Rapid screening and characterization of glucosinolates in 25 Brassicaceae tissues by UHPLC-Q-exactive orbitrap-MS

An efficient method for rapid screening of triterpenoid saponins in three Glycyrrhiza species using rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometry combined with mass defect filtering

Triterpenoid saponins, a major bioactive component of liquorice, possess high hydrophilicity and often co-occur with other impurities of similar polarity. Additionally, subtle structural differences of some triterpenoid saponins bring challenges to comprehensive characterisation. In this study, triterpenoid saponins of three Glycyrrhiza species were systematically analysed using rapid resolution liquid chromatography quadrupole time-of-flight mass spectrometry (RRLC-Q-TOF-MS) coupled with mass defect filtering (MDF). Firstly, comprehensive date acquisition was achieved using RRLC-Q-TOF-MS. Secondly, a polygonal MDF method was established by summarizing known and speculated substituents and modifications based on the core structure to rapidly screen potential triterpenoid saponins. Thirdly, based on the fragmentation patterns of reference compounds, an identification strategy for characterisation of triterpenoid saponins was proposed. The strategy divided triterpenoid saponins into three distinct classes. By this strategy, 98 triterpenoid saponins including 10 potential new ones were tentatively characterised. Finally, triterpenoid saponins of three Glycyrrhiza species were further analysed using principle component analysis (PCA) and orthogonality partial least squares discriminant analysis (OPLS-DA). Among these, 18 compounds with variable importance in projections (VIP) > 1.0 and P values < 0.05 were selected to distinguish three Glycyrrhiza species. Overall, our study provided a reference for quality control and rational use of the three species.

Heating conversion of indole-3-carbinol into N-substituted oligomers with anti-melanoma effect

Cruciferous vegetables (CVs) are globally consumed with some health benefits believed to arise from indole-3-carbinol (I3C), a labile phytochemical liberated from indole glucosinolates, but few reports describe the effect of cooking on I3C reactions. Here, we present heat-promoted direct conversions of I3C in broccoli florets into indole derivatives, which are unique in the N-indolylmethylation and -hydroxymethylation of indole nuclei by 3-methyleneindole and formaldehyde formed in situ from the I3C dehydration and the dimerization of I3C to 3,3'-diindolylmethane (DIM), respectively. Such N-substituted indoles were found in a range of 0.4-4.6 μg per gram of steamed broccoli florets, with a novel compound N-(indol-3-ylmethyl)-3,3'-diindolylmethane (DIM-1) bio-evaluated to inhibit A375 cells with an IC50 value of 1.87 μM. In aggregation, the investigation discloses the promoting effect of heating on the I3C transformation in CVs and identifies DIM-1 as an anti-cancer drug candidate, and thus updates the knowledge of I3C and bioactive derivatives thereof.

The "depict" strategy for discovering new compounds in complex matrices: Lycibarbarspermidines as a case

The comprehensive detection and identification of active ingredients in complex matrices is a crucial challenge. Liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) is the most prominent analytical platform for the exploration of novel active compounds from complex matrices. However, the LC-HRMS-based analysis workflow suffers from several bottleneck issues, such as trace content of target compounds, limited acquisition for fragment information, and uncertainty in interpreting relevant MS2 spectra. Lycibarbarspermidines are vital antioxidant active ingredients in Lycii Fructus, while the reported structures are merely focused on dicaffeoylspermidines due to their low content. To comprehensively detect the new structures of lycibarbarspermidine derivatives, a "depict" strategy was developed in this study. First, potential new lycibarbarspermidine derivatives were designed according to the biosynthetic pathway, and a comprehensive database was established, which enlarged the coverage of lycibarbarspermidine derivatives. Second, the polarity-oriented sample preparation of potential new compounds increased the concentration of the target compounds. Third, the construction of the molecular network based on the fragmentation pathway of lycibarbarspermidine derivatives broadened the comprehensiveness of identification. Finally, the weak response signals were captured by data-dependent scanning (DDA) followed by parallel reaction monitoring (PRM), and the efficiency of acquiring MS2 fragment ions of target compounds was significantly improved. Based on the integrated strategy above, 210 lycibarbarspermidine derivatives were detected and identified from Lycii Fructus, and in particular, 170 potential new compounds were structurally characterized. The integrated strategy improved the sensitivity of detection and the coverage of low-response components, and it is expected to be a promising pipeline for discovering new compounds.

Broccoli, Amaranth, and Red Beet Microgreen Juices: The Influence of Cold-Pressing on the Phytochemical Composition and the Antioxidant and Sensory Properties

The aim of this study was to analyze in detail the phytochemical composition of amaranth (AMJ), red beet (RBJ), and broccoli (BCJ) microgreens and cold-pressed juices and to evaluate the antioxidant and sensory properties of the juices. The results showed the presence of various phenolic compounds in all samples, namely betalains in amaranth and red beet microgreens, while glucosinolates were only detected in broccoli microgreens. Phenolic acids and derivatives dominated in amaranth and broccoli microgreens, while apigenin C-glycosides were most abundant in red beet microgreens. Cold-pressing of microgreens into juice significantly altered the profiles of bioactive compounds. Various isothiocyanates were detected in BCJ, while more phenolic acid aglycones and their derivatives with organic acids (quinic acid and malic acid) were identified in all juices. Microgreen juices exhibited good antioxidant properties, especially ABTS•+ scavenging activity and ferric reducing antioxidant power. Microgreen juices had mild acidity, low sugar content, and good sensory acceptability and quality with the typical flavors of the respective microgreen species. Cold-pressed microgreen juices from AMJ, RBJ, and BCJ represent a rich source of bioactive compounds and can be characterized as novel functional products.

Chemical profiling of Simiao pill and quantification of main effective constituents in it by ultra-high-performance liquid chromatography coupled with Q Exactive Orbitrap and triple quadrupole mass spectrometry

Simiao pill is one of the most commonly used prescriptions in traditional Chinese medicine for the treatment of hyperuricemia and gout. However, methods based on more accurate and comprehensive qualitative and quantitative analyses of the active ingredients are not yet perfect due to limited methodology. This not only hinders the elucidation of the pharmacological mechanism of Simiao pill, but also its comprehensive clinical development and utilization. In this study, we employed ultra-high-performance liquid chromatography-Q Exactive Orbitrap-mass spectrometry technology to perform rapid analysis and identification of the chemical constituents in Simiao pill. A total of 101 chemical components were identified, including 26 alkaloids, 15 terpenoids, 11 flavonoids, eight steroids, six fatty acids, five limonoids, four saponins, five phenylpropanoids, and 21 other compounds. In addition, we established a new method by high-throughput ultra-high-performance liquid chromatography-Q Exactive Orbitrap-mass spectrometry combined with ultra-high-performance liquid chromatography-triple quadrupole-tandem mass spectrometry technology for quantification of 14 main active ingredients, such as adenosine (1), phellodendrine (2), mangnoflorine (3), β-ecdysterone (4), 25R-inokosterone (5), 25S-inokosterone (6), jatrorrhizine (7), palmatine (8), chikusetsu saponin IVa (9), limonin (10), atractylenolide III (11), atractylenolide I (12), obacunone (13), and atractylenolide II (14) in Simiao pill. This work laid a foundation for further analysis and quality control of effective components in Simiao pill.

Phenylpropanoid-enriched broccoli seedling extract can reduce inflammatory markers and pain behavior

BACKGROUND

Pain is a worldwide problem requiring an effective, affordable, non-addictive therapy. Using the edible plant broccoli, a growth protocol was developed to induce a concentrated combinatorial of potential anti-inflammatories in seedlings.

METHODS

A growth method was utilized to produce a phenylpropanoid-rich broccoli sprout extract, referred to as Original Extract (OE). OE was concentrated and then resuspended for study of the effects on inflammation events. A rabbit disc model of inflammation and degeneration, and, a mouse model of pain behavior were used for in vivo and in vitro tests. To address aspects of mammalian metabolic processing, the OE was treated with the S9 liver microsome fraction derived from mouse, for use in a mouse in vivo study. Analytical chemistry was performed to identify major chemical species. Continuous variables were analyzed with a number of methods including ANOVA, and two-tailed t tests, as appropriate.

RESULTS

In a rabbit spine (disc) injury model, inflammatory markers were reduced, and levels of regenerative markers were increased as a result of OE treatment, both in vivo and in vitro. In a mouse pain behavioral model, after treatment with S9 liver microsome fraction, the resultant extract significantly reduced early and late pain behavior in response to a pain stimulus. The OE itself reduced pain behavior in the mouse pain model, but did not achieve the level of significance observed for S9-treated extract. Analytical chemistry undertaken on the extract constituents revealed identities of the chemical species in OE, and how S9 liver microsome fraction treatment altered species identities and proportions.

CONCLUSIONS

In vitro and in vivo results indicate that the OE, and S9-treated OE broccoli extracts are worthwhile materials to develop a non-opiate inflammation and pain-reducing treatment.

Dynamic profiling of intact glucosinolates in radish by combining UHPLC-HRMS/MS and UHPLC-QqQ-MS/MS

Glucosinolates (GSLs) and their degradation products in radish confer plant defense, promote human health, and generate pungent flavor. However, the intact GSLs in radish have not been investigated comprehensively yet. Here, an accurate qualitative and quantitative analyses of 15 intact GSLs from radish, including four major GSLs of glucoraphasatin (GRH), glucoerucin (GER), glucoraphenin (GRE), and 4-methoxyglucobrassicin (4MGBS), were conducted using UHPLC-HRMS/MS in combination with UHPLC-QqQ-MS/MS. Simultaneously, three isomers of hexyl GSL, 3-methylpentyl GSL, and 4-methylpentyl GSL were identified in radish. The highest content of GSLs was up to 232.46 μmol/g DW at the 42 DAG stage in the 'SQY' taproot, with an approximately 184.49-fold increase compared to the lowest content in another sample. That the GSLs content in the taproots of two radishes fluctuated in a similar pattern throughout the five vegetative growth stages according to the metabolic profiling, whereas the GSLs content in the '55' leaf steadily decreased over the same period. Additionally, the proposed biosynthetic pathways of radish-specific GSLs were elucidated in this study. Our findings will provide an abundance of qualitative and quantitative data on intact GSLs, as well as a method for detecting GSLs, thus providing direction for the scientific progress and practical utilization of GSLs in radish.

Screening and quantification of 146 veterinary drug residues in beef and chicken using QuEChERS combined with high performance liquid chromatography-quadrupole orbitrap mass spectrometry

This work aimed to develop an integrated high-throughput screening and quantification for multi-class veterinary drug residues by HPLC-Q-Orbitrap mass spectrometry. A qualitative screening mass database of 171 veterinary drugs was created using full scanning mode, which improved the screening accuracy and scope. Beef and chicken samples were chosen to validate the quantification method at three spiked concentration levels. The quantification method of 146 veterinary drug residues was developed. After enzymatic hydrolysis, beef and chicken samples were treated using optimized QuEChERS. The calibration curves showed good linearities with correlation coefficients of 0.9921-0.9994. The recovery rates were within 52.1-138.2 % with relative standard deviations 0.4-17.7 %. The limits of detection and limits of quantification were in the range of 0.15-3.03 μg/kg and 0.5-10 μg/kg, respectively. The proposed method was demonstrated to be reliable for the simultaneous analysis of multi-class veterinary drugs. It is of significance to expand the screening scope and quantitative analysis efficiency.

Identification of volatile and nonvolatile compounds in Citri Reticulatae Pericarpium Viride using GC-MS, UPLC-Q-Exactive Orbitrap-MS, and HPLC-PDA

Gas chromatograph-mass spectrometer (GC-MS), ultra-high-performance liquid chromatograph-Q-Exactive Orbitrap tandem mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS), and high-performance liquid chromatography-photodiode array detection (HPLC-PDA) were used to qualitatively and quantitatively analyze the chemical component of Citri Reticulatae Pericarpium Viride "Geqingpi" (GQP). First of all, the volatile components of GQP are identified by GC-MS. Totally 56 volatile components were determined, and γ-Terpinene (33.39%) and D-Limonene (22.95%) were the main terpenes. Secondly, UHPLC-Q-Exactive Orbitrap-MS was used for identifying nonvolatile compositions and 42 compositions were identified totally, including 23 flavonoids, nine organic acids, three coumarins, two alkaloids compounds, and five other compounds, among which nine of the determined constituents were detected for the first time in GQP. Thirdly, the content of seven main constituents in GQP was quantitatively analyzed via HPLC-PDA, which were synephrine, hesperidin, limonin, nobiletin, HMF, tangeretin, and 5-HPMF. Further investigation for quantitative analysis of seven bioactive compounds suggested that the concentration of hesperidin in GQP approximately was 16.0% (160.78 ± 0.95 mg·g^-1), which was far higher than the standard for identification and quality control of CRPV in Chinese Pharmacopoeia (2020 edition) that "the content of hesperidin shall not be less than 5.0%." The phytochemicals of GQP were elucidated in this study, which might be supporting information for identification between GQP and Citri Reticulatae Pericarpium Viride "Sihuaqingpi" (SHQP) and provided a scientific basis for the further active ingredient for pharmacological research and development prospects of GQP.

Cauliflower by-products as functional ingredient in bakery foods: Fortification of pizza with glucosinolates, carotenoids and phytosterols

Industrial cauliflower by-products still represent a no-value food waste, even though they are rich in bioactive compounds. With the aim of valorizing them, optimized special flours rich in glucobrassicin, lutein, β-carotene, and β-sitosterol obtained from leaves, orange and violet stalks were used at 10 and 30% w/w in the formulation of functional leavened bakery. For the first time, the effect of bioactive compounds enrichment in pizza products as well as the rheological properties were evaluated. As results, pizza making process affected the recovery of the bioactive compounds. The recovery of glucobrassicin and carotenoids in pizza depended on the aerial part of cauliflower. Pizza with violet stalks was the richest in glucobrassicin, providing 8.4 mg per portion (200 g). Pizza with leaves showed the highest carotenoid content with a 90% of recovery rate while pizza with orange stalks provided up to 5.8% of the phytosterols health claim requirement. All 10% enriched pizzas revealed viscoelastic and springiness properties similar to the control, contrary to 30% fortification level. Therefore, the use of 10% special flour in pizza should meet both technological industrial processing and consumer acceptance. Orange stalks are the most promising ingredients for high levels of fortification in pizzas.

Variation in glucosinolates and the formation of functional degradation products in two Brassica species during spontaneous fermentation

Vegetables from the Brassica species are excellent sources of glucosinolates (GLSs), the precursors of health-promoting isothiocyanates (ITCs). Fermentation enhances the biotransformation of GLSs into potential bioactive ITCs. To explore the biotransformation of GLSs during Brassica fermentation, the changes in GLSs during the fermentation of two Brassica species (i.e., cauliflower and broccoli); the formation of corresponding breakdown products; and the shifts in physicochemical parameters, bacterial communities, and myrosinase activities involved in GLSs degradation were systematically investigated. Nine aliphatic, three indolic, and two benzenic GLSs were identified in fermented cauliflower (FC) and fermented broccoli (FB). Aliphatic glucoiberin and glucoraphanin were the major forms of GLS in FC and FB, respectively; indolic glucobrassicin was also abundant in both FC and FB. The total GLS content decreased by 85.29% and 65.48% after 3 d of fermentation in FC and FB, respectively. After 2 d of fermentation, a significant increase in bioactive GLS degradation products (P < 0.05), including sulforaphane (SFN), iberin (IBN), 3,3-diindolylmethane (DIM), and ascorbigen (ARG), was observed in FC and FB compared to in fresh cauliflower and broccoli. Moreover, variations in pH value and titratable acidity in FC and FB correlated with Brassica fermentation and were accomplished by lactic acid bacteria, including Weissella, Lactobacillus-related genera, Leuconostoc, Lactococcus, and Streptococcus. These changes may enhance the biotransformation of GSLs to ITCs. Overall, our results indicate fermentation leads to the degradation of GLSs and the accumulation of functional degradation products in FC and FB.

All Ion Fragmentation Analysis Enhances the Untargeted Profiling of Glucosinolates in Brassica Microgreens by Liquid Chromatography and High-Resolution Mass Spectrometry

An analytical approach based on reversed-phase liquid chromatography coupled to electrospray ionization Fourier-transform mass spectrometry in negative ion mode (RPLC-ESI-(-)-FTMS) was developed for the untargeted characterization of glucosinolates (GSL) in the polar extracts of four Brassica microgreen crops, namely, garden cress, rapeseed, kale, and broccoli raab. Specifically, the all ion fragmentation (AIF) operation mode enabled by a quadrupole-Orbitrap mass spectrometer, i.e., the systematic fragmentation of all ions generated in the electrospray source, followed by the acquisition of an FTMS spectrum, was exploited. First, the best qualifying product ions for GSL were recognized from higher-energy collisional dissociation (HCD)-FTMS² spectra of representative standard GSL. Extracted ion chromatograms (EIC) were subsequently obtained for those ions from RPLC-ESI(-)-AIF-FTMS data referred to microgreen extracts, by plotting the intensity of their signals as a function of retention time. The alignment of peaks detected in the EIC traces was finally exploited for the recognition of peaks potentially related to GSL, with the EIC obtained for the sulfate radical anion [SO₄]^•- (exact m/z 95.9523) providing the highest selectivity. Each putative GSL was subsequently characterized by HCD-FTMS² analyses and by collisionally induced dissociation (CID) multistage MSⁿ (n = 2, 3) acquisitions based on a linear ion trap mass spectrometer. As a result, up to 27 different GSLs were identified in the four Brassica microgreens. The general method described in this work appears as a promising approach for the study of GSL, known and novel, in plant extracts.

Characterization of anti-proliferative and anti-oxidant effects of nano-sized vesicles from Brassica oleracea L. (Broccoli)

In this in vitro study, we test our hypothesis that Broccoli-derived vesicles (BDVs), combining the anti-oxidant properties of their components and the advantages of their structure, can influence the metabolic activity of different cancer cell lines. BDVs were isolated from homogenized fresh broccoli (Brassica oleracea L.) using a sucrose gradient ultracentrifugation method and were characterized in terms of physical properties, such as particle size, morphology, and surface charge by transmission electron microscopy (TEM) and laser doppler electrophoresis (LDE). Glucosinolates content was assessed by RPLC–ESI–MS analysis. Three different human cancer cell lines (colorectal adenocarcinoma Caco-2, lung adenocarcinoma NCI-H441 and neuroblastoma SHSY5Y) were evaluated for metabolic activity by the MTT assay, uptake by fluorescence and confocal microscopy, and anti-oxidant activity by a fluorimetric assay detecting intracellular reactive oxygen species (ROS). Three bands were obtained with average size measured by TEM based size distribution analysis of 52 nm (Band 1), 70 nm (Band 2), and 82 nm (Band 3). Glucobrassicin, glucoraphanin and neoglucobrassicin were found mostly concentrated in Band 1. BDVs affected the metabolic activity of different cancer cell lines in a dose dependent manner compared with untreated cells. Overall, Band 2 and 3 were more toxic than Band 1 irrespective of the cell lines. BDVs were taken up by cells in a dose- and time-dependent manner. Pre-incubation of cells with BDVs resulted in a significant decrease in ROS production in Caco-2 and NCI-H441 stimulated with hydrogen peroxide and SHSY5Y treated with 6-hydroxydopamine, with all three Bands. Our findings open to the possibility to find a novel “green” approach for cancer treatment, focused on using vesicles from broccoli, although a more in-depth characterization of bioactive molecules is warranted.

Glucosinolates as Markers of the Origin and Harvesting Period for Discrimination of Bee Pollen by UPLC-MS/MS

Bee pollen is currently one of the most commonly consumed food supplements, as it is considered to be a good source of bioactive substances and energy. It contains various health-promoting compounds, such as proteins, amino acids, lipids, as well as glucosinolates. In the present study, the glucosinolate content was determined, by means of ultra-performance liquid chromatography coupled to a quadrupole time-of-flight mass detector, in 72 bee pollen samples from four different apiaries in Guadalajara (Spain), harvested in three different periods. In addition, 11 commercial multifloral samples from different Spanish regions were also analyzed. The aim was to verify the suitability of these compounds as biomarkers of their geographical origin, and to test their potential for distinguishing the harvesting period. By means of a canonical discriminant analysis, it was possible to differentiate the apiary of origin of most of the samples, and these could also be clearly differentiated from the commercial ones, simply as a result of the glucosinolate content. In addition, it was also demonstrated for the first time that bee pollen samples were capable of being differentiated according to the time of harvesting and their glucosinolate content.

Genome-Wide Association Study of Phenylalanine Derived Glucosinolates in Brassica rapa

Glucosinolates (GSLs) are sulfur-containing bioactive compounds usually present in Brassicaceae plants and are usually responsible for a pungent flavor and reduction of the nutritional values of seeds. Therefore, breeding rapeseed varieties with low GSL levels is an important breeding objective. Most GSLs in Brassica rapa are derived from methionine or tryptophan, but two are derived from phenylalanine, one directly (benzylGSL) and one after a round of chain elongation (phenethylGSL). In the present study, two phenylalanine (Phe)-derived GSLs (benzylGSL and phenethylGSL) were identified and quantified in seeds by liquid chromatography and mass spectrometry (LC-MS) analysis. Levels of benzylGSL were low but differed among investigated low and high GSL genotypes. Levels of phenethylGSL (also known as 2-phenylethylGSL) were high but did not differ among GSL genotypes. Subsequently, a genome-wide association study (GWAS) was conducted using 159 B. rapa accessions to demarcate candidate regions underlying 43 and 59 QTNs associated with benzylGSL and phenethylGSL that were distributed on 10 chromosomes and 9 scaffolds, explaining 0.56% to 70.86% of phenotypic variations, respectively. Furthermore, we find that 15 and 18 known or novel candidate genes were identified for the biosynthesis of benzylGSL and phenethylGSL, including known regulators of GSL biosynthesis, such as BrMYB34, BrMYB51, BrMYB28, BrMYB29 and BrMYB122, and novel regulators or structural genes, such as BrMYB44/BrMYB77 and BrMYB60 for benzylGSL and BrCYP79B2 for phenethylGSL. Finally, we investigate the expression profiles of the biosynthetic genes for two Phe-derived GSLs by transcriptomic analysis. Our findings provide new insight into the complex machinery of Phe-derived GSLs in seeds of B. rapa and help to improve the quality of Brassicaceae plant breeding.

Separation and Determination of Chemopreventive Phytochemicals of Flavonoids from Brassicaceae Plants

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