Ultrasonic treatment as a modern technique to facilitate the extraction of phenolic compounds from organic sunflower seed cakes

BACKGROUND

Three different organic sunflower seed cakes, produced from seeds differing in the content of their hulls, were extracted by two different extraction methods - conventional extraction (CE) and ultrasound-assisted extraction (UAE). The total phenolic compound (TPC) content of the extracts was evaluated using Folin-Ciocâlteu reagent (FCR) and high-performance liquid chromatography (HPLC). The antioxidant capacity of extracts was evaluated with the Trolox equivalent antioxidant capacity (TEAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays.

RESULTS

The results showed that both extracts displayed high TPC content and antioxidant capacity. The UAE method showed significantly higher TPC content and antioxidant capacity values than CE. Individual phenolic compounds such as chlorogenic acid (CGA) isomers (3-, 4- and 5-O-caffeoylquinic acids), di-CGA isomers, and feruloylquinic and coumaroylquinic acids were identified according to their exact masses by HPLC coupled to time-of-flight mass spectrometry.

CONCLUSION

The results revealed that the UAE method could be used effectively to facilitate the extraction of phenolic compounds from sunflower seed cake. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Electrochemical Sensing Platform Based on Carbon Dots for the Simultaneous Determination of Theophylline and Caffeine in Tea

A simple and selective method for the determination of caffeine (CAF) and theophylline (THEO) has been developed for a glassy carbon electrode (GCE) modified with a composite including carbon dots (CDs) and chitosan (CS). To our knowledge, there are no previous studies that analyze a CDs-modified GCE for the presence of CAF and THEO. The electrochemical behavior of a GCE modified with a CDs-CS composite was studied in acidic medium by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Considering the sensor analytical parameters, the same linear concentrations range was found for CAF and THEO ranging from 1 × 10-5 to 5 × 10-3 mol L-1 with the same detection limit (LOD) of 1 × 10-6 mol L-1. The reproducibility and repeatability data were satisfactory in terms of RSD%. Moreover, the storage stability was evaluated, evidencing good results whatever the experimental conditions used. The developed sensor was applied for the simultaneous determination of CAF and THEO in tea and drug, and results were compared with those obtained with HPLC-ESI-MS in SIR mode as an independent method optimized on purpose. The electrochemical sensor presents the undoubled advantages in terms of cheapness, portability, and ease of use, since it does not require skilled personnel.

Resonance Raman and Visible Micro-Spectroscopy for the In-Vivo and In-Vitro Characterization of Anthocyanin-Based Pigments in Blue and Violet Flowers: A Comparison with HPLC-ESI- MS Analysis of the Extracts

Microanalysis techniques based on resonance Raman and reflection visible spectroscopy have been applied to the characterization of pigments responsible for the blue or violet coloration in flowers; in particular of Lobelia erinus, Campanula portenschlagiana, Cineraria, Viola tricolor, Anemone coronaria, Agapanthus, Platycodon, Salvia farinacea, Plumbago capensis, Ceratostigma plumbaginoides, Commelina communis and Salvia patens. The spectroscopic methods were applied both in vivo on the flower petals and in vitro on extracts obtained through a procedure based on SPE (solid-phase extraction) optimized for minimal quantities of vegetable raw material. Different patterns obtained for the Raman spectra have been correlated, also on the basis of density functional theory (DFT) calculations, with different schemes of substitution of the benzopyrilium nucleus of the anthocyanins and with various possible forms of copigmentation responsible for the stabilization of the blue color. The results obtained were verified by comparison with the analysis of the extracts by HPLC-ESI-MS (liquid chromatography-electrospray ionization-mass spectrometry).

Characterization and Comparison of Steroidal Glycosides from Polygonatum Species by High-Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry

Polygonatum species have been used as traditional medicines and functional foods in Asia and Europe since ancient times. In this study, a fast and simple method based on liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) was developed to systematically analyze and identify the steroidal glycosides in four major Polygonatum species distributed in Japan, including P. odoratum, P. falcatum, P. macranthum, and P. sibiricum. As a result, 31 steroidal glycosides were tentatively identified, including 18 known and 13 previously unreported glycosides. Their structures were identified by the interpretation of chromatographic behavior and ESI-MS fragmentation patterns. The identification of 31 steroidal glycosides was indicative of a common biogenetic pathway in Polygonatum species. Our study disclosed the chemical profiling of steroidal glycosides in the plants of Polygonatum species, which will benefit better phytochemotaxonomical and phytochemical understanding and quality control for their medicinal usage.

Antimicrobial Activity of Propolis from the Brazilian Stingless Bees Melipona quadrifasciata anthidioides and Scaptotrigona depilis (Hymenoptera, Apidae, Meliponini)

Melipona quadrifasciata anthidioides and Scaptotrigona depilis are species of stingless bees capable of producing propolis, which has considerable bioprospecting potential. In this context, the objective of this study was to determine the chemical compositions and evaluate the antimicrobial activity of propolis produced by M. q. anthidioides and S. depilis. The ethanolic extracts of propolis of M. q. anthidioides (EEP-M) and S. depilis (EEP-S) were prepared, and their chemical constituents were characterized by HPLC-ESI-MS. The antimicrobial activity was evaluated against bacteria and fungi, isolated from reference strains and hospital origin resistant to the action of antibiotics. From EEP-M, phenolic compounds were annotated, including gallic acid, ellagic acid, and flavonoids, as well as diterpenes and triterpenes. EEP-S showed mainly triterpene in its chemical composition. Both extracts inhibited the growth of medically relevant bacteria and fungi, including hospital-acquired and antimicrobial-resistant. In general, EEP-S showed better antimicrobial activity compared to EEP-M. The MIC of EEP-S against vancomycin-resistant Enterococcus faecalis was 3.50 mg/mL, while the MIC of EEP-M was 5.33 ± 0.16 mg/mL. In conclusion, this study shows that propolis produced by M. q. anthidioides and S. depilis has the potential to be used for the prevention or treatment of microbial infections.

Determination of 1-Deoxynojirimycin (1-DNJ) in Leaves of Italian or Italy-Adapted Cultivars of Mulberry (Morus sp.pl.) by HPLC-MS

Recently, 1-DNJ has been widely studied by scientists for its capacity to inhibit α-glucosidase and reduce postprandial blood glucose and fat accumulation. To the best of our knowledge, this is the first analytical determination of 1-DNJ in Morus sp.pl. leaves carried out on Italian crops, and it could be used as a reference to assess the quality of the plant material in comparison to Far Eastern Asia cultivations. The effects of two thermal treatments were compared to test the incidence of the drying process on the 1-DNJ extractability. In addition, two harvesting seasons in the same year (2017) and two subsequent harvesting years (2017-2018) were considered. The amount of 1-DNJ herein found was comparable to that reported in the scientific literature for Asian cultivations. The increase in 1-DNJ along the summer and the higher level of this compound in the apical leaves also complies with previous findings. However, a strong implication for the climatic conditions in the different years and a significant interaction between climate and genotypes suggest exploring very carefully the agronomic practices and selecting cultivars according to different environmental conditions with a view to standardize the 1-DNJ amount in leaves.

Varietal and Geographical Origin Characterization of Peaches and Nectarines by Combining Analytical Techniques and Statistical Approach

Prunus persica L. is one of the most important fruit crops in European production, after grapes, apples, oranges and watermelons. Most varieties are rich in secondary metabolites, showing antioxidant properties for human health. The purpose of this study was to develop a chemical analysis methodology, which involves the use of different analytical-instrumental techniques to deepen the knowledge related to the profile of metabolites present in selected cultivars of peaches and nectarines cultivated in the Mediterranean area (Southern Italy). The comparative study was conducted by choosing yellow-fleshed peaches (RomeStar, ZeeLady) and yellow-fleshed nectarines (Nectaross, Venus) from two geographical areas (Piana di Sibari and Piana di Metaponto), and by determining the chemical parameters for the flesh and skin that allow for identification of any distinctive varietal and/or geographical characteristics. A combined analytical and chemometric approach was used, trough rheological, thermogravimetric (TGA), chromatographic (HPLC-ESI-MS), spectroscopic (UV-Vis, ATR-FTIR, NMR) and spectrometric (ToF-SIMS) analysis. This approach allowed us to identify the characterizing parameters for the analysis of a plant matrix so that the developed methodology could define an easily exportable and extendable model for the characterization of other types of vegetable matrices.

Spectral Characteristics Related to Chemical Substructures and Structures Indicative of Organic Precursors from Fulvic Acids in Sediments by NMR and HPLC-ESI-MS

The aim of this work was to determine Fulvic Acids (FAs) in sediments to better know their composition at the molecular level and to propose substructures and structures of organic precursors. The sediment samples were obtained from a priority area for the conservation of ecosystems and biodiversity in Mexico. FAs were extracted and purified using modifications to the International Humic Substances Society method. The characterization was carried out by 1D and 2D nuclear magnetic resonance (NMR) and high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) in positive (ESI⁺) and negative (ESI⁻) modes. Twelve substructures were proposed by the COSY and HSQC experiments, correlating with compounds likely belonging to lignin derivatives obtained from soils as previously reported. The analysis of spectra obtained by HPLC-ESI-MS indicated likely presence of compounds chemically similar to that of the substructures elucidated by NMR. FAs studied are mainly constituted by carboxylic acids, hydroxyl, esters, vinyls, aliphatics, substituted aromatic rings, and amines, presenting structures related to organic precursors, such as lignin derivatives and polysaccharides.

[Systematic analysis on chemical constituents of Mori Cortex, mulberry root bark and its phellem layer based on HPLC-ESI-MS]

In this study, HPLC-ESI-MS and HPLC methods were established to explore the differences in the main chemical components and content of Mori Cortex with(mulberry root bark) and without(Mori Cortex) the phellem layer from both qualitative and quantitative aspects. The HPLC-ESI-MS method was used for quality analysis in positive and negative ion modes, and 33 compounds were identified in mulberry root bark, 22 compounds in Mori Cortex, and 26 compounds in phellem layer; mulberry root bark and Mori Cortex shared 22 components, and mulberry root bark has 11 unique compounds; Mori Cortex and its phellem layer shared 15 components, while Mori Cortex has 7 unique compounds. HPLC method was used to simultaneously determine 7 major constituents, including mulberroside A, chlorogenic acid, dihydromorin, oxyresveratrol, moracin O, kuwanon G, and kuwanon H, and the developed method showed good linearity(r>0.998 9) within the concentration range and the recoveries varied from 99.88% to 103.0%, and the RSD was 1.7%-2.9%. The HPLC results showed that the contents of the 7 compounds have great differences in 13 batches samples, compared with mulberry root bark, the contents of mulberroside A, chlorogenic acid, dihydromorin and moracin O of Mori Cortex were increased, while the contents of oxyresveratrol, kuwanon G and kuwanon H were decreased after peeling process. These results can provide a basis for the rationality and quality control of Mori Cortex required to remove the phellem layer.

Effect of in vitro gastro-intestinal digestion on the phenolic composition and antioxidant capacity of Burdock roots at different harvest time

The current study aimed to evaluate how the harvest time affects the phenolic composition in Burdock root flours (BRF) and how these phenolics are influenced by the gastro-intestinal digestive environment. Burdock roots were harvested in 2020 in Jiangsu Province in June (B1), July (B2) and August (B3). The main phenolic, 5-O-caffeoylquinic acid (5-CQA) decreased after in vitro digestion from 1.14 to 0.22 mg/g (B1 < B2 < B3). Total phenolic content of BRF was 61% lower after in vitro digestion whereas 5-CQA bioaccessibility remained at about 60%. Twelve other phenolic compounds were tentatively identified after in vitro digestion. An average reduction in antioxidant capacity of 27% and 10% was observed for DPPH and ABTS, respectively. In conclusion, data demonstrated that phenolic composition, bioaccessibility and antioxidant capacity of Burdock roots harvested at different times were subject to the influence of in vitro gastrointestinal digestion.

Genetic diversity, LC-ESI-MS chemical profile and in vivo antitumor activity of three Egyptian soybean cultivars

Soybean (Glycine max L.) is one of the most important and widely consumed food plants worldwide. The objective of this study was to investigate the metabolite profiling of three Egyptian soybean cultivars (Giza 22, Giza 35 and Giza 111) and their in vivo antitumor effect. Random amplified polymorphic DNA (RAPD) analysis developed polymorphism level of 75% in 72 distinct markers. Applying LC-ESI-MS analysis, twenty-nine metabolites were recognized from the 80% methanol extract of all cultivars. In vivo antitumor activity of the 80% methanolic extract against solid Ehrlich ascites carcinoma (EAC) inoculated in mice model, showed a significant diminishing in tumor volume and reduced Glutathione (rGSH) and a significant increase in malondialdehyde (MDA) which was supported by histopathological examination. Among the studied cultivars, Giza 22 cultivar contained the highest total phenolic content (TPC) that may contribute to its impressive antioxidant capacity and antitumor activity.

The concentration of polyphenolic compounds and trace elements in the Coffea arabica leaves: Potential chemometric pattern recognition of coffee leaf rust resistance

Coffee (Coffea arabica L.) is an important commodity, involving about 500 million people from the cultivation of the coffee trees to final consumption of infusions of the ground roasted coffee beans. In contrast to a considerable amount of research performed on green coffee beans, there are relatively few studies regarding the chemical constituents of coffee leaves. Hemileia vastatrix is a parasite, specific to coffee plants and causes coffee leaf rust, which is a very destructive disease. Some coffee plants have natural resistance which is mainly linked to a gene and specific host resistance response. An increase in flavonoid production may be related to fungal disease resistance, with the levels and flavonoid types being an early physiological response to rust infection. Trace inorganic elements can be related to many roles in the defense response of higher plants and can be used as a biomarker for some diseases. To address this, coffee leaves from 16 different cultivars of Coffea arabica were harvested from Minas Gerais, Brazil (susceptible and resistant to rust) and their polyphenolic compounds were extracted using the QuEChERS technique and quantitated by HPLC-ESI-MS. The same leaves were decomposed using an acid mixture in a block digester and the content of Al, Cu, Mg, Mn, Ni, Sn and Zn was quantitated by ICP-OES. Principal component analysis (PCA) was applied and we could establish a relation between polyphenolic and trace element concentration in the leaves with resistance to rust infection. On this basis in this preliminary study we were able to separate the resistant from the susceptible cultivars. The main compounds responsible for this differentiation were the content of chlorogenic acid and magnesium in the leaves. The content of polyphenolic compounds was lower in susceptible cultivars and a diametric effect was observed between Mn and Mg concentrations. This study shows potential for the discrimination of resistant and susceptible coffee trees based on the analyses of both trace element and polyphenolic concentration.

Quantitation of Inositol Phosphates by HPLC-ESI-MS

The coupling of anion exchange high-pressure liquid chromatography (HPLC) with electrospray ionization mass spectrometry (ESI-MS) allows for the simultaneous detection of the six forms of inositol phosphate (InsP). Here we describe a rapid quantitative analysis of InsPs by HPLC-ESI-MS, which can be applied to a wide array of sample types. With this method, InsPs could be separated and detected within 20 min of sample injection. The detection limit was as low as 25 pmol (i.e., ca. 2 nmol/g sample) for each type of InsP, which is particularly important for analytes that are often present at low abundance in nature.

Oxidation of Procyanidins with Various Degrees of Condensation: Influence on the Color-Deepening Phenomenon

Color deepening in red rice is a known phenomenon that occurs during postharvest storage. As procyanidins potentially causes this color deepening, we previously subjected synthetic procyanidin B3, a model procyanidin, to chemical oxidation and determined the structures of the products. To further elucidate the effects of various degrees of polymerization on color deepening, in this study we oxidized synthetic procyanidin C2. The intensity of the UV-vis absorption between 300 and 500 nm in the spectrum of the reaction mixture increased with increasing oxidation time. This absorption following the oxidation of procyanidin C2 was more intense than that of procyanidin B3. HPLC-ESI-MS of the oxidized reaction mixture revealed several new peaks that suggested the formation of products with new intramolecular rather than intermolecular bonds. The major product was structurally identified by comparison with the UPLC-ESI-MS/MS data for a synthetic procyanidin C2 oxide, independently prepared by condensing procyanidin B3 oxide and taxifolin.

Anti-atherosclerosis of oligomeric proanthocyanidins from Rhodiola rosea on rat model via hypolipemic, antioxidant, anti-inflammatory activities together with regulation of endothelial function

BACKGROUND

Rhodiola rosea has been used as a traditional medicine for a long history. Previous studies on oligomeric proanthocyanidins from Rhodiola rosea (OPCRR) have showed that it exhibited significant free radical-scavenging activities, antioxidant activities in aging mice and lipid lowering effects.

HYPOTHESIS/PURPOSE

We hypothesized that OPCRR can improve the atherosclerosis pathological in rats. In the present study, we investigated the effects of OPCRR on the serum lipid profiles, oxidant stress status, inflammatory cytokines and atherosclerotic mediators, and endothelial dysfunction as well as changes in abdominal aorta of atherosclerosis rats.

METHODS

The major components of OPCRR were analyzed by using infrared spectrum and HPLC-ESI-MS. The atherosclerosis rat model was induced by high fat and vitamin D3 feeding for 9 weeks and two OPCRR doses (60 and 120 mg/kg b.w.) were orally administered daily for 9 weeks. The rats were then sacrificed and the blood was collected via abdominal aorta and serum was separated by centrifugated for biochemical analysis. Part of the aorta tissues were excised immediately for histopathological examination and western blotting.

RESULTS

Compared to model group, OPCRR treatments significantly decreased the serum lipid profiles including total cholesterol, total triglycerides, low-density lipoprotein cholesterol (LDL-C) and ox-LDL and increased the high-density lipoprotein cholesterol (HDL-C); significant increased serum antioxidant enzymes (SOD and GSH-Px) and decrease of MDA content as a product of lipid peroxidation; lowered serum levels of TNF-α, IL-1β, IL-6, ICAM-1 and VCAM-1 and enhanced IL-10 level; increased the serum release of nitric oxide and expression of iNOS in aortic, whereas decreased the expression of eNOS.

CONCLUSION

OPCRR can improve the progress of atherosclerosis by regulation of lipid metabolism, restoring of the antioxidant capacities, and attenuation of pro-inflammatory cytokines and chemcytokines release, and improving the endothelial dysfunction indicated by nitric oxide system.

Effects of Different Cultivation Parameters on the Production of Surfactin Variants by a Bacillus subtilis Strain

Surfactins are lipopeptide-type biosurfactants produced mainly by Bacillus species, consisting of a peptide loop of seven amino acids and a hydrophobic fatty acid chain (C₁₂–C₁₆). These molecules have been proven to exhibit various biological activities; thus, their therapeutic and environmental applications are considered. Within the surfactin lipopeptide family, there is a wide spectrum of different homologues and isomers; to date, more than 30 variants have been described. Since the newest members of these lipopeptides were described recently, there is no information that is available on their characteristic features, e.g., the dependence of their production from different cultivation parameters. This study examined the effects of both the different carbon sources and various metal ions on the surfactin production of a selected B. subtilis strain. Among the applied carbon sources, fructose and xylose had the highest impacts on the ratio of the different variants, regarding both the peptide sequences and the lengths of the fatty acids. Furthermore, the application of metal ions Mn²⁺, Cu²⁺ and Ni²⁺ in the media completely changed the surfactin variant compositions of the fermenting broths leading to the appearance of methyl esterified surfactin forms, and resulted in the appearance of novel surfactin variants with fatty acid chains containing no more than 11 carbon atoms.

From 'green' technologies to 'red' antioxidant compounds extraction of purple corn: a combined ultrasound-ultrafiltration-purification approach

BACKGROUND

A pilot scale process consisting of ultrasound-assisted extraction, ammonium sulfate precipitation, cross-flow ultrafiltration and AB-8 macroporous resins purification aiming to recover anthocyanins and zein from purple corn (PC) was optimized and scaled-up. The effects of five independent variables (ethanol concentration, liquid to solid ratio, ultrasound temperature, time and power) were discussed and the most influential factors were optimized.

RESULTS

The highest total anthocyanin (0.45 ± 0.01 g kg^-1 ) and zein (17.14 ± 1.73 g kg^-1 ) contents from purple corn were obtained using an ultrasound power of 105 W, an extraction time of 90 min, an ethanol concentration of 74% and a liquid to solid ratio of 26:1, at 70 °C, and this was consistent with the predicted values (0.46 and 17.36 g kg^-1 , for anthocyanin and zein, respectively). Subsequently, ammonium sulfate precipitation was used to isolate anthocyanins and zein. After cross-flow ultrafiltration, zein (6.30 g) was obtained with 80% purity. Anthocyanins were purified by AB-8 macroporous resins, resulting in 1.60 g of anthocyanins. High-performance liquid chromatography-electrospray ionization-mass spectrometry analysis revealed eight different anthocyanins in purple corn extracts.

CONCLUSION

From the results obtained in the present study, it can be concluded that the proposed extraction-separation-filtration-purification method applied under the optimal conditions could be scaled-up to recover anthocyanins and zein simultaneously. Moreover, under the selected conditions, no significant degradation of anthocyanins was observed. © 2018 Society of Chemical Industry.

C60 fullerene accumulation in human leukemic cells and perspectives of LED-mediated photodynamic therapy

Recent progress in nanobiotechnology has attracted interest to a biomedical application of the carbon nanostructure C₆₀ fullerene since it possesses a unique structure and versatile biological activity. C₆₀ fullerene potential application in the frame of cancer photodynamic therapy (PDT) relies on rapid development of new light sources as well as on better understanding of the fullerene interaction with cells. The aim of this study was to analyze C₆₀ fullerene effects on human leukemic cells (CCRF-CEM) in combination with high power single chip light-emitting diodes (LEDs) light irradiation of different wavelengths: ultraviolet (UV, 365 nm), violet (405 nm), green (515 nm) and red (632 nm). The time-dependent accumulation of fullerene C₆₀ in CCRF-CEM cells up to 250 ng/10⁶ cells at 24 h with predominant localization within mitochondria was demonstrated with immunocytochemical staining and liquid chromatography mass spectrometry. In a cell viability assay we studied photoexcitation of the accumulated C₆₀ nanostructures with ultraviolet or violet LEDs and could prove that significant phototoxic effects did arise. A less pronounced C₆₀ fullerene phototoxic effect was observed after irradiation with green, and no effect was detected with red light. A C₆₀ fullerene photoactivation with violet light induced substantial ROS generation and apoptotic cell death, confirmed by caspase3/7 activation and plasma membrane phosphatidylserine externalization. Our work proved C₆₀ fullerene ability to induce apoptosis of leukemic cells after photoexcitation with high power single chip 405 nm LED as a light source. This underlined the potential for application of C₆₀ nanostructure as a photosensitizer for anticancer therapy.

Wine industry by-product: Full polyphenolic characterization of grape stalks

In this research work grape stalk samples from the Douro region were analyzed concerning polyphenolic composition. Different solid-liquid extraction conditions were tested for reaching the optimal parameters to obtain higher amounts of polyphenols. In general, the best conditions comprise the use of a mixture of acetone/ethanol/water (1:1:1) at room temperature during 20 min, using a pre-wash treatment with deionized water. The polyphenolic extractions with acetone are generally more effective than without acetone. Total phenolic determination (Folin-Ciocalteu), antioxidant capacity (DPPH/FRAP) and more accurate methods such as HPLC-DAD and HPLC-ESI-MS were performed. An intensive polyphenolic characterization (including a possible identification of a new polyphenol) and compound quantification was achieved. A comparative study between these two analysis approaches was accomplished, which allowed to conclude that the Folin-Ciocalteu and DPPH/FRAP determinations do not always allow a direct correspondence between high phenolic content or antioxidant/reducing capacity and real high polyphenolic content on crude polyphenolic extracts.

Antityrosinase and antioxidant properties of mung bean seed proanthocyanidins: Novel insights into the inhibitory mechanism

This study investigated the structure, antioxidant activity, antityrosinase activity and mechanism of proanthocyanidins from mung bean seed [Vigna radiata (L.) Wilczek]. The structural composition were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization-full-mass spectrometry (ESI-Full-MS), and high-pressure liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) techniques. The mung bean seed proanthocyanidins were composed of procyanidins, prodelphinidins, and their rhamnosides. According to enzyme kinetic analysis, these compounds were potent, reversible, and mixed-type inhibitors of tyrosinase. They inhibited the enzyme activity by interacting with enzyme as well as substrates. The results of molecular docking showed that the interaction between mung bean seed proanthocyanidins and tyrosinase was driven by hydrogen bond, hydrophobic and electrostatic interactions. In addition, mung bean seed proanthocyanidins were demonstrated as powerful antioxidants. Therefore, this study confirmed a novel tyrosinase inhibitor and would lay a scientific foundation for their utilization in pharmaceutical and food industries.

Oxidation of Hydroxy- and Dihydroxybenzoic Acids Under the Udenfriend's Conditions. An HPLC Study

Background:

Non-enzymatic hydroxylation of aromatic compounds to the respective phenolic derivatives is a possible metabolic pathway of xenobiotics. The formed metabolites can undergo consecutive oxidative reactions with free radicals to form potential toxic molecules.

Objective:

Development of HPLC methods to separate, identify and quantitate the main products formed from salicylic acid, 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid under in vitro hydroxylation conditions (Udenfriend's system).

Method:

An RP-HPLC-UV-Vis method was developed to separate salicylic acid and isomeric dihydroxybenzoic acids formed in the Udenfriend's system. Confirmation of structures of the oxidized products of salicylic acid, 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid was performed by HPLC-ESI-MS/MS method.

Results:

The HPLC-UV-Vis method was evaluated for a number of validation characteristics (selectivity, repeatability and intermediate precision, LOD, LOQ and calibration range). It was found that oxidation of salicylic acid resulted in the formation of 2,3- and 2,5-dihydroxybenzoic acids. Furthermore, the hydroxylated metabolites can be further metabolized under the Udenfriend’s conditions.

Conclusion:

The results give evidence for possible involvement of the oxidized metabolites of salicylic acid in the development of biological action of salicylates at the site of inflammation, where high hydroxyl radical level can be detected.

Quantification of inositol phosphates in almond meal and almond brown skins by HPLC/ESI/MS

The extraction and measurement of all six forms of inositol phosphates (InsPs) in almond meal and brown skins were improved from existing methods by pH adjustment, supplementation of EDTA, and rapid analysis via anion-exchange high-performance liquid chromatography coupled with electrospray ionization mass spectrometry. The quantity of InsPs in six major almond cultivars ranged from 8 to 12μmol/g in the meal and 5 to 14μmol/g in the brown skins. InsP₆ was the dominant form, but lower forms still accounted for ∼20% of the total InsPs molar concentration in a majority of the samples. InsPs contributed 32-55% of the organic phosphorus content and 20-38% of the total phosphorus content in the meal. In brown skins, these ranges were 44-77% and 30-52%, respectively. The successful application of this analytical method with almonds demonstrates its potential use for re-examination of the reported phytic acid contents in many other tree nuts, legumes, grains, and complex foods.

Phytochemical screening by LC-MS and LC-PDA of ethanolic extracts from the fruits of Kigelia africana (Lam.) Benth

Kigelia africana is a tree native to Africa, with a local employment in numerous fields, ranging from traditional medicine to cosmetics and religious rituals. Parts of the plant generally used are stem bark, fruits, roots and leaves. The fruits, which have a singular 'sausage' shape, are widely exploited by local folk, in particular for applications/products involving genito-urinary apparatus of both human genders. The scope of this work was to make a consistent chemical investigation on this plant species, in order to clarify and increase the information at present available in literature. To this aim, ethanolic extracts of K. africana fruits were analysed by high-performance liquid chromatography with photodiode array (HPLC-PDA) and electrospray-mass spectrometry (HPLC-ESI-MS) detection, revealing the presence of polyphenols and iridoids. The two detection systems used along with standard co-injection and comparison with previous reports, led to the identification and quantification of six phenolic compounds and three iridoids.

Assessment of the antidiarrhoeal properties of the aqueous extract and its soluble fractions of Chebulae Fructus (Terminalia chebula fruits)

Context Chebulae Fructus is used as an herbal remedy for diarrhoea in traditional Chinese medicine. However, there is no scientific evidence to support its antidiarrhoeal activity. Objective This study evaluates the antidiarrhoeal properties of Chebulae Fructus aqueous extract (CFAE) and determines the active fraction. Materials and methods The antidiarrhoeal effect of CFAE (200-800 mg/kg) was investigated by determining the wet dropping, intestinal transit in BALB/c mice and enteropooling in Wister rats. The protective effects of the CFAE on the intestinal and liver were tested by histopathological analyses. The antidiarrhoeal fraction was determined by castor oil-induced diarrhoea and its main constituents were identified by HPLC-ESI-MS. Results The extract at doses of 200, 400 and 800 mg/kg reduced the diarrhoea by 9.1, 40.0 and 58.2% and inhibited intestinal transit by 18.3, 24.1 and 35.7%, respectively. Additionally, the CFAE (200, 400 and 800 mg/kg) decreased the volume of enteropooling by 47.1, 58.8 and 64.7%, respectively. Mice treated with castor oil presented morphological alterations in the small intestine and the liver. However, the lesions of mice treated with CFAE were alleviated. Moreover, the ethyl acetate fraction was the active fraction of CFAE, the fraction (41.7, 83.4 and 166.8 mg/kg) reduced the diarrhoea by 9.1, 38.2 and 54.5%, respectively. The major components of the ethyl acetate fraction were tannins, including gallic acid, 3, 4, 6-tri-O-galloyl-β-d-Glc, corilagin and ellagic acid according to the HPLC-ESI-MS analysis. Conclusion The CFAE possessed antidiarrhoeal property and the ethyl acetate fraction was its main active fraction.

Identification and analysis of anthocyanin components in fruit color variation in Schisandra chinensis

BACKGROUND

Fruit color is an important index and parameter for measuring fruit quality. As an important pigment, anthocyanin is a determinant which appears in all sorts of colors of fruits in nature.

RESULTS

Color parameters were measured using a spectrometer and used as a basis to divide the materials into three groups: reddish-orange, orange and yellow. A validated high-performance liquid chromatographic-electrospray ionization-mass spectrometric method was used for the analysis of anthocyanin in Schisandra chinensis and for determining major anthocyanin components in S. chinensis fruits, i.e. cyanidin xylosyl-glucoside (CyXylGlu), cyanidin glucosyl-rutinoside (CyGluRutin), cyanidin rutinoside (CyRutin) and cyanidin xylosyl-rutinoside (CyXylRutin). The anthocyanin contents vary obviously in different colored fruits in S. chinensis. The impact of anthocyanin on coloration of fruits was investigated by multiple regression analysis between color parameters and anthocyanin components, which indicated that CyRutin is the primary cause of fruit color variation in S. chinensis.

CONCLUSION

The content and type of anthocyanin determine fruit coloration in S. chinensis, laying the early foundations for systematically interpreting the mechanism of fruit coloration in S. chinensis. © 2015 Society of Chemical Industry.

Diversity of Kale (Brassica oleracea var. sabellica): Glucosinolate Content and Phylogenetic Relationships

Recently, kale has become popular due to nutritive components beneficial for human health. It is an important source of phytochemicals such as glucosinolates that trigger associated cancer-preventive activity. However, nutritional value varies among glucosinolates and among cultivars. Here, we start a systematic determination of the content of five glucosinolates in 25 kale varieties and 11 non-kale Brassica oleracea cultivars by HPLC-DAD-ESI-MS(n) and compare the profiles with results from the analysis of SNPs derived from a KASP genotyping assay. Our results demonstrate that the glucosinolate levels differ markedly among varieties of different origin. Comparison of the phytochemical data with phylogenetic relationships revealed that the common name kale refers to at least three different groups. German, American, and Italian kales differ morphologically and phytochemically. Landraces do not show outstanding glucosinolate levels. Our results demonstrate the diversity of kale and the importance of preserving a broad genepool for future breeding purposes.

Protective effects of the extracts of Barringtonia racemosa shoots against oxidative damage in HepG2 cells

Barringtonia racemosa is a tropical plant with medicinal values. In this study, the ability of the water extracts of the leaf (BLE) and stem (BSE) from the shoots to protect HepG2 cells against oxidative damage was studied. Five major polyphenolic compounds consisting of gallic acid, ellagic acid, protocatechuic acid, quercetin and kaempferol were identified using HPLC-DAD and ESI-MS. Cell viability assay revealed that BLE and BSE were non-cytotoxic (cell viabilities >80%) at concentration less than 250 µg/ml and 500 µg/ml, respectively. BLE and BSE improved cellular antioxidant status measured by FRAP assay and protected HepG2 cells against H2O2-induced cytotoxicity. The extracts also inhibited lipid peroxidation in HepG2 cells as well as the production of reactive oxygen species. BLE and BSE could also suppress the activities of superoxide dismutase and catalase during oxidative stress. The shoots of B. racemosa can be an alternative bioactive ingredient in the prevention of oxidative damage.

Rapid characterization of ginsenosides in the roots and rhizomes of Panax ginseng by UPLC-DAD-QTOF-MS/MS and simultaneous determination of 19 ginsenosides by HPLC-ESI-MS

BACKGROUND

Ginsenosides are the characteristic and principal components which manifest a variety of the biological and pharmacological activities of the roots and rhizomes of Panax ginseng (GRR). This study was carried out to qualitatively and quantitatively determine the ginsenosides in the cultivated and forest GRR.

METHODS

A rapid and sensitive ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time of flight tandem mass spectrometry (UPLC-DAD-QTOF-MS/MS) was applied to the qualitative analysis of ginsenosides and a 4000 QTRAP triple quadrupole tandem mass spectrometer (HPLC-ESI-MS) was applied to quantitative analysis of 19 ginsenosides.

RESULTS

In the qualitative analysis, all ingredients were separated in 10 min. A total of 131 ginsenosides were detected in cultivated and forest GRR. The method for the quantitative determination was validated for linearity, precision, and limits of detection and quantification. 19 representative ginsenosides were quantitated. The total content of all 19 ginsenosides in the forest GRR were much higher than those in the cultivated GRR, and were increased with the growing ages.

CONCLUSION

This newly developed analysis method could be applied to the quality assessment of GRR as well as the distinction between cultivated and forest GRR.

Submerged fermentation production and characterization of intracellular triterpenoids from Ganoderma lucidum using HPLC-ESI-MS

As the main bioactive metabolites of Ganoderma lucidum, triterpenoids have various pharmacological effects. In this paper, the nutritional requirements and culture conditions of a submerged culture of G. lucidum were optimized using the response surface methodology; maximum mycelia biomass and intracellular triterpenoid production reached 1.87 g/100 ml and 93.21 mg/100 ml, respectively, for a culture consisting of wort 4.10% (0.041 g/ml) and yeast extract 1.89% (0.0189 g/ml), pH 5.40. For the first time, we established that wort, which is cheap and abundant, can replace the more commonly used glucose as the sole source of carbohydrate. Using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS), 10 major ganoderic acids were tentatively identified based on the predominant fragmentation pathways with the elimination of H2O and CO2, as well as cleavage of the D-ring.

The Spectrum-Effect integrated fingerprint of Polygonum cuspidatum based on HPLC-diode array detection-flow injection-chemiluminescence

AIM

To establish the Spectrum-Effect integrated fingerprint of Polygonum cuspidatum to evaluate the quality of P. cuspidatum.

METHODS

An on-line HPLC-DAD-flow injection chemiluminescence (FICL) method was developed to investigate the quality of P. cuspidatum from different habitats based on the established Spectrum-Effect integrated fingerprint.

RESULTS

Nineteen batches of samples of P. cuspidatum were evaluated for the similarity of their chromatographic and free radical scavenging fingerprints, and the results compared. Main antioxidants were estimated by regression analysis between peak areas of thirteen compounds and their activities. Some active compounds were identified by HPLC-ESI-MS.

CONSULSIONS

The results indicated that main antioxidants in P. cuspidatum could be rapidly screened by the established Spectrum-Effect integrated fingerprint based on on-line HPLC-DAD-FICL, and would be more efficient and objective method to evaluate the quality of P. cuspidatum.

Analysis of phenolic compounds in commercial dried grape pomace by high-performance liquid chromatography electrospray ionization mass spectrometry

By-products obtained from winemaking processes still contain large amounts of phenolic compounds, especially phenolic acids, flavanols, flavonols, stilbenes, and flavonoids. Enzymatic hydrolysis was used for determination and characterization of phenolic acids, flavanols, flavonols, and stilbenes. Characterization of the flavonoids was achieved using acid hydrolysis with 0.1% hydrochloric acid. In addition, organic solvents as 50% methanol, 70% methanol, 50% acetone, 0.01% pectinase, and 100% petroleum ether were also evaluated. Reversed phase high-performance liquid chromatography (RP-HPLC) with diode array detector was used to identify phenolic compounds. Internal standard quantification was implemented using a five points of the UV-visible absorption data collected at the wavelength of maximum absorbance. A total of 16 phenolic compounds were determined. The content differed from 1.19 to 1124 mg kg⁻¹. Outcomes from HPLC study showed that gallic acid, (+) catechin hydrate, and (−) epicatechin gallate were the major phenolic compounds presented in the sample. Malvidin and pelargonidin 3-O-glucoside were the major anthocyanins monoglucosides.

Isoflavonoids in the Amaryllidaceae family

Plants of the Amaryllidaceae family are known as producers of biologically active alkaloids. Besides these a variety of flavonoids, including flavones, chalcones and chromones, have been detected in the Amaryllidaceous plants. In this study, we have analysed 16 representatives of the family for the presence of isoflavonoids. The water/ethanolic extracts were analysed with HPLC-ESI-MS both without any pre-treatment and after immunoaffinity chromatography as a clean-up step. Four individual immunosorbents specific for biochanin A, daidzein and genistein were used. In addition, five enzyme-linked immunosorbent assays specific for the above-mentioned isoflavonoids and their derivatives have been used for the analysis of the extracts after fractionation by semi-preparative HPLC. Fifteen selected isoflavonoids were detected in the studied samples, and the amount of individual compounds ranged between ca. 0.8 and 400 ng/g of dry weight. This study extends the number of known isoflavonoid-producing families within the monocotyledonous plants.

Structural analysis of proanthocyanidins isolated from fruit stone of Chinese hawthorn with potent antityrosinase and antioxidant activity

Proanthocyanidins were isolated from fruit stone of Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.). Their structures were analyzed and elucidated by methods of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS). The results demonstrated that these compounds are complicated mixtures of homo- and heteropolymers consisting of procyanidin/procyanidin gallate and prodelphinidin. They possessed structural heterogeneity in monomer units, polymer length, and interflavan linkage (A-type and B-type). Their antityrosinase and antioxidant activity were then investigated. The results revealed that they can inhibit tyrosinase activities, including the monophenolase activity and the diphenolase activity. In addition, proanthocyanidins possessed potent antioxidant activity. Our studies revealed that proanthocyanidins isolated from fruit stone of Chinese hawthorn may be applied in food, agriculture, pharmaceutical, and cosmetic industries.

Determination of chikusetsusaponin V and chikusetsusaponin IV in rat plasma by liquid chromatography-mass spectrometry and its application to a preliminary pharmacokinetic study

A sensitive liquid chromatography-electrospray ionization-mass spectrometry method has been developed and validated for determination of two major bioactive saponins in rat plasma after oral administration of saponins extracted from Rhizoma Panacis Japonici, including chikusetsusaponin V and chikusetsusaponin IV for the first time. Akebia saponin D was used as the internal standard (IS). Plasma samples were prepared by protein precipitation with methanol. A Phenomenex C18 column (150 × 4.6 mm, 4 µm) was used as the analytical column with a mobile phase of acetonitrile and 0.05% aqueous formic acid. Mass spectrometric detection was achieved by single quadrupole mass spectrometer equipped with an electrospray ionization interface operating in negative ionization mode. Calibration curves showed good linearity over the concentration range of 5-500 ng/mL for the two analytes in rat plasma. The lower limit of quantification was 5 ng/mL. The intra- and inter-batch precisions were within 10.3% and accuracy ranged from -3.9 to 5.4%. The method was validated and successfully applied to the preliminary pharmacokinetic study of chikusetsusaponin V and chikusetsusaponin IV in rat plasma after oral administration of saponins extracted from Rhizoma Panacis Japonici.

Optimization of the extraction of anthocyanins from the fruit skin of Rhodomyrtus tomentosa (Ait.) Hassk and identification of anthocyanins in the extract using High-Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS)

Anthocyanins are naturally occurring polyphenols that impart bright color to fruits, vegetables and plants. In this study, the extraction of anthocyanins from freeze-dried fruit skin of downy rose-myrtle (Rhodomyrtus tomentosa (Ait.) Hassk var. Gangren) was optimized using response surface methodology (RSM). Using 60% ethanol containing 0.1% (v/v) hydrochloric acid as extraction solvent, the optimal conditions for maximum yields of anthocyanin (4.358 ± 0.045 mg/g) were 15.7:1 (v/w) liquid to solid ratio, 64.38 °C with a 116.88 min extraction time. The results showed good fits with the proposed model for the anthocyanin extraction (R(2) = 0.9944). Furthermore, the results of high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) analysis of the anthocyanins extracted from the fruit skin of downy rose-myrtle revealed the presence of five anthocyanin components, which were tentatively identified as delphinidin-3-glucoside, cyanidin-3-glucoside, peonidin-3-glucoside, petunidin-3-glucoside and malvidin-3-glucoside.

Proteomics of saliva: personal experience

The salivary proteome is a complex protein mixture resulting from the activity of salivary glands with the contribution of other components that form the oral environment such as oral tissues and micro-organisms. For diagnosis purposes, saliva collection has the great advantage of being an easy and non-invasive technique. Human saliva proteomics have proven to be a novel approach in the search for protein biomarkers for detection of different local and systemic diseases. Currently, more than 1400 salivary proteins have been identified. In the last few years, our research group has extensively studied the salivary proteomics in order to analyse the salivary composition, investigating the major families of proteins present in human and mammalian saliva, the post-translational modifications, the different contributions of glands, the physiological and pathological modifications of saliva. The aim of this report is to present our personal experience in salivary proteomics. In conclusion, salivary proteome analysis represents an important field both for diagnosis and monitoring of various diseases and could be considered a novel approach to prevention of various pathological conditions.

Antioxidant activity of a red lentil extract and its fractions

Phenolic compounds were extracted from red lentil seeds using 80% (v/v) aqueous acetone. The crude extract was applied to a Sephadex LH-20 column. Fraction 1, consisting of sugars and low-molecular-weight phenolics, was eluted from the column by ethanol. Fraction 2, consisting of tannins, was obtained using acetone-water (1:1; v/v) as the mobile phase. Phenolic compounds present in the crude extract and its fractions demonstrated antioxidant and antiradical activities as revealed from studies using a β-carotene-linoleate model system, the total antioxidant activity (TAA) method, the DPPH radical-scavenging activity assay, and a reducing power evaluation. Results of these assays showed the highest values when tannins (fraction 2) were tested. For instance, the TAA of the tannin fraction was 5.85 μmol Trolox^® eq./mg, whereas the crude extract and fraction 1 showed 0.68 and 0.33 μmol Trolox^® eq./mg, respectively. The content of total phenolics in fraction 2 was the highest (290 mg/g); the tannin content, determined using the vanillin method and expressed as absorbance units at 500 nm per 1 g, was 129. There were 24 compounds identified in the crude extract using an HPLC-ESI-MS method: quercetin diglycoside, catechin, digallate procyanidin, and p-hydroxybenzoic were the dominant phenolics in the extract.

Modification of the IFCC reference measurement procedure for determination of HbA 1c by HPLC-ESI-MS

The reference measurement procedure for determination of HbA(1c) (glycated haemoglobin) using HPLC(high performance liquid chromatography)-ESI(electrospray ionisation)-MS(mass spectrometry) has been modified. Main modifications were a change in the buffer composition of the HPLC, a change in the gradient elution profile and the introduction of a post-column splitting system. The long-term stability of the HPLC-ESI-MS system proved to be of high importance to get reproducible results. Using the modified HPLC conditions stable retention times, high peak symmetry and a good column batch-to-batch reproducibility of the analytical results were obtained. The mean deviation from the target values was less than 0.7% with an imprecision of less than 2%.