Determination of Flavonoids and Phenolic Acids in Plant Materials Using SLE-SPE-UHPLC-MS/MS Method

Core-shell magnetic covalent organic polymer nanocomposites as an adsorbent for the extraction of flavonoids

A novel 3D magnetic nanocomposite material based on covalent organic polymers was successfully synthesized and utilized as an efficient sorbent for magnetic solid-phase extraction. It exhibited a regular core-shell structure, large specific surface area, superior stability, and paramagnetism. To evaluate its extraction efficiency, six flavonoids were tested, demonstrating maximum adsorption capacities ranging from 90 to 218 mg/g. Additionally, the material exhibited remarkable reusability and mechanical stability, maintaining its original state over eight cycles with consistent recovery. An analytical strategy combining magnetic solid-phase extraction with high performance liquid chromatography and tandem mass spectrometry was developed for the determination of flavonoids in orange, honey, soybean, and Dioscorea bulbifera L. samples. The low limits of detection (0.01-0.1 ng/mL) and limits of quantification (0.05-0.5 ng/mL), as well as satisfactory recovery (80.4-114.8%), were obtained. The linear range started from the limits of quantification to 500 ng/mL with R2 ≥ 0.9929. These results suggest that the prepared adsorbent possesses excellent adsorption capabilities for flavonoids, highlighting its significant potential for detecting these compounds in complex sample matrices.

Chemometrics-based analysis of the phytochemical profile and antioxidant activity of Salvia species from Iran

In recent years, the exploration of the therapeutic potential of Salvia has gained considerable attention, leading to a growing number of scientific studies emphasizing its pharmacological properties. Despite this, therapeutic applications of Salvia remain underexploited, requiring further investigation. Iran is a major center for sage diversity in Asia, boasting 60 Salvia species, 17 of which are unique to the area. This study aimed to comprehensively explore and compare the extracts of 102 Salvia samples belonging to 20 distinct Salvia species from Iran, providing a deeper understanding of their specific polyphenol content and, consequently, their antioxidant capabilities and potential therapeutic uses. All samples were analyzed to determine the contents of total phenolics, total flavonoids, total tannin, photosynthetic pigments, and ascorbic acid, along with their antioxidant activity. These data were then combined with the forty distinct chemical fingerprints identified by ultrafast high-pressure liquid chromatography coupled with high-resolution mass spectrometry. Multivariate data analysis was employed to find correlations and differences among the huge number of data obtained and to identify Salvia species with similar phytochemical and/or antioxidant properties. The results show that each Salvia species is characterized by a distinct class of polyphenols recognized for their antidiabetic, anti-inflammatory, cardioprotective and neuroprotective properties. Overall, our findings reveal the potential of some Salvia species for targeted therapeutic applications and provide a rational basis for the development of Salvia-derived nutraceuticals, ultimately improving the prospects for the use of Salvia in medicine.

Phytochemical Composition and Antimicrobial Properties of New Lavandula angustifolia Ecotypes

The purpose of this study was to characterize ethanol extracts from leaves and flowers of two ecotypes (PL-intended for industrial plantations and KC-intended for cut flowers) of Lavandula angustifolia Mill. The plant was cultivated in 2019 in southern Poland as part of a long-term research plan to develop new varieties resistant to difficult environmental conditions. The collected leaves and flowers were used to prepare ethanol extracts, which were then analyzed in terms of phytochemical composition and antioxidant, bactericidal, and fungicidal properties. Using UPLC techniques, 22 compounds belonging to phenolic acids and flavonoids were identified. UPLC test results indicated that ethanol extracts from leaves and flowers differ in phytochemical composition. Lower amounts of phenolic acids and flavonoids were identified in leaf extracts than in flower extracts. The predominant substances in the flower extracts were rosmarinic acid (829.68-1229.33 µg/g), ferulic acid glucoside III (810.97-980.55 µg/g), and ferulic acid glucoside II (789.30-885.06 µg/g). Ferulic acid glucoside II (3981.95-6561.19 µg/g), ferulic acid glucoside I (2349.46-5503.81 µg/g), and ferulic acid glucoside III (1303.84-2774.17 µg/g) contained the highest amounts in the ethanol extracts of the leaves. The following substances were present in the extracts in trace amounts or at low levels: apigenin, kaempferol, and caftaric acid. Leaf extracts of the PL ecotype quantitatively (µg/g) contained more phytochemicals than leaf extracts of the KC ecotype. The results obtained in this study indicate that antioxidant activity depends on the ecotype. Extracts from the PL ecotype have a better ability to eliminate free radicals than extracts from the KC ecotype. At the same time, it was found that the antioxidant activity (total phenolic content, ABTS•+, DPPH•, and FRAP) of PL ecotype leaf extracts was higher (24.49, 177.75, 164.88, and 89.10 μmol (TE)/g) than that determined in flower extracts (15.84, 125.05, 82.35, and 54.64 μmol (TE)/g). The test results confirmed that leaf and flower extracts, even at low concentrations (0.313-0.63%), significantly inhibit the growth of selected Gram-negative and Gram-positive bacteria and Candida yeasts. Inhibition of mold growth was observed at a dose extract of at least 1 mL/100 mL.

Miniaturized centrifugation accelerated pipette-tip matrix solid-phase dispersion based on poly(deep eutectic solvents) surface imprinted graphene oxide composite adsorbent for rapid extraction of anti-adipogenesis markers from Solidago decurrens Lour

Overweight and obesity are the causes of many diseases and have become global "epidemics". Research on natural active components with anti-adipogenesis effects in plants has aroused the interest of researchers. One of the most critical problems is establishing sample preparation and analytical techniques for quickly and selectively extracting and determining the active anti-adipogenesis components in complex plant matrices for developing new anti-adipogenic drugs. In this study, a new poly(deep eutectic solvents) surface imprinted graphene oxide composite (PDESs-MIP/GO) with high selectivity for phenolic acids was prepared using deep eutectic solvents as monomers and crosslinkers. A miniaturized centrifugation-accelerated pipette-tip matrix solid-phase dispersion method (CPT-MSPD) with PDESs-MIP/GO as adsorbent, coupled with high-performance liquid chromatography, was further developed for the rapid determination of anti-adipogenesis markers in Solidago decurrens Lour. (SDL). The established method was successfully used to determination anti-adipogenesis markers in SDL from different regions, with the advantages of accuracy (recoveries: 94.4 - 115.9 %, RSDs ≤ 9.8 %), speed (CPT-MSPD time: 11 min), selectivity (imprinting factor: ∼2.0), and economy (2 mg of adsorbent and 1 mL of solvents), which is in line with the current advanced principle of "3S+2A" in analytical chemistry.

Evaluating the Antioxidant and Antidiabetic Properties of Medicago sativa and Solidago virgaurea Polyphenolic-Rich Extracts

The present study evaluated the antioxidant and antidiabetic properties of Medicago sativa and Solidago virgaurea extracts enriched in polyphenolic compounds. The extracts were obtained by accelerated solvent extraction (ASE) and laser irradiation. Then, microfiltration was used for purification, followed by nanofiltration used to concentrate the two extracts. The obtained extracts were analyzed to determine their antioxidant activity using DPPH radical scavenging and reducing power methods. The antidiabetic properties have been investigated in vitro on a murine insulinoma cell line (β-TC-6) by the inhibition of α-amylase and α-glucosidase. M. sativa obtained by laser irradiation and concentrated by nanofiltration showed the highest DPPH• scavenging (EC50 = 105.2 ± 1.1 µg/mL) and reducing power activities (EC50 = 40.98 ± 0.2 µg/mL). M. sativa extracts had higher inhibition on α-amylase (IC50 = 23.9 ± 1.2 µg/mL for concentrated extract obtained after ASE, and 26.8 ± 1.1), while S. virgaurea had the highest α-glucosidase inhibition (9.3 ± 0.9 µg/mL for concentrated extract obtained after ASE, and 8.6 ± 0.7 µg/mL for concentrated extract obtained after laser extraction). The obtained results after evaluating in vitro the antidiabetic activity showed that the treatment with M. sativa and S. virgaurea polyphenolic-rich extracts stimulated the insulin secretion of β-TC-6 cells, both under normal conditions and under hyperglycemic conditions as well. This paper argues that M. sativa and S. virgaurea polyphenolic-rich extracts could be excellent natural sources with promising antidiabetic potential.

Enrichment of Water Bodies with Phenolic Compounds Released from Betula and Pinus Pollen in Surface Water

Betula and Pinus pollen, which are dispersed in natural surface waters, release biologically active compounds into the water bodies. This study aims to evaluate variations in the distribution and composition of phenolic compounds in suspended particles in natural water bodies during pollen spreading. Samples taken from water bodies of different trophic levels were analyzed by microscopy, UV/VIS spectroscopy, HPTLC, and HPLC/DAD. The study revealed that the total phenolic content in water-suspended particles varied from 3.0 mg/g to 11.0 mg/g during Betula and Pinus pollen spreading. It was also observed that the surface water of dystrophic natural lakes had a higher content of phenolic compounds than the eutrophic, hypereutrophic, and mesotrophic water bodies. Chlorogenic, trans-ferulic, vanillin, and 3,4-dihydroxybenzoic acids were frequently detected in the surface water samples. Experimental measurements have shown variations in the release of phenolic compounds from Betula pollen into water (p < 0.05). After the exhibition of pollen, the distilled water predominantly contained bioactive chlorogenic acid. Further in situ investigations are necessary to gain a more comprehensive understanding of the function of phenolic compounds in aquatic ecosystems. The exploration of the release of bioactive compounds from pollen could provide valuable insights into the potential nutritional value of pollen as a nutrient source for aquaculture.

Room-temperature synthesis of imine-linked magnetic covalent organic polymers in deep eutectic solvents for the extraction of flavonoids and their determination with HPLC-MS/MS

A novel imine-linked magnetic covalent organic polymer, Fe3O4@TAB-TFPT, was synthesized using environmentally friendly deep eutectic solvents as the reaction medium instead of conventional organic solvents. The materials were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), FT-IR, N2 adsorption-desorption isotherms, energy dispersive spectrometer (EDS), X-ray photoelectron spectra (XPS), and thermo gravimetric analysis (TGA). Subsequently, the materials were employed as an adsorbent for magnetic solid-phase extraction (MSPE) of flavonoids, including Kurarinone, Norkurarinone, Xanthohumol, and Isoxanthohumol, prior to their determination by HPLC-MS/MS. The validation results demonstrate good linearity within the concentration range 0.1-1000 ng∙mL-1 (R2 ≥ 0.9963), high enrichment factors ranging from 18.9 to 30.7, and low LODs (0.01-0.05 ng∙mL-1) and LOQs (0.05-0.1 ng∙mL-1). Furthermore, recoveries between 80.60% and 108.40% with relative standard deviations ≤ 8.49% were achieved. The proposed MSPE-HPLC-MS/MS method was successfully applied to the determination of flavonoids in Sophora flavescens Aition sample.

Antioxidant Activity of Flavonoids and Phenolic Acids from Dodonaea angustifolia Flower: HPLC Profile and PASS Prediction

Background. Dodonaea angustifolia is a known medicinal plant across East Arica. The flower of D. angustifolia is not well investigated in terms of phytochemistry and biological activities. This study aims to investigate the presence of flavonoids and phenolic acids in the flower of D. angustifolia and its antioxidant activity. Methods. Preliminary phytochemical screening was carried out using the standard protocols. Antioxidant activity evaluation using DPPH assay and total phenol content (TPC) and total flavonoid content (TFC) determinations in the flower extract were compared with the values of the leaf extract. UHPLC-DAD analysis was managed to develop the profile of the flower extract. Prediction of biological activity spectra for substances (PASS) was done using an online server for antioxidant and related activities. Results. Preliminary phytochemical screening and TPC and TFC values confirmed the presence of flavonoids and phenolic acids. From the HPLC analysis of flavonoids, quercetin, myricetin, rutin, and phenolic acids such as chlorogenic acid, gallic acid, and syringic acid were detected and quantified. The biological activity spectrum was predicted for the detected and quantified polyphenols. Conclusions. D. angustifolia flower is a rich source of flavonoids and phenolic acids, which are extractable and can be checked for further biological activity. It was possible to identify and quantify phenolic compounds through HPLC analysis in the methanol extract of D. angustifolia flower. The PASS biological activity prediction results showed that there were stronger antioxidant activities for the identified flavonoids. Future work will emphasize the isolation and characterization of active principles responsible for bioactivity.

Patterns of Phenolic Compounds in Betula and Pinus Pollen

In this study, phenolic compounds and their antioxidant activity in the pollen of anemophilous Betula and Pinus were determined. Spectrophotometric, high-performance thin-layer and liquid chromatography methods were applied. Free phenolic compounds (free PC) and phenolic compounds bound to the cell wall (bound PC) were analysed in the pollen extracts. Regardless of the pollen species, their content was 20% higher than that in bound PC extracts. Pinus pollen extracts contained 2.5 times less phenolic compounds compared to Betula. Free PC extraction from the deeper layers of Pinus pollen was minimal; the same content of phenolic compounds was obtained in both types of extracts. The bioactivity of pollen (p < 0.05) is related to the content of phenolic compounds and flavonoids in Betula free PC and in bound PC, and only in free PC extracts of Pinus. Rutin, chlorogenic and trans-ferulic acids were characterised by antioxidant activity. Phenolic acids accounted for 70−94%, while rutin constituted 2−3% of the total amount in the extracts. One of the dominant phenolic acids was trans-ferulic acid in all the Betula and Pinus samples. The specific compounds were vanillic and chlorogenic acids of Betula pollen extracts, while Pinus extracts contained gallic acid. The data obtained for the phenolic profiles and antioxidant activity of Betula and Pinus pollen can be useful for modelling food chains in ecosystems.

Phytochemical Profiling, Antioxidant and Anti-Inflammatory Activity of Plants Belonging to the Lavandula Genus

Lavender is a valuable medicinal plant belonging to the Lamiaceae family. Currently 39 species are known, but only Lavandula angustifolia is a pharmacopoeial raw material. Lavender has a long history of medicinal use and mainly exhibits antioxidant, anti-inflammatory, sedative, antidepressant, spasmolytic, anticholinesterases, antifungal and antibacterial properties. Used internally, it relieves symptoms of mental stress and insomnia and supports digestion. Topical use of lavender in aromatherapy, neuralgia and antiseptics is also known. The constant interest in lavender, and in particular in Lavandula angustifolia, in the field of medicine and pharmacy is evidenced by the growing number of publications. In view of so many studies, it seems important to review traditional and modern extraction techniques that determine the chemical composition responsible for the antioxidant and anti-inflammatory effects of various extracts from the species of the Lavandula genus.

Characterization of Forage Quality, Phenolic Profiles, and Antioxidant Activity in Alfalfa (Medicago sativa L.)

Alfalfa (Medicago sativa L.) is one of the most important forage species and is recently more in focus for human consumption mainly due to its content of bioactive phenolics. Samples of the seventeen alfalfa cultivars/populations were collected at the Agricultural Institute Osijek with the aim to evaluate their forage quality, phenolic profiles, and antioxidant potential. Significant differences (p < 0.05) existed among studied alfalfa in all analyzed traits. The cultivar OS 99 and populations L7 and L20 were characterized by high crude protein content (22.5−24.7%) and the lowest neutral (40.2−42.9%) and acid detergent fibres (33−35.5%). The soluble-free phenolics from alfalfa leaves were extracted by methanol while insoluble cell-wall bound phenolics were released by alkaline hydrolysis. The bound phenolic extract showed a stronger DPPH scavenging capacity (20.8 mg TE/g dm) than the soluble (11.4 mg TE/g dm). The HPLC data revealed that more phenolics were found in the bound (3638.0 μg/g dm) than in the soluble form (912.3 μg/g dm). In the soluble extract of the alfalfa leaves, the major compound was catechin (338.3 μg/g dm), while rutin, epicatechin, and ferulic acid were minor ones. In the bound phenolic extract, the most abundant was ferulic (2198.2 μg/g dm) and p-coumaric acid (983.7 μg/g dm), followed by myricetin, apigenin, and quercetin. The principal component analysis revealed that alfalfa cultivars/populations were better discriminated based on the data on phenolics, rather than on forage quality. The cultivars/populations Florida 66, OS 66, L 40, L 42, Seed Force 4, and Torlesse were the most interesting in terms of phenolic health-promoting characteristics.

High-Throughput Method for Wide-Coverage and Quantitative Phenolic Fingerprinting in Plant-Origin Foods and Urine Samples

The use of mass spectrometry is currently widespread in polyphenol research because of its sensitivity and selectivity, but its usual high cost, reduced robustness, and nonavailability in many analytical laboratories considerably hinder its routine implementation. Herein, we describe the optimization and validation of a high-throughput, wide-coverage, and robust metabolomics method based on reversed-phase ultra-high-performance liquid chromatography with diode array detection for the identification and quantification of 69 phenolic compounds and related metabolites covering a broad chemical space of the characteristic secondary metabolome of plant foods. The method was satisfactorily validated following the Food and Drug Administration guidelines in terms of linearity (4-5 orders of magnitude), limits of quantification (0.007-3.6 mg L-1), matrix effect (60.5-124.4%), accuracy (63.4-126.7%), intraday precision (0.1-9.6%), interday precision (0.6-13.7%), specificity, and carryover. Then, it was successfully applied to characterize the phenolic fingerprints of diverse food products (i.e., olive oil, red wine, strawberry) and biological samples (i.e., urine), enabling not only the detection of many of the target compounds but also the semi-quantification of other phenolic metabolites tentatively identified based on their characteristic absorption spectra. Therefore, this method represents one step further toward time-efficient and low-cost polyphenol fingerprinting, with suitable applicability in the food industry to ensure food quality, safety, authenticity, and traceability.

Phytochemical Profiling, Anti-Inflammatory, Anti-Oxidant and In-Silico Approach of Cornus macrophylla Bioss (Bark)

The objective of the current study was to evaluate the phytochemical and pharmacological potential of the Cornus macrophylla. C. macrophylla belongs to the family Cornaceae. It is locally known as khadang and is used for the treatment of different diseases such as analgesic, tonic, diuretic, malaria, inflammation, allergy, infections, cancer, diabetes, and lipid peroxidative. The crude extract and different fractions of C. macrophyll were evaluated by gas chromatography and mass spectroscopy (GC-MS), which identified the most potent bioactive phytochemicals. The antioxidant ability of C. macrophylla was studied by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and 1,1 diphenyl-2-picryl-hydrazyl (DPPH) methods. The crude and subsequent fractions of the C. macrophylla were also tested against anti-inflammatory enzymes using COX-2 (Cyclooxygenase-2) and 5-LOX (5-lipoxygenase) assays. The molecular docking was carried out using molecular operating environment (MOE) software. The GC-MS study of C. macrophylla confirmed forty-eight compounds in ethyl acetate (Et.AC) fraction and revealed that the Et.AC fraction was the most active fraction. The antioxidant ability of the Et.AC fraction showed an IC₅₀ values of 09.54 μg/mL and 7.8 μg/mL against ABTS and DPPH assay respectively. Among all the fractions of C. macrophylla, Et.AC showed excellent activity against COX-2 and 5-LOX enzyme. The observed IC₅₀ values were 93.35 μg/mL against COX-2 and 75.64 μg/mL for 5-LOX respectively. Molecular docking studies supported these in vitro results and confirmed the anti-inflammatory potential of C. macrophylla. C. macrophylla has promising potential as a source for the development of new drugs against inflammation in the future.

Chemical composition, antioxidant and antibacterial activity of Adiantum capillus-veneris L. extract from Algeria

The present study evaluates the antioxidant and antibacterial activities as well as the chemical composition of the aerial part of Adiantum capillus-veneris L., which are endemic to the flora of Algeria. The total phenolic amount of the hydromethanolic extract, as measured by the Folin-Ciocalteu reagent procedure, was found to be about 23.44 ± 0.14 mg GAE/g DW, while the flavonoid content value was 4.66 ± 0.01 mg CE/g DW, as measured by aluminum chloride colorimetric method. The antioxidant power of the extract was analyzed using the DPPH method. DPPH radicals were scavenged with an IC50 value of 65.85 µg/mL. The antibacterial activity of hydromethanolic extract against five bacterial strains of Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 25853), Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae and Bacillus cereus (ATCC 10876) were carried out using the disc diffusion test and the microdilution method. Streptococcus pneumoniae is the most sensitive bacterium with inhibition zone of 9.0 ± 1.1 cm and MIC=10 mg/mL. Based on HPLC analysis, we find that quercetin 3-O-glucoside was the most abundant compound in the plant extract. This study demonstrates that Adiantum capillus-veneris could be a potential natural source of antibacterial and antioxidant compounds.

Rapid and Simultaneous Determination of Free Aromatic Carboxylic Acids and Phenols in Commercial Juices by GC-MS after Ethyl Chloroformate Derivatization

Natural phenol and phenolic acids are widely distributed in the plant kingdom and the major dietary sources include fruits and beverages derived therefrom. Over the past decades, these compounds have been widely investigated for their beneficial effects on human health and, at the same time, several analytical methods have been developed for their determination in these matrices. In the present paper, 19 different aromatic carboxylic acids and phenols were characterized by GC-MS using ethyl chloroformate as the derivatizing agent. This procedure occurs quickly at room temperature and takes place in aqueous media simultaneously with the extraction step in the presence of ethanol using pyridine as a catalyst. The analytical method herein developed and validated presents excellent linearity in a wide concentration range (25–3000 ng/mL), low LOQ (in the range 25–100 ng/mL) and LOD (in the range 12.5–50 ng/mL), and good accuracy and precision. As a proof of concept, ethyl chloroformate derivatization was successfully applied to the analysis of a selection of commercial fruit juices (berries, grape, apple, pomegranate) particularly rich in phenolic compounds. Some of these juices are made up of a single fruit, whereas others are blends of several fruits. Our results show that among the juices analyzed, those containing cranberry have a total concentration of the free aromatic carboxylic acids and phenols tested up to 15 times higher than other juices.

LC-MS Identification and Quantification of Phenolic Compounds in Solid Residues from the Essential Oil Industry

Plant solid residues obtained from the essential oil industry represent a rich source of phenolic compounds with bioactive properties to be used in the food and pharmaceutical industries. A selective and sensitive liquid chromatography-mass spectrometry (LC-MS) method was developed for the simultaneous determination of phenolic compounds in solid residues of the Lamiaceae family plants. A total of 48 compounds can be separated within 35 min by using the Poroshell-120 EC-C₁₈ column, and a gradient mobile phase of 0.1% formic acid and acetonitrile with flow rate of 0.5 mL/min; salicylic acid was used as internal standard. The calibration curves showed good linearity in the tested concentration range for each analyte (R² > 0.9921), while recoveries ranged from 70.1% to 115.0% with an intra-day and inter-day precision of less than 6.63% and 15.00%, respectively. Based on the retention behavior, as well as absorption and mass spectra, 17 phenolic acids, 19 flavonoids and 2 phenolic diterpenes were identified and quantified in the solid residues obtained by distillation of six aromatic plants: oregano, rosemary, sage, satureja, lemon balm, and spearmint. The method constitutes an accurate analytical and quality control tool for the simultaneous quantitation of phenolics present in solid waste residues from the essential oil industry.

A Validated Ultrasound-Assisted Extraction Coupled with SPE-HPLC-DAD for the Determination of Flavonoids in By-Products of Plant Origin: An Application Study for the Valorization of the Walnut Septum Membrane

Walnut byproducts have been shown to exert functional properties, but the literature on their bioactive content is still scarce. Among walnut byproducts, walnut septum is a dry ligneous diaphragm tissue that divides the two halves of the kernel, exhibiting nutritional and medicinal properties. These functional properties are owing to its flavonoid content, and in order to explore the flavonoid fraction, an ultrasound-assisted (UAE) protocol was combined with solid phase extraction (SPE) and coupled to high-performance liquid chromatography with diode array detection (HPLC-DAD) for the determination of flavonoids in Greek walnut septa membranes belonging to Chandler, Vina, and Franquette varieties. The proposed UAE-SPE-HPLC-DAD method was validated and the relative standard deviations (RSD%) of the within-day and between-day assays were lower than 6.2 and 8.5, respectively, showing good precision, and high accuracy ranging from 90.8 (apigenin) to 97.5% (catechin) for within-day assay, and from 88.5 (myricetin) to 96.2% (catechin) for between-day assay. Overall, seven flavonoids were determined (catechin, rutin, myricetin, luteolin, quercetin, apigenin, and kaempferol) suggesting that the walnut septum is a rich source of bioactive constituents. The quantification results were further processed using ANOVA analysis to examine if there are statistically significant differences between the concentration of each flavonoid and the variety of the walnut septum.

Separation and Determination of Chemopreventive Phytochemicals of Flavonoids from Brassicaceae Plants

The main aim of this study was to develop a method for the isolation and determination of polyphenols-in particular, flavonoids present in various morphological parts of plants belonging to the cabbage family (Brassicaceae). Therefore, a procedure consisting of maceration, acid hydrolysis and measurement of the total antioxidant capacity of plant extracts (using DPPH assay) was conducted. Qualitative analysis was performed employing thin-layer chromatography (TLC), which was presented to be a suitable methodology for the separation and determination of chemopreventive phytochemicals from plants belonging to the cabbage family. The study involved the analysis of 25 vegetal samples, including radish, broccoli, Brussels sprouts, kale, canola, kohlrabi, cabbage, Chinese cabbage, red cabbage, pak choi and cauliflower. In addition, selected flavonoids content in free form and bonded to glycosides was determined by using an RP-UHPLC-ESI-MS/MS method.

Study on the environmental fate of three insecticides in garlic by in vivo sampling rate calibrated-solid phase microextraction-gas chromatography-mass spectrometry

Traditional sample preparation methods for insecticide analysis are laborious and fatal to living organisms. In the work, an in vivo sampling rate calibrated-solid phase microextraction-gas chromatography-mass spectrometry method was established and successfully used for in vivo sampling and quantitative determination of three insecticides (hexachlorobenzene, fipronil and chlorfenapyr) by direct exposing micron-sized fiber in living garlic. Absorption, enrichment, migration and elimination behavior of insecticides in garlic were investigated. Bioaccumulative effects with obvious tissue differences were observed to all three insecticides, especially for chlorfenapyr. Bioconcentration factors (BCFs) ranging from 0.0342 to 1.0887 were obtained, and the closer to roots, the higher BCFs. The half-life of insecticides in garlic ranged from 0.43 to 0.96 d. In the first 24 h, 55.0% - 80.3% insecticides residues in garlic were eliminated with first-order elimination kinetics. The research provides in vivo insights into the environmental fates of insecticides in complex living system with minimized organism damage.

The Oleaster (Elaeagnus angustifolia): A Comprehensive Review on Its Composition, Ethnobotanical and Prebiotic Values>

BACKGROUND

Oleaster or Elaeagnus angustifolia is a deciduous plant from Elaegnacea family and is well-known for its remedial applications.

OBJECTIVE

This paper presents a comprehensive review of the potential application of Oleaster's flour incorporated in some food products. Emphasis is given to the physicochemical, biochemical, and functional properties of Oleaster's flour.

METHODS

A comprehensive search was carried out to find publications on Oleaster's flour and its application as a prebiotic. The results of the related studies were extracted and summarized in this paper.

RESULTS

Oleaster's flour as a prebiotic ingredient enhances antioxidants, polyphenols, fiber, flavonoids, Sterols, carbohydrates, and protein content of food products.

CONCLUSION

Further advanced investigations on Oleaster and its functional ingredients revealed that these are efficacious and can be applied as a substitute source in pharmacological industries for medical applications.

Green and cost-effective extraction techniques of quercetin from mixture of nutraceuticals with yield analysis via spectrophotometry and high performance liquid chromatograph methods

BACKGROUND

Extraction is the leading critical stage in the analysis of nutraceuticals. Ginkgo biloba (GB) has gained an interest because of its therapeutic usages.

OBJECTIVES

Development of four cost effective extraction techniques for extraction of quercetin from GB in mixture of nutraceuticals sachet. These techniques are solid phase extraction (SPE), liquid-liquid extraction (LLE), inverted dispersive liquid-liquid microextraction (IDLLME) and QuEChERS.

METHODS

Direct spectrophotometry was used to monitor the recovery of the standard quercetin throughout the optimization steps. HPLC-UV method of analysis was optimized to quantify the yields from the extracts present in the complicated sachets. The presented study was assessed by analytical eco-scale assessment (ESA) and National Environmental Method Index (NEMI) for greenness in comparison with literature.

RESULTS

Only SPE showed the best cleanup outcomes. ESA and NEMI showed an adequate greenness of proposed extraction protocol.

CONCLUSION

Quercetin (marker for GB) extraction from market nutraceutical sachets is considered an exemplary for analysis in quality control of nutraceuticals. Regarding the greenness results, the proposed method of extraction is grander even with adequate greenness as the extraction was one-step, in comparison with multi-steps in previously published protocols. Accordingly, it is recommended to be used in routine extraction and analysis of such kind of nutraceuticals.

HIGHLIGHTS

Four extraction protocols had been developed. For GB ternary sachets, proper recovery was obtained from C18 SPE. The assessment of greenness of the proposed protocol guaranteed the superiority of the presented study. Safer sorbents and chemicals favor to be used for routine extraction of nutraceuticals.

Advanced Analytical Approaches for the Analysis of Polyphenols in Plants Matrices—A Review

Phenolic compounds are plants’ bioactive metabolites that have been studied for their ability to confer extensive benefits to human health. As currently there is an increased interest in natural compounds identification and characterization, new analytical methods based on advanced technologies have been developed. This paper summarizes current advances in the state of the art for polyphenols identification and quantification. Analytical techniques ranging from high-pressure liquid chromatography to hyphenated spectrometric methods are discussed. The topic of high-resolution mass spectrometry, from targeted quantification to untargeted comprehensive chemical profiling, is particularly addressed. Structure elucidation is one of the important steps for natural products research. Mass spectral data handling approaches, including acquisition mode selection, accurate mass measurements, elemental composition, mass spectral library search algorithms and structure confirmation through mass fragmentation pathways, are discussed.

A Comprehensive Targeted Metabolomics Assay for Crop Plant Sample Analysis

Metabolomics plays an important role in various fields from health to agriculture. However, the comprehensive quantitative metabolomic analysis of plants and plant metabolites has not been widely performed. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based plant metabolomics offers the sensitivity and breadth of coverage for both phenotyping and disease diagnosis of plants. Here, we report a high-coverage and quantitative MS-based assay for plant metabolite analysis. The assay detects and quantifies 206 primary and secondary plant metabolites, including many key plant hormones. In total, it measures 28 amino acids and derivatives, 27 organic acids, 20 biogenic amines and derivatives, 40 acylcarnitines, 90 phospholipids and C-6 sugars. All the analysis methods in this assay are based on LC-MS/MS techniques using both positive and negative-mode multiple reaction monitoring (MRM). The recovery rates of spiked plant samples at three different concentration levels (low, medium and high) ranged from 80% to 120%, with satisfactory precision values of less than 20%. This targeted plant metabolomic assay has been successfully applied to the analysis of large numbers of pine and spruce needle samples, canola root samples, as well as cannabis samples. Moreover, the assay was specifically developed in a 96-well plate format, which enables automated, high-throughput sample analysis. This assay has already been used to analyze over 1500 crop plant samples in less than two months.

Polyphenol-rich extract and fractions of Terminalia phaeocarpa Eichler possess hypoglycemic effect, reduce the release of cytokines, and inhibit lipase, α-glucosidase, and α-amilase enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

species of Terminalia (Combretaceae) are used to treat diabetes and metabolic disorders in Asia, Africa, and America. Terminalia phaeocarpa Eichler is an endemic tree from Brazil, popularly known as capitão. This species is closely related to Terminalia argentea Mart., also vulgarly known as capitão, a native but not endemic tree. Due to their phenotype similarity, these species might eventually prove inseparable and they are indistinctly used by locals to treat diabetes, among other diseases. The potential antidiabetic effect of T. argentea has been previously reported, whereas the biological effects and chemical composition of T. phaeocarpa have never been addressed so far.

AIM OF THE STUDY

investigate the hypoglycaemic effect of an ethanol extract (EE) of T. phaeocarpa leaves and its ethyl acetate (FrEtOAc) and hydromethanolic (FrMEOH) fractions, in addition to their activity on the release of pro-inflammatory mediators and inhibition of lipase, α-amylase, and α-glucosidase enzymes. Additionally, it aimed to characterize the chemical composition of the extract and fractions, seeking to identify the compounds related to the biological activities.

MATERIALS AND METHODS

The effect on the release of TNF-α, IL-1β, and CCL-2 was evaluated in LPS-stimulated THP-1 cells (ATCC TIB-202). The inhibition of lipase, α-amylase, and α-glucosidase was tested in vitro, whereas the hypoglycemic effect was assayed in the oral starch tolerance test. The chemical composition was investigated by extensive UHPLC-DAD-ESI-MS/MS analyses.

RESULTS

The extract and derived fractions reduced TNF-α (EE pIC₅₀ = 4.58 ± 0.01; FrEtOAc pIC₅₀ = 4.69 ± 0.01; FrMeOH pIC₅₀ = 4.54 ± 0.02) and IL-1β (EE pIC₅₀ = 4.86 ± 0.02; FrEtOAc pIC₅₀ = 4.86 ± 0.02; FrMeOH pIC₅₀ = 4.75 ± 0.01) release by LPS-stimulated THP-1 cells in a concentration-dependent manner, whereas the inhibitory effect on CCL-2 release did not reach a clear linear relationship for the tested concentrations. The extract and fractions also inhibited in vitro the activity of lipase (EE pIC₅₀ = 3.97 ± 0.12; FrEtOAc pIC₅₀ = 3.87 ± 0.04; FrMeOH pIC₅₀ = 3.67 ± 0.14), α-amylase (EE pIC₅₀ = 4.46 ± 0.27; FrEtOAc pIC₅₀ = 5.47 ± 0.27; FrMeOH pIC₅₀ = 4.26 ± 0.22), and α-glucosidase (EE pIC₅₀ = 5.46 ± 0.05; FrEtOAc pIC₅₀ = 5.79 ± 0.11; FrMeOH pIC₅₀ = 5.74 ± 0.05). The pIC₅₀ values of the test samples were lower than those obtained with orlistat (7.59 ± 0.08) and acarbose (6.04 ± 0.37 and 7.63 ± 0.04) employed as the positive controls respectively in the lipase, α-amylase, and α-glucosidase assays. When assayed in the oral starch tolerance test, the extract and fractions also reduced animal glycaemia. UHPLC-DAD-ESI-MS/MS analyses of the extract and fractions led to the identification of 38 phenolic compounds, mainly phenolic acids, ellagitannins and flavonoids, among others, all of them first-time described for the species.

CONCLUSION

Based on our findings, T. phaeocarpa has hypoglycaemic activity and polyphenols are the probable bioactive compounds, which support the ethnomedical use of the species.

Optimization of Plant Extract Purification Procedure for Rapid Screening Analysis of Sixteen Phenolics by Liquid Chromatography

A solid-phase extraction (SPE) procedure was developed for simultaneous monitoring of sixteen different phenolics of various polarity, quantified by high-performance liquid chromatography (HPLC). The procedure allowed screening the accumulation of intermediates in different metabolic pathways that play a crucial role in plant physiology and/or are beneficial for human health. Metabolites mostly involved in phenylpropanoid, shikimate, and polyketide pathways comprise chlorogenic acid, gentisic acid, vanillic acid, caffeic acid, protocatechuic acid, ferulic acid, rutin, quercetin, epicatechin, gallic acid, sinapic acid, p-coumaric acid, o-coumaric acid, vanillin; two rarely quantified metabolites, 2,5-dimethoxybenzoic acid and 4-methoxycinnamic acid, were included as well. The procedure offered low cost, good overall efficiency, and applicability in laboratories with standard laboratory equipment. SPE recoveries were up to 99.8% at various concentration levels. The method allowed for routine analysis of compounds with a wide range of polarity within a single run, while its applicability was demonstrated for various model plant species (tobacco, wheat, and soybean), as well as different tissue types (shoots and roots).

Extraction and Analyses of Flavonoids and Phenolic Acids from Canadian Goldenrod and Giant Goldenrod

Invasive alien plant species Canadian goldenrod (Solidago canadensis L.) and giant goldenrod (Solidago gigantea Aiton) were investigated as a source of phytochemicals and yellow dyes. Flavonoids and phenolic acids were extracted from the inflorescence of Canadian goldenrod with thirteen extraction solvents ethanol, methanol, acetone, water, and mixtures of organic solvents (70%, 80%, and 90%) with water. High performance thin-layer chromatography (HPTLC) coupled to densitometry and high-performance liquid chromatography with photo-diode array detector (HPLC-PDA) were used for analyses of the obtained sample test solutions (STSs), which showed the best and comparable extraction efficiencies for 70% acetone(aq), 70% methanol(aq), and 70% ethanol(aq). HPTLC combined with image analyses in fluorescent mode resulted in different chromatographic fingerprints for Canadian goldenrod and giant goldenrod STSs (70% acetone(aq)) after development, after post-chromatographic derivatization with NP reagent and after use of PEG reagent. The developed HPLC methods enabled analyses of phenolic acids and flavonoids (aglycones and glycosylated) in STSs and hydrolyzed STSs form inflorescence of Canadian and giant goldenrod. Different contents of chlorogenic acid, rutin, hyperoside, isoquercetin, and quercetin were observed in STSs of both goldenrod species. The analyses of hydrolyzed STSs confirmed that glycosylated flavonoids in Canadian and giant goldenrod inflorescence are mainly glycosides of quercetin, kaempferol, and isorhamnetin. Additional analyses using HPTLC and HPLC coupled to tandem mass spectrometry (MS/MS; HPTLC-MS/MS and LC-MS/MS) enabled tentative identification of phenolic acids and flavonoids (10 with HPTLC-MS/MS and 15 with LC-MS/MS), from which several were identified in Canadian (4 with HPTLC-MS/MS and 8 with LC-MS/MS) and in giant (7 with HPTLC-MS/MS and 9 with LC-MS/MS) goldenrod for the first time.

Solidago virgaurea L.: A Review of Its Ethnomedicinal Uses, Phytochemistry, and Pharmacological Activities

Solidago virgaurea L. (European goldenrod, Woundwort), Asteraceae, is a familiar medicinal plant in Europe and other parts of the world, widely used and among the most researched species from its genus. The aerial parts of European goldenrod have long been used for urinary tract conditions and as an anti-inflammatory agent in the traditional medicine of different peoples. Its main chemical constituents are flavonoids (mainly derived from quercetin and kaempferol), C6-C1 and C6-C3 compounds, terpenes (mostly from the essential oil), and a large number of saponin molecules (mainly virgaureasaponins and solidagosaponins). Published research on its potential activities is critically reviewed here: antioxidant, anti-inflammatory, analgesic, spasmolitic, antihypertensive, diuretic, antibacterial, antifungal, antiparasite, cytotoxic and antitumor, antimutagenic, antiadipogenic, antidiabetic, cardioprotective, and antisenescence. The evidence concerning its potential benefits is mainly derived from non-clinical studies, some effects are rather modest, whereas others are more promising, but need more confirmation in both non-clinical models and clinical trials.

Determination of Quercetin and Flavonol Synthase in <i>Boesenbergia rotunda</i> Rhizome

BACKGROUND AND OBJECTIVE

Flavonols in plants are catalyzed by flavonol synthase (FLS) enzyme. FLS was reported expressed in flowers and fruits, i.e., Dianthus caryophyllus L. (Caryophyllaceae), Petunia hybrida Hort. (Solanaceae), Arabidopsis thaliana L. (Brassicaceae), Citrus unshiu Marc. (Rutaceae). However, none reported about FLS in medicinal plants, particularly those which possess anti-inflammatory activity. This study was aimed to extract and identify FLS in the rhizome of Boesenbergia rotunda (Zingiberaceae) and to determine quercetin in the ethanol extract of the rhizome.

MATERIALS AND METHODS

The protein extraction of the rhizome was carried out by employing Laing and Christeller's (2004) and Wang's (2014) methods. The extracted-proteins were separated by using SDS-PAGE, followed by the measurement of FLS intensity by using Gel Analyzer. The FLS-1 of recombinant A. thaliana was employed as the standard. The determination of quercetin in the rhizome was carried out using LC-MS.

RESULTS

The FLS occurred as a thick band at 38 kDa with intensity 116-158. The LC chromatogram of the extract indicated a small peak at 7.94 min similar to that of quercetin standard. The MS spectra at 7.94 min indicated that quercetin is present in the B. rotunda rhizome (m/z = 303.0549). The concentration of quercetin in the extract is 0.022% w/v.

CONCLUSION

The FLS, an enzyme which plays an important role in producing quercetin, was detected in B. rotunda rhizome planted in Indonesia. As a consequence, quercetin in a small amount, was also quantified in the rhizome of this plant. This report will add a scientific insight of B. rotunda for biological sciences.

Development of an analytical method for the quantitative determination of multi-class nutrients in different food matrices by solid-phase extraction and liquid chromatography-tandem mass spectrometry using design of experiments

A simple and rapid analytical method based on solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with the aid of design of experiments (DOE) approach was developed and validated for simultaneous determination of multi-class nutrients (water- and fat-soluble vitamins and flavonoids) in various food matrices (vegetables, fruits, and cereals). The factors affecting the SPE method were optimized using DOE tools. The separation was achieved in 13 min using the C18 column by gradient LC programme. The SPE-LC-MS/MS method was validated in terms of limit of detection (1.29-29.17 ng/g), linearity range (25-1000 ng/g), coefficient of determination (0.993-0.999) and recovery (72.53-104.24%) for multi-class nutrients in different food samples. Inter- and intra-day precision were evaluated and found to be within acceptable range. The developed method finds extensive application in the routine analysis of multi-class nutrients in various food matrices.

Carotenoid, Tocopherol, and Phenolic Compound Content and Composition in Cover Crops Used as Forage

Secondary compounds of grassland and forage plant species such as vitamins or phenolic compounds are involved in different health-promoting effects in animals. However, information on their concentration and composition in forage plant species remains scarce. The objective of this study was to characterize the composition of secondary compounds of seven grazed cover crop plant species harvested at two stages of growth. Carotenoids and tocopherols were characterized and quantified using ultraperformance liquid chromatography with a photodiode array, and soluble phenolic compounds were characterized using high-performance liquid chromatography with diode-array detection. All species were rich in carotenoids, especially at the vegetative stage, even if the concentrations varied between plant species. Variations in tocopherol concentrations and phenolic composition were more important between plant species than between stages within species. Among the plant species tested, sainfoin (Onobrychis viciifolia Scop) contained the most secondary metabolites.

Determination of Polyphenols Using Liquid Chromatography-Tandem Mass Spectrometry Technique (LC-MS/MS): A Review

In recent years, the consumption of polyphenols has been increasing, largely due to its beneficial effects on health. They are present in a wide variety of foods, but their extraction and characterization are complicated since they are mostly in complex matrices. For this reason, the use of selective, sensitive, and versatile analytical techniques such as liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) is necessary. In this review, the most relevant studies of the last years regarding the analysis of polyphenols in different matrices by comprehensive LC–MS/MS are discussed. Relevant steps such as extraction, sample purification, and chromatographic analysis methods are emphasized. In particular, the following methodological aspects are discussed: (a) the proper selection of the extraction technique, (b) the extraction and elution solvents, (c) the purification step, (d) the selection of both stationary and mobile phases for the chromatographic separation of compounds, and (e) the different conditions for mass spectrometry. Overall, this review presents the data from the most recent studies, in a comprehensive way, thus providing and simplifying the information of the great variety of works that exist in the literature on this wide topic.