol-3-O-beta-D-sophoroside(III), quercetin-3-O-beta-L-ramnopyranosyl-(1 - 6)-beta-D-glucopyranoside (IV), genistein-4'-beta-L-rhamnopyransoyl-(1 - 2)-alpha-D-glucopyranoside (V), and kaempferol-3-O-beta-L-ramnopyranosyl-(1 - 6)-beta-D-glucopyranoside (VI) from the Chinese medicinal herb Sophora japonica L. The crude extracts from the pericarps of Sophora japonica L. were pre-separated on a D-101 macroporous resin column and divided into two parts as sample 1 and sample 2. An 80-mg portion of sample 1 was separated by using n-butanol-acetic acid (1%) (5:5, v/v) as the two-phase solvent system and yielded 30.1 mg of compound I, 23.3 mg of compound II. A 120 mg portion of sample 2 was separated by using ethyl acetate-n-butanol-acetic acid (1%) (5:0.8:5, v/v) as the two-phase solvent system and yielded 5.5 mg of compound III, 31.7 mg of compound IV, 37.4 mg of compound V, and 6.2 mg of compound VI. The purities of compounds I, II, III, IV, V, and VI were 98.7, 98.2, 97.8, 98.5, 99.3, and 98.9%, respectively, as determined by HPLC. The chemical structures of these components were identified by 1H-NMR and 13C-NMR.     

A new cytotoxic acylated apigenin glucoside from Phyllanthus emblica L

A new acylated apigenin glucoside (apigenin-7-O-(6'-butyryl-beta-glucopyranoside) (1) was isolated from the methanolic extract of the leaves of Phyllanthus emblica L. (Euphorbiaceae) together with the known compounds; gallic acid (2), methyl gallate (3), 1,2,3,4,6-penta-O-galloylglucose (4) and luteolin-4'-O-neohesperiodoside (5). Their chemical structures were elucidated on the basis of spectroscopic studies ((1)H NMR, (13)C NMR, DEPT, HSQC, HMBC).