Capillary electrochromatography of selected phenolic compounds of Chamomilla recutita

Formulation and Characterization of Nanoemulsion Incorporating Chamomilla recutita L. Extract Stabilized with Hyaluronic Acid

Skin lesions are an important health concern, exposing the body to infection risks. Utilizing natural products containing chamomile (Chamomilla recutita L.) holds promise for curative purposes. Additionally, hyaluronic acid (HA), an active ingredient known for its tissue regeneration capacity, can expedite healing. In this study, we prepared and characterized an extract of C. recutita and integrated it into a nanoemulsion system stabilized with HA, aiming at harnessing its healing potential. We assessed the impact of alcoholic strength on flavonoid extraction and chemically characterized the extract using UHPLC/MS while quantifying its antioxidant and antimicrobial capacity. We developed a nanoemulsion loaded with C. recutita extract and evaluated the effect of HA stabilization on pH, droplet size, polydispersity index (PDI), zeta potential, and viscosity. Results indicated that 70% hydroalcoholic extraction yielded a higher flavonoid content. The extract exhibited antioxidant capacity in vitro, a desirable trait for skin regeneration, and demonstrated efficacy against key microbial strains (Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa) associated with skin colonization and infections. Flavonoids spireoside and apiin emerged as the most abundant bioactives. The addition of HA led to increased viscosity while maintaining a suitable pH for topical application. Zeta potential, droplet size, and PDI met acceptable criteria. Moreover, incorporating C. recutita extract into the nanoemulsion enhanced its antimicrobial effect. Hence, the nanoemulsion system loaded with C. recutita and HA stabilization exhibits favorable characteristics for topical application, showing promise in aiding the healing processes.

Chromatographic speed classification for liquid chromatography using average theoretical peak time (ATPT)

BACKGROUND

The development of analytical techniques in the field of liquid chromatography has brought new frontiers in performance and analytical speed for the technique. The proper evaluation of the analytical boundaries achieved with those developments was not addressed in the literature, since different liquid chromatography (LC) techniques have not yet received any classification regarding their chromatographic speed. Defining chromatographic analysis speed based simply on analysis time is an outdated concept since it is sample and analyte-dependent. In this context, the application of the Average Theoretical Peak Time concept (ATPT) is proposed as a unified metric for chromatographic speed classification.

RESULTS

This metric was evaluated using PCA analysis in a group of more than 50 publications, which generated the classification of LC methods in normal, high, hyper, and ultra-high-speed separations using ATPT. Normal speed (ATPT values greater than 18000 ms/peak) was found in HPLC, nano-LC, SFC, and CEC methods. Therefore, high-speed methods (ATPT values between 4000 and 18000 ms/peak) were found in UHPLC techniques, while LC × LC methods presented higher ATPT values between 1000 and 4000 ms/peak being classified as hyper-speed separations. ATPT can also be used as an optimization parameter, since older methods show higher ATPT values, while recent published papers show lower values of this metric. This behavior is justified due to the improvement of the LC methods over the years.

SIGNIFICANCE

This work fulfills the gap in chromatographic definitions and metrics, regarding analytical speed in one-dimensional and multidimensional liquid chromatographic techniques and shows that ATPT metrics is a robust parameter that can be used to classify the separation speed as well as a metric to evaluate the LC Method optimization. It also corrects the historical application of separation time as a metric for chromatographic speed.

Luteolin: A promising natural agent in management of pain in chronic conditions

Pain due to chronic conditions is a frequent and insufficiently addressed problem. Current drug options for pain management (either in cases of chronic inflammatory conditions or neuropathy) do not adequately treat pain. Moreover, they are associated with important adverse events in long term use. Luteolin is a flavonoid widely present in the plant kingdom and its sources have been assembled in a comprehensive list of this paper. Luteolin has shown in several research studies a range of pharmacological properties; anti-inflammatory, antioxidant, neuroprotective, and analgesic. In this article, we summarize the effects and potential benefits from introducing luteolin as an adjuvant agent in established protocols for pain management. We review the most indicative in vivo and in vitro evidence of how luteolin can target the molecular pathways involved in pathogenesis of chronic inflammatory and neuropathic pain. The data reviewed strongly support luteolin's promising benefits in pain management and raise the need for further clinical trials that can establish its role in clinical practice.

Traditional Herbal Remedies Used for Managing Anxiety and Insomnia in Italy: An Ethnopharmacological Overview

Anxiety and insomnia are among the most common mental health disorders and are a major cause of disability around the world. Traditional herbal medicines are receiving significant attention in global health debates. Several Italian regions maintain rural traditions and are among the most extensively studied areas of Europe regarding medicinal plant uses. The present overview aims to highlight the use of wild and cultivated plants, specifically as sedatives and for insomnia treatment in Italy, and to collect, analyze, and summarize the available literature about their pharmacological activity as well as clinical and pre-clinical studies concerning the most cited plants. In total, 106 wild taxa are used in Italy for sedative purposes. The plant species belong to 76 genera and 32 families, of which the most cited are Asteraceae (24.2%) and Lamiaceae (21.1%). Leaves (29%) and flowers (27%) are the plant parts mostly used as infusion (70%) and decoction (25%). Out of 106 taxa documented, only the most cited are analyzed in this overview (A. arvensis L., C. nepeta L., C. monogyna Jacq., H. lupulus L., L. nobilis L., L. angustifolia Mill., M. sylvestris L., M. chamomilla L., M. officinalis L., O. basilicum L., P. rhoeas L., P. somniferum L., R. officinalis L., T. platyphyllus Scop., and V. officinalis L.). Among the fifteen species selected, only seven have been studied for their pharmacological activity as hypnotic-sedatives. Future pre-clinical and clinical studies are needed to better clarify the mechanism of action of bioactive compounds and confirm the potential of these alternative therapies.

Application of Capillary Electrophoresis to the Analysis of Bioactive Compounds in Herbal Raw Materials

The article is a summary of scientific reports from the last 16 years (2005-2021) on the use of capillary electrophoresis to analyze polyphenolic compounds, coumarins, amino acids, and alkaloids in teas or different parts of plants used to prepare aqueous infusions, commonly known as "tea" or decoctions. This literature review is based on PRISMA guidelines and articles selected in base of criteria carried out using PICOS (Population, Intervention, Comparison, Outcome, Study type). The analysis showed that over 60% of articles included in this manuscript comes from China. The literature review shows that for the selective electrophoretic separation of polyphenolic and flavonoid compounds, the most frequently used capillary electromigration technique is capillary electrophoresis with ultraviolet detection. Nevertheless, the use of capillary electrophoresis-mass spectrometry allows for the sensitive determination of analytes with a lower limit of detection and gives hope for routine use in the analysis of functional foods. Moreover, using the modifications in electrochemical techniques allows methods sensitivity reduction along with the reduction of analysis time.

Development and optimization of a high-throughput HPLC-MS/MS method for the simultaneous determination of naringenin and its valine carbamate prodrug in rat plasma

A valine carbamate prodrug of naringenin (NAR) called 4'V was synthesized to enhance its oral bioavailability because of low water solubility and poor membrane permeability of NAR. This study developed and fully validated a sensitive, rapid, and robust HPLC-MS/MS method for the simultaneous determination of NAR and 4'V in plasma. The analytes were treated using liquid-liquid extraction, separated on a Phenomenex Kinetex XB-C₁₈ column, and detected using a triple-quadrupole tandem mass spectrometer equipped with an electrospray ionization interface. The analytes were eluted within only 4 min by gradient procedure. The excellent linear correlations were validated over the range of 4-400 ng/mL (r = 0.9990) for NAR and 2-2000 ng/mL (r = 0.9951) for 4'V, with lower limits of quantification of 4 and 2 ng/mL, respectively. For all quality control samples, the intra-day and inter-day precision and accuracy were within ±15%. The validated method was economical, high throughput, and reliable and was first successfully applied to a pharmacokinetic study of NAR and 4'V after oral administration to Sprague-Dawley rats. The results of the pharmacokinetic study demonstrated that the idea of amino acid carbamate prodrug is a promising strategy to improve the bioavailability of NAR.

HPLC–MS/MS profiling of wild-growing scentless chamomile

Scentless chamomile (Tripleurospermum inodorum = M. inodora) is a plant belonging to Anthemideae tribe of Asteraceae family, with phenotype similar to the common chamomile, a plant used in human consumption in the form of herbal tea infusion. In order to be able to understand possible health-promoting properties and adverse effects of the scentless chamomile's consumption, it is of essence to examine its chemical composition. The aim of the study was to perform phenolic profiling using high-performance liquid chromatography–tandem mass spectroscopy (HPLC–MS/MS), in comparison to the common chamomile. In the investigated extracts, qualitative and quantitative analyses enabled the identification of 66 compounds based on their retention times, mass (MS/MS) spectra, and analysis of their characteristic fragmentation patterns in MS/MS Product Ion Scan experiments. A new HPLC–MS/MS method for quantitation of common plant metabolites was hereby developed, enabling quantitation of 47 compounds. All examined M. inodora samples have relatively high combined phenolic and flavonoid contents (25.2–51.9 mg/g). Apigenin, apigenin-7-O-glucoside, luteolin, luteolin-7-O-glucoside, quinic acid, and 5-O-caffeoyl quinic acid were the compounds with highest concentration in both inodorous and common chamomile. The results obtained hereby represent the first and most detailed chemical profile of scentless chamomile so far.

Phytomedicines containing Matricaria species for the treatment of skin diseases: A biotechnological approach

Skin diseases have a notable impact on the life of the affected and in their health conditions. In order to allow a more effective and economical treatment for such disorders, new therapeutic approaches have been continuously investigated. Due to its high therapeutic and phytochemical potential, Matricaria species emerges as a pleasant alternative, since it is an important source of bioactive secondary metabolites suitable for the treatment of varied skin diseases. Therefore, this review aimed to catalog inventions that have used Matricaria species as the active component for skin disease treatment in order to assess the status of the technological development of the fitomedicines. For this, a search of patents was performed in four specialized patent database, which have reported the discovery of pharmaceutical bioproducts that used Matricaria species in its composition for skin treatment. Therefore, it is possible to notice that the pharmaceutical industry has driven efforts and investment to produce medicines for the dermatopathies, using species of this genus as an active principle. Besides, a trend of growth has been identified for the last years, which is accompanied by the continuous publication of scientific articles on the subject. It is known that a long journey is traversed between the scientific findings and their applications in the pharmaceutical market, creating the perspective that new Matricaria-based medicines may reach the pharmaceutical market in the coming years.

Germinación y multiplicación in vitro de Matricaria recutita L.: los fenoles totales determinan su germinación

La manzanilla (Matricaria recutita L., Chamomilla recutita L. y Matricaria chamomilla L.), es conocida por su alto contenido de compuestos fenólicos que le confieren propiedades antiinflamatorias, antisépticas y antimutagénicas. En este estudio se evaluó el porcentaje de fenoles totales y la germinación en cinco periodos de almacenamiento de semillas de M. recutita (5, 31, 75, 96 y 128 días). Además, se evaluó el efecto de citoquininas (6-Bencil Amino Purina, BAP y Kinetina) y auxinas (α-Ácido Naftalen Acético, ANA) en la brotación in vitro de esta especie. Se evidenció que la concentración total de fenoles disminuyó de 13.8% a 1.9% en los cinco periodos de almacenamiento evaluados y que los porcentajes de germinación aumentaron de 2.2% a los cinco días a 8,9% a los 128  días  de almacenamiento, mostrándose  evidencia de  una  correlación  de -0.989 entre la germinación y el contenido de fenoles totales. Los mejores resultados para inducir brotación (5 brotes/explante) fueron obtenidos en el medio de cultivo MS con citoquininas. 

A Review on Pharmacological and Analytical Aspects of Naringenin

Flavonoids are a widely distributed group of phytochemicals having benzo-pyrone nucleus, and more than 4,000 different flavonoids have been described and categorized into flavonols, flavones, flavanones, isoflavones, catechins and anthocyanidins. Flavonoids occurs naturally in fruits, vegetables, nuts, and beverages such as coffee, tea, and red wine, as well as in medical herbs. Flavonoids are responsible for the different colors of plant parts and are important constituents of the human diet. Flavanoids have different pharmacological activities, such as antioxidant, anti-allergic, antibacterial, anti-inflammatory, antimutagenic and anticancer activity. Naringenin belongs to the flavanones and is mainly found in fruits (grapefruit and oranges) and vegetables. Pharmacologically, it has anticancer, antimutagenic, anti-inflammatory, antioxidant, antiproliferative and antiatherogenic activities. Naringenin is used for the treatments of osteoporosis, cancer and cardiovascular diseases, and showed lipid-lowering and insulin-like properties. In the present review, detailed pharmacological and analytical aspects of naringenin have been presented, which revealed the impressive pharmacological profile and the possible usefulness in the treatment of different types of diseases in the future. The information provided in this communication will act as an important source for development of effective medicines for the treatment of various disorders.

Methods for Extraction and Determination of Phenolic Acids in Medicinal Plants: A Review

Phenolic acids constitute a group of potentially immunostimulating compounds. They occur in all medicinal plants and are widely used in phytotherapy and foods of plant origin. In recent years, phenolic acids have attracted much interest owing to their biological functions. This paper reviews the extraction and determination methods of phenolic acids in medicinal plants over the last 10 years. Although Soxhlet extraction and ultrasonic assisted extraction (UAE) are commonly used for the extraction of phenolic acids from plant materials, alternative techniques such as supercritical fluid extraction (SFE), and accelerated solvent extraction (ASE) can also be used. After extraction, phenolic acids are determined usually by liquid chromatography (LC) owing to the recent developments in this technique, especially when it is coupled with mass spectrometry (MS). Also detection systems are discussed, including UV-Vis, diode array, electrochemical and fluorimetric. Other popular techniques for the analysis of this group of secondary metabolites are gas chromatography coupled with mass spectrometry (GC-MS) and capillary electrophoresis (CE).

Techniques for analysis of plant phenolic compounds

Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.

HPLC-ESI-MS/MS analysis and pharmacokinetics of luteoloside, a potential anticarcinogenic component isolated from Lonicera japonica, in beagle dogs

Luteoloside is a potential anticarcinogenic component isolated from Lonicera japonica, a traditional Chinese medicine (TCM). This study details the development and validation of a sensitive and accurate HPLC-ESI-MS/MS method for the quantification of luteoloside in dog plasma. Sample pretreatment includes simple protein precipitation using methanol-acetonitrile (1:1, v/v). A Phenomenex Gemini C(18) column (2.0 × 50 mm, i.d., 3.5 µm) was used to separate luteoloside and internal standard by gradient mode with mobile phase consisting of water containing 0.1% formic acid and methanol containing 0.1% formic acid at a flow rate of 0.40 mL/min with a column temperature of 25°C. The detection was performed by positive ion electrospray ionization (ESI) in multiple reaction monitoring mode. The calibration curves were linear (R > 0.995) over the concentration range 1.0-2000 ng/mL and the lower limit of quantification was 1.0 ng/mL. The intra-day and inter-day precisions (RSD) were all <15%, accuracies (RE) were within the range of ±15%, and recoveries were between 85.0 and 115%. The validated HPLC-ESI-MS/MS method was successfully applied to determine plasma concentrations of luteoloside after intravenous administration of luteoloside at a dose level of 20 mg/kg.

LC-PDA-ESI/MS Identification of the Phenolic Components of Three Compositae Spices: Chamomile, Tarragon, and Mexican Arnica

Chamomile ( Matricaria chamomilla L.), tarragon ( Artemisia dracunculus L.) and Mexican arnica ( Heterotheca inuoides) are common compositae spices and herbs found in the US market. They contain flavonoids and hydroxycinnamates that are potentially beneficial to human health. A standardized LC-PDA-ESI/MS profiling method was used to identify 51 flavonoids and 17 hydroxycinnamates. Many of the identifications were confirmed with authentic standards or through references in the literature or the laboratory's database. More than half of the phenol compounds for each spice had not been previously reported. The phenolic profile can be used for plant authentication and to correlate with biological activities.

HPLC separation of acetaminophen and its impurities using a mixed-mode reversed-phase/cation exchange stationary phase

Determination of acetaminophen and its main impurities: 4-nitrophenol, 4'-chloroacetanilide, as well as 4-aminophenol and its degradation products, p-benzoquinone and hydroquinone has been developed and validated by a new high-performance liquid chromatography method. Chromatographic separation has been obtained on a Hypersil Duet C18/SCX column, using gradient elution, with a mixture of phosphate buffer (pH = 4.88) and methanol as a mobile phase. Analysis time did not exceed 14.5 min and good resolutions, peak shapes and asymmetries have resulted. The linearity of the method has been tested in the range of 5.0-60 µg/mL for acetaminophen and 0.5-6 µg/mL for the other compounds. The limits of detection and quantification have been also established to be lower than 0.1 µg/mL and 0.5 µg/mL, respectively. The method has been successfully applied for the analysis of commercial acetaminophen preparations.

Development and validation of a micellar electrokinetic chromatography method for quantitative determination of butenolides in Piper malacophyllum (C. Presl) C. DC

INTRODUCTION

A large number of natural and synthetic compounds having butenolides as a core unit have been described and many of them display a wide range of biological activities. Butenolides from P. malacophyllum have presented potential antifungal activities but no specific, fast, and precise method has been developed for their determination.

OBJECTIVE

To develop a methodology based on micellar electrokinetic chromatography to determine butenolides in Piper species.

METHODOLOGY

The extracts were analysed in an uncoated fused-silica capillaries and for the micellar system 20 mmol/L SDS, 20% (v/v) acetonitrile (ACN) and 10 mmol/L STB aqueous buffer at pH 9.2 were used. The method was validated for precision, linearity, limit of detection (LOD) and limit of quantitation (LOQ) and the standard deviations were determined from the standard errors estimated by the regression line.

RESULTS

A micellar electrokinetic chromatography (MEKC) method for determination of butenolides in extracts gave full resolution for 1 and 2. The analytical curve in the range 10.0-50.0 µg/mL (r(2) = 0.999) provided LOD and LOQ for 1 and 2 of 2.1/6.3 and 1.1/3.5 µg/mL, respectively. The RSD for migration times were 0.12 and 1.0% for peak area ratios with 100.0 ± 1.4% of recovery.

CONCLUSIONS

A novel high-performance MEKC method developed for the analysis of butenolides 1 and 2 in leaf extracts of P. malacophyllum allowed their quantitative determined within an analysis time shorter than 5 min and the results indicated CE to be a feasible analytical technique for the quantitative determination of butenolides in Piper extracts.

Fast separation and determination of coumarins in Fructus cnidii extracts by CEC using poly(butyl methacrylate-co-ethylene dimethacrylate-co-[2-(methacryloyloxy)ethyl] trimethylammonium chloride) monolithic columns

A rapid CEC method with poly(butyl methacrylate-co-ethylene dimethacrylate-co-[2-(methacryloyloxy)ethyl] trimethylammonium chloride) monolithic column has been developed for separation and determination of four coumarins (isopimpinelline, bergapten, imperatorin, and osthole) in Fructus cnidii extracts. The effect of polymerization condition including the monomers ratio and the porogens ratio were studied. The mobile-phase composition, such as the composition of organic solvent, the concentration and pH of buffer, was also optimized. Under the same condition (50% ACN and 50% of a 10 mM sodium dihydrogen phosphate electrolyte at pH 4.95), in contrast to 25 min of analysis time in HPLC and 10 min of analysis time in pCEC, a fast separation of these analytes was achieved in less than 5 min in CEC. Method validation was developed in accordance with the analytical procedures. Intra- and interday precisions (RSD) for relative retention time and peak area were less than 1.69 and 4.63%, and LODs were lower than 0.5 microg/mL. Calibration curves of four compounds also showed good linearity (r(2)>0.995). The mean recoveries ranged between 93.91 and 98.65%. With this CEC system, the quality of F. cnidii extracts from various resources was evaluated by determining the contents of the four coumarins.

Application and potential of capillary electroseparation methods to determine antioxidant phenolic compounds from plant food material

Antioxidants are one of the most common active ingredients of nutritionally functional foods which can play an important role in the prevention of oxidation and cellular damage inhibiting or delaying the oxidative processes. In recent years there has been an increased interest in the application of antioxidants to medical treatment as information is constantly gathered linking the development of human diseases to oxidative stress. Within antioxidants, phenolic molecules are an important category of compounds, commonly present in a wide variety of plant food materials. Their correct determination is pivotal nowadays and involves their extraction from the sample, analytical separation, identification, quantification and interpretation of the data. The aim of this review is to provide an overview about all the necessary steps of any analytical procedure to achieve the determination of phenolic compounds from plant matrices, paying particular attention to the application and potential of capillary electroseparation methods. Since it is quite complicated to establish a classification of plant food material, and to structure the current review, we will group the different matrices as follows: fruits, vegetables, herbs, spices and medicinal plants, beverages, vegetable oils, cereals, legumes and nuts and other matrices (including cocoa beans and bee products). At the end of the overview, we include two sections to explain the usefulness of the data about phenols provided by capillary electrophoresis and the newest trends.

CEC of phytochemical bioactive compounds

Although there are many publications related to technological or methodological developments of CEC, few focus on the analysis of natural products, especially phytochemical bioactive compounds. This review summarized the application of CEC in the analysis of phytochemical bioactive components, including flavonoids, nucleosides, steroids, lignans, quinones and coumarins, as well as fingerprint analysis of herbs. The strategies for optimization of CEC conditions and detection were also discussed.

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

The use of capillary electromigration methods to analyze foods and food components is reviewed in this work. Papers that were published during the period April 2007 to March 2009 are included following the previous review by García-Cañas and Cifuentes (Electrophoresis, 2008, 29, 294-309). These works include the analysis of amino acids, biogenic amines, peptides, proteins, DNAs, carbohydrates, phenols, polyphenols, pigments, toxins, pesticides, vitamins, additives, small organic and inorganic ions and other compounds found in foods and beverages, as well as those applications of CE for monitoring food interactions and food processing. The use of microchips, CE-MS, chiral-CE as well as other foreseen trends in food analysis are also discussed including their possibilities in the very new field of Foodomics.

Determination of natural colorants in plant extracts by high performance liquid chromatography

The determination of the colouring compounds apigenin (1), lawsone (2), juglone (3) and indigotin (4) in plant extracts using HPLC - UV/VIS methods is reported. The methods were applied to the analysis of 1-4 in ethanolic and propylene glycolic extracts originating, respectively, from chamomile (Chamomilla recutita [L] Rauschert, Asteraceae), henna (Lawsonia inermis L., Lythraceae), walnut (Juglans regia L., Juglandaceae) and natural indigo (Indigofera sp., Fabaceae). In the case of the indigo extracts, an optimized acid hydrolysis was applied. HPLC separations were performed on a Hypersil ODS RP18 column using linear gradient elution programs. The detection limits for 1-4 were 0.11, 0.6, 0.10, 0.089 ?g mL-1, respectively. The procedure did not involve any sample ?clean -up? methods. The amounts of the colouring compounds ranged from 0.006 mg mL-1 (3) to 0.13 mg mL-1 (4) in the ethanolic extracts and from 0.22 mg mL-1 (2) to 1.44 mg mL-1 (4) in propylene glycolic extracts. The proposed HPLC methods are advantageous in terms of sample preparation and the selective separation of the compounds. The plant dye extracts are commonly used in hair colouring formulations. The results indicate that the methods developed may serve for the quantitative control of dying plants and cosmetic products.

Advanced separation methods of food anthocyanins, isoflavones and flavanols

In recent years, increasing knowledge of the positive health effects of food polyphenols has prompted the need to develop new separation techniques for their extraction, fractionation and analysis. This article provides an updated and exhaustive review of the application of counter-current chromatography, high performance liquid chromatography, capillary electrophoresis, and their hyphenation with mass spectrometry to the study of food polyphenols. Flavonoids constitute the largest class of polyphenols, widely spread in the plant kingdom and common in human diet which has been the most widely studied with respect to their antioxidant and biological activities. The main subgroups are anthocyanins, catechins, isoflavones, flavonols and flavones. They are reported to exhibit antioxidant, anti-carcinogenic, anti-inflammatory, anti-atherogenic, anti-thrombotic, and immune modulating functions, among others. Since red fruit anthocyanins, soy isoflavones and flavanols from grapes and teas are currently the most used phenolic compounds for producing new nutraceuticals and functional foods, this review is focused on these three flavonoid groups.

Analysis of phenolic compounds in extra virgin olive oil by using reversed-phase capillary electrochromatography

In this work, the simultaneous separation of ten phenolic compounds (protocatechuic, p-coumaric, o-coumaric, vanillic, ferulic, caffeic, syringic acids, hydroxytyrosol, tyrosol and oleuropein) in extra virgin olive oils (EVOOs) by isocratic RP CEC is proposed. A CEC method was optimized in order to completely resolve all the analyzed compounds by studying several experimental parameters. The influence of the stationary phase type (C(18) and C(8) modified silica gel), buffer concentration and pH as well as the organic modifier content of the mobile phase on retention factors, selectivity and efficiency were evaluated in details. A capillary column packed with Cogent bidentate C(18) particles for 23 cm and a mobile phase composed by 100 mM ammonium formate buffer pH 3/H(2)O/ACN (5:65:30 v/v/v) allowed the baseline resolution of the compounds under study in less than 35 min setting the applied voltage and temperature at 22 kV and 20 degrees C, respectively. A study, evaluating the intra- and interday precision as well as LOD and LOQ and method linearity was developed in accordance with the analytical procedures for method validation. LODs were in the range of 0.015-2.5 microg/mL, while calibration curves showed a good linearity (r(2) >0.997). The CEC method was applied to the separation and determination of these compounds in EVOO samples after a suitable liquid-liquid extraction procedure. The mean recovery values of the studied compounds ranged between 87 and 99%.

Inhibition of human cAMP-phosphodiesterase as a mechanism of the spasmolytic effect of Matricaria recutita L

Mechanisms underlying the spasmolytic activity of chamomile still remain unclear. Inhibition of cAMP- and cGMP-phosphodiesterases (PDE) is one of the mechanisms operated by spasmolytic drugs. In this study, the effect of chamomile on PDE was investigated. Human platelet cAMP-PDE and recombinant PDE5A1 were assayed in the presence of infusions prepared from sifted flowers and capitula. LC-ESI-MS/MS analysis showed different compositions in infusions made with sifted flowers and capitula. Chamomile inhibited cAMP-PDE activity (IC50 = 17.9-40.5 microg/mL), while cGMP-PDE5 was less affected (-15% at 50 microg/mL). Among the individual compounds tested, only flavonoids showed an inhibitory effect (IC50 = 1.3-14.9 microM), contributing to around 39% of the infusion inhibition; other compounds responsible for cAMP-PDE inhibition still remain unknown. Although experimental evidence supporting the use of chamomile for gastrointestinal minor spasms dates back to the fifties, cAMP-PDE inhibition as a likely mechanism underlying the spasmolytic activity is reported for the first time.

Simultaneous determination of seven flavonoids in Epimedium using pressurized liquid extraction and capillary electrochromatography

Herba Epimedii (known as Yinyanghuo in China) is one of the commonly used Chinese medicines. Flavonoids are considered as its active components. In this study, a CEC method was developed for the simultaneous determination of seven flavonoids, including hexandraside E, kaempferol-3-O-rhamnoside, hexandraside F, icariin, epimedin A, B, and C, in Epimedium using baicalein as internal standard (IS). The influence of relevant parameters such as buffer concentration, pH, and proportion of ACN was investigated and optimized. Baseline separation was obtained using a Hypersil C18 capillary (3 microm, 100 microm/25 cm) with a mixture of 20 mM phosphate buffer (pH 4.0)/ACN (70:30 v/v) as mobile phase running at 30 kV and 25 degrees C in 20 min. All calibration curves showed good linearity (r2 >0.9992) within test ranges. The LOD and LOQ were lower than 8.6 and 42.8 microg/mL, respectively. The RSDs of intra- and interday for relative peak areas of seven analytes were less than 3.1 and 4.4%, and the recoveries were 95.2-103.3%. Samples of different Epimedium species were analyzed using the validated method, which is useful for quality control of Epimedium and its medical preparations.

Advances of modern chromatographic and electrophoretic methods in separation and analysis of flavonoids

Flavonoids, one of the largest groups of secondary metabolites, are widespread in vegetable crops such as herbs, fruits, vegetables, grains, seeds and derived foods such as juices, wines, oils, etc. They receive considerable attention due to their biological and physiological importance. Hundreds of publications on the analysis of flavonoids have appeared over the past decade. Traditional and more advanced techniques have come to prominence for sample preparation, separation, detection, and identification. This review intends to provide an updated, concise overview on the recent development and trends of separation, identification and quantification for flavonoids by modern chromatographic and spectrophotometric analytical techniques, including gas chromatography (GC), liquid chromatography (LC), and capillary electrophoresis (CE). The sample preparation before analysis is also briefly summarized.