Showing papers on "Isovitexin published in 2014"

Four Flavonoid Compounds from Phyllostachys edulis Leaf Extract Retard the Digestion of Starch and Its Working Mechanisms

Abstract: Bamboo leaf extract as a food additive has been used for preventing the oxidation of food. In the present study, we investigated the influence of Phyllostachys edulis leaf extract on starch digestion. Orientin, isoorientin, vitexin, and isovitexin were determined as its α-amylase inhibitory constituents. An inhibitory kinetics experiment demonstrated that they competitively inhibit α-amylase with Ki values of respectively 152.6, 11.5, 569.6, and 75.8 μg/mL. Molecular docking showed the four flavones can interact with the active site of α-amylase, and their inhibitory activity was greatly influenced by the glucoside linking position and 3'-hydroxyl. Moreover, the results of starch-iodine complex spectroscopy, X-ray diffraction, and scanning electron microscopy indicated that P. edulis flavonoids retard the digestion of starch not only through interaction with digestive enzymes, but also through interaction with starch. Thus, P. edulis leaf extract can be potentially used as a starch-based food additive for adjusting postprandial hyperglycemia.

Antibacterial and anti-biofilm activity of flavonoids and triterpenes isolated from the extracts of Ficus sansibarica Warb. subsp. sansibarica (Moraceae) extracts.

Abstract: Background: Ficus species are used in African traditional medicine in the treatment of a wide variety of ailments and diseases such as convulsive disorder, wound healing, gonorrhea, tuberculosis, diabetes, diarrhoeal infections, dysentery, malaria and HIV. The aim of this study was to isolate the phytochemical constituents in the plant and test them for their antibacterial activity. Materials and methods: The fruits, leaves and stem bark were extracted with organic solvents and the compounds in the extracts separated and purified by column chromatography before being identified by NMR spectroscopy and by comparison of the NMR data against values reported in the literature. The antibacterial activity of the pure compounds and extracts were tested using the disk diffusion method. Results: Three triterpenes and three flavonoids: lupeol acetate (1); cycloart-23-ene-3,25-diol (2); β-sitosterol (3); 5,7,4'-trihydroxyflavan-3-ol (4); epicatechin (5); and isovitexin (6) were isolated in this study. Antimicrobial activity was observed at 8 mg mL-1 for Staphylococcus aureus ATCC 29213 with four of the six isolated compounds, with no activity being observed at 1 – 4 mg mL-1 against Escherichia coli ATCC 25922, E. coli ATCC 35218 and S. aureus ATCC 43300. Epicatechin (5) was found to decrease adhesion of E. coli ATCC 25922 and S. aureus ATCC 29213. Decreased adhesion of S. aureus ATCC 29213 was also observed with 5,7,4'-trihydroxyflavan-3-ol (4) and isovitexin (6). Conclusions: The results of this study provide baseline information on F. sansibarica’s potential validity in the treatment of infections associated with Gram-positive microorganisms.

Analysis of Flavone C-Glycosides in the Leaves of Clinacanthus nutans (Burm. f.) Lindau by HPTLC and HPLC-UV/DAD

Abstract: Clinacanthus nutans (family Acanthaceae) has been used for the treatment of inflammation and herpes viral infection. Currently, there has not been any report on the qualitative and quantitative determination of the chemical markers in the leaves of C. nutans. The C-glycosidic flavones such as shaftoside, isoorientin, orientin, isovitexin, and vitexin have been found to be major flavonoids in the leaves of this plant. Therefore, we had developed a two-step method using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC) for the rapid identification and quantification of the flavones C-glycosides in C. nutans leaves. The TLC separation of the chemical markers was achieved on silica gel 60 plate using ethyl acetate : formic acid : acetic acid : water (100 : 11 : 11 : 27 v/v/v/v) as the mobile phase. HPLC method was optimized and validated for the quantification of shaftoside, orientin, isovitexin, and vitexin and was shown to be linear in concentration range tested (0.4–200 μg/mL, r2 ≥ 0.996), precise (RSD ≤ 4.54%), and accurate (95–105%). The concentration of shaftoside, orientin, vitexin, and isovitexin in C. nutans leave samples was 2.55–17.43, 0.00–0.86, 0.00–2.01, and 0.00–0.91 mmol/g, respectively.

Inhibitory effects of Colocasia esculenta (L.) Schott constituents on aldose reductase.

Abstract: The goal of this study was to determine the rat lens aldose reductase-inhibitory effects of 95% ethanol extracts from the leaves of C. esculenta and, its organic solvent soluble fractions, including the dichloromethane (CH2Cl2), ethyl acetate (EtOAc), n-butanol (BuOH) and water (H2O) layers, using dl-glyceraldehyde as a substrate. Ten compounds, namely tryptophan (1), orientin (2), isoorientin (3), vitexin (4), isovitexin (5), luteolin-7-O-glucoside (6), luteolin-7-O-rutinoside (7), rosmarinic acid (8), 1-O-feruloyl-d-glucoside (9) and 1-O-caffeoyl-d-glucoside (10) were isolated from the EtOAc and BuOH fractions of C. esculenta. The structures of compounds 1–10 were elucidated by spectroscopic methods and comparison with previous reports. All the isolates were subjected to an in vitro bioassay to evaluate their inhibitory activity against rat lens aldose reductase. Among tested compounds, compounds 2 and 3 significantly inhibited rat lens aldose reductase, with IC50 values of 1.65 and 1.92 μM, respectively. Notably, the inhibitory activity of orientin was 3.9 times greater than that of the positive control, quercetin (4.12 μM). However, the isolated compounds showed only moderate ABTS+ [2,29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] activity. These results suggest that flavonoid derivatives from Colocasia esculenta (L.) Schott represent potential compounds for the prevention and/or treatment of diabetic complications.

Flavones from Erythrina falcata are modulators of fear memory

Abstract: Flavonoids, which have been identified in a variety of plants, have been demonstrated to elicit beneficial effects on memory. Some studies have reported that flavonoids derived from Erythrina plants can provide such beneficial effects on memory. The aim of this study was to identify the flavonoids present in the stem bark crude extract of Erythrina falcata (CE) and to perform a bioactivity-guided study on conditioned fear memory. The secondary metabolites of CE were identified by high performance liquid chromatography combined with a diode array detector, electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI/MSn) and nuclear magnetic resonance (NMR). The buthanolic fraction (BuF) was obtained by partitioning. Subfractions from BuF (BuF1 – BuF6) and fraction flavonoidic (FfA and FfB) were obtained by flash chromatography. The BuF3 and BuF4 fractions were used for the isolation of flavonoids, which was performed using HPLC-PAD. The isolated substances were quantified by HPLC-DAD and their structures were confirmed by nuclear magnetic resonance (NMR). The activities of CE and the subfractions were monitored using a one-trial, step-down inhibitory avoidance (IA) task to identify the effects of these substances on the acquisition and extinction of conditioned fear in rats. Six subclasses of flavonoids were identified for the first time in CE. According to our behavioral data, CE, BuF, BuF3 and BuF4, the flavonoidic fractions, vitexin, isovitexin and 6-C-glycoside-diosmetin improved the acquisition of fear memory. Rats treated with BuF, BuF3 and BuF4 were particularly resistant to extinction. Nevertheless, rats treated with FfA and FfB, vitexin, isovitexin and 6-C-glycoside-diosmetin exhibited gradual reduction in conditioned fear response during the extinction retest session, which was measured at 48 to 480 h after conditioning. Our results demonstrate that vitexin, isovitexin and diosmetin-6-C-glucoside and flavonoidic fractions resulted in a significant retention of fear memory but did not prevent the extinction of fear memory. These results further substantiate that the treatment with pure flavonoids or flavanoid-rich fractions might represent potential therapeutic approaches for the treatment of neurocognitive disorders, improvement of memory acquisition and spontaneous recovery of fear.

Antioxidant and Cytoprotective Activities of Flavonoid Glycosides-rich Extract from the Leaves of Zanthoxylum bungeanum

Abstract: The Zanthoxylum bungeanum leaf has been traditionally taken as a vegetable and seasoning in . To disclose the mechanisms of its benefit for human health, antioxidant activity and cytoprotective effect of the leaf were investigated. The ethyl acetate fraction exhibited the strongest ABTS and DPPH radicals scavenging activities as compared with chloroform and water fractions, as well as the crude extract. This fraction exhibited a protective effect against hydrogen peroxide-induced cytotoxicity in PC12 cells by MTT reduction assay. Furthermore, the cytoprotective effect was confirmed using flow cytometry analysis. Comparing with the model cells, the ethyl acetate fraction significantly increased G0/G1 and G2/M phase cells together with reducing S phase cells. Ten flavonoid glycosides were identified as isovitexin, vitexin, hyperoside, rutin, isoquercitrin, foeniculin, trifolin, quercitrin, astragalin, and afzelin from this fraction using high performance liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance spectroscopy. This is the first report for the presence of vitexin, isovitexin, astragalin, trifolin and afzelin in Z. bungeanum. Hence, the results present here suggest the potential utility of Z. bungeanum leaf as a source of natural antioxidant due to its diversity and high content of flavonoids.

로스팅 녹두를 이용한 다식 제조 및 품질특성

Abstract: In this study, we manufactured mung bean Dasik (pattern pressed candy) after selecting the optimum roasting conditions through physiochemical analysis and sensory evaluation. Then anti-oxidative abilities of roasted mung bean were measured in order to develop beauty food (Dasik) using roasted mung bean. In the content of vitexin and isovitexin of roasted mung bean, about 10 times the vitexin in the seed(60.85 mg/g) is found in the skin of raw mung bean, and about 9 times the isovitexin in the seed(71.42 mg/g) is also found in the peel. As a result of analyzing the seed and peel of mung bean after roasting it for 10, 20 and 30 minutes respectively, the optimum roasting condition is thought to be 110℃ for 30 minutes as the contents of vitexin and isovitexin showed the highest values of 104.94 mg/g and 122.02 mg/g respectively when the mung bean was roasted at 110℃ for 30 minutes. In the anti-oxidative activity evaluation of the optimum mung bean Dasik, the total content of phenol was shown to be 0.15 mg/mL, and the total content of flavonoid was shown to be 0.026 mg/mL. The DPPH radical scavenging ability showed a high vitality of 58.19%, and the ABTS radical scavenging ability was shown to be 13.26%.

Antioxidant activity of flavonoids from leaves of Jatropha curcas

Abstract: The objective of this study was to characterize the antioxidant properties of ethanol extracted from leaves of Jatropha curcas and to determinate the compounds. The IC50 values of DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2 0 -azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt) were found to be 7.47 and 6.6 µg/ml, respectively, for the extracts. The reducing power of the extracts increased from 0.09 to 0.16, respectively, for 1-32 µg/ml of standard reagent. The assignment of the flavone compounds using HPLC-DAD-MS n was based on the evaluation of their UV-Vis absorption maxima ( max) and mass spectral analyses. Tentatively, 4 compounds (orientin, vitexin, isovitexin, rhoifolin) were identified.

Isolation and Purification of Six Bioactive Compounds from the Seeds of Trigonella foenum-graecum L. using High-Speed Counter-Current Chromatography

Abstract: It is difficult to simultaneously isolate and purify flavonoids and polyhydroxystilbenes due to their similar polarities. In this study, we isolated and purified these compounds from Trigonella foenum-graecum L. seed extracts using high-speed counter-current chromatography (HSCCC) in two steps with two different kinds of solvent systems. In the first step, n-hexane:ethyl acetate:methanol:water (1:5:1:5, v/v) was used as the two-phase solvent system, desoxy-rhaponticin and rhapontigenin were purified, and orientin, vitexin, isovitexin, and rhaponticin were eluted together. In the second step, ethyl acetate:water (1:1, v/v) was used as the two-phase solvent system, and orientin, vitexin, rhaponticin, and isovitexin were isolated and purified. Purities of the isolated compounds were determined using HPLC, while UV spectra, 1 H-NMR, and 13 C-NMR aided in structure identification.

Identification and evaluation of flavone-glucosides isolated from barley sprouts and their inhibitory activity against bacterial neuraminidase.

Abstract: Neuraminidase (NA) is one of the key enzymes responsible for bacterial infection and pathogenesis. This study aimed to gain deeper insights into the inhibitory effects of flavone-glucosides (1-9) isolated from barley sprouts (BS) on neuraminidase activity. The isolated compounds were identified as, lutonarin (1), saponarin (2), isoorientin (3), orientin (4), isovitexin (5), isoscoparin-7-O-[6-sinapoyl]-glucoside (6), isoscoparin-7-O-[6-feruloyl]-glucoside (7), isovitexin-7-O-[6-sinapoyl]-glucoside (8), and isovitexin-7-O-[6-feruloyl]-glucoside (9). Among them, compounds 1-5 exhibited neuraminidase-inhibitory activities in a dose-dependent manner, with IC50 values ranging from 20.1 to 32.7 μM, in a non-competitive inhibition mode according to kinetic studies. Moreover, the individual flavone-glucoside levels differed notably, in particular, lutonarin (1) and saponarin (2) were shown to be present in the greatest amounts, according to UPLC analysis. Consequently, our results suggest that BS may be utilized as an effective NA inhibitor in human health food, additives, and feed.

New Flavone from the Aerial Parts of Bougainvillea Glabra

Abstract: New flavone was isolated for the first time from the methanolic extract of the aerial part of Bougainvillea glabra (Nyctaginaceae) & identified as luteolin-7-O-(2''-O-(5'''-O-feruloyl)- b-D- apiofuranosyl)- b-D-glucopyranoside in addition to five flavonoids isolated& identified after comparing their spectra with reported ones as vitexin, isovitexin, chrysoeriol, apigenin& luteolin .

Chemical constituents of Artemisia lactiflora(II)

Abstract: To study the chemical constituents of Artemisia lactiflora. The compounds were isolated by column chromatography with silica gel, C18 reverse-phase silica gel, semi-preparative HPLC, and their structures were elucidated on the basis of spectral analysis. Twelve compounds were isolated from alcohol extracts of A. lactiflora and identified as 7-hydroxycoumarin (1), 7-methoxycoumarin (2), balanophonin (3), aurantiamide (4), aurantiamide acetate (5), isovitexin (6), kaempferol-3-O-beta-D-rutinoside (7), rutin (8), caffeic acid ethyl ester (9), quercetin (10), methyl 3, 5-di-O-caffeoyl quinate (11) and methyl 3, 4-di-O-caffeoyl quinate (12), respectively. Compounds 3-12 were obtained from this plant for the first time.

Seasonal variations in the amount of isoorientin and isovitexin in Cecropia glaziovii Sneth. leaves over a two-year period

Abstract: Cecropia glaziovii Sneth (Urticaceae) is a common tree from Southeast and South of Brazil, being widely used in traditional medicine to treat heart and respiratory conditions. C-glycosylflavonoids have being described as the major compounds for this genus, however, no seasonality studies of individual flavonoids was conducted for any Cecropia specie. In this work, the content of isoorientin and isovitexin in aqueous extract from the leaves of C glaziovii during a two-year period was determined by high-performance liquid chromatography with diode array detector (hplc-dad). Seasonal alterations in the content of these two majority C-glycosylflavonoids as well its possible correlation with the pluviosity in the period of January/2008 to January/2010 were determined. Isoorientin presented higher content in November/09 (6.04 mg/g of extract) and lower content in May/08 (1.01 mg/g of extract). The higher content of isovitexin was observed in March/09 and the lower in September/08 (11.42 and 4.47 mg/g of extract, respectively). Although they have distinct behaviors, it was not observed correlation between the values of pluviosity and the production of these C-glycosylflavonoids.

Chemical constituents in higher polar substances from Desmodium caudatum

Abstract: In this study the chemical constituents of the higher polar sustances from Desmodium caudatum were investigated.The compounds were isolated by using column chromatographies over silicagel, polyamide, ODS, Sephadex LH-20, and preparative HPLC. The structures of these compounds were identified on the basis of NMR and MS spectra. Thirteen compounds were obtained and their structures were identified as vanillin(1), loliolide(2), indole-3-carboxaldehyde(3), salicylic acid(4), swertisin(5), saccharumoside C(6), isosinensin (7), kaempferol 3-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (8), isovitexin (9), vitexin (10), nothofagin(11), resveratroloside (12), and 2"-α-rhamnopyranosyl-7-O-methylvitexin (13). Except for compound 5, the remaining compounds were isolated from D. caudatum for the first time. Compounds 2, 3, 6-8, 11-13 were separated from the genus Desmodium for the first time.

HPLC with switching wavelength simultaneous determination of six constituents in Gentiana crassicaulis

Abstract: To establish an HPLC with switching wavelength method for determination of six components(loganic acid,swertiamarin,gentiopicroside,sweroside,isoorientin,isovitexin) in Gentiana crassicaulis.Sepax Gp-C18(150 mm × 4.6 mm,5 μm) column was used,the mobile phase was methanol-0.1% phosphoric acid solution with gradient elution at a flow rate of 1.0 mL·min-1.The column temperature was set at 25℃,detection wavelength was 235 nm(0 ~ 51 min) 、270 nm(51 ~ 57 min) 、243 nm(57 ~ 65 min) 、270 nm(65 ~ 80 min).The six components(loganic acid,swertiamarin,gentiopicroside,sweroside,isoorientin,isovitexin) content in the ranges of 0.01000 ~ 10.0000,0.00216 ~ 2.1600,0.048 ~ 48.0000,0.0010 ~ 1.0000,0.00034 ~ 0.3400 and 0.00026 ~0.2600 μg respectively,had a good linearity.The average recoveries were 98.52% ~ 99.31%,the RSD was less than 3.5%.There were significant correlations between the content of the four iridoid glucosides,the content of the two flavone constituents had correlations too.There was no correlations between the flavone constituents and the iridoid glucosides constituents.Conclusion:This method was simple,rapid,accurate,dependable.And may be use to control quality of Gentiana crassicaulis.

Biologically active secondary metabolites from kalanchoe tomentosa

Abstract: Phytochemical study of the ethanolic extract of Kalanchoe tomentosa (Crassulaceae) resulted in the isolation of 14 compounds identified as; α-amyrin acetate (1), friedelin (2), glutinol (3), 1-dotriacontanol (4), phytol (5), Stigmasta-7,25-dien-3b-ol (6), β-sitosterol (7), Isorhamnetin (8), 2,3-dihydroxypropyl tetradecanoate (9), Eriodictyol (10), Gallic acid (11), quercetin (12), kampferol-3-O-Rutinoside (13) and isovitexin (14). These compounds were isolated for the first time from this species. The structure elucidation of isolated metabolites was carried out using spectroscopic data (1D and 2D NMR). Antioxidant, cytotoxic and antimicrobial activities of different plant extracts were also studied and significant results were obtained. Key words:Kalanchoetomentosa; Crassulaceae; cytotoxicity and antimicrobial activities.

Application of hptlc and ftir profilingcoupled with chemometrics for the differentiation of the varieties officus deltoideajack

Abstract: Objective: The aims of this study were to identify and evaluate the chemical markers of Ficus deltoidea Jack (FD)varieties namely var. deltoidea , var. trengganuensis , var. kunstleri, var. motleyana , var. intermedia , var. borneensis , var. bilobata and var. angustifolia by High Performance Thin Layer Chromatography (HPTLC) and to discriminate between the varieties based on Fourier Transform Infra Red (FTIR) data. Methods: Methanol extracts of eight varieties and water extracts of five varieties were subjected to HPTLC and FTIR fingerprinting analysis. Quantification of markers (vitexin and isovitexin) was performed by HPTLC. Cluster analysis of Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) was employed to discriminate between the varieties based on their FTIR data. Results: Two markers, vitexin and isovitexin, were found in all of the varieties, but their contentswere varied in the different samples.Cluster analysis (PCA and HCA) was employedto discriminate between the varieties based on their FTIR data. Clear separation between the methanol extracts of the varieties was observed, whereas the discrimination of the water extracts of the varieties showed some disparities. Conclusion: The findings indicate that HPTLC combined with FTIR coupled with chemometricanalysis isa reliable analytical tool for the identificationand discrimination of Ficus deltoidea varieties. Keywords: Ficus deltoidea Jack, HPTLC, FTIR profiling, vitexin, isovitexin

[Simultaneous determination of four flavone C-glycosides in Phyllostachys edulis leaves by high-performance liquid chromatography with ultraviolet spectrometry].

Abstract: High-performance liquid chromatography with ultraviolet spectrometer (HPLC-UV) was used to simultaneously detect the four flavone C-glycosides, i. e. orientin, isoorientin, vitexin and isovitexin. Analytes were separated with Waters XTerra MS C18 column (250 mm x 4.6 mm, 5 μm) using acetonitrile and 0.5% (φ) formic acid as mobile phase. The flow rate was set at 1.0 mL · min(-1) with the column temperature at 30 °C, and the detection wavelength was 360 nm. The calibration curve was linear over the concentration range of 0.1-10.0 mg · L(-1) for the mixed standard solution. Analytes were separated in 22 minutes, and the relative standard deviation values were all above 0.999. LOD values of standards were found to be between 0.03 and 0.07 mg · L(-1), and LOQ values were in the range of 0.04-0.08 mg · L(-1). After comparing the spectra (240-400 nm) of four flavone C-glycosides in mixed standards and the final product purified by macroporous resin, respectively, the curve shape and characteristic ultraviolet absorption wavelength of each flavone C-glycoside including orientin, isoorientin, vitexin and isovitexin were fitted well. The bamboo leaves sample was extracted by ethanol under reflux, and then partitioned with water and petroleum ether. The aqueous phase was added onto macroporous resin (AB-8), and the fraction of ethanol-water (40%, φ) was concentrated. It was found that the contents of orientin, isoorientin, vitexin and isovitexin relative to the fraction of ethanol- water were 13.73, 49.68, 7.85 and 30.70 mg · g(-1), respectively. In addition, the average recovery of the four flavone C-glycosides ranged from 34.90% to 87.64% with RSD values from 0.41% to 10.83%. The results showed that bamboo leaves sample had good stability and repeatability. The new method was used to analyze the four flavone C-glycosides quickly and provide quality control for commercial products.

A Study on Pharmacognosticaland Phytochemical Evaluation of Leaves of Passiflora nepalensis wall

Abstract: Now-a-days, herbal medication is proving to be better and safer mode of therapy of various diseases, without exhibiting any adverse effects as those with the allopathic medication. Passifloranepalensisbelongs to the family (Passifloraceae family). It is commonly known as Passion flower. The plant is a glabrous climber with slender branches and distant leaves growing in shady areas. Passifloranepalensisis distributed throughout Sikkim, Himalayan region of India, at about 4000-6000 ft. The present study provides updated information on its pharmacognostic, phytochemical analysis and pharmacological properties. Transverse sections of Passifloranepalensisleaf showeddorsiventral leaf structure. Midrib region showed layers of thick walled collenchyma cells below the upper epidermis & above the lower epidermis along with highly lignified vascular bundles. The flower and tender shoots has sedative, antispasmodic and tranquilizing activity. Physicochemical studies shows, total moisture content (8.33%), total ash value (13.33%), acid insoluble ash value (16.66%), alcohol soluble extractive values (96%) and water soluble extractive values (40%). Preliminary phytochemical analysis (organic analysis) revealed alkaloids, carbohydrates, glycosides, saponins, proteins, phenolic compounds and flavonoids are present. The other variety of this species having several important constituents like apigenin and isovitexin flavonoids, cyanogenic glycosides and indole alkaloids (harman). As there is no detailed work reported in leaf, therefore pharmacognostical evaluation including physicochemical parameters, preliminary phytochemical standards were determined .The study revealed specific identities for the plant, which will be useful in identification, as a control to abet adulterants and for future standardization work.

Method for extracting isovitexin from ficus microcarpa

Abstract: The invention relates to a method for extracting isovitexin from ficus microcarpa, and particularly relates to a method for extracting the isovitexin by combining an application flash extraction technology and enzymolysis-ultrasonic-assisted extraction. The method comprises the following treatment steps: placing fresh or dry ficus microcarpa into a container, adding 70%-80% ethanol, and carrying out smashing extraction on the ficus microcarpa on a traditional Chinese medicine extractor for 5-10 minutes; taking out, regulating a pH value to 4.0-5.5, and carrying out enzymolysis and ultrasonic-assisted extraction; filtering, alkalifying filter liquor for neutralization, purifying by adopting macroporous adsorption resin, and recrystallizing to obtain the high-purity isovitexin. The method disclosed by the invention is simple in process, has complementary advantages by combining two technologies, greatly shortens the extraction time and is low in cost, more favorable to environmental protection and suitable for industrialized production.

Chemical constituents of flavonoids and their glycosides in Melastoma dodecandrum

Abstract: The chemical constituents of 95% ethanol extract of Melastoma dodecandrum were isolated and purified by chromatography on silica gel, Sephadex LH-20, and HPLC, to obtain thirteen compounds eventually On the basis of their physico-chemical properties and spectroscopic data, these compounds were identified as quercetin (1), quercetin-3-O-β-D-glucopyranoside (2), quercetin-3-O-(6"-O-p-coumaroyl) -β-D-glucopyranoside (3), kaempferol (4), kaempferol-3-O-β-D-glucopyranoside (5), kaempferol-3-O- [2",6"-di-O-(E)-coumaroyl]-β-D-glucopyra-noside (6), luteolin (7), luteolin-7-O-(6"-p-coumaroyl) -β-D-glucopyranoside (8), apigenin (9), apigenin-7-(6"-acetyl-glucopyranoside) (10) , naringenin (11), isovitexin (12), and epicatechin-[8,7-e] -4β-(4-hydroxyphenyl)-3,4-dyhydroxyl-2(3H)-pyranone (13) Eight compounds(3,5,6,8-11 and 13) were obtained from M dodecandrum for the first time

The Second Study of Chemical Compositions of South-east Swertia Plant

Abstract: South-east swertia plant belongs to gentianaceae swertia genus with the functions of heat-clearing,detoxicating,cholagogic and anti-inflammatory.From water soluble part of 80% methanol extracts of southwest swertia plant three compounds,isovitexin,Homoorientin,6''- arabinose isovitexin,are isolated using modern separation and analysis techniques,which are first extracted from the plant.