Simultaneous determination of 14 phenolic compounds in grape canes by HPLC-DAD-UV using wavelength switching detection

Phenolic profiles of Australian monofloral Eucalyptus, Corymbia, Macadamia and Lophostemon honeys via HPLC-DAD analysis

Australian honey samples from four botanical genera (Lophostemon, Eucalyptus, Macadamia and Corymbia) were investigated for their phenolic content. An improved phenolic extraction and high-performance liquid chromatography-diode array detection (HPLC-DAD) analysis method allowed for the rapid and reliable identification of phenolic compounds. A concentrated liquid-liquid extraction method with an acidified aqueous solution and acetonitrile was optimised to isolate phenolic compounds from the honey matrix. The concentrated extraction method improved sensitivity and permitted the identification of phenolics present at low concentrations (LOD: 0.012-0.25 mg/kg and LOQ: 0.040-2.99 mg/kg). The optimised HPLC-DAD chromatographic conditions gave stable retention times, improved peak separation and allowed for the inexpensive detection of each of the 109 phenolic compounds at their maximum absorbance wavelength. Out of the 109 phenolic compounds included in this study, 49 were identified in the Australian honeys tested. Furthermore, 25 of the 49 compounds were determined to be markers specific to honey floral origin.

Methyl salicylate induces endogenous jasmonic acid and salicylic acid in 'Nam Dok Mai' mango to maintain postharvest ripening and quality

Salicylic acid (SA) and jasmonic acid (JA) are indispensable phytohormones whose interaction influences the ripening process in plants. Methyl salicylate (MeSA) and methyl jasmonate (MeJA) have been utilized to elevate the endogenous levels of SA and JA in horticultural products after harvest. However, their ability to preserve mango is uncertain. Individually and combined effects of exogenous MeSA and MeJA on mango ripening quality were investigated. 'Nam Dok Mai' mangoes were fumigated with MeSA, MeJA, and MeSA plus MeJA (MeSAJA) prior to storage for 6 d at 25 °C and 80-85% relative humidity (RH). Fruit ripening attributes, respiration rate, ethylene (ET) production, total phenolics (TP), and malondialdehyde (MDA) were assessed. Endogenous SA and JA levels were measured, as were the activities of lipoxygenase (LOX) and phenylalanine ammonia-lyase (PAL), and the expression of related genes MiPAL, MiICS, and MiLOX. Individual application of MeSA or MeJA preserved the mango quality by reducing ET production, respiration rate, and MDA levels while raising TP shortly after treatment. The ripening quality mirrored the induced SA and JA levels and correlated with the high expression of biosynthetic-related genes (MiPAL, MiICS, and MiLOX). Individual treatments stimulated SA and JA biosynthesis, demonstrating that these phytohormones are functionally connected and interdependent. When combined, MeSAJA caused a tradeoff response and distinct phenotypic outcomes compared to the individual treatments. As a result, MeSA fumigation is a practical method for preserving mango quality after harvest.

Developing a rapid analytical method for simultaneous determination of apigenin and gallic acid: validation and application in a nanoliposomal formulation

OBJECTIVE

Apigenin and gallic acid are natural compounds that are useful as antioxidant, anti-inflammatory and anticancer agents, especially when used together in combination. Therefore, the development and validation of a simultaneous method of analysis for both compounds in pure form and when encapsulated in an advanced delivery system such as liposomes would be useful.

METHODS

Analysis was performed using C18 column under isocratic conditions. The mobile phase was acetonitrile: water containing 0.2% orthophosphoric acid at a ratio of 67:33, flow rate 1 ml/min, and detection wavelength 334 nm for apigenin and 271 nm for gallic acid.

RESULTS

The assay method was linear at the concentration range (5-600 µg/mL) with R2 of 1 for both drugs. The method was also shown to be precise and robust with RSD less than 2% with LOD (0.12, 0.1 µg/mL) and LOQ (4.14, 3.58 µg/mL) for apigenin and gallic acid respectively. The method was also applicable for the determination of the entrapment efficiency of both drugs when co-loaded in a nanoliposomal formulation.

CONCLUSION

The described HPLC method was shown to be suitable, sensitive, and reproducible for the simultaneous identification and quantification of apigenin and gallic acid. The analytical results were accurate and precise, with good recovery, low limit of detection, and the chromatographic assay was accomplished in less than 3 min, suggesting the suitability of the method for routine analysis of both drugs in pharmaceutical formulations.

Validation of an HPLC-DAD Method for Quercetin Quantification in Nanoparticles

The evaluation of the efficacy of incorporation of quercetin in nanoparticles is crucial, both for the development and quality control of pharmaceutical formulations. The validation of analytical methods for the precise quantification of quercetin is useful for the evaluation of various potential quercetin delivery systems and quercetin pharmacokinetics. This work aimed to validate a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for quercetin detection and quantification in nanoparticles. Different mobile phase conditions and detection wavelengths (254 and 368 nm) were tested, and the major validation parameters were assessed (precision, accuracy, linearity, sensitivity, stability, and selectivity). The best peak resolution was obtained when quercetin was analyzed at 368 nm with a mobile phase of 1.5% acetic acid and a water/acetonitrile/methanol ratio of 55:40:5. Under these conditions, quercetin also eluted rapidly (retention time of 3.6 min). The method proved to be linear (R2 > 0.995), specific, and repeatable (variation coefficient between 2.4% and 6.7%) and presented intermediate precision (variation coefficient between 7.2% and 9.4%). The accuracy of the analysis ranged between 88.6% and 110.7%, and detection and quantification limits were 0.046 and 0.14 µg/mL, respectively. Quercetin solutions were more stable when stored at 4 °C than at room temperature or -20 °C. This validated method satisfied more parameters of bias assessment than most recent methods for quercetin determination and presented itself as more sensitive and efficient than general spectrophotometric methods. The method was successfully used for the analysis of quercetin incorporation in nanoparticles and will be evaluated in the future for its adequacy for the determination of quercetin in more complex matrices.

Progressive Vertical and Horizontal Phytocompound Changes during Agarwood Formation in Aquilaria sinensis after Geotrichum candidum Injection

(1) Background: Agarwood is an aromatic resin produced by the host tree through an immunological response against biotic and abiotic stress. The aim was, first, to use the fungus Geotrichum candidum to stimulate compound changes in Aquilaria sinensis horizontally (color formation) and vertically (cutting layers) after injection with it. (2) Methods: Horizontal and vertical sections were collected and separated five months after injection with the fungal broth. Two grams of dry powder was mixed with 20 mL methanol for 3 h at room temperature, and the solution was vibrated in an ultrasonic cleaner bath at 40 °C for 1 h. After vacuum drying, a concentration of 10 mg/mL of the tested samples in methanol was prepared for reversed-phase high-performance liquid chromatography (RP-HPLC), gas chromatography/mass spectrometry (GC/MS), and thin-layer chromatography (TLC) analysis. (3) Results: The horizontal changes in the compounds and their concentrations were associated with color. Compared to the normal (N) group, G. candidum injection stimulated more compounds at RT 27-42 in the white (W) group, brown (BR) group, and black (B) group. Furthermore, a significant increase in fatty acids was observed in the W group, implying an early plant response after G. candidum injection. In the BR group, the compounds were more similar to commercial agarwood (Out group). In the B group, alkaloids were the main compounds. Vertical changes in the main compounds were not observed, although the compound level varied. A TLC analysis determined the main compounds in the BR group at 254 nm and in the B group at 365 nm. Higher fatty acid levels were found in L6 and L5 and were correlated with higher terpenoid and sesquiterpene levels, suggesting that these compounds were possibly the first stage of agarwood formation. A GC/MS analysis demonstrated that the main compound groups were almost identical to the BR parts. (4) Conclusions: The injection of G. candidum led A. sinensis to synthesize different phytochemicals horizontally, not vertically, in the BR group.

Assessment of Polyphenols Bioaccessibility, Stability, and Antioxidant Activity of White Mugwort (Artemisia lactiflora Wall.) during Static In Vitro Gastrointestinal Digestion

White mugwort (Artemisia lactiflora Wall.), a traditional Chinese medicine, has been widely consumed in different forms for health care purposes. In this study, the in vitro digestion model of INFOGEST was used to investigate the bioaccessibility, stability, and antioxidant activity of polyphenols from two different forms of white mugwort, including dried powder (P 50, 100, and 150 mg/mL) and fresh extract (FE 5, 15, and 30 mg/mL). During digestion, the bioaccessibility of TPC and antioxidant activity were influenced by the form and ingested concentration of white mugwort. The highest bioaccessibility of the total phenolic content (TPC) and relative antioxidant activity were found at the lowest P and FE concentrations, as calculated relative to the TPC and antioxidant activity of P-MetOH and FE-MetOH based on the dry weight of the sample. Post-digestion, in comparison to P, FE had higher bioaccessibility (FE = 287.7% and P = 130.7%), relative DPPH radical scavenging activity (FE = 104.2% and P = 47.3%), and relative FRAP (FE = 673.5% and P = 66.5%). Nine compounds, 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-di-caffeoylquinic acid, sinapolymalate, isovitexin, kaempferol, morin, rutin, and quercetin, identified in both samples were modified during digestion, yet still provided strong antioxidant activity. These findings suggest that white mugwort extract possesses a higher polyphenol bioaccessibility, showing great potential as a functional ingredient.

Antioxidant and In Vivo Hypoglycemic Activities of Ethanol Extract from the Leaves of Engelhardia roxburghiana Wall, a Comparative Study of the Extract and Astilbin

The leaves of Engelhardia roxburghiana Wall (LERW) has been used as sweet tea in China throughout history. In this study, the ethanol extract of LERW (E-LERW) was prepared and the compositions were identified by HPLC-MS/MS. It indicates that astilbin was the predominant component in E-LERW. In addition, E-LERW was abundant in polyphenols. Compared to astilbin, E-LERW presented much more powerful antioxidant activity. The E-LERW also had stronger affinity with α-glucosidase and exerted more vigorous inhibitory effect on the enzyme. Alloxan-induced diabetic mice had significantly elevated glucose and lipid levels. Treatment with E-LERW at the medium dose (M) of 300 mg/kg could reduce the levels of glucose, TG, TC, and LDL by 16.64%, 12.87%, 32.70%, and 22.99%, respectively. In addition, E-LERW (M) decreased food intake, water intake, and excretion by 27.29%, 36.15%, and 30.93%, respectively. Moreover, E-LERW (M) therapy increased the mouse weight and insulin secretion by 25.30% and 494.52%. With respect to the astilbin control, E-LERW was more efficient in reducing the food and drink consumption and protecting pancreatic islet and body organs from alloxan-induced damage. The study demonstrates that E-LERW may be a promising functional ingredient for the adjuvant therapy of diabetes.

Development of an LC/MS/MS Method for Simultaneous Detection of 11 Polyphenols in Rat Plasma and Its Pharmacokinetic Application after Oral Administration of Coreopsis tinctoria Extract

Eleven polyphenols, classified as flavonoid glycosides, flavonoid aglycones, and phenolic acids, are important bioactive components in the capitula of Coreopsis tinctoria (CCT). Nevertheless, their full pharmacokinetic profiles have not been demonstrated simultaneously. Therefore, a liquid chromatography - tandem mass spectrometry (LC/MS/MS) method was developed in the present work and used it to study the pharmacokinetics of these 11 compounds. We performed LC/MS/MS with a gradient mobile phase composed of water containing 0.1 % formic acid and acetonitrile containing 0.1 % formic acid on a Proshell 120 SB C18 column (2.1 mm×100 mm, 2.7 μm). We achieved a good chromatographic peak shape, resolution, and mass signal response, and multiple reaction monitoring facilitated the simultaneous detection of 11 analytes. In addition, we validated the selectivity, correlation coefficient, precision, extraction recovery, matrix effects, and stability of the LC/MS/MS method to be acceptable for 11 analytes in rat plasma. Subsequently, rats were orally administered with 50 % ethanol eluent of CCT (ECCT). Nine of 11 polyphenols were absorbed quickly (except for QCD and TCA), and their plasma levels peaked within 40 min. The exposure and C_max values of flavonoid glycosides and phenolic acids were lower than those of flavonoid aglycones. This is the first report to demonstrate the pharmacokinetics of 11 polyphenols in ECCT, which may play an important role in future studies of the bioactive components of ECCT and their bioactive mechanisms.

Identification of Novel Parishin Compounds from the Twig of Maclura tricuspidata and Comparative Analysis of Parishin Derivatives in Different Parts

Parishin compounds are rare polyphenolic glucosides mainly found in the rhizome of the traditional Chinese medicinal plant, Gastrodia elata. These constituents are reported to have several biological and pharmacological activities. In the present study, two novel parishin derivatives not previously reported as plant-based phytochemicals were identified from a twig of Maclura tricuspidata (MT) and two new compounds were elucidated as 1-(4-(β-d-glucopyranosyloxy)benzyl)-3-hydroxy-3-methylpentane-1,5-dioate (named macluraparishin E) and 1,3-bis(4-(β-d-glucopyranosyloxy)benzyl)-3-hydroxy-3-methylpentane- 1,5-dioate (macluraparishin C), based on the experimental data obtained by UV-Visible (UV-Vis) spectroscopy, high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) and nuclear magnetic resonance (NMR) spectroscopy. Additionally, gastrodin, parishin A and parishin B were positively identified by spectroscopic evidence and the comparison of HPLC retention time with the corresponding authentic standards. Gastrodin, parishin A and parishin B, macluraparishin E and macluraparishin C were found to be the most abundant constituents in the MT twig. The compositions and contents of these constituents were found to vary depending on the different parts of the MT plant. In particular, the contents of parishin A, parishin B, macluraparishin C and macluraparishin E were higher in the twig, bark and root than in the leaves, xylem and fruit.

Spatial Distribution of Polyphenolic Compounds in Corn Grains (Zea mays L. var. Pioneer) Studied by Laser Confocal Microscopy and High-Resolution Mass Spectrometry

Desirable changes in the biochemical composition of food plants is a key outcome of breeding strategies. The subsequent localization of nutritional phytochemicals in plant tissues gives important information regarding the extent of their synthesis across a tissue. We performed a detailed metabolomic analysis of phytochemical substances of grains from Zea mays L. (var. Pioneer) by tandem mass spectrometry and localization by confocal microscopy. We found that anthocyanins are located mainly in the aleurone layer of the grain. High-performance liquid chromatography in combination with ion trap tandem mass spectrometry revealed the presence of 56 compounds, including 30 polyphenols. This method allows for effective and rapid analysis of anthocyanins by plotting their distribution in seeds and grains of different plants. This approach will permit a more efficient screening of phenotypic varieties during food plant breeding.

Development, Validation, and Application of the UPLC-DAD Methodology for the Evaluation of the Qualitative and Quantitative Composition of Phenolic Compounds in the Fruit of American Cranberry (Vaccinium macrocarpon Aiton)

Phenolic compounds in the fruit of American cranberry (Vaccinium macrocarpon Aiton) determine the antioxidant, anti-inflammatory, anticancer, and other biological effects. The berries are used in the production of medicinal preparations and food supplements, which highlights the importance of qualitative and quantitative analysis of phenolic compounds in cranberry fruit raw material. The aim of our study was to develop and validate an efficient, cost-effective, reproducible, and fast UPLC-DAD methodology for the evaluation of the qualitative and quantitative composition of phenolic compounds in raw material and preparations of American cranberry fruit. During the development of the methodology, chlorogenic acid and the following flavonols were identified in cranberry fruit samples: myricetin-3-galactoside, quercetin-3-galactoside, quercetin-3-glucoside, quercetin-3-α-L-arabinopyranoside, quercetin-3-α-L-arabinofuranoside, quercetin-3-rhamnoside, myricetin, and quercetin. The developed and optimized UPLC-DAD methodology was validated according to the guidelines of the International Council for Harmonization (ICH), evaluating the following parameters: range, specificity, linearity (R² > 0.999), precision (%RSD < 2%), LOD (0.38–1.01 µg/mL), LOQ (0.54–3.06 µg/mL), and recovery (80–110%). The developed methodology was applied to evaluate the qualitative and quantitative composition of phenolic compounds in fruit samples of cranberry cultivars ‘Baifay’, ‘Bergman’, ‘Prolific’, and ‘Searles’, as well as ‘Bain-MC’ and ‘BL-12′ clones. In the tested samples, the majority (about 70%) of the identified flavonols were quercetin derivatives. The greatest amount of quercetin-3-galactoside (1035.35 ± 4.26 µg/g DW) was found in fruit samples of the ‘Searles’ cultivar, and the greatest amount of myricetin-3-galactoside (940.06 ± 24.91 µg/g DW) was detected in fruit samples of the ‘Woolman’ cultivar.

A Brief Review of Phenolic Compounds Identified from Plants: Their Extraction, Analysis, and Biological Activity

Phenolic compounds are the most abundant secondary metabolites in plants, showing a wide range of distinct biological activities, have received more and more attention in recent years. This review aims to gather and systematize available information on the phenolic compounds from plants by discussing different types of phenolic compounds, extraction, and analysis methods, with an emphasis on their potential biological activities. The research direction and problems that should be paid attention to in the future are also put forward to provide some references for the further study of phenolic compounds.

Discovery and Characterization of Phenolic Compounds in Bearberry (Arctostaphylos uva-ursi) Leaves Using Liquid Chromatography-Ion Mobility-High-Resolution Mass Spectrometry

The characterization and quantification of phenolic compounds in bearberry leaves were performed using hyphenated ion mobility spectroscopy (IMS) and a quadrupole time-of-flight mass spectrometer. A higher identification confidence level was obtained by comparing the measured collision cross section (^TWCCS_N2) with predicted values using a machine learning algorithm. A total of 88 compounds were identified, including 14 arbutin derivatives, 33 hydrolyzable tannins, 6 flavanols, 26 flavonols, 9 saccharide derivatives, and glycosidic compounds. Those most reliably reproduced in all samples were quantified against respective standards. Arbutin (47-107 mg/g), 1,2,3,4,6-pentagalloylglucose (6.6-12.9 mg/g), and quercetin 3-galactoside/quercetin 3-glucoside (2.7-5.7 mg/g) were the most abundant phenolic components in the leaves. Quinic acid and ellagic acid were also detected at relatively high concentrations. The antioxidant activity of the most abundant compounds was evaluated. A critical view of the advantages and limitations of traveling wave IMS and CCS for the discovery of natural products is given.

From Diospyros kaki L. (Persimmon) Phytochemical Profile and Health Impact to New Product Perspectives and Waste Valorization

Persimmon (Diospyros kaki L.) fruit's phytochemical profile includes carotenoids, proanthocyanidins, and gallic acid among other phenolic compounds and vitamins. A huge antioxidant potential is present given this richness in antioxidant compounds. These bioactive compounds impact on health benefits. The intersection of nutrition and sustainability, the key idea behind the EAT-Lancet Commission, which could improve human health and decrease the global impact of food-related health conditions such as cancer, heart disease, diabetes, and obesity, bring the discussion regarding persimmon beyond the health effects from its consumption, but also on the valorization of a very perishable food that spoils quickly. A broad option of edible products with better storage stability or solutions that apply persimmon and its byproducts in the reinvention of old products or even creating new products, or with new and better packaging for the preservation of food products with postharvest technologies to preserve and extend the shelf-life of persimmon food products. Facing a global food crisis and the climate emergency, new and better day-to-day solutions are needed right now. Therefore, the use of persimmon waste has also been discussed as a good solution to produce biofuel, eco-friendly alternative reductants for fabric dyes, green plant growth regulator, biodegradable and edible films for vegetable packaging, antimicrobial activity against foodborne methicillin-resistant Staphylococcus aureus found in retail pork, anti-Helicobacter pylori agents from pedicel extracts, and persimmon pectin-based emulsifiers to prevent lipid peroxidation, among other solutions presented in the revised literature. It has become clear that the uses for persimmon go far beyond the kitchen table and the health impact consumption demonstrated over the years. The desired sustainable transition is already in progress, however, mechanistic studies and clinical trials are essential and scaling-up is fundamental to the future.

The High Content of Quercetin and Catechin in Airen Grape Juice Supports Its Application in Functional Food Production

Ensuring healthy lives and well-being constitutes one of the Sustainable Development Goals of the UN 2030 agenda. Consequently, research into how natural products may promote health is essential for the new generation of nutraceuticals and functional foods that are in high demand today. Grape juice is a natural foodstuff composed of water, sugars, minerals, vitamins and a wide array of polyphenols. Polyphenols are bioactive compounds of great interest due to their antioxidant properties and benefits to health, supporting antimicrobial, anti-aging, and anticarcinogenic activity. The majority of grape juice produced in the world is used for the production of wine, although a small part is used in the food industry, mainly in baby food and sports drinks. The aim of this work is to determine the polyphenol content in the natural and concentrated juice of Airen grapes, the main white grape variety produced in Spain. For this, fresh juices from five grape varietals (Airen, Sauvignon Blanc, Gewürztraminer, Verdejo and Tempranillo) and concentrated Airen juice were analyzed and compared. Results showed similar contents of phenolic acids and stilbenes in all grape varietals studied, although the Airen variety demonstrated a higher concentration of two flavonoids: quercetin and catechin. It can be concluded that the grape juice concentration process negatively affects the stability of these compounds, causing a reduction in the polyphenol content that ranges between 54–71%, with the exception of quercetin and catechin.

Pulsed electric field assisted process for extraction of bioactive compounds from custard apple (Annona squamosa) leaves

Impact of pulsed electric field (PEF) assisted process on preparation of custard apple leaf extract (CALE) using ethanol (70%, v/v) was studied. Different electric field strengths (2-6 kV/cm), pulse numbers (100-300 pulses) with specific energies (45-142 kJ/kg) for 2.5 to 5 min were implemented. Cell disintegration index was higher in CALE when PEF 6 kV/cm, 300 pulses, 142 kJ/kg for 5 min was applied. Extraction yield was higher (+5.2%) than the untreated counterpart (13.28%). Chlorophyll A and B contents were negligible in PEF pre-treated CALE. PEF improved radical scavenging activities assessed by DPPH, ABTS radical scavening activities and FRAP. The antibacterial properties of CALE against Staphylococcus aureus and Escherichia coli were highest. Purpureacin 2 and rutin were abundant in PEF pre-treated CALE. Therefore PEF was the potential aid in augmenting extraction yield and bioactivities of the extract from custard apple leaves.

Two Origins, Two Functions: The Discovery of Distinct Secretory Ducts Formed during the Primary and Secondary Growth in Kielmeyera

Secretory ducts have been reported for more than 50 families of vascular plants among primary and secondary tissues. A priori, all ducts of a plant are of the same type, and only slight variations in the concentration of their compounds have been reported for few species. However, two types of secretion were observed in primary and secondary tissues of Kielmeyera appariciana, leading us to investigate the possible influence of duct origins on the structure and metabolism of this gland. Kielmeyera appariciana has primary ducts in the cortex and pith and secondary ducts in the phloem. Both ducts are composed of uniseriate epithelium surrounded by a sheath and a lumen formed by a schizogenous process. Despite their similar structure and formation, the primary ducts produce resin, while the secondary ducts produce gum. This is the first report of two types of ducts in the same plant. The distinct origin of the ducts might be related to the metabolic alteration, which likely led to suppression of the biosynthetic pathway of terpenoids and phenolics in the secondary ducts. The functional and evolutionary implications of this innovation are discussed in our study and may be related to the diversification of Kielmeyera and Calophyllaceae in tropical environments.

Nematicidal Effect of Shiitake (Lentinula edodes) Extracts Against Haemonchus contortus

During the previous decades, the indiscriminate use of anthelmintics for the control of gastrointestinal nematodes has generated anthelmintic resistance in different parts of the world. It is necessary to search for new sustainable control alternatives, such as the use of extracts from plants and edible mushrooms. Therefore, the aim of the present study was to evaluate the nematicidal activity of extracts and fractions of the edible mushroom Lentinula edodes against Haemonchus contortus eggs and infective larvae. The basidiomata of L. edodes ECS-401 were provided by the Tropical Fungi Laboratory of El Colegio de la Frontera Sur and were extracted with ethyl acetate, methanol, and water. Fractionation of the most active extract was carried out by open column chromatography. The bioassays were performed in 96-well microtiter plates using 100 eggs/larvae, a final volume of 100 μL, and different concentrations of extracts/fractions (n = 4). Bioassay readings were taken at 48 h for egg hatching inhibition (EHI) and at 24, 48 and 72 h for larval mortality (LM). The ethyl acetate extract exhibited the highest percentage of EHI (100%). For the LM bioassay, the aqueous extract was the most active (69%), but its fractions did not show larvicidal activity. The chemical profile of the aqueous extract was analyzed by high-performance liquid chromatography, which showed the presence of phenols, flavonoids, and terpenes. L. edodes extracts showed ovicidal and/or larvicidal activity.

Polyphenol Profiles of Just Pruned Grapevine Canes from Wild Vitis Accessions and Vitis vinifera Cultivars

Grapevine canes are an abundant byproduct of the wine industry. The stilbene contents of Vitis vinifera cultivars have been largely studied, but little is known about the stilbene contents of wild Vitis accessions. Moreover, there have only been few studies on the quantification of other phenolic compounds in just pruned grapevine canes. In our study, we investigated the polyphenol profile of 51 genotypes belonging to 15 Vitis spp. A total of 36 polyphenols (20 stilbenes, 6 flavanols, 7 flavonols, and 3 phenolic acids) were analyzed by high-performance liquid chromatography coupled with a triple quadrupole mass spectrometer. Our results suggest that some wild Vitis accessions could be of interest in terms of the concentration of bioactive polyphenols and that flavanols contribute significantly to the antioxidant activity of grapevine cane extracts. To the best of our knowledge, this is the most exhaustive study of the polyphenolic composition of grapevine canes of wild Vitis spp.

The acute diuretic effects with low-doses of natural prenylated xanthones in rats

The diuretic effect of 3-demethyl-2-geranyl-4-prenylbellidypholine xanthone (DGP) and 1,5,8-trihydroxy-4',5'-dimethyl-2H-pyrano(2,3:3,2)-4-(3-methylbut-2-enyl) xanthone (TDP), two natural prenylated xanthones, was investigated in female normotensive (NTR) and spontaneously hypertensive rats (SHR). The rats received a single treatment with DGP, TDP, hydrochlorothiazide (HCTZ), or vehicle (VEH) after an oral load of physiological saline. The effects of DGP and TDP in combination with diuretics of clinical use, as well as with L-NAME, atropine and indomethacin were also explored. The urinary parameters were measured at the end of the 8-h experiment. When orally given to rats, DGP was able to increase the urine volume, at doses of 0.03-0.3 mg/kg, associated with a K⁺-sparing effect. TDP, in turn, at doses of 0.03-0.3 mg/kg, induced diuresis and saluresis (i.e. augmented urinary levels of Na⁺ and Cl^-) in NTR, while decreased the urinary content of Ca²⁺ in both NTR and SHR. The combination with HCTZ, but not with furosemide or amiloride, significantly enhanced DGP and TDP induced diuresis, which was accompanied by an increase of the electrolytes content in the urine. Instead, amiloride in combination with DGP or TDP enhanced urinary Na⁺ and Cl^- and decreased K⁺ elimination. Furthermore, the effect of DGP and TDP were heightened after pretreatment with L-NAME. While atropine was able to prevent DGP-induced diuresis, the pretreatment with indomethacin precluded TDP-induced diuresis. Besides, TDP exerted protective effects against urinary calcium oxalate crystals formation. Taken together, our data revealed the diuretic effect of two xanthones in rats and their possible underlying mode of action.

Ethanolic guava leaf extracts with different chlorophyll removal processes: Anti-melanosis, antibacterial properties and the impact on qualities of Pacific white shrimp during refrigerated storage

Ethanolic guava leaf extract (EGLE) without chlorophyll removal (GLE-C) and those with chlorophyll removal using sedimentation process (GLE-S) or dechlorophyllization using chloroform (GLE-Ch) were prepared. Antibacterial and anti-melanosis properties of all extracts were examined. All extracts showed promising antibacterial properties, polyphenoloxidase inhibitory activity and copper chelating activity. These activities were highest in GLE-S (P < 0.05). Piceatannol 4'-galloylglucoside, epicatechin, 8-hydroxyluteolin 8-sulfate, quercetin 3-(2''-galloyl-alpha-l-arabinopyranoside), and aclurin 3-C-(6''-p-hydroxybenzoyl-glucoside) were dominant in GLE-S. When Pacific white shrimp were treated with GLE-S at different concentrations (0.5 and 1%), the quality changes were monitored compared to those treated with 1.25% sodium metabisulphite (SMS-1.25) and the control (without any treatment) during 12 days of storage at 4 °C. Changes in microbial and chemical qualities were lower in shrimps treated with GLE-S solution as compared to others. Therefore, melanosis and quality deterioration were effectively reduced by pretreating shrimps in GLE-S before refrigerated storage.

Chemical profiling of secondary metabolites from Himatanthus drasticus (Mart.) Plumel latex with inhibitory action against the enzymes α-amylase and α-glucosidase: In vitro and in silico assays

ETHNOPHARMACOLOGICAL RELEVANCE

Himatanthus drasticus is an important medicinal plant whose latex is traditionally used in Northeast Brazil to treat various diseases, including diabetes. The use of α-amylase and α-glucosidase inhibitors can be an effective strategy to modulate levels of postprandial hyperglycemia via control of starch metabolism.

AIMS OF THE STUDY

This study aimed to verify if H. drasticus latex has inhibitory activity against enzymes linked to type 2 diabetes, besides chemically characterizing the metabolites responsible for such activities. In addition, in silico analysis was performed to support the traditional claim of possible antidiabetic activity of this latex.

MATERIALS AND METHODS

Latex from H. drasticus stems was sequentially partitioned with n-hexane (FHDH), CHCl₃ (FHDC) and EtOH (FHDHA). Wash extraction of the FHDHA fraction was performed to obtain the other extract fractions. The FHDHA was submitted to chromatography in a SPE C₁₈ cartridge using gradient elution with MeOH/H₂O to produce five fractions: FHDHA1, FHDHA2, FHDHA3, FHDHA4 and FHDHA5. The FHDHA1 was subjected to semi-preparative reverse phase HPLC. Lineweaver-Burk plots were used to investigate the kinetic parameters of α-amylase and α-glucosidase inhibitory activity. The interactions between plumieride and porcine pancreatic α-amylase and α-glucosidase were analyzed through an in silico molecular docking study.

RESULTS

Phytochemical identification of compounds present in the FHDHA fraction of H. drasticus latex was possible by 1H, 13C NMR analysis and mass spectrometry, and the results were compared with the literature. The identified compounds were α-ethyl glucoside, protocatechuic acid, 3-O-caffeoylquinic acid, 15-demethylplumieride acid, 5-O-caffeoylquinic acid, caffeic acid, vanillic acid, plumieride, and catechin. The inhibition results of the fractions tested against α-amylase and α-glucosidase showed inhibitory activities dependent on the increase of fractions and compound concentrations. The IC₅₀ results obtained from FHDHA, FHDHA1 and plumieride fractions against α-amylase were 36.46, 72.61, 33.87 μg/mL respectively. The IC₅₀ of plumieride was the closest to that of acarbose (22.52 μg/mL), a result similar to that obtained for α-glucosidase. The type of inhibition was competitive for both enzymes.

CONCLUSIONS

There was strong inhibition of α-amylase and α-glucosidase by FHDHA, FHDHA1 and plumieride, suggesting that these enzymes slow glucose absorption.

The genus Tragopogon (Asteraceae): A review of its traditional uses, phytochemistry, and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Species of Tragopogon are used in traditional medicine, and consumed as vegetables across the world. In terms of the medicinal uses of Tragopogon, different species have found use in traditional medicine, including uses for wound-healing, treatment of gastrointestinal and hepatic complaints, cancer, kidney and liver dysfunction, inflamed skin and certain cutaneous diseases, as well as constipation, fatigue and anoxia.

AIM OF THE STUDY

The aim of this review is to highlight and critically summarize those species of the genus that have been studied as a source of interesting lead compounds, and their traditional uses and bioactivities.

MATERIALS AND METHODS

A comprehensive and systematic review of literature on traditional uses, phytochemicals and pharmacological properties of the genus Tragopogon was carried out. Information was retrieved from secondary databases such as Scopus, Chemical Abstracts Services (Scifinder), Pubmed, Google Scholar and ScienceDirect, in addition to primary sources including books, PhD and MSc dissertations, and official websites. Species names were validated using "The Plant List" (www.theplantlist.org).

RESULTS

The taxa of the genus Tragopogon are known for their local and traditional uses as medicine for treatment of various diseases, and have been consumed as vegetables and snacks for generations in Eurasia, the Mediterranean, Caucasus, Europe and North America. From the approximately 110 species of Tragopogon, only twelve species have been scientifically evaluated for their bioactivity and/or phytochemical composition. Tragopogon species are a rich source of phytochemical constituents and among those that have been identified are 19 flavonoids, 35 terpenoids, seven bibenzyl derivatives, five benzylphtalides, six stilbenes, nine dihydroisocoumarin derivatives, nine phenylmethane derivatives, three hydroxyphenylacetic acid derivatives, four phenylpropane derivatives, four esters of phenylpropanoic acids, a coumarin derivative, and a spermine derivative. Various extracts of the taxa, in addition to the isolated compounds, demonstrated pharmacological properties such as antitumor, antimicrobial, anti-inflammatory and enzyme inhibitory activities, in addition to hepatoprotective, antihyperlipidaemic and wound-healing properties.

CONCLUSION

This review highlights the traditional uses, phytochemistry and pharmacological properties of the few studied taxa of the genus Tragopogon. Some of the reviewed papers were not of an appropriate methodological standard. For instance, phytochemical profiles were not determined, and the fundamental requirements of the pharmacological properties were not defined such as including appropriate positive and negative controls, and calculating the MIC values. Furthermore, these studies did not provide an in depth evaluation of bioactivity of the extracts and the isolated compounds or in vivo experiments which could indicate therapeutic relevance. From a phytopharmacological point of view, this review recommends more high quality evidence-based research on Tragopogon species for further development of plant-derived remedies and compounds.

Simultaneous quantification of thirty polyphenols in blackthorn flowers and dry extracts prepared thereof: HPLC-PDA method development and validation for quality control

The paper presents development and validation of a RP-HPLC-PDA method for quantification of 30 phenolic constituents of the blackthorn (Prunus spinosa L.) flower, a traditional European herbal medicine with a unique and complex composition. The target analytes were selected from over 50 active compounds present in the investigated plant material, and their separation was optimized on a C18 Ascentis Express fused-core column (2.7 μm, 150 mm × 4.6 mm), in a step-by-step process, in terms of elution solvents, gradient profile, temperature, and flow rate. The final procedure was carried out with an acetonitrile-tetrahydrofuran gradient at a flow rate of 1.09 mL/min and column temperature of 28°C. Under those conditions, the matrix peaks were satisfactorily separated within 35 min. The validation showed good precision (RSD < 5 %), accuracy (93.5-102.1 %), linearity (r > 0.9998), and sensitivity (LODs 0.51-2.05 ng) of the method. The real sample analysis demonstrated its applicability for quantification of the phenolics both in commercial samples of P. spinosa flowers (different manufacturers and years of collection), as well as in the extracts (of different polarity) prepared thereof. Thus, the developed procedure proved to be a useful tool in quality control, and the optimization approach might serve as a practical guideline for LC-method development in complex matrices.

Phenolic Profile of Grape Canes: Novel Compounds Identified by LC-ESI-LTQ-Orbitrap-MS

Grape canes (Vitis vinifera L.) are a viticulture industry by-product with an important content of secondary metabolites, mainly polyphenols with a broad spectrum of demonstrated health benefits. Grape canes, therefore, have considerable economic potential as a source of high-value phytochemicals. In this work, liquid chromatography coupled with electrospray ionization hybrid linear trap quadrupole-Orbitrap mass spectrometry (LC-LTQ-Orbitrap) was used for the comprehensive identification of polyphenolic compounds in grape canes. Identification of polyphenols was performed by comparing their retention times, accurate mass measured, and mass fragmentation patterns with those of reference substances or available data in the literature. A total of 75 compounds were identified, including phenolic acids, flavanols, flavonols, flavanonols, flavanones, and stilbenoids. The most abundant polyphenols were proanthocyanidins and stilbenoids and their oligomers. Moreover, the high-resolution mass spectrometry analysis revealed the occurrence of 17 polyphenols never described before in grape canes, thereby providing a more complete polyphenolic profile of this potentially valuable by-product.

Nutrients, Bioactive Compounds and Bioactivity: The Health Benefits of Sweet Cherries (Prunus avium L.)

Background:

Sweet cherries are one of the most appreciated fruits worldwide as well as one of the great sources of several active substances, as phytochemical compounds (carotenoids, serotonin, melatonin and phenolic compounds) as well as in nutritive compounds (sugars and organic acids). Accumulating research demonstrate that their supplementation in our daily diet can contradict oxidative stress, mitigating or even attenuating chronic diseases, as cancerous processes, antiinflammatory- related disorders, diabetes, and neurological and cardiovascular pathologies. Therefore, the aims of this review are to present an overview on the effects of sweet cherries as health promotors, giving emphasis to the health benefits of their bioactive compounds, particularly their antimicrobial, antioxidant, antidiabetic, anticancer, anti-neurodegeneration, anti-inflammatory and cardiovascular effects.

Methods:

Research and online content about sweet cherry fruits is reviewed. The information available has been read several times to avoid inconsistencies. In addition, according what we read, original figures were done and added to facilitate understanding and to enrich the paper.

Results:

In this review, a total of 202 original reports were used. In respect to health benefits, it is possible to confirm by several studies that, in fact, the consumption of sweet cherries has positive impacts in human health, owing to their wealthy and vast constitution, particularly in phenolic compounds, vitamins and carotenoids whose health properties were already documented.

Conclusion:

The findings of this review support the evidence that sweet cherries can be applied in pharmaceutical and food formulations, since they are able to diminish free radical species and proinflammatory markers, preventing and/ or ameliorating oxidative-stress disorders.

Simultaneous Voltammetric Determination of Gallic and Protocatechuic Acids in Mango Juice Using a Reduced Graphene Oxide-Based Electrochemical Sensor

A simple and sensitive reduced graphene oxide-modified glassy carbon electrode-based electrochemical sensor was used for the concomitant determination of gallic acid (GA) and protocatechuic (PA) acid. The prepared sensor showed a significant enhancement in synergetic electro-catalytic performance towards GA and PA oxidation. A good resolution of the voltammetry peaks was obtained and a method of square wave voltammetry was developed for detection. The modified electrode was characterized by electrochemical techniques. The optimal experimental parameters were considered. GA and PA exhibited a linear increase in the peak currents with their concentrations in the range from 20 to 144 µmol·L−1 for GA and from 20 to 166 µmol·L−1 for PA, with limits of detection (S/N = 3) of 30.8 µmol·L−1 for GA and 10.2 µmol·L−1 for PA. The sensor applicability was simultaneously tested for the analytical determination of GA and PA in mango juice and exhibited a robust functionality.

Environmental plasticity of Pinot noir grapevine leaves: A trans-European study of morphological and biochemical changes along a 1,500-km latitudinal climatic gradient

A 2-year study explored metabolic and phenotypic plasticity of sun-acclimated Vitis vinifera cv. Pinot noir leaves collected from 12 locations across a 36.69-49.98°N latitudinal gradient. Leaf morphological and biochemical parameters were analysed in the context of meteorological parameters and the latitudinal gradient. We found that leaf fresh weight and area were negatively correlated with both global and ultraviolet (UV) radiation, cumulated global radiation being a stronger correlator. Cumulative UV radiation (sumUVR) was the strongest correlator with most leaf metabolites and pigments. Leaf UV-absorbing pigments, total antioxidant capacities, and phenolic compounds increased with increasing sumUVR, whereas total carotenoids and xanthophylls decreased. Despite of this reallocation of metabolic resources from carotenoids to phenolics, an increase in xanthophyll-cycle pigments (the sum of the amounts of three xanthophylls: violaxanthin, antheraxanthin, and zeaxanthin) with increasing sumUVR indicates active, dynamic protection for the photosynthetic apparatus. In addition, increased amounts of flavonoids (quercetin glycosides) and constitutive β-carotene and α-tocopherol pools provide antioxidant protection against reactive oxygen species. However, rather than a continuum of plant acclimation responses, principal component analysis indicates clusters of metabolic states across the explored 1,500-km-long latitudinal gradient. This study emphasizes the physiological component of plant responses to latitudinal gradients and reveals the physiological plasticity that may act to complement genetic adaptations.