Development and validation of UHPLC–MS/MS method for determination of eight naturally occurring catechin derivatives in various tea samples and the role of matrix effects

Polyphenolic Characterization and Anti-Inflammatory Effect of In Vitro Digested Extracts of Echinacea purpurea L. Plant Parts in an Inflammatory Model of Human Colon Cells

Echinacea purpurea L. (EP) preparations are globally popular herbal supplements known for their medicinal benefits, including anti-inflammatory activities, partly related to their phenolic composition. However, regarding their use for the management of inflammation-related intestinal diseases, the knowledge about the fate of orally ingested constituents throughout the human gastrointestinal tract and the exposition of in vitro digested extracts in relevant inflammatory models are unknown. This study investigated for the first time the impact of in vitro gastrointestinal digestion (INFOGEST) on the phenolic composition and anti-inflammatory properties of EP extracts from flowers (EF), leaves (EL), and roots (ER) on IL-1β-treated human colon-derived CCD-18Co cells. Among the seven hydroxycinnamic acids identified using HPLC-UV-MS/MS, chicoric and caftaric acids showed the highest concentrations in EL, followed by EF and ER, and all extracts exerted significant reductions in IL-6, IL-8, and PGE2 levels. After digestion, despite reducing the bioaccessibility of their phenolics, the anti-inflammatory effects were preserved for digested EL and, to a lesser extent, for EF, but not for digested ER. The lower phenolic content in digested EF and ER could explain these findings. Overall, this study emphasizes the potential of EP in alleviating intestinal inflammatory conditions and related disorders.

Supercritical Fluid Extraction (SFE) of Polar Compounds from Camellia sinensis Leaves: Use of Ethanol/Water as a Green Polarity Modifier

The use of bioactive plant extracts in cosmetic products is a common practice. Most of these extracts are obtained by maceration in organic solvents, and depending on which solvents are used, the polarity and the structure of the target molecules will vary. Polyphenols are polar compounds that often display antioxidant and/or antibacterial activities. To extract them, ethanol/water mixtures are usually selected as green solvents. This solid-liquid extraction (assisted or not) requires the use of high volumes of solvents and many additional steps like mixing, agitation, filtration, and evaporation. Alternatively, supercritical carbon dioxide (SC-CO₂) offers many benefits for plant extraction: economical, non-toxic, and naturally concentrated extracts. However, its low polarity is not suitable to solubilize polar compounds. In this study, an experimental design was used to optimize supercritical fluid extraction (SFE) of caffeine and catechins from Camellia sinensis. Catechins are recognized for skin care use (antioxidant) and caffeine is also used for its skin care properties and to prevent excess storage of fat in cells. The temperature, modifier content, and water additive percentage were used as independent variables. The results showed that while the temperature was an insignificant parameter, a higher percentage of water (up to 20% in ethanol) and modifier favored the extraction of the polar target molecules. Additionally, the SFE results were compared with ultrasound-assisted extraction (UAE). Finally, a sequential selective extraction of caffeine from catechins is also presented.

Characterisation of catechins and their oxidised derivatives in Ceylon tea using multi-dimensional liquid chromatography and high-resolution mass spectrometry

Tea is a complex food matrix comprising of many structurally diverse compounds, of which catechins and their oxidised derivatives are of particular interest due to their nutritional functionality. However, these catechins and derivatives exist in various isomeric forms with few or no pure standards available, rendering their analysis challenging. A method combining multi-dimensional liquid chromatography (MDLC) and high-resolution mass spectrometry (HRMS) was developed for the characterisation of these compounds using Ceylon tea as a model. Based on a Plackett-Burman (PB) design, flow rate and initial methanol percentage were identified as the most significant factors (p < 0.05) affecting chromatogram coverage and resolution (Rs) for comprehensive two-dimensional LC (LCxLC) and heart-cutting two-dimensional LC (LC-LC) respectively. Central composite design (CCD) was then applied using these parameters for method optimisation and to identify second-order relationships between screened parameters. The optimised LCxLC (flow rate: 2.18 mL/min and initial methanol percentage: 28.0%) and LC-LC (flow rate: 0.86 mL/min and initial methanol percentage for different cuts: A- 10.0%; B- 15.8%; and C- 18.7%) methods were applied to the analysis of Ceylon tea samples from seven regions of Sri Lanka and demonstrated an improved separation of co-eluting isomeric compounds. Finally, with the mass spectral information from HRMS, a total of 31 compounds (eight monomers, 17 dimers, five trimers and one tetramer) were detected and putatively identified in Ceylon tea.

Supervised Statistical Learning Prediction of Soybean Varieties and Cultivation Sites Using Rapid UPLC-MS Separation, Method Validation, and Targeted Metabolomic Analysis of 31 Phenolic Compounds in the Leaves

Soybean (Glycine max; SB) leaf (SL) is an abundant non-conventional edible resource that possesses value-adding bioactive compounds. We predicted the attributes of SB based on the metabolomes of an SL using targeted metabolomics. The SB was planted in two cities, and SLs were regularly obtained from the SB plant. Nine flavonol glycosides were purified from SLs, and a validated simultaneous quantification method was used to establish rapid separation by ultrahigh-performance liquid chromatography-mass detection. Changes in 31 targeted compounds were monitored, and the compounds were discriminated by various supervised machine learning (ML) models. Isoflavones, quercetin derivatives, and flavonol derivatives were discriminators for cultivation days, varieties, and cultivation sites, respectively, using the combined criteria of supervised ML models. The neural model exhibited higher prediction power of the factors with high fitness and low misclassification rates while other models showed lower. We propose that a set of phytochemicals of SL is a useful predictor for discriminating characteristics of edible plants.

Accurate Determination, Matrix Effect Estimation, and Uncertainty Evaluation of Three Sulfonamides in Milk by Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the most commonly used method for sulfonamide determination. Its accuracy, however, can be affected by many factors. In this study, sulfadiazine (SDZ), sulfadimidine (SMZ), and sulfadimethoxine (SDM) in milk were selected to investigate an accurate determination method and the potential influencing factors in the use of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Milk samples were extracted by 25 mL perchloric acid solution (pH = 2) and cleaned up using HLB solid-phase extraction (SPE) cartridges. Four kinds of filters, including PTFE, GHP, nylon, and glass fiber, were compared, and PTFE was selected since it had the best recoveries of target sulfonamides (SAs). Three quantitative methods, including external standard (ES), matrix matching (MM), and isotope dilution mass spectrometry (IDMS), were compared, among which IDMS exhibited the best accuracy. The matrix effect under different mobile phase compositions and of different sample matrices were evaluated and discussed. Ion suppression effects were observed during the determination of all SAs, which got stronger with the increase of the methanol composition percent in the mobile phase. After correction by IDMS, the matrix effect could be neglected. Matrix spiked recoveries at three spiked levels (1 μg/kg, 10 μg/kg, and 20 μg/kg) ranged from 96.8% to 103.8% by IDMS. The expanded relative uncertainties were in the range of 2.02% to 5.75%. The method exhibited wide application range, high accuracy, good stability, and high sensitivity.

Rapid identification of chemical constituents of Rhodiola crenulata using liquid chromatography-mass spectrometry pseudotargeted analysis

Rhodiola crenulata (R. crenulata), is a famous traditional Chinese medicine, with observable effects such as anti-high-altitude illness and fatigue resistance. Nevertheless, comprehensive and systematic structural identification of its components remains a challenge. In this study, a pseudotargeted analytical method, involving key fragment filtering by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry and ultra-high performance liquid chromatography-linear ion trap-Orbitrap mass spectrometry, was developed for rapid detection and identification of the chemical constituents of R. crenulata. The process consists of three steps: (i) acquiring sufficient mass spectral data, (ii) constructing a key fragments schedule and discovering the substructures rapidly by pseudotargeted key fragment filtering, and (iii) further identification of the compound structures based on accurate masses, fragment ions, related literatures, and authentic standards. As a result, 104 compounds were identified and divided into five categories, among which three potentially new and 59 ones were reported for the first time in R. crenulata. These results indicated that the major types of components are flavanols and gallic acid derivatives, organic acids, alcohols and their glycosides, flavonoids and their glycosides. This study enhances the understanding of R. crenulata and provides a reference for rapid and comprehensive identification of constituents in other herbal medicines.

Cost-Effective Simultaneous Separation and Quantification of Phenolics in Green and Processed Tea Using HPLC–UV–ESI Single-Quadrupole MS Detector and Python Script

Phenolic composition of green tea (Camellia sinensis) varies according to manufacturing processes that result in deglycosylation of glycosylated phenolics and condensation, epimerization, and degalloylation of flavan-3-ols (catechins). Ambiguous phenolic assignments based on UV absorbance alone can occur when the chromatographic peaks overlapped slightly. We established an improved method using an HPLC–UV coupled with a single-quadrupole MS detector (MS1) that can reject false UV peaks after checking the preceding MS1 peaks. Adjusted UV data coded by the Python algorithm were deployed to compare tea phenolics. Performance validation of the MS1 and UV analysis methods for 19 phenolics revealed a sensitivity of 0.17 and 0.47 pmol/injection, limit of detection of 15 and 33 μg/L, limit of quantification of 50 and 110 μg/L, intra-day precision of 5% and 1% relative standard deviation, and trueness of 83–135% and 97–100%, respectively. Our results suggest that the HPLC–UV–MS1 method, which is a low operational cost method, potentially provides the precise phenolic composition of teas.

Chocolate as a food matrix reduces the bioavailability of galloylated catechins from green tea in healthy women

In this study, we evaluated the food matrix effects of chocolate on the absorption of green tea catechins (GTCs), (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), and (-)-epigallocatechin gallate (EGCg), in five healthy 22-year-old women. In the single-intake experiment, the plasma concentrations of ECg (P < 0.05, at 1.5 h) and EGCg (P < 0.05, at 6 h) but not those of EC and EGC were reduced by the chocolate matrix. Regardless of the chocolate matrix, ECg and EGCg were mainly present as their aglycones in the plasma, whereas EGC and EC were found mostly as conjugated metabolites. After daily intake of GTCs mixed with chocolate for 14 days followed by overnight fasting, ECg but not EGCg was detected in the plasma. To compare the plasma profiles of ECg and EGCg, a mixture containing approximately equal amounts of ECg and EGCg was administered to nine rats for 14 days. Following treatment and overnight food deprivation, the plasma content of ECg was higher than that of EGCg. After a single injection of the same mixture in seven rats, ECg levels were higher than those of EGCg, and a greater amount of conjugated metabolites of ECg than those of EGCg was detected in the plasma 10 h after administration. In conclusion, the chocolate matrix affects the plasma profiles of GTCs, particularly ECg. ECg appears to persist in the plasma for a longer period, regardless of the chocolate matrix.

Urolithins in Human Breast Milk after Walnut Intake and Kinetics of Gordonibacter Colonization in Newly Born: The Role of Mothers' Urolithin Metabotypes

The maternal-infant transmission of several urolithins through breast milk and the gut colonization of infants by the urolithin-producing bacterium Gordonibacter during their first year of life were explored. Two trials (proof-of-concept study: n = 11; validation study: n = 30) were conducted, where breastfeeding mothers consumed walnuts as a dietary source of urolithin precursors. An analytical method was developed and validated to characterize the urolithin profile in breast milk. Total urolithins ranged from 8.5 to 176.9 nM, while they were not detected in breast milk of three mothers. The mothers' urolithin metabotypes governed the urolithin profile in breast milk, which might have biological significance on infants. A specific quantitative polymerase chain reaction method allowed monitoring the gut colonization of infants by Gordonibacter during their first year of life, and neither breastfeeding nor vaginal delivery was essential for this. The pattern of Gordonibacter establishment in babies was conditioned by their mother's urolithin metabotype, probably because of mother-baby close contact.

A Chitosan-PLGA based catechin hydrate nanoparticles used in targeting of lungs and cancer treatment

OBJECTIVE

To prepare a novel Chitosan (CS)-coated-PLGA-NPs of catechin hydrate (CTH) and to improve lungs bioavailability via direct nose to lungs-delivery for the comparative assessment of a pulmokinetics study by the first-time UHPLC-MS/MS developed method in the treatment of lungs cancer via anticancer activities on H1299 lung cancer cells.

MATERIAL AND METHODS

PLGA-NPs was prepared by solvent evaporation (double emulsion) method followed by coated with chitosan (CS) and evaluated based on release and permeation of drug, a comparative pulmokinetics study with their anticancer activities on H1299 lung cancer cells.

RESULTS

The particle size, PDI and ZP of the optimized CAT-PLGA-NPs and CS-CAT-PLGA-NPs were determined 124.64 ± 12.09 nm and 150.81 ± 15.91 nm, 0.163 ± 0.03 and 0.306 ± 0.03, -3.94 ± 0.19 mV and 26.01 ± 1.19 mV respectively. Furthermore, higher entrapment efficiency was observed for CS-CAT PLGA NPs. The release pattern of the CS-CAT-PLGA NPs was found to favor the release of entrapped CAT within the cancer microenvironment. CS-CAT-PLGA-NPs exposed on H1299 cancer cells upto 24.0 h was found to be higher cytotoxic as compared to CAT-solution (CAT-S). CS-CAT-PLGA-NPs showed higher apoptosis of cancer cells after their exposure as compared to CAT-S. CS-CTH-PLGA-NPs showed tremendous mucoadhesive-nature as compared to CTH-S and CS-CTH-PLGA NPs by retention time (RT) of 0.589 min, and m/z of 289.21/109.21 for CTH alongwith RT of 0.613 min and m/z of 301.21/151.21 was found out for IS (internal standard), i.e. Quercetin). Likewise, for 1-1000 ng mL-1 (linear range) of % accuracy (92.01-99.31%) and %CV (inter & intra-day, i.e. 2.14-3.33%) was determined. The improved Cmax with AUC0-24 was observed extremely significant (p < 0.001) via i.n. as compared oral and i.v. in the wistar rat's lungs. The CS-approach was successfully designed and safely delivered CAT to the lungs without causing any risk.

CONCLUSION

CS-CTH-PLGA-NPs were showed a significant role (p < 0.001) for the enhancement of lungs-bioavailability and potentially promising approach to treat lung cancers. CS-CTH-PLGA-NPs did not cause any toxicity, it showed safety and have no obvious toxic-effects on the rat's lungs and does not produce any mortality followed by no abnormal findings in the treated-rats.

Quantification and Evaluations of Catechin Hydrate Polymeric Nanoparticles Used in Brain Targeting for the Treatment of Epilepsy

To formulate novel chitosan (CS)-coated-PLGA-nanoparticles (NPs) using a central composite design approach and use them in order to improve brain bioavailability for catechin hydrate (CH) through direct nose-to-central nervous system (CNS) delivery for the evaluation of a comparative biodistribution study of CH by the newly developed ultra high performance liquid chromatography mass spectroscopy and mass spectroscopy (UHPLC-MS/MS) method in the treatment of epilepsy. For PLGA-NPs' preparation, a double emulsion-solvent evaporation method was used, where a four-factor, three-level central composite design was used to obtain the best nanoformulation. For the optimization, four independent variables were chosen, that is, PLGA, polyvinyl alcohol (PVA), sonication time, and temperature. The optimized PLGA-NPs were further coated with chitosan and assessed for drug release, nasal permeation study, as well as a comparative pharmacokinetic and pharmacodynamic study. Independent and dependent variables helped to optimize the best nanoformulation based on the composition of PLGA (50.0 mg), PVA (1.10%), sonication time (90.0 s), and temperature (25.0 °C). The values of dependent variables were observed, such as polydispersity index (PDI), particle size, and zeta potential (ZP)-that is, 0.106 ± 0.01, 93.46 ± 3.94 nm, and -12.63 ± 0.08 mV, respectively. The ZPs of CS-coated PLGA-NPs were changed from negative to positive value with some alteration in the distribution of particle size. Excellent mucoadhesive-nature of CS-CH-PLGA-NPs as compared with CH-S and CH-PLGA-NPs was seen, with a retention time of 0.856 min and m/z of 289.23/245.20 for CH, together with a retention time of 1.04 min and m/z of 301.21/151.21 for Quercetin as an internal standard (IS). For a linear range (1-1000 ng mL^-1), % accuracy (93.07-99.41%) and inter- and intraday % precision (0.39-4.90%) were determined. The improved C_max with area under curve (AUC)_0-24 was found to be highly significant (p < 0.001) in Wistar rats' brain as compared with the i.n. and i.v. treated group based on the pharmacokinetics (PK) results. Furthermore, CS-CH-PLGA-NPs were found to be more significant (p < 0.001) for the treatment of seizure threshold rodent models, that is, increasing current electroshock and pentylenetetrazole-induced seizures. A significant role of CS-CH-PLGA-NPs was observed, that is, p < 0.001, for the enhancement of brain bioavailability and the treatment of epilepsy.

Rapid quantitative analysis of 18 chemical constituents in HuangQi JianZhong Tang based on UHPLC-MS

A rapid, highly sensitive, and specific analytical method using ultra-high-performance liquid chromatography-triple quadruple MS was developed to quantitatively measure 18 chemical constituents in Huangqi Jianzhong Tang (HQJZ), a famous traditional Chinese medicine formula. Chromatographic separation was performed on a Waters ACQUITY UPLC HSS T3 column (2.1 mm × 100 mm, 1.8 μm) with a gradient mobile phase (A: 0.1% aqueous formic acid and B: acetonitrile) at a flow rate of 0.25 mL/min. The chromatographic peaks of 18 components were identified by comparing with the reference compounds. Multiple reaction monitoring was employed for quantitative analysis of the components. Seven batches of HQJZ samples were analyzed with a good linear regression relationship (R² , .9978-.9993), precisions [relative standard deviation (RSD), 0.90%-3.60%], repeatability (RSD, 2.50%-4.00%), stability (RSD, 1.00%-4.00%), and recovery (96.10%-104.30%). Based on this established method, the present study offered a highly sensitive, specific, and rapid determination method for identification of 18 compounds, which greatly promoted the systemic quality control of HQJZ.

Chiral analysis of theanine and catechin in characterization of green tea by cyclodextrin-modified micellar electrokinetic chromatography and high performance liquid chromatography

Monomeric catechins are important compounds in green tea accounting for potential bioactivity against a wide range of diseases. Besides catechins, l-Theanine (γ-glutamylethylamide), a characteristic amino acid in tea leaves, has become a further focus of the phytochemical research for the reported beneficial effects mainly on cognitive performance, emotional state and sleep quality. In the present study has been developed a CD-MEKC method based on sodium dodecyl sulfate (SDS) and Heptakis (2,6-di-O-methyl)-β-cyclodextrin for the separation of six major green tea catechins and enantiomers of theanine. The latter, because of the poor detectability was derivatized prior analysis by o-phthaldialdehyde in the presence of N-acetyl-l-cysteine which, under mild conditions (neutral pH, in two minutes) allowed two diastereomers isoindole derivatives to be obtained. The derivatization reaction was directly carried out on tea infusion and derivatized samples were analysed by CD-MEKC involving 65 mM SDS and 28 mM cyclodextrin in acidic buffer (pH 2.5). The separation of six major green tea catechins including enantioresolution of (±)-Catechin and d/l-Theanine was obtained in about 5 min allowing d-Theanine to be quantified at least at 0.5% m/m level with respect to l-Theanine. Since (-)-Catechin and d-Theanine can be considered as non-native enantiomers (distomers), their presence in real samples provides an indication of tea leaves treatments (thermal treatment, fermentation, etc.) and could represent an opportunity for grading tea. The obtained results were confirmed by a RP-HPLC approach; even though the chromatography was developed in achiral conditions, the derivatization approach applied to theanine (diastereomers formation), allowed for d/l-Theanine chiral analysis.

Fast gradient HPLC/MS separation of phenolics in green tea to monitor their degradation

The degradation of catechins and other phenolics in green tea infusions were monitored using fast HPLC/MS separation. The final separation was performed within 2.5min using Ascentis Express C18 column (50mm×2.1mm i.d.) packed with 2μm porous shell particles. Degradation was studied in relation to the temperature of water (70, 80, 90°C) and the standing time of the infusion (up to 6h). Along with chromatographic separation, the antioxidant properties of the infusions were monitored using two spectrophotometric methods. During staying of green tea infusion, the degradation of some catechins probably to gallic acid was observed. Finally, the influence of tea bag storage on antioxidant properties of green tea was evaluated. Rapid degradation of antioxidants after 3weeks was observed. The principal component analysis, factor analysis and discriminant analysis were used for the statistical evaluation of obtained experimental data.

Development and validation of a selective and effective pressurized liquid extraction followed by liquid chromatography-mass spectrometry method for the determination of fructosazine analogues in the ammonia treated extract of Eugenia jambolana Lamarck seeds

This study describes a selective and effective pressurized liquid extraction (PLE) coupled with HPLC-DAD-ESI/MS method for the identification and quantification of three fructosazine analogues (FZAs), fructosazine, 2,6- and 2,5-deoxyfructosazine in Madeglucyl^® (MG) which is an ammonia treated extract of Eugenia jambolana Lamarck seeds, and is the world's first anti-diabetic phytodrug. FZAs were extracted from MG by PLE using methanol as extraction solvent. The PLE extract was then analyzed directly by HPLC-DAD-ESI/MS without cleanup step. Chromatographic separation of these highly related structures was achieved on a porous graphic carbon (PGC) column. The identification of the target FZAs was confirmed by the similar retention time, similar UV and MS spectra to the corresponding pure standards. The quantification was performed by using an electrospray positive ionization mass spectrometry in the selected ion monitoring (SIM) mode. The PLE procedure was optimized and overall method was validated in terms of sensitivity, linearity, selectivity and matrix effect, precision, accuracy and recovery, and stability of the target FZAs in the aqueous solution and in the PLE extracts solution of MG. The developed method was proved to be selective, sensitive, precise, accurate for the quantification of FZAs in MG.

Noni leaf and black tea enhance bone regeneration in estrogen-deficient rats

OBJECTIVE

Black tea and Nonileaf are among the dietary compounds that can benefit patients with bone resorption disorders. Their bone regeneration effects and their mechanisms were studied in estrogen-deficient rats.

METHODS

Noni leaves (three doses) and black tea water extracts were fed to ovariectomized rats for 4 mo, and their effects (analyzed via mechanical measurements, micro-computed tomography scan, and reverse transcriptase polymerase chain reaction mRNA) were compared with Remifemin (a commercial phytoestrogen product from black cohosh).

RESULTS

The water extracts (dose-dependently for noni leaves) increased bone regeneration biomarker (runt-related transcription factor 2, bone morphogenetic protein 2, osteoprotegerin, estrogen receptor 1 [ESR1], collagen type I alpha 1A) expressions and reduced the inflammatory biomarkers (interleukin-6, tumor necrosis factor-α, nuclear factor [NF]-κB, and receptor activator of NF-κB ligand) mRNA expressions/levels in the rats. The extracts also improved bone physical and mechanical properties. The extracts demonstrated bone regeneration through improving bone size and structure, bone mechanical properties (strength and flexibility), and bone mineralization and density.

CONCLUSIONS

The catechin-rich extract favored bone regeneration and suppressed bone resorption. The mechanisms involved enhancing osteoblast generation and survival, inhibiting osteoclast growth and activities, suppressing inflammation, improving bone collagen synthesis and upregulating ESR1 expression to augment phytoestrogenic effects. Estrogen deficiency bone loss and all extracts studied (best effect from Morinda leaf at 300 mg/kg body weight) mitigated the loss, indicating benefits for the aged and menopausal women.

Simultaneous determination of eight catechins and four theaflavins in green, black and oolong tea using new HPLC-MS-MS method

A simple, rapid and accurate analytical method was developed for the analysis of eight tea catechins and four theaflavins simultaneously in three types of tea (green, black and oolong tea), using ultra high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HPLC-MS-MS) in multiple-reaction monitoring (MRM) mode. This method using HPLC-MS-MS in positive mode was performed on a CAPCELL PAK C18 MGIII (2.0mm×100mm, 3μm) column (Shiseido) with the mobile phase consisting of 0.1% aqueous formic acid (A) and methanol (B) in gradient elution at a flow rate of 0.3mLmin^-1, and the column temperature set at 30°C. The optimized HPLC-MS-MS methodology is selective and specific, and was validated for eight catechins and four theaflavins widely reported in different teas. Satisfactory linearity was achieved in linear range (0.02-5μgmL^-1 for catechins and 0.02-20μgmL^-1 for theaflavins) and fine determination coefficient (r²>0.9935). The recoveries ranged from 65% to 115% with the RSD ranging from 2.4% to 6.7%. The methodology was used to evaluate the target polyphenols concentration in three types of tea samples.

Characterization of chemical constituents in Rhodiola Crenulate by high-performance liquid chromatography coupled with Fourier-transform ion cyclotron resonance mass spectrometer (HPLC-FT-ICR MS)

In this work, an approach using high-performance liquid chromatography coupled with diode-array detection and Fourier-transform ion cyclotron resonance mass spectrometer (HPLC-FT-ICR MS) for the identification and profiling of chemical constituents in Rhodiola crenulata was developed for the first time. The chromatographic separation was achieved on an Inertsil ODS-3 column (150 mm × 4.6 mm,3 µm) using a gradient elution program, and the detection was performed on a Bruker Solarix 7.0 T mass spectrometer equipped with electrospray ionization source in both positive and negative modes. Under the optimized conditions, a total of 48 chemical compounds, including 26 alcohols and their glycosides, 12 flavonoids and their glycosides, 5 flavanols and gallic acid derivatives, 4 organic acids and 1 cyanogenic glycoside were identified or tentatively characterized. The results indicated that the developed HPLC-FT-ICR MS method with ultra-high sensitivity and resolution is suitable for identifying and characterizing the chemical constituents in R. crenulata. And it provides a helpful chemical basis for further research on R. crenulata. Copyright © 2016 John Wiley & Sons, Ltd.

Experimental variability and data pre-processing as factors affecting the discrimination power of some chemometric approaches (PCA, CA and a new algorithm based on linear regression) applied to (+/-)ESI/MS and RPLC/UV data: Application on green tea extracts

The influence of the experimental variability (instrumental repeatability, instrumental intermediate precision and sample preparation variability) and data pre-processing (normalization, peak alignment, background subtraction) on the discrimination power of multivariate data analysis methods (Principal Component Analysis -PCA- and Cluster Analysis -CA-) as well as a new algorithm based on linear regression was studied. Data used in the study were obtained through positive or negative ion monitoring electrospray mass spectrometry (+/-ESI/MS) and reversed phase liquid chromatography/UV spectrometric detection (RPLC/UV) applied to green tea extracts. Extractions in ethanol and heated water infusion were used as sample preparation procedures. The multivariate methods were directly applied to mass spectra and chromatograms, involving strictly a holistic comparison of shapes, without assignment of any structural identity to compounds. An alternative data interpretation based on linear regression analysis mutually applied to data series is also discussed. Slopes, intercepts and correlation coefficients produced by the linear regression analysis applied on pairs of very large experimental data series successfully retain information resulting from high frequency instrumental acquisition rates, obviously better defining the profiles being compared. Consequently, each type of sample or comparison between samples produces in the Cartesian space an ellipsoidal volume defined by the normal variation intervals of the slope, intercept and correlation coefficient. Distances between volumes graphically illustrates (dis)similarities between compared data. The instrumental intermediate precision had the major effect on the discrimination power of the multivariate data analysis methods. Mass spectra produced through ionization from liquid state in atmospheric pressure conditions of bulk complex mixtures resulting from extracted materials of natural origins provided an excellent data basis for multivariate analysis methods, equivalent to data resulting from chromatographic separations. The alternative evaluation of very large data series based on linear regression analysis produced information equivalent to results obtained through application of PCA an CA.

The impact of green tea polyphenols on development and reproduction in Drosophila melanogaster

Although, green tea has numerous health benefits, adverse effects with excessive consumption have been reported. Using Drosophila melanogaster, a decrease in male fertility with green tea was evidenced. Here, the extent of green tea toxicity on development and reproduction was investigated. Drosophila melanogaster embryos and larvae were exposed to various doses of green tea polyphenols (GTP). Larvae exposed to 10 mg/mL GTP were slower to develop, emerged smaller, and exhibited a dramatic decline in the number of emerged offspring. GTP protected flies against desiccation but sensitized them to starvation and heat stress. Female offspring exhibited a decline in reproductive output and decreased survival while males were unaffected. GTP had a negative impact on reproductive organs in both males and females (e.g., atrophic testes in males, absence of mature eggs in females). Collectively, the data show that high doses of GTP adversely affect development and reproduction of Drosophila melanogaster.