This work aimed to unravel the retention mechanisms of 30 structurally different flavonoids separated on three chromatographic columns: conventional Kinetex C18 (K-C18), Kinetex F5 (K-F5), and ...IAM.PC.DD2. Interactions between analytes and chromatographic phases governing the retention were analyzed and mechanistically interpreted via quantum chemical descriptors as compared to the typical 'black box' approach. Statistically significant consensus genetic algorithm-partial least squares (GA-PLS) quantitative structure retention relationship (QSRR) models were built and comprehensively validated. Results showed that for the K-C18 column, hydrophobicity and solvent effects were dominating, whereas electrostatic interactions were less pronounced. Similarly, for the K-F5 column, hydrophobicity, dispersion effects, and electrostatic interactions were found to be governing the retention of flavonoids. Conversely, besides hydrophobic forces and dispersion effects, electrostatic interactions were found to be dominating the IAM.PC.DD2 retention mechanism. As such, the developed approach has a great potential for gaining insights into biological activity upon analysis of interactions between analytes and stationary phases imitating molecular targets, giving rise to an exceptional alternative to existing methods lacking exhaustive interpretations.
Carrot (
Daucus carota) shoots were enriched by selenium using foliar application. Solutions of sodium selenite or sodium selenate at 10 and 100
μg
Se
ml
−1, were sprayed on the carrot leaves and the ...selenium content and uptake rate of selenium were estimated by ICP–MS analysis. Anion and cation exchange HPLC were tailored to and applied for the separation of selenium species in proteolytic extracts of the biological tissues using detection by ICP–MS or ESI–MS/MS. Foliar application of solutions of selenite or selenate at 100
μg
Se
ml
−1 resulted in a selenium concentration of up to 2
μg
Se
g
−1 (dry mass) in the carrot root whereas the selenium concentration in the controls was below the limit of detection at 0.045
μg
Se
g
−1 (dry mass). Selenate-enriched carrot leaves accumulated as much as 80
μg
Se
g
−1 (dry mass), while the selenite-enriched leaves contained approximately 50
μg
Se
g
−1 (dry mass). The speciation analyses showed that inorganic selenium was present in both roots and leaves. The predominant metabolised organic forms of selenium in the roots were selenomethionine and γ-glutamyl-selenomethyl-selenocysteine, regardless of which of the inorganic species were used for foliar application. Only selenomethionine was detected in the carrot leaves. The identity of selenomethionine contained in carrot roots and leaves was successfully confirmed by HPLC–ESI–MS/MS.
•Metabolic profile of pomegranate flower in vivo was firstly investigated.•Mono-glucuronide metabolite of ellagitannin compound was firstly reported.•Phase II conjugate metabolites of ellagitannins ...after oral administration of pomegranate flowers were firstly reported.•The reason sometimes biological effects of screened compounds in vitro do not live up to in vivo study was explained.
Pomegranate flowers is an ancient medicine that has commonly been used to treat various diseases such as diabetes. However, no reports are available on the metabolic profile of pomegranate flowers in vivo. In the present study, with the aid of HPLC-Q-TOF-MS2, 67 compounds were identified in pomegranate flowers extract, including 18 ellagitannins, 14 gallic acid and galloyl derivatives, five anthocyanins and 18 flavonoids. Seven compounds were firstly identified. In vivo, 22 absorbed compounds and 35 metabolites were identified in rat biosamples (urine, feces, plasma and tissues) after orally administered with pomegranate flowers extract. This result showed that not all compounds abundant in pomegranate flowers extract could be absorbed well in plasma and tissues. This finding also suggested a potential correlation between study on metabolic profile of these compounds in vivo and study on strategy of screening bioactivity of the isolates with in vitro cell systems evaluation. Notably, mono-glucuronide conjugated metabolite of ellagitannin compound (corilagin) was firstly identified. In addition, this is first report to identify phase II conjugate metabolites of ellagitannins in vivo after oral administration of ellagitannins-rich extracts (or foods). Thus, characterizing its multiple constitution, absorption and metabolic fate of these compounds in vivo is helpful to better analyze the active components in pomegranate flowers.
Metabolic fingerprinting was applied to the classification of section Moutan of genus Paeonia. HPLC–DAD multivariate analyses exhibited a clear separation between the species and contributed to the ...clarification of the confusion and skepticism associated with the taxonomy of tree peonies. Display omitted
•Clear separation into four groups was obtained between tree peony species.•Good agreement was obtained with the two subsections Vaginatae and Delavayanae.•P. decomposita was found to be a transition species between the two subsections.•P. ostii and P. suffruticosa can be classified as one species (s.l.).•There is significant variation in the metabolic profiles of P. delavayi.
The section Moutan of the genus Paeonia consists of eight species that are confined to a small area in China. A wide range of metabolites, including monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids, steroids, paeonols, and phenols, have been found in the species belonging to section Moutan. However, although previous studies have analyzed the metabolites found in these species, the metabolic similarities that can be used for the chemotaxonomic distinction of section Moutan species are not yet clear. In this study, HPLC–DAD-based metabolic fingerprinting was applied to the classification of eight species: Paeoniasuffruticosa, Paeoniaqiui, Paeoniaostii, Paeoniarockii, Paeoniajishanensis, Paeoniadecomposita, Paeoniadelavayi, and Paeonialudlowii. In total, of the 47 peaks that exhibited an occurrence frequency of 75% in all 23 tree peony samples, 43 of these metabolites were identified according to their retention times and UV absorption spectra, together with combined HPLC–QTOF-MS. These data were compared with reference standard compounds. The 43 isolated compounds included 17 monoterpenoid glucosides, 11 galloyl glucoses, 5 flavonoids, 6 paeonols and 4 phenols. Principal component analysis (PCA), and hierarchical cluster analysis (HCA), showed a clear separation between the species based on metabolomics similarities and four groups were identified. The results exhibited good agreement with the classical classification based on the morphological characteristics and geographical distributions of the subsections Vaginatae F.C. Stern and Delavayanae F.C. Stern with the exception of P. decomposita, which was found to be a transition species between these two subsections. According to their metabolic fingerprinting characteristics, P. ostii and P. suffruticosa can be considered one species, and this result is consistent with the viewpoint of medicinal plant scientists but different from that of classical morphological processing. Significantly large variations were obtained in the metabolic profiles of P. delavayi, whereas no significant difference was found between P. delavayi and P. ludlowii. This indicates that these two species have a close genetic relationship. In conclusion, the combination of HPLC–DAD and multivariate analyses has great potential for guiding future chemotaxonomic studies to examine the potential pharmaceutical value of the effective constituents of tree peony species and appears to be able to clarify the confusion and skepticism associated with the reported morphology- and molecular phylogenetics-based taxonomy of tree peonies.
Spent coffee ground (SCG) is the remaining residue produced after extraction of coffee, and it is considered a source of unextracted bioactive compounds. For this, in the latest years, the attention ...has been focused to innovative reuses that can exploit the potentiality of SCG. Unfortunately, the content of bioactive compounds has not been thoroughly studied yet, and the major of publication has investigated the caffeine and chlorogenic acids levels, total polyphenol contents, and total flavonoid content. Hence, these approaches have determined only an estimation of flavonoids and polyphenols content and lack on single polyphenols investigation. Therefore, the objective of the current work was to provide a deep characterization of bioactive compounds in SCG. For this purpose, a new analytical method for the quantification of 30 molecules, including caffeine, chlorogenic acids, phenolic acids, flavonoids, and secoiridoids, has been developed using high‐performance liquid chromatography tandem mass spectrometry. Moreover, several extraction procedures, that is, liquid–solid extraction assisted and not by ultrasounds, testing diverse solvents, were evaluated. Liquid–solid extraction assisted by sonication, with water/ethanol (30/70, v/v), resulted the best in terms of total bioactive compounds, and, once validated, the new analytical method was applied to five different espresso SCG samples. Data showed that caffeine (means: 1193.886 ± 57.307 mg kg−1) and chlorogenic acids (means of total CQAs: 1705.656 ± 88.694 mg kg−1) were the most abundant compounds in all SCG samples followed by phenolic acids such as caffeic, ferulic, gallic, p‐coumaric, syringic, trans‐cinnamic, and vanillic acid. Moreover, some flavonoids, that is, rutin, cyanidin 3‐glucoside, and quercetin, occurred in almost all samples. This work provided a deepened characterization of bioactive compounds in SCG and can contribute to develop new strategies of reuses.
Introduction
Viticis Fructus is the dried ripe fruit of Vitex trifolia L. (VTF) or V. trifolia subsp. litoralis Steenis (VTLF). Different botanical sources of the same herbal medicines may have ...different clinical efficacies, but few studies have reported the comparative identification of VTF and VTLF.
Objectives
To establish a high‐performance liquid chromatography (HPLC) method for the simultaneous assay of 11 constituents in Viticis Fructus, to compare the chemical compositions of VTF and VTLF, and to identify chemical markers for the discrimination and quality evaluation of the two botanical origins of Viticis Fructus.
Methodology
An HPLC‐diode array detection (DAD)‐high‐resolution mass spectrometry (HRMS) method was developed for the simultaneous separation and quantification of 11 constituents in 21 batches of Viticis Fructus samples from different sources in China. Moreover, chemometrics were performed to compare and discriminate VTF and VTLF samples.
Results
The results from 11 batches of VTF and 10 batches of VTLF were compared for 11 components, of which 3,4‐dicaffeoylquinic acid and 3,5‐dicaffeoylquinic acid were identified and quantified in Viticis Fructus for the first time. The quantitative analysis showed significantly higher chlorogenic acid and casticin contents in VTLF than in VTF, and the chemometric analysis indicated that chlorogenic acid and casticin were responsible for the significant differences between VTF and VTLF; these two compounds might be used as chemical markers to distinguish the two original plant sources of Viticis Fructus.
Conclusions
The present work provides useful information for understanding the chemical differences between VTF and VTLF. This work also provides feasible methods for the quality evaluation and discrimination of herbal medicines originating from multiple botanical sources.
The present study provides useful information for understanding the chemical differences between two botanical origins of Viticis Fructus. The content of 11 components of Viticis Fructus was determined, of which 3,4‐dicaffeoylquinic acid and 3,5‐dicaffeoylquinic acid were identified and quantified in Viticis Fructus for the first time. The chemometric analysis indicated that chlorogenic acid and casticin were responsible for the significant differences between two botanical origins of Viticis Fructus.
•RP-HPLC–DAD detected various α-dicarbonyls in coffee, barley coffee and soy sauce.•Coffee, barley brew and soy sauce α-dicarbonyls were characterised by HPLC–ESI/MS2.•An RP-HPLC–DAD method was ...validated for each food matrix to quantify glyoxal, methylglyoxal and diacetyl.•Coffee, barley coffee and soy sauce were subjected to simulated in vitro digestion.•Digestion seemed to induce both increases and reductions in free α-dicarbonyls.
α-Dicarbonyl (α-DC) compounds were characterised in roasted (coffee, barley coffee) and in fermented (soy sauce) food matrices. Glyoxal (GO), methylglyoxal (MGO), diacetyl (DA) and 3-deoxyglucosone (3-DG) were found in all samples, and hydroxypyruvaldehyde and 5-hydroxypentane-2,3-dione in barley and soy. Cis and trans 3,4-dideoxyglucosone-3-ene (3,4-DGE) isomers and 4-glucosyl-5,6-dihydroxy-2-oxohexanal (4-G,3-DG) were found only in barley, and 3,4-DGE only in soy sauce with molasses. GO, MGO, and DA were quantified. Findings indicate that i) α-DC profiles depend on the food matrix and any technological treatments applied; ii) α-DC quantitation by HPLC requires matrix-specific, validated methods; iii) GO and MGO were the most abundant α-DCs; and iv) barley coffee was the matrix richest in α-DCs both qualitatively and quantitatively.
In vitro simulated digestion reduced (coffee) or strongly increased (barley, soy sauce) free α-DC content.
These findings suggest that α-DC bioavailability could actually depend not on food content but rather on reactions occurring during digestion.
The paper presents an independent application of two hyphenated techniques, wherein an identical chromatographic system i.e. high performance liquid chromatography (HPLC) was coupled to microwave ...induced plasma optical emission spectrometry (MIP OES) or inductively coupled plasma optical emission spectrometry (ICP OES). A cation–exchange column and a mobile phase based on pyridine–2,6–dicarboxylic acid (PDCA) were employed to separate Fe(II) and Fe(III) within 300 s. Additionally, two methods of sample preparation were employed. Optimization and validation of both methods were conducted parallel. The applicability was presented with different sample matrix types: post–glacial sediments, archaeological pottery, soils located in the proximity of industry wastes disposal site, river sediments and yerba mate (Ilex paraguariensis). Obtained results were compared in terms of the excitation source (microwave induced or inductively coupled) and supplied gas (nitrogen or argon). The research introduces HPLC–MIP OES for iron speciation analysis and its applicability were critically evaluated with HPLC–ICP OES.
Display omitted
•The optical emission detectors with different plasma sources has been applied for iron species determination.•The hyphenated techniques HPLC–MIP–OES and HPLC–ICP–OES has been optimized and validated.•The application of speciation analysis has been elaborated for different matrixes.
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