Determination of Flavonoids Compounds of Three Species and Different Harvesting Periods in Crataegi folium Based on LC-MS/MS

Crataegi folium have been used as medicinal and food materials worldwide due to its pharmacological activities. Although the leaves of Crataegus songorica (CS), Crataegus altaica (CA) and Crataegus kansuensis (CK) have rich resources in Xinjiang, China, they can not provide insights into edible and medicinal aspects. Few reports are available on the qualitative and quantitative analysis of flavonoids compounds of their leaves. Therefore, it is necessary to develop efficient methods to determine qualitative and quantitative flavonoids compounds in leaves of CS, CA and CK. In the study, 28 unique compounds were identified in CS versus CK by qualitative analysis. The validated quantitative method was employed to determine the content of eight flavonoids of the leaves of CS, CA and CK within 6 min. The total content of eight flavonoids was 7.8–15.1 mg/g, 0.1–9.1 mg/g and 4.8–10.7 mg/g in the leaves of CS, CA and CK respectively. Besides, the best harvesting periods of the three species were from 17th to 26th September for CS, from 30th September to 15th October for CA and CK. The validated and time-saving method was successfully implemented for the analysis of the content of eight flavonoids compounds in CS, CA and CK for the first time.     

Chromatographic investigations of flavonoid compounds in the leaves and flowers of some species of the genusAlthaea

Summary The flavonoids present in the leaves and flowers ofAlthaea armeniaca Ten., A. cannabina L., A. narbonesis Pourr. andA. broussonetiifolia Iljin were investigated and compared to the flavonoids present in the leaves and flowers ofA. officinalis L. The inliquid chromatography and two-dimensional paper chromatography. The same flavonoids were found in the flowers of all the investigated species while differences could be noted in the flavonoid composition of the leaves. Both the qualitative and quantitative difference was the greatest in the flavonoids of the leaves ofA. cannabina L.     

Two New C—glucoside Flavonoids from Leaves of Crataegus pinnatifida Bge. var. major N.E.Br.

Two new C-glucoside flavonoids,namely 8-C-β-D-（2″-O-acetyl) glucofuranosyl apigenin and 3″-O-acetylvitexin, were isolated from beaves of Crataegus pinnatifida Bge. var. major N.E.Br.Their structures were elucidated by the spectroscopic means and chemical evidence.     

Determination of flavones in Crataegus pinnatifida by capillary zone electrophoresis

A capillary electrophoretic method for the separation of four flavones in Crataegus pinnatifida is developed. The four flavones in Crataegus pinnatifida are separated on baseline within 15 min using 50mM borax buffer containing 15% acetonitrile and adjusted to pH 8.15 with phosphoric acid. The detection limits of vitexin-2"-rhamnoside, hyperside, rutin, and vitexin are 0.35, 0.30, 0.40 and, 0.29 microg/mL, respectively. The recovery of these flavones is as follows: vitexn-2"-rhamnoside 96.8%, hyperside 99.9%, rutin 97.1%, and vitexin 97.8%. The results are in accordance with those obtained in the high-performance liquid chromatography system. The content of flavones is higher in Crataegus pinnatifida leaves than in its fruits, and hyperside is not detected in either Crataegus pinnatifida fruits or flowers.     

On-line coupling of capillary isotachophoresis and zone electrophoresis for the assay of phenolic compounds in plant extracts

The combination of capillary isotachophoresis (ITP) and capillary zone electrophoresis (CZE) in the column coupling configuration was optimized in a mode where the electrolyte for the CZE step is different from the leading and terminating ITP electrolytes. Two colored markers, picric acid and 1-nitroso-2-naphthol, were used for exact timing of the transfer of isotachophoretically stacked analyte zones into the CZE column and for the control of the residual amount of the leading and terminating ITP electrolytes entering the CZE capillary together with the analytes, thus controlling the duration of transient ITP migration in the CZE capillary and ensuring good separation of the analytes and reproducibility of the migration times (relative standard deviations 1%). ITP-CZE was applied to the simultaneous assay of several cinnamic acid derivatives and flavonoids in methanolic extracts of Sambucus flowers and Crataegus leaves and flowers. The preconcentrating and cleansing effect of the ITP step allowed injection of relatively large sample volumes (30 microL). The limits of detection were approximately 20-50 ng x mL(-1) and 100 ng x mL(-1) for the acids and flavonoids, respectively ( thick similar 200-times lower compared to conventional CE) with spectrophotometric detection at 254 nm. The ITP-CZE exhibited satisfactory linearity and precision when using CZE buffer of pseudo "pH" 9.0; 1-nitroso-2-naphthol was employed as the internal standard. The separation took approximately 35 min. The ITP-CZE results for rutin, hyperoside, and vitexin-2-O"-rhamnoside were in good accordance with those obtained previously by high-performance liquid chromatography.     

Evaluation of the hypocholesterolemic effect and phytochemical screening of the hydroethanolic extract of Crataegus aronia from Jordan

Chemical screening of the leaves and flowers of Crataegus aronia resulted in the isolation of hyperoside, quercetin, rutin and beta-sitosterol for the first time from this plant. The effects of the hydroethanolic extract of C. aronia (CAHE) on hypercholesterolemic rats were investigated. The rats, treated orally for four weeks with 400 mg/kg/day CAHE, exhibited significant decreases in serum total cholesterol (TC) and low-density lipoprotein (LDL). The results were compared with those obtained after oral administration of atorvastatin (10 mg/kg/day). Furthermore, 10-week daily co-administration of a high cholesterol diet and CAHE (200 mg/kg/day) prevented the increase in TC and LDL. These observations indicate that CAHE has a hypocholesterolemic effect.     

Liquid chromatography with mass spectrometry method based two‐step precursor ion scanning for the structural elucidation of flavonoids

Plant flavonoids are very important secondary metabolites for insect and virus control of their host plant and are potent nutrients for humans. To be able to understand the bioavailability and functions of plant flavonoids, it is necessary to reveal their exact chemical structures. Liquid chromatography with tandem mass spectrometry is a powerful approach for structural elucidation of metabolites. In this report, a two‐step precursor ion scanning based liquid chromatography with tandem mass spectrometry method was developed for the structural elucidation of plant flavonoids. The established method consists of the two‐step precursor ions scanning for possible flavonoids extraction, MS² fragment spectra acquisition and comparison with an online database, liquid chromatography retention rules correction, and commercial standards verification. The developed method was used for the structure elucidation of flavonoids in flowers and leaves of tobacco (Nicotiana tabacum), and 17 flavonoids were identified in the tobacco variety Yunyan 97. Nine of the 17 identified flavonoids were considered to be found in tobacco flowers or/and leaves for the first time based on the available references. This method was proved to be very effective and can be used for the identification of flavonoids in other plants.     

Bioactive compounds and antioxidant capacity of Chuquiraga jussieui J.F.Gmel from the highlands of Ecuador

Abstract

Chuquiraga jussieui J.F.Gmel is grown between 3000 and 5000 meters above sea level throughout the Andean region of Ecuador and used by the indigenous populations of the Andes for medicinal purposes. Here, we determined the total phenolic, flavonoids, vitamin C and carotenoids content of the leaves and flowers of Ch. jussieui J.F.Gmel from different highlands of Ecuador as well as the capacity of a crude methanolic extract from the both parts of the plant to scavenge free radicals and protect red blood cell membranes from lipid oxidation. The leaves showed a high bioactive compound content in comparison to the flowers. The crude extract from the leaves proved to be more effective than the flowers in reducing iron and scavenging the DPPH, O₂^? and H₂O₂ radicals, as well as in protecting cellular membrane against lipid oxidation, demonstrating that Ch. jussieui J.F.Gmel represents an important source of bioactive compounds with relevant healthy properties.     

Chemotaxonomic features associated with flavonoids of cannabinoid-free cannabis (Cannabis sativa subsp. sativa L.) in relation to hops (Humulus lupulus L.)

The major flavonoids present in the leaves and flowers of the cannabinoid-free cannabis (Cannabis sativa subsp. sativa L.) cultivars Felina and Futura are orientin (1), vitexin (2), luteolin-7-O-beta-D-glucuronide (3), and apigenin-7-O-beta-D-glucuronide (4), while prenylated flavonoids, to which the potent estrogenicity of hops (Humilus lupulus L.) is associated, are absent. The different composition of flavonoids has chemotaxonomic value.     

Flavonoid concentrations in three grass species and a sedge grown in the field and under controlled environment conditions in response to enhanced UV-B radiation

An investigation was carried out to find whether enhanced levels of UV-B radiation induce increased concentrations of flavonoids in the leaves of the grass species Deschampsia antarctica, Deschampsia borealis and Calamagrostis epigeios and the sedge Carex arenaria. Whether the enhanced levels of UV-B influenced the proportions of the various flavonoids in the leaves was also studied. Increased flavonoid concentrations would improve the UV-B shielding of UV-B susceptible tissues. Using HPLC analysis the flavonoids orientin and luteolin were identified in D. antarctica, orientin in D. borealis and tricin in C. arenaria. Neither flavonoid concentrations nor the proportion of the various flavonoids in climate room grown D. antarctica and D. borealis plants differed between individuals grown under 0, ambient or elevated UV-B levels. After 12 weeks of growth biomass production and shoot-to-root ratios of D. antarctica were not affected by elevated UV-B radiation. Greenhouse grown C. epigeios plants contained higher concentrations and different proportions of flavonoids grown under elevated levels of UV-B than when grown under ambient or 0 UV-B. In C. epigeios plants grown in their natural habitat in the field under ambient or elevated levels of UV-B, flavonoid concentrations and proportions were the same in plants from both treatments. In the leaves of the sedge C. arenaria grown in a greenhouse flavonoid concentrations and proportions were not affected by UV-B radiation. Leaves were harvested four times during the growing season from C. arenaria plants grown in their natural habitat in the field under ambient or elevated levels of UV-B. Leaves harvested in January contained higher concentrations of flavonoids when grown under elevated UV-B than when grown under ambient UV-B radiation. In leaves harvested in May, September and December flavonoid concentrations were the same in plants grown under ambient or elevated UV-B. The proportion of the different flavonoids was the same for both treatments in all months. These results indicate that constitutive levels of flavonoids in these grass and sedge species are adequately high to protect them against ambient and elevated levels of solar UV-B radiation.     

A comparative study of phytochemical metabolites and antioxidant properties of Rhodiola

Rhodiola crenulata (RC) and Rhodiola fastigiata (RF) are representative species of Rhodiola with well-accepted health benefits; the roots are the medicinal part. However, prior to this study, the differences in phytochemicals between these two species and different parts of the same species remained unclear. Using LC-ESI-MS/MS, HS-SPME-GC–MS, chemical and sensory analyses, volatile compounds and non-volatile compounds, and antioxidant activities of the roots of Rhodiola crenulata and Rhodiola fastigiata and four parts (roots, leaves, flowers, and above-ground stems) of RC were investigated. The volatile compounds and non-volatile compounds of RC roots exhibited upregulation overall compared to those of RF roots, and the odorousness, phenolic content, and antioxidant activity were more pronounced in the RC roots. The phenolic content and antioxidant activity of roots and leaves, alongside the odorousness of roots and flowers, were more significant among the four parts of RC, and the RC roots and RC flowers exhibited similar odorousness. Comparison of non-volatile differential metabolites between RC roots and RC leaves showed upregulations of saccharides and phospholipids, and minor upregulations of flavonoids and phenylpropanoids in the roots; in addition, amino acids, organic acids, and vitamins were upregulated in the leaves. These results revealed the following: 1) RC roots are superior to RF roots regarding volatile compounds and non-volatile compounds, and antioxidant activity; 2) it is more favorable to select RC roots for exploiting volatile compounds compared with RC flowers in consideration of the biomass available; 3) in terms of non-volatile compounds, and antioxidant ability, RC leaves are also of great value in addition to RC roots, though these two parts show distinct characteristics.     

Capillary electrophoretic analysis of flavonoids in single-styled hawthorn (Crataegus monogyna Jacq.) ethanolic extracts

Flavonoids are an important group of natural compounds, which can prevent coronary heart disease and have antioxidant properties. Hawthorn is a well known and widely used medicinal plant due to its cardiotonic activity. Previous studies refer mostly to the HPLC analysis of the flavonoids: vitexin, quercetin, hyperoside, oligomeric procyanidins, which appear to be primarily responsible for the cardiac action of the plant. Aqueous ethanolic extracts of single-styled hawthorn (Crataegus monogyna Jacq., f.: Rosaceae Juss.) leaves and sprouts were analyzed by means of capillary zone electrophoresis (CZE). Influence of vegetation period on the extract qualitative composition and flavonoids quantities was evaluated. Sample preparation by extraction using different concentration of aqueous ethanol (40-96%, v/v) and the influence of extractant composition on the recovery of flavonoids are discussed in detail. The results obtained using CZE are compared to the results of spectrophotometric and HPLC analysis of the extracts. The effect of storage conditions of extracts (solar irradiation, temperature and duration) on degradation of flavonoids was investigated.     

Active Flavonoids from Colubrina greggii var. greggii S. Watson against Clinical Isolates of Candida spp.

Candida albicans is the most commonly implicated agent in invasive human fungal infections. The disease could be presented as minimal symptomatic candidemia or can be fulminant sepsis. Candidemia is associated with a high rate of mortality and high healthcare and hospitalization costs. The surveillance programs have reported the distribution of other Candida species reflecting the trends and antifungal susceptibilities. Previous studies have demonstrated that C. glabrata more frequently presents fluconazole-resistant strains. Extracts from Mexican plants have been reported with activity against pulmonary mycosis, among them Colubrina greggii. In the present study, extracts from the aerial parts (leaves, flowers, and fruits) of this plant were evaluated against clinical isolates of several species of Candida (C. albicans, C. glabrata, C. parapsilosis, C. krusei, and C. tropicalis) by the broth microdilution assay. Through bioassay-guided fractionation, three antifungal glycosylated flavonoids were isolated and characterized. The isolated compounds showed antifungal activity only against C. glabrata resistant to fluconazole, and were non-toxic toward brine shrimp lethality bioassay and in vitro Vero cell line assay. The ethyl acetate and butanol extracts, as well as the fractions containing the mixture of flavonoids, were more active against Candida spp.     

Chemical Identification of Specialized Metabolites from Sulla (Hedysarum coronarium L.) Collected in Southern Italy

Sulla (Hedysarum coronarium L.) is a biennal forage legume originated from the Mediterranean basin and used for animal feeding due to its high forage quality and palatability. Several species of Hedysarum have been considered for their nutritional, pharmaceutical, and biological properties, and different applications have been reported, both for human consumption and animal nutrition. Although a systematic investigation of the chemical constituents of Hedysarum spp. has been performed in order to provide chemotaxonomic evidences for the genus and to support the pharmacological application of several species within the genus, few data are available on the chemical constituents of H. coronarium, and only the content of condensed tannins and flavonoids in leaves has been previously reported. In the present paper, results from a detailed chemical analysis of the extracts from the leaves and flowers of H. coronarium grown wild in southern Italy are presented. Identification of the main specialized metabolites within the chemical classes of flavonoids, proanthocyanidins and saponins, is described, including considerations on their content in the two plant organs. Information acquired from this study expands the knowledge on H. coronarium as a source of valuable phytochemicals for different applications in human and animal health and nutrition.     

Evaluation of flavonoid contents and antioxidant capacity of the aerial parts of common and tartary buckwheat plants

The analysis of major and minor flavonoids, and antioxidant capacity of stems, leaves, flowers, unripe seeds and ripe seeds of common and tartary buckwheat plants collected during different growth periods was addressed in this study. The highest rutin contents were observed in flowers and leaves collected from common and tartary buckwheat at early flowering as well as flowering and seed formation states. A low quercetin contents were found in all studied aerial part of buckwheat plants. Quercitrin (quercetin-3-rhamnoside) was only found in flowers collected at different growth periods while flavone C-glucosides were accumulated preferentially only in unripe seeds collected from common buckwheat at an early flowering state. The rank of antioxidant capacity provided for aerial parts of common and tartary buckwheat at early flowering state was as follows: flowers > leaves > stems. The highest contribution of rutin to the antioxidant capacity of the aerial parts of common and tartary buckwheat was found for stems followed by leaves, flowers and unripe seeds. The results demonstrate that flowers from common and tartary buckwheat collected at early flowering as well as flowering and seed formation states have the future potential to be a useful food ingredient.     

Simultaneous determination of vitexin-2"-O-glucoside, vitexin-2"-O-rhamnoside, rutin, and hyperoside in the extract of hawthorn (Crataegus pinnatifida Bge.) leaves by RP-HPLC with ultraviolet photodiode array detection

RP-HPLC with UV photodiode array detection (UV-DAD) was developed and validated for the simultaneous determination of vitexin-2"-O-glucoside, vitexin-2"-O-rhamnoside, rutin, and hyperoside in the extract of hawthorn (Crataegus pinnatifida Bge.) leaves. The analytes of interest were separated on a Diamonsil C18 column (250 x 4.6 mm id, 5 microm) with the mobile phase consisting of THF/ACN/methanol/ 0.05% phosphoric acid solution (pH 5.0) (18:1:1:80 v/vl/v). The flow rate was set at 1.0 mL/min and the eluent was detected at 340 nm for the four flavonoids. The method was linear over the studied range of 1.00-100 microg/mL for the four analytes of interest with the correlation coefficient for each analyte greater than 0.999. The LOD and LOQwere 0.03 and 0.10 microg/mL, 0.03 and 0.10 microg/mL, 0.05 and 0.15 pg/mL, 0.10 and 0.30 microg/mL for vitexin-2"-O-glucoside, vitexin-2"-0-rhamnoside, rutin, and hyperoside, respectively. The optimized method was successfully applied to the analysis of four important flavonoids in the extract of hawthorn leaves. The total amounts of the four flavonoids were 22.2, 62.3, 4.27, and 8.24 mg/g dry weight for vitexin-2"-O-glucoside, vitexin-2"-O-rhamnoside, rutin, and hyperoside in the extract of hawthorn leaves, respectively.     

Chemical Profile,Cytotoxic Activity and Oxidative Stress Reduction of Different Syringa vulgaris L. Extracts

Syringa vulgaris L. (common lilac) is one of the most popular ornamental species, but also a promising not comprehensively studied source of bioactive compounds with important therapeutic potential. Our study was designed to characterize the chemical composition and to assess the antioxidant and cytotoxic properties of ethanolic extracts obtained from S. vulgaris L. flowers, leaves, bark, and fruit. The chemical profile of the ethanolic extracts was investigated using chromatographic (HPLC-DAD-ESI⁺, GC-MS) and spectral (UV-Vis, FT-IR) methods, while the protective effect against free radicals was evaluated in vitro by different chemical assays (DPPH, FRAP, CUPRAC). The cytotoxic activity was tested on two tumoral cell lines, HeLa, B16F10, using the MTT assay. Significant amounts of free or glycosylated chemical components belonging to various therapeutically important structural classes, such as phenyl-propanoids (syringin, acteoside, echinacoside), flavonoids (quercetin, kaempferol derivatives) and secoiridoids (secologanoside, oleuropein, 10-hydroxy oleuropein, demethyloleuropein, syringalactone A, nuzhenide, lingstroside) were obtained for the flowers, leaves and bark extracts, respectively. Furthermore, MTT tests pointed out a significant cytotoxic potential expressed in a non-dose-dependent manner toward the tumoral lines. The performed methods underlined that S. vulgaris extracts, in particular belonging to flowers and leaves, represent valuable sources of compounds with antioxidant and antitumoral potential.     

微乳液相色谱法同时测定山楂叶提取物中4种黄酮成分

建立了一种新的微乳体系,用于微乳液相色谱同时分析山楂叶提取物中牡荆素鼠李糖苷、芦丁、牡荆素及金丝桃苷4种黄酮成分.通过对影响分离选择性的主要因素进行考察,得到最佳微乳体系的组成为: 1.0%(w/w) 聚氧乙烯月桂醇(Brij35)-1.1%(w/w)正丁醇-0.1%(w/w)正辛醇-0.3%三乙胺(V/V)(H_3PO_4调节至pH 2.5).在此微乳体系中,表面活性剂类型和浓度、油相种类、添加剂三乙胺、流动相的pH值对4种黄酮成分的分离起到了重要的作用.选择Venusil ASB C_(18)色谱柱(150 mm×4.6 mm, 5μm),流速为0.8 mL/min,检测波长为360 nm,柱温为35 ℃.结果显示,4种黄酮成分在27 min内达到基线分离,在0.95～140.8 mg/L范围内,4个黄酮成分的线性相关系数r≥0.9995,平均回收率98.6%～101.6%.本方法可应用于山楂叶提取物中4种主要黄酮成分的质量分析.     

Fractionation of polyphenols in hawthorn into polymeric procyanidins, phenolic acids and flavonoids prior to high-performance liquid chromatographic analysis

Polymeric procyanidins, phenolic carboxylic acids and flavonoids of hawthorn (Crataegus laevigata) were fractionated prior to HPLC analysis using column chromatography and solid-phase extraction (SPE). The flavonoid fraction also contained (-)-epicatechin. The three groups of phenolics, each with clearly different UV spectra, were examined by means of high-performance liquid chromatography-diode array detection (HPLC-DAD) analysis. The average repeatability of the method (RSD) was in the range of 8-13% for chlorogenic acid, (-)-epicatechin and hyperoside. The polymeric procyanidins of hawthorn flowers consisted mainly of (-)-epicatechin subunits, and their mean degree of polymerization (DP) was 22.2. The HPLC methods developed can be used for the qualitative and quantitative analysis of different phenolic compounds in hawthorn plant material and their extracts.