UHPLC Method Research Articles

Application of the UHPLC method for separation and characterization of major photolytic degradation products of trazodone by LC-MS and NMR

This article is about the characterization of degradation products of trazodone which is used in the treatment of depression.

New Developed UHPLC Method for Selected Urine Metabolites

An ultra-high-performance chromatography for simultaneous separation and determination of the phenylalanine, tyrosine and their metabolites (vanillylmandelic acid, homovanillic acid, homogentisic acid), tryptophan and its metabolites (5-hydroxyindolacetic acid, kynurenic acid, indoxylsulphate, 3-indolacetic acid) was developed. The separation was carried out on Thermo Scientific AcclaimTM 120 C18 column with a mobile phase composed of methanol and water (containing 0.1% formic acid) in gradient mode at a flow rate of 0.6 mL/min. The limit of detection of 10-15 ng/mL and limit of quantitation of 29-45 ng/mL were determined. The method was evaluated in terms of recovery, precision, linearity, limit of detection, limit of quantification. The determined parameters are in the commonly acceptable ranges for that kind of analysis. The developed chromatographic method allows the rapid screening of urine metabolites, which can serve as potential markers of various tumor diseases as well as for the monitoring of treatment processes.

Ultra-high-performance liquid chromatography-based identification and quantification of thymoquinone in Nigella sativa extract from different geographical regions

Background: Thymoquinone (THQ) is a major bioactive constituent of traditional medicinal plant such as Black seed (Nigella sativa, Family: Ranunculaceae). Objective: The objective of this study was to identify and quantify THQ in Black seeds from different geographical regions and to develop a new ultra-high-performance liquid chromatography-photodiode array detector (UHPLC-PDA) method. Materials and Methods: Black seeds were collected in the end of autumn season. The mobile phase was used in this study [Acetonitrile (2 mM): Ammonium Formate at 50:50 proportions, with a flow rate of 0.200 mL min-1 and also with Isocratic elution on the Accucoro Vanguish C18 UHPLC column (1.5 μm; 100 × 2.1 mm)]. Results: Retention and total run times were 3.147 and 6.0 min, respectively, with injection volume of 5 μL at 254 nm. The method was validated for linearity (r2 ≥ 0.9987), accuracy (≥92.90%), and precision (coefficient of variance [CV] ≤2.54%) with a calibration curve range of 100.00–2000.00 ng/mL. THQ was degraded under ultra-violet-light, basic, acidic, and oxidation stress conditions during forced degradation studies. Our developed UHPLC method reported the degradation peaks of the final product of THQ. UHPLC-PDA analysis showed large variation (0.01%–3.03% w/w) of THQ in the samples of different regions in respect to their concentration and occurrence of metabolite. Conclusions: Turkey has the maximum quantity of THQ throughout the world. The authors suggested that Turkey is the best region for cultivating Black seed plant of superior variety. One more important study performed, i.e., the gas chromatography and mass spectrometry study, reported THQ (2.863%) to be the primary constituent in the extract of N. sativa. Abbreviations used: THQ: Thymoquinone; UHPLC-PDA: Ultra-high-performance liquid chromatography-photodiode array detector; ACN: Acetonitrile; UV: Ultraviolet; GC-MS: Gas chromatography and mass spectrometry; NSO: Nigella sativa extracted oil; TLC: Thin-layer chromatography; IR: Infrared spectroscopy; DSC: Differential scanning calorimetry; QC: Quality control; HQC: High-quality control; MQC: Middle-quality control' LQC: Low-quality control; LLOQQC: Lower limit of quality control; US-FDA: United States of Food and Drug Administration; PSS: Primary stock solution; SS: System suitability; LOD: Limit of detection; LOQ: Limit of quantification.

Analysis of nectar from low‐volume flowers: A comparison of collection methods for free amino acids

Floral nectar is a reward offered by flowering plants to visiting pollinators. Nectar chemistry is important for understanding plant nutrient allocation and plant–pollinator interactions. However, many plant species are difficult to sample as their flowers are small and produce low amounts of nectar.We compared the effects of different methods of nectar collection on the amino acid composition of flowers with low volumes of nectar. We used five methods to collect nectar from 60 (5 × 12) Calluna vulgaris flowers: microcapillary tubes, a low‐volume flower rinse (the micro‐rinse method, using 2 μl water), filter paper, a high‐volume flower rinse (2 ml water) and a flower wash (2 ml water). We analysed the samples for free amino acids using quantitative UHPLC methods .We found that the micro‐rinse method (rinsing the nectary with enough water to only cover the nectary) recovered amino acid proportions similar to raw nectar extracted using microcapillary tubes. The filter paper, 2 ml rinse and 2 ml wash methods measured significantly higher values of free amino acids and also altered the profile of amino acids. We discuss our concerns about the increased contamination risk of the filter paper and high‐volume rinse and wash samples from dried nectar across the floral tissue (nectar unavailable to floral visitors), pollen, vascular fluid and cellular fluid.Our study will enable researchers to make informed decisions about nectar collection methods depending on their intended chemical analysis. These methods of sampling will enable researchers to examine a larger array of plant species' flowers to include those with low volumes of nectar.

UHPLC method for multiproduct pharmaceutical analysis by Quality-by-Design

An innovative Analytical Quality-by-Design (AQbD) methodology was followed to develop a specific and robust UHPLC method for the simultaneous separation of 16 active pharmaceutical ingredients (APIs). In the context of pharmaceutical repositioning, these molecules have been selected as good candidates for buccal per mucous (BPM®) administration route. Given the structural and physico-chemical diversity of compounds, an innovative development strategy based on QbD was applied. The main advantage of QbD is to ensure the robustness of the method. During a first scouting phase, the C18 chromatographic column was selected. Throughout the study, acetonitrile and ethanol based-mobile phases were investigated and compared. Ethanol was chosen as an alternative to acetonitrile due to its green properties coming from its lower toxicity and sourcing from renewable sources. Screening designs were performed to identify critical process parameters (CPPs). In ethanol media, temperature turned out to be a critical factor on peak retention and separation. Response surface methodology was then carried out to optimize CPPs and define the experimental domain of the method where complete separation between all peaks was obtained. Because changes in the elution order of the compounds occurred when modifying the experimental conditions, time differences between peaks were chosen as critical quality attributes, and an original data treatment was developed. It consisted in a systematic modelling of the time intervals between all possible pairs of peaks over the whole 3D experimental domain. Finally, a desirability analysis based on the smallest predicted time interval between peaks enabled to find optimal conditions only with ethanol based-mobile phases. Optimal conditions using ethanol, a Xbridge BEH Shield RP18 column and a 500 mL starting isocratic step, were determined by maximizing the desirability value and corresponded to a gradient slope of 2.57 %/min, a pH of 4.85, and a temperature of 33.7°C. A baseline separation of the 16 APIs was achieved with resolutions superior to 2.4 and the robustness of the method was experimentally validated.

A high-throughput UHPLC method for the analysis of 5-nitroimidazole residues in milk based on salting-out assisted liquid-liquid extraction.

A novel salting-out assisted liquid-liquid extraction (SALLE) method has been developed for the extraction of eight 5-NDZ antibiotics from milk samples prior to their analysis by UHPLC. An exhaustive study of the parameters involved in the SALLE procedure has been carried out, optimizing the extraction solvent volume, the amount of the salt agent, and the centrifugation and vortex timing by an experimental design. After sample treatment, the obtained extract was reconstituted in the mobile phase (6:94 (v/v) acetonitrile/water containing 0.1% (v/v) of formic acid) and analyzed by the proposed UHPLC-UV method. Separation was accomplished in a C18 Zorbax Eclipse Plus (50mm×2.1mm, 1.8μm) column at 45°C within 8min. Gradient mode was considered using a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and acetonitrile containing 0.1% (v/v) formic acid at a flow rate of 0.45mL/min. Analytical signals were monitored at 320nm. Matrix-matched calibration curves showed satisfactory linearity (R2≥0.996). LODs, ranging from 2 to 4μg/L, were achieved and precision studies showed RSDs lower than 12.8% in terms of peak height. Additionally, recoveries higher than 62.8% were obtained for all studied compounds in milk samples.

Lipidomic analysis of biological samples: Comparison of liquid chromatography, supercritical fluid chromatography and direct infusion mass spectrometry methods

Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography – mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements.

AMINO ACID AND FATTY ACID COMPOSITION OF ETHIOPIAN TARO

The purpose of this study was designed to investigate the amino acid and fatty acid composition of taro leaf and corm samples. An UHPLC and GC-FID method was used for the determination of amino acids and fatty acid composition, respectively. Taro leaf was processed as a powder and pre-curd concentrates while the corm was pre-gelatinized with and without peel prior to the analysis. The amino acid and fatty acid composition (%) of the analyzed samples were quantified with their relative area comparing with respective standards. In the present study, the leaf and corm of taro contained the three essential amino acids leucine, lysine and methionine. For the study, the calculated amino acid values were low in corm samples, but amino acid composition was higher in the leaf samples. Concerning fatty acids, the dominant fatty acid in the leaf and corm was oleic acid (C18:1, n-9) which ranged from 140.697 ± 0.054 to 216.775 ± 0.043 and 101.932 ± 0.023 to 101.950 ± 0. 04 mg/100 g, respectively. In the study, the fatty acid compositions in leaf were higher than the corm. This means that taro leaf would be considered as a good source of essential amino acid and fatty acid than the corm. Finally, from the proportion (mg/100 g) of saturated, monounsaturated and polyunsaturated fatty acids, the unsaturated fatty acids were the predominant fatty acids observed. The presence of high levels of unsaturated fatty acids in the entire investigation of our study taro is nutritionally rich.

Ornamental Asteraceae Species as New Sources of Secondary Metabolites

Abstract: Objective: This paper presents the results regarding the morphological characters, the content in total phenols, the metabolites profile and the antioxidant activity of outdoor cultivated Rudbeckia hirta var. Goldilocks and Tagetes erecta plants. Material and Methods: The plant material was represented by flower buds and fully bloomed inflorescences taken from Rudbeckia hirta var. Goldilocks and Tagetes erecta. Morphological assessment was carried using microscopy, while chemical assessment used thin layer chromatography (TLC) and UHPLC methods. The total phenolic content was established with Folin- Ciocalteu method. The antioxidant activity was evaluated with DPPH radical scavenging tests. The secondary metabolites were evaluated in two different nutritional statuses. Results: The results indicated that the studied ornamental Asteraceae species represent rich sources of phenols. However, the fertilization lowers the plant’s biosynthetic capacity for polyphenols for both Rudbeckia and Tagetes flowers. Thus, by fertilizing, the flowers of Tagetes lose components such as polyphenolic acids, modifying their spectrum. Regarding the antioxidant activity, Tagetes erecta showed a promising activity against free radicals. Conclusion: The concentration of plant secondary metabolites was found to be influenced by the nutritional status. Both species represent a good source for secondary metabolites, but their biological potential remains to be established. Key words: Rudbeckia, Tagetes, Secondary metabolites, Ornamental plants, Antioxidant activity.

Development and Validation of HPLC-DAD and UHPLC-DAD Methods for the Simultaneous Determination of Guanylhydrazone Derivatives Employing a Factorial Design.

Guanylhydrazones are molecules with great pharmacological potential in various therapeutic areas, including antitumoral activity. Factorial design is an excellent tool in the optimization of a chromatographic method, because it is possible quickly change factors such as temperature, mobile phase composition, mobile phase pH, column length, among others to establish the optimal conditions of analysis. The aim of the present work was to develop and validate a HPLC and UHPLC methods for the simultaneous determination of guanylhydrazones with anticancer activity employing experimental design. Precise, exact, linear and robust HPLC and UHPLC methods were developed and validated for the simultaneous quantification of the guanylhydrazones LQM10, LQM14, and LQM17. The UHPLC method was more economic, with a four times less solvent consumption, and 20 times less injection volume, what allowed better column performance. Comparing the empirical approach employed in the HPLC method development to the DoE approach employed in the UHPLC method development, we can conclude that the factorial design made the method development faster, more practical and rational. This resulted in methods that can be employed in the analysis, evaluation and quality control of these new synthetic guanylhydrazones.

Stability-Indicating Reversed-Phase UHPLC Method Development and Characterization of Degradation Products of Almotriptan Maleate by LC-QTOF-MS/MS.

Almotriptan maleate (ALMT), a highly selective 5-hydroxy tryptamine 1B/1D (5-HT1B/1D) receptor agonist used in the treatment of migraine headache was subjected to various ICH (Q1A (R2)) specified guidelines. The drug underwent significant degradation under hydrolytic (acid, base and neutral), oxidative and photolytic stress conditions, while it was stable under thermal stress condition. A total of seven significant degradation products (DPs) were obtained. A simple, selective and reliable UPLC method has been developed for the separation of ALMT and its DPs using Acquity UPLC HSS Cyano (100 × 2.1 mm, 1.8 μm) column with mobile phase consisting of ammonium acetate (10 mM, pH 4.4) buffer and acetonitrile in gradient elution mode. Chromatographic analysis was performed at a flow rate of 0.3 mL/min using a PDA detector at a wavelength of 230 nm. All the DPs (DP-1 to DP-7) were characterized using UHPLC-ESI-QTOF based on mass fragmentation pattern and accurate m/z values. The developed UPLC method was validated in terms of specificity, linearity, precision and accuracy. The developed stability-indicating method helps in quantification of drug in the presence of DPs.

Comparison of high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and ultra-high performance liquid chromatography with evaporative light scattering (UHPLC-ELSD) for the analyses of fructooligosaccharides in onion (Allium cepa L.)

Fructooligosaccharides (FOS) in foods are controversially discussed due to their probiotic activity and their putative contribution to the irritable bowel syndrome (IBS). Besides their nutritional relevance, the genuine composition of carbohydrates in onions has high impact on non-enzymatic browning during thermal processing of onions. In the present study, a method based on high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was validated and compared to an ultra-high performance liquid chromatographic method using evaporative light scattering detection (UHPLC-ELSD) for analysing saccharide contents of various onion (Allium cepa L.) cultivars substantially differing in their FOS pattern. Analyte identity was confirmed by authentic standards and UHPLC-electrospray ionization-high resolution mass spectrometry (UHPLC-ESI-HRMS). A total of 41 saccharides was detected with both methods, including FOS with a DP of up to 20. Specific validation parameters obtained with authentic standards are presented for FOS with a DP of up to 9. Although run times were significantly shorter using the UHPLC method, baseline separation and analytical range of FOS with higher DP were clearly superior using HPAEC-PAD, reaching lower quantification limits (0.12–2.3mg/L) compared to UHPLC-ELSD (34–68mg/L). This work provides guidance for method selection when analysing FOS from plant samples.

Derivatives of the Lignan 7'-Hydroxymatairesinol with Antioxidant Properties and Enhanced Lipophilicity.

The lignan 7'-hydroxymatairesinol (1), extracted from the knotwoods of fir (Abies alba), spruce (Picea abies), and Douglas fir (Pseudotsuga menziesii), exhibited unexpected reactivity when esterification reactions were attempted on the hydroxy group at position C-7'. To circumvent the rapid intramolecular cyclization procedure, leading quantitatively to the lignan conidendrin (7), a simple strategy for 7'-esterification of 1 under mild conditions (three steps, up to 80% overall yield) was developed. Compared to hydroxymatairesinol (1) (log K'w = 1.49), the derivatives (2-5) had increased lipophilicity with log K'w > 3.1, as determined by a UHPLC method. Compounds 1-5 exhibited potent antioxidant properties in the same range as the standards ascorbic acid and α-tocopherol (IC50 = 20-25 μM) and higher than that of BHT using a DPPH radical-scavenging assay.

A UHPLC method for the rapid separation and quantification of anthocyanins in acai berry and dry blueberry extracts

The presented work describes the development and validation of a rapid UHPLC-UV method using a core-shell particle column with a pentafluorophenyl stationary phase for the separation and quantitative analysis of the six anthocyanins in acai berry and dry blueberry extracts. The anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutenoside, delphinidin-3-galactoside, delphinidin-3-glucoside, delphinidin-3-rutenoside, and peonidin-3-glucoside) were separated and analyzed in 5min. The chromatographic separation was performed on a Kinetex PFP (150×2.1mm) core-shell column with a particle size of 1.7μm at a temperature of 50°C. Acetonitrile was used as mobile phase B and 5% formic acid, filtrated through a 0.22μm filter, as mobile phase A. They were delivered at a flow rate of 0.55mLmin−1 according to the elution gradient program. The detection wavelength was set at 520nm. A solid-liquid extraction with a solution of methanol and a 5% water solution of formic acid (25+75v/v) using an ultrasonic bath was chosen for the preparation of the available commercial samples of food supplements with a content of acai berry extract and blueberry extract. Under optimal chromatographic conditions, the method was validated. Recoveries for all analyzed anthocyanins were 97.8–102.6% and the relative standard deviation ranged from 0.4% to 3.0% for within-day and from 0.6% to 3.1% for between-day repeatability. The limits of detection were in the range of 0.11–0.14μgmL−1.

Esterification of Ibuprofen in Soft Gelatin Capsules Formulations-Identification, Synthesis and Liquid Chromatography Separation of the Degradation Products.

Unknown impurities were identified in ibuprofen (IBU) soft gelatin capsules (SGCs) during long-term stability testing by a UHPLC method with UV detection and its chemical formula was determined using high resolution/accurate mass (HRAM) LC-MS. Reference standards of the impurities were subsequently synthesized, isolated by semi-preparative HPLC and characterized using HRAM LC-MS, NMR and IR. Two impurities were formed by esterification of IBU with polyethylene glycol (PEG), which is used as a fill of the SGCs, and were identified as IBU-PEG monoester and IBU-PEG diester. Two other degradants arised from reaction of IBU with sorbitol and sorbitan, which are components of the shell and serves as plasticizers. Thus, IBU sorbitol monoester (IBU-sorbitol) and IBU sorbitan monoester (IBU-sorbitan ester) were identified. An UHPLC method was further optimized in order to separate, selectively detect and quantify the degradation products in IBU SGCs.

Shear Dependent LC Purification of an Engineered DNA Nanoswitch and Implications for DNA Origami.

As DNA nanotechnology matures, there is increasing need for fast, reliable, and automated purification methods. Here, we develop UHPLC methods to purify self-assembled DNA nanoswitches, which are formed using DNA origami approaches and are designed to change conformations in response to a binding partner. We found that shear degradation hindered LC purification of the DNA nanoswitches, removing oligonucleotides from the scaffold strand and causing loss of function. However, proper choice of column, flow rate, and buffers enabled robust and automated purification of DNA nanoswitches without loss of function in under a half hour. Applying our approach to DNA origami structures, we found that ∼400 nm long nanotubes degraded under the gentlest flow conditions while ∼40 nm diameter nanospheres remained intact even under aggressive conditions. These examples show how fluid stresses can affect different DNA nanostructures during LC purification and suggest that shear forces may be relevant for some applications of DNA nanotechnology. Further development of this approach could lead to fast and automated purification of DNA nanostructures of various shapes and sizes, which would be an important advance for the field.

Novel Pure Component Contribution Algorithm (PCCA) and UHPLC Methods for Separation and Quantification of Amlodipine, Valsartan, and Hydrochlorothiazide in Ternary Mixture.

Two accurate and sensitive methods were developed and validated for the simultaneous determination of amlodipine (AML), valsartan (VAL), and hydrochlorothiazide (HCT) in their ternary mixture. The first method is a novel simple algorithm capable of extracting the contribution of each component from a mixture signal in which the components are partially or completely overlapped. It is based on the use of a coded function that eliminates the signal of interfering components using mean centering as a processing tool. Determination was performed at 237.6, 250.0, and 270.6 nm for AML, VAL, and HCT, respectively. Two fit values were developed and calculated for optimization of the method for each drug, one to test that the absorptivity values of the extracted spectra are within the confidence limits of the slope, and the other for correlation between the pure and extracted spectra. The fit values for AML, VAL, and HCT were α = 0.0449, 0.03981, and 0.07251, respectively, and r = 1 for each drug. The second method is an ultra-HPLC (UHPLC®) method in which separation of AML, VAL, and HCT was carried out on a UHPLC C18 column (100 × 2.1 mm, 2.2 μm) using a mobile phase of acetonitrile-methanol-phosphate buffer (pH 2.8; 25 + 50 + 25, v/v/v). The flow rate was 0.5 mL/min, and the detection was set at 255.0 nm. The proposed methods were successfully applied to the analysis of AML, VAL, and HCT in pharmaceutical formulations, without interference from the dosage-form additives. The results were statistically compared to a previously reported method, and no significant difference was found regarding accuracy or precision.

A UHPLC method for the rapid separation and quantification of phytosterols using tandem UV/Charged aerosol detection – A comparison of both detection techniques

The presented work describes the development and validation of a rapid UHPLC-UV/CAD method using a core–shell particle column for the separation and quantitative analysis of seven plant sterols and stanols. The phytosterols (ergosterol, brassicasterol, campesterol, fucosterol, stigmasterol, and β-sitosterol) and the phytostanol stigmastanol were separated and analyzed in 8.5min. The sample pre-treatment procedure was optimized to be less time-consuming than any other published method, especially due to no need of derivatization, evaporation and even reconstitution step. The chromatographic separation was performed on the Kinetex 1.7μ Phenyl-hexyl column (100×2.1mm) with a mobile phase acetonitrile/water according to the gradient program at a flow rate of 0.9mLmin−1 and a temperature of 60°C. A tandem connection of PDA and CAD (Corona Charged Aerosol Detector) was used and both detection techniques were compared. The method was validated using saponification as a first step in sample pre-treatment and an universal CAD as the detector. Recoveries for all analyzed compounds were between 95.4% and 103.4% and relative standard deviation ranged from 1.0% to 5.8% for within-day and from 1.4% to 6.7% for between-day repeatability. The limits of detection were in the range of 0.4–0.6μgmL−1 for standard solutions and 0.3–1.2μgmL−1 for phytosterols in real samples. Although several gradient programs and different stationary phases were tested, two compounds, campesterol and campestanol, were not separated. Their peak was quantified as a sum of both analytes.

Quantitation of capsaicinoids in different chilies from Austria by a novel UHPLC method

Besides sensorial assays for quantifying pungent components in chilies, nowadays mainly HPLC methods focus on the determination of individual capsaicinoids. Compared to HPLC, ultra-highperformance chromatography (UHPLC) enables shorter runtimes and enhanced resolution. Thus, the aim of this work was to establish a rapid UHPLC method for the determination of capsaicin and dihydrocapsaicin, the most powerful pungent capsaicinoids found in chili fruits. The developed UHPLC method features a significantly reduced separation time (1.7min) and high chromatographic resolution, hence presenting a feasible approach for high-throughput pungency profiling. Compared to UV, fluorescence detection showed superior sensitivity with a limit of quantification for capsaicin of 0.160μgg−1 and 0.175μgg−1 for dihydrocapsaicin and proving suitable for analysing even very low pungency chili products. Moreover, to investigate the massive variability between chilies, typical varieties that were grown in Austria were characterized for their intrinsic pungency, with total capsaicinoids amounts ranging from 213μgg−1 for Jalapeño to 28200μgg−1 dry weight for ‘Bhut Jolokia’. Moreover, analyses of different fruit compartments showed tremendous deviation between the pericarp and the placenta with seeds.

Chemical composition of edible aerial parts of meadow bistort (Persicaria bistorta (L.) Samp.).

Persicaria bistorta (syn. Polygonum bistorta) is a herbaceous plant native to Europe and Asia. The leaves, young shoots or aerial parts of bistort are one of the main ingredients in a savoury pudding common to parts of the North of England. The aim of the present study was to investigate the chemical composition of extracts from aerial parts of common bistort. The UHPLC method allowed the detection of thirty-five major and minor compounds in the analysed plant material. Major constituents were isolated and identified. Two new natural products were obtained namely quercetin and kaempferol 3-O-(5″-O-malonyl)-α-l-arabinofuranosides. The bioactivity assays showed that isolated malonylated flavonoids inhibit the production of reactive oxygen species (IC50 in the range 22.4-40.6μM) and myeloperoxidase release (IC50 in the range 22.2-32.2μM) from stimulated human neutrophils. Aerial parts of P. bistorta are a rich source of polyphenols and some of them have anti-inflammatory potential.