High resolution mass spectrometry studies of sulforaphane and indole-3-carbinol in broccoli

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.

Expanding the Use of Benzothioxanthene Imides to Photochemistry: Eco-Friendly Aerobic Oxidation of Sulfides to Sulfoxides

The sulfoxide moiety is one of the most commonly utilized groups in pharmaceutical and industrial chemistry. The need for sustainability and easy accessibility to sulfoxide moieties is deemed necessary, due to its ubiquity in natural products and potentially pharmaceutically active compounds. In this context, we report herein a sustainable, aerobic and environmentally friendly photochemical protocol based on the use of a benzothioxathene imide as the photocatalyst to selectively oxidize sulfides under mild irradiation (456 nm), in very low catalyst loading (0.01 mol %) and on water. In addition, to demonstrate the compatibility of our protocol with wide scope of substrates, the latter was successfully applied to the synthesis of the biologically-active Sulforaphane and Modafinil.

Free Fatty Acid Determination in Broccoli Tissues Using Liquid Chromatography-High-Resolution Mass Spectrometry

Broccoli (Brassica oleracea L. var. italica Plenck) is a widely consumed vegetable, very popular due to its various nutritional and bioactive components. Since studies on the lipid components of broccoli have been limited so far, the aim of the present work was the study of free fatty acids (FFAs) present in different broccoli parts, aerial and underground. The direct determination of twenty-four FFAs in broccoli tissues (roots, leaves, and florets) was carried out, using a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method in a 10 min single run. Linolenic acid was found to be the most abundant FFA in all different broccoli parts in quantities ranging from 0.76 to 1.46 mg/g, followed by palmitic acid (0.17-0.22 mg/g) and linoleic acid (0.06-0.08 mg/g). To extend our knowledge on broccoli's bioactive components, for the first time, the existence of bioactive oxidized fatty acids, namely hydroxy and oxo fatty acids, was explored in broccoli tissues adopting an HRMS-based lipidomics approach. 16- and 2-hydroxypalmitic acids were detected in all parts of broccoli studied, while ricinoleic acid was detected for the first time as a component of broccoli.

Plant sources, extraction techniques, analytical methods, bioactivity, and bioavailability of sulforaphane: a review

Sulforaphane (SFN) is an isothiocyanate commonly found in cruciferous vegetables. It is formed via the enzymatic hydrolysis of glucoraphanin by myrosinase. SFN exerts various biological effects, including anti-cancer, anti-oxidation, anti-obesity, and anti-inflammatory effects, and is widely used in functional foods and clinical medicine. However, the structure of SFN is unstable and easily degradable, and its production is easily affected by temperature, pH, and enzyme activity, which limit its application. Hence, several studies are investigating its physicochemical properties, stability, and biological activity to identify methods to increase its content. This article provides a comprehensive review of the plant sources, extraction and analysis techniques, in vitro and in vivo biological activities, and bioavailability of SFN. This article highlights the importance and provides a reference for the research and application of SFN in the future.

Facile Preparation of Magnetic COF-on-COF for Rapid Adsorption and Determination of Sulforaphane from Cruciferous Vegetables

Sulforaphane (SFN) is a natural isothiocyanate compound widely abundant in cruciferous vegetables with multiple bioactive functions. However, traditional analytical methods for the extraction and determination of SFN are cumbersome, time-consuming, and low sensitivity with large amounts of organic solvents. Herein, novel magnetic COF-on-COFs (MB-COFs) were fabricated using Fe3O4 as a magnetic core and COFs-1 grown with COFs-2 as a shell, and they were used as efficient adsorbents of magnetic dispersive solid-phase extraction for rapid quantification of SFN in cruciferous vegetables by combining with HPLC-MS/MS. At the optimal ratio of COFs-1 to COFs-2, MB-COFs had a spherical cluster-like structure and a rough surface, with a sufficient magnetic response for rapid magnetic separation (1 min). Due to the introduction of Fe3O4 and COFs-2, MB-COFs exhibited outstanding extraction efficiencies for SFN (92.5-97.3%), which was about 18-72% higher than that of the bare COFs. Moreover, MB-COFs showed good adsorption capacity (Qm of 18.0 mg/g), rapid adsorption (5 min) and desorption (30 s) to SFN, and favorable reusability (≥7 cycles) by virtue of their unique hierarchical porous structure. The adsorption kinetic data were well fitted by the pseudo-second-order, Ritchie-second-order, intra-particle diffusion, and Elovich models, while the adsorption isotherm data were highly consistent with the Langmuir, Temkin, and Redlich-Peterson models. Finally, under the optimized conditions, the developed method showed a wide linear range (0.001-0.5 mg/L), high sensitivity (limits of quantification of 0.18-0.31 μg/L), satisfactory recoveries (82.2-96.2%) and precisions (1.8-7.9%), and a negligible matrix effect (0.82-0.97). Compared to previous methods, the proposed method is faster and more sensitive and significantly reduces the use of organic solvents, which can achieve the efficient detection of large-scale samples in practical scenarios. This work reveals the high practical potential of MB-COFs as adsorbents for efficient extraction and sensitive analysis of SFN in cruciferous vegetables.

Maximizing the value of indole-3-carbinol, from its distribution in dietary sources, health effects, metabolism, extraction, and analysis in food and biofluids

Indole-3-carbinol (I3C) is a major dietary component produced in Brassica vegetables from glucosinolates (GLS) upon herbivores' attack. The compound is gaining increasing interest due to its anticancer activity. However, reports about improving its level in plants or other sources are still rare. Unfortunately, I3C is unstable in acidic media and tends to polymerize rendering its extraction and detection challenging. This review presents a multifaceted overview of I3C regarding its natural occurrence, biosynthesis, isolation, and extraction procedure from dietary sources, and optimization for the best recovery yield. Further, an overview is presented on its metabolism and biotransformation inside the body to account for its health benefits and factors to ensure the best metabolic yield. Compile of the different analytical approaches for I3C analysis in dietary sources is presented for the first time, together with approaches for its detection and its metabolism in body fluids for proof of efficacy. Lastly, the chemopreventive effects of I3C and the underlying action mechanisms are summarized. Optimizing the yield and methods for the detection of I3C will assist for its incorporation as a nutraceutical or adjuvant in cancer treatment programs. Highlighting the complete biosynthetic pathway and factors involved in I3C production will aid for its future biotechnological production.

Simulated Digestion and Fermentation In Vitro by Obese Human Gut Microbiota of Sulforaphane from Broccoli Seeds

BACKGROUND

sulforaphane is a kind of isothiocyanate, which is obtained by hydrolysis of glucosinolate by the unique myrosinase in plants. It has been proved to prevent the occurrence of many chronic diseases, such as obesity, diabetes and cancer.

OBJECTIVE

The impact of SFN on obese human gut flora, however, has not been established.

METHODS

In this research, SFN was isolated from broccoli seeds and then refined to achieve 95% purity. Next, an investigation was conducted into the digestion and fermentation processes of SFN.

RESULTS

The stability of the SFN in simulated saliva, gastric fluid, and intestinal juice provides evidence that it can reach the gut and be available for utilization by gut microflora. In vitro fermentation of SFN by gut microbes in obese patients results in alteration in constitution of microbiota and production of short chain fatty acids. As the result of SFN ingestion by human gut bacteria, the content of butyric and valeric acids increased 1.21- and 1.46-fold, respectively. In obese human guts, the relative abundances of the beneficial genera including Lactobacillus, Weissella, Leuconosto, Algiphilus and Faecalibacterium significantly increased, whilst the detrimental genera, such as Escherichia-Shigella, Klebsiella, Clostridium_sensu_stricto_1, Sutterella, Megamonas and Proteus drastically declined.

CONCLUSION

Taken together, these findings demonstrate that SFN can be used as a nutraceutical ingredient for obese patients and for improving human health.

Folic acid engineered sulforaphane loaded microbeads for targeting breast cancer

Non-targeted cancer therapy poses a huge risk to the cancer patients' life due to high toxicity offered by chemotherapy. Breast carcinoma is one of such deleterious disease, demanding a highly effectual treatment option which could reduce the toxicity and extend survival rate. Since, folate receptors extensively display themselves on the cancer cell surface, targeting them would help to ameliorate the progression and metastasis. Considering this, we envisaged and developed sulforaphane loaded folate engineered microbeads to target breast cancer cells over-expressing folate receptors. The surface engineered microbeads were optimized and developed using emulsion gelation technique, among which the best developed preparation demonstrated the particle size of 1302 ± 3.98 µm, % EE of 84.1 ± 3.32% and in vitro drug release of 98.1 ± 4.42%@24h. The spherical sized microbead showed controlled release with improved haem-compatibility in comparison to the bare drug. Free radical scavenging activity by ABTS assay showed strong anti-oxidant activity (IC₅₀ 20.62 µg/ml) of the targeted microbeads with profound cancer cell sup pressing effect (IC₅₀ 17.48 ± 3.5 µM) as observed in MCF-7 cells by MTT assay. Finally, in comparison to lone SFN, the targeted therapy showed enhanced uptake by the intestinal villi indicating a suitable oral targeted therapy against breast carcinoma.

A microplate spectrophotometric method for analysis of indole-3-carbinol in dietary supplements using p-dimethylaminocinnamaldehyde (DMACA) as a chromogenic reagent

This work presents the development of a microplate spectrophotometric method for determination of indole-3-carbinol in dietary supplements. The colorimetric procedure is based on the reaction of indole-3-carbinol with the p-dimethylaminocinnamaldehyde (DMACA) reagent under acidic conditions. The absorbance of the colored product measured at 675 nm was used to determine the target analyte. To achieve optimal spectrophotometric performance, the DMACA reagent concentration, the hydrochloric acid concentration, and the reaction time were optimized. The developed technique performed well under the optimal conditions, with a linear calibration range of 30 to 300 mg L^-1 and a high correlation coefficient (r² = 0.9954). The limit of detection and limit of quantification were 7.8 mg L^-1 and 26.2 mg L^-1, respectively. This approach demonstrated good repeatability (intra- and inter-day precision) with a % RSD lower than 9.4%, good accuracy with acceptable relative recoveries in the range of 98 to 106%, and high sample throughput (24 detection per min). This simple, rapid, and multi-sample analysis approach for routine analysis of indole-3-carbinol has the potential to be used for the quality control of dietary supplements.

Development of a "Turn off-on" whole-cell biosensor for sulforaphane detection based on the ultrasensitive activator HrpRS

Sulforaphane (SFN), a defense secondary metabolite, can be used to predict the health status of plants and also has pharmacological effects, including anticancer, antioxidant, and anti-inflammatory properties. The detection of SFN is therefore of great significance for the prevention and treatment of diseases. In this study, a "Turn off" whole-cell biosensor that can rapidly and robustly respond to the presence of SFN was constructed based on the orthogonal genetic components (hrpR, hrpS, and P_hrpL ) of Pseudomonas syringae (PS). The final optimized biosensor, p114(30R-30S), was able to inhibit 91.7% of the fluorescence intensity in the presence of 100-μM SFN. Subsequently, a HrpRS-regulated OFF-ON genetic switch was designed by reconstituting a reverse σ⁷⁰ promoter on the σ⁵⁴ -P_hrpL promoter sequence; this was coupled with dual-color reporter genes to construct a "Turn off-on" whole-cell SFN biosensor. The P_hrpLB variant increased the expression of green fluorescence a factor of 11.9 and reduced the expression of red fluorescence by 85.8% compared with the system in the absence of SFN. Thus, a robust switching of signal output from "turn off" to "turn on" was realized. In addition, the biosensor showed good linearity in the SFN concentration ranges of 0.1-10 μM (R² = 0.99429) and 10-100 μM (R² = 0.99465) and a detection limit of ⁓0.1 μM. This article is protected by copyright. All rights reserved.

A sustainable photochemical aerobic sulfide oxidation: access to sulforaphane and modafinil

Sulfoxide-containing molecules are an important class of compounds in the pharmaceutical industry and many efforts have been made to develop new and green protocols, targeting the chemoselective transformation of sulfides into sulfoxides. Photochemistry is a rapidly expanding research field employing light as the energy source. Photochemical aerobic processes possess additional advantages to photochemistry and may find applications in the chemical industries. Herein, a 370 nm catalyst-free aerobic protocol was developed, using 2-Me-THF as the green solvent. At the same time, two low-catalyst-loading anthraquinone-based processes (under a CFL lamp or 427 nm irradiation) in 2-Me-THF were developed. Furthermore, a broad range of substrates was tested. We also implemented our protocols towards the synthesis of the pharmaceutical active ingredients (APIs) sulforaphane and modafinil.

Minor bioactive indoles from kimchi mirror the regioselectivity in indole-3-carbinol oligomerization

Kimchi is a globally consumed food with diverse health-benefits, but the low-abundance bioactive compounds in kimchi remain largely neglected. Here we show that kimchi contains a family of low-abundance (0.5-1.6 μg/g, dried weight) high-order indole oligomers derived from indole-3-carbinol (I3C), a breakdown product released from cruciferous vegetables used for producing the traditional subsidiary food. The structure determination of such complex molecules was accomplished by synthesizing linear indole oligomers as standard materials followed by the LC-HR-MS analysis. One indole tetramer (LTe2) is substantially toxic to tumor MV4-11 (IC₅₀ = 1.94 μM) and THP-1 cells (IC₅₀ = 7.12 μM). Collectively, the work adds valuable information to the knowledge package about kimchi, and may inspire the generation of indole-based molecules, to which many drugs belong.

Effect of aqueous extract of seed of broccoli on inflammatory cytokines and Helicobacter pylori infection: a randomized, double-blind, controlled trial in patients without atrophic gastritis

The purpose of this study was to investigate the anti-inflammatory effect of an aqueous extract of seed of broccoli (AESB) in Helicobacter pylori (HP)-infected patients without atrophic gastritis. This was a double-centre, randomized, double-blind, controlled study. A total of 110 HP-infected subjects were randomized to receive either AESB or placebo for 2 months. Inflammatory cytokine (IL-8, IFN-γ, TNF-α, CRP, IL-17A, IL-1β, IL-18), pepsinogen I, II (PG I, PG II), and gastrin-17 (G-17) measurements and ¹³C-urea breath tests were performed at baseline and at 60 days. At 60 days, there was no significant difference in any of the inflammatory cytokines, pepsinogen or gastrin between the two groups. However, IL-8, IFN-γ, PG I, PG I/PG II ratio (PGR), and G-17 were reduced by 9.02 pg/mL, 5.08 pg/mL, 24.56 ng/mL, 1.75 and 0.3 pmol/L, respectively, in the AESB group compared with baseline (all P < 0.05). The HP eradication rates in the AESB group and placebo group were 11.11 and 3.70% at 60 days, respectively (P > 0.05). No treatment-related adverse events were reported. Thus, AESB may reduce the risk of gastric mucosal lesions and decrease the risk of gastric cancer by relieving inflammatory cytokines. The safety profile of AESB was satisfactory. This study is registered with the Chinese Clinical Trials Registry (Registration No. ChiCTR2100054249).

Layered Double Hydroxide@Metal-Organic Framework Hybrids for Extraction of Indole-3-Carbinol From Cruciferous Vegetables

Cruciferous vegetables are rich in glucosinolates, which can be metabolized to produce the antitumor compound indole-3-carbinol (I3C). The conventional solvent extraction method for I3C is inefficient. To improve the extraction efficiency of I3C from cruciferous vegetables, we prepared a metal-organic framework (MOF) material (Fe₃O₄@Zn-Al-LDH@B-D-MIL-100). First, Fe₃O₄ nanoparticles were introduced to layered double hydroxides by in situ polymerization. Then, the MOF material was grown on the surface of the layered double hydroxide by co-precipitation and the layer-by-layer self-assembly method. This gave Fe₃O₄@Zn-Al-LDH@B-D-MIL-100, which was characterized using a variety of techniques. The results showed that Fe₃O₄@Zn-Al-LDH@B-D-MIL-100 had a double-layer porous structure, excellent superparamagnetism (11.54955 emu/g), a large specific surface area (174.04 m²/g), and a pore volume (0.26 cm³/g). The extraction conditions for I3C were optimized. Non-linear fitting of the static adsorption model showed that the adsorption was mainly monolayer. Fe₃O₄@Zn-Al-LDH@B-D-MIL-100 had fast adsorption kinetics and could extract 95% of I3C in 45 min. It is superior to the traditional solvent extraction method because of its high enrichment efficiency in a short time and environmental friendliness. The successful preparation of the new nanomaterial will provide a new reference for the enrichment and extraction of the I3C industry.

Salicylic Acid Regulates Indole-3-Carbinol Biosynthesis Under Blue Light in Broccoli Sprouts (Brassica oleracea L.)

Indole-3-carbinol (I3C), an important secondary metabolite with strong anti-cancer ability, is widely found in cruciferous plants. Light and phytohormones are one of the most important external and internal signals, respectively, that control the growth, development, and secondary metabolism of the plant life cycle. However, there are few studies about the influence of the blue light and salicylic acid (SA) on the regulation of I3C accumulation. In this study, a negative correlation was found between the content of I3C and SA in different species. Among this, broccoli and Arabidopsis thaliana were chosen for further studies. We observed that blue light treatment increased the accumulation of I3C, and exogenous SA treatment significantly inhibited the accumulation of I3C in broccoli sprouts. Based on the RNA sequence, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that blue light promoted the enrichment of differentially expressed genes (DEGs) in plant hormone signal transduction pathways. More specifically, downregulated expression of genes related to SA biosynthesis and upregulated expression of I3C genes related to metabolic pathway were observed under blue light. Taken together, these results suggested that SA negatively regulates blue light-induced I3C accumulation in broccoli sprouts.

Analysis of anticancer compound, indole-3-carbinol, in broccoli using a new ultrasound-assisted dispersive-filter extraction method based on poly(deep eutectic solvent)-graphene oxide nanocomposite

Indole-3-carbinol (I3C), an important anticancer compound found in broccoli, has attracted considerable attention. The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature. In this study, a rapid, accurate, and low-cost ultrasound-assisted dispersive-filter extraction (UADFE) technique based on poly(deep eutectic solvent)-graphene oxide (PDES-GO) adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time. PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption. UADFE was developed by combining dispersive solid-phase extraction (DSPE) and filter solid-phase extraction (FSPE) to realize rapid extraction and separation. Based on the above two strategies, the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography (HPLC) allowed the rapid (15-16 min), accurate (84.3%-96.4%), and low-cost (adsorbent: 3.00 mg) analysis of I3C in broccoli and was superior to solid-phase extraction, DSPE, and FSPE methods. The proposed method showed remarkable linearity (r=0.9998; range: 0.0840-48.0 μg/g), low limit of quantification (0.0840 μg/g), and high precision (relative standard deviation ≤5.6%). Therefore, the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples.

Aerobic Photocatalysis: Oxidation of Sulfides to Sulfoxides

Sulfoxides constitute one of the most important functional groups in organic chemistry found in numerous pharmaceuticals and natural products. Sulfoxides are usually obtained from the oxidation of the corresponding sulfides. Among various oxidants, oxygen or air are considered the greenest and most sustainable reagent. Photochemistry and photocatalysis is increasingly applied in new, as well as traditional, yet demanding, reaction, like the aerobic oxidation of sulfides to sulfoxides, since photocatalysis has provided the means to access them in mild and effective ways. In this review, we will summarize the photochemical protocols that have been developed for the oxidation of sulfides to sulfoxides, employing air or oxygen as the oxidant. The aim of this review is to present: i) a historical overview, ii) the key mechanistic studies and proposed mechanisms and iii) categorize the different catalytic systems in literature.

Current Methods for the Extraction and Analysis of Isothiocyanates and Indoles in Cruciferous Vegetables

Cruciferous vegetables are characterized by the presence of sulfur-containing secondary plant metabolites known as glucosinolates (GLS). The consumption of cruciferous vegetables such as broccoli, cabbage, rocket salad, and cauliflower has been related to the prevention of non-communicable diseases. Their beneficial effects are attributed to the enzymatic degradation products of GLS, e.g., isothiocyanates and indoles. Owing to these properties, there has been a shift in the last few years towards the research of these compounds and a wide range of methods for their extraction and analytical determination have been developed. The aim of this review is to present the sample preparation and extraction procedures of isothiocyanates and indoles from cruciferous vegetables and the analytical methods for their determination. The majority of the references that have been reviewed are from the last decade. Although efforts towards the application of eco-friendly non-conventional extraction methods have been made, the use of conventional solvent extraction is mainly applied. The major analytical techniques employed for the qualitative and quantitative analysis of isothiocyanates and indoles are high-performance liquid chromatography and gas chromatography coupled with or without mass spectrometry detection. Nevertheless, the analytical determination of isothiocyanates presents several problems due to their instability and the absence of chromophores, making the simultaneous determination of isothiocyanates and indoles a challenging task.

Pharmacophore-inspired discovery of FLT3 inhibitor from kimchi

Globally consumed kimchi is manufactured through fermenting cruciferous vegetables containing indole glucosinolates (IG). But few reports describe the IG metabolism during the fermentation. Here, we show that indole-3-carbinol (I3C), a breakdown product of IG, is transformed during the kimchi fermentation into 3,3'-diindolylmethane (DIM) and 2-(indol-3-ylmethyl)-3,3'-diindolylmethane (LTr1). LTr1 was found to kill the acute myeloid leukemia (AML) cells with FMS-like tyrosine kinase 3 (FLT3) receptor mutations, by inhibiting the FLT3 phosphorylation and the expression of downstream proteins (STAT5, ERK, and AKT). In the immune-depleted mice xenografted with human MV4-11 cells, LTr1 was demonstrated to reduce the tumor growth and synergize with sorafenib, an anti-AML agent in clinic. The work updates the chemical and biological knowledge about kimchi, and in particular establishes LTr1 as an FLT3 inhibitor that is effective and synergistic with sorafenib in treating AML.

Rapid measurement of indole levels in Brassica vegetables using one millilitre binary organic extraction solvent and capillary electrophoresis-UV analysis

INTRODUCTION

Brassica vegetables contain high levels of indole compounds which have been found to provide health benefits, especially as cancer-preventive agents. An efficient and rapid method using solvent extraction with capillary electrophoresis (CE) and ultraviolet (UV) detection was developed for the determination of four major indoles from four types of Brassica vegetables.

MATERIALS AND METHODS

Freeze-dried samples of four Brassica vegetables, i.e. broccoli, cauliflower, Chinese cabbage and cabbage, were selected. Hence, 1 mL of the binary solvent dimethylformamide (DMF)-methanol, 4:1 (v/v), was used for sample extraction. The extracts were diluted with the running buffer and directly analysed using CE with UV detection of four indole compounds.

RESULTS

The binary solvent DMF-methanol, 4:1 (v/v) was selected from studies of the extraction efficiency of standard indoles spiked in ivy gourd (as the negative control sample) and using diphenylamine as the internal standard. Recovery was 80(±10)-120(±3)% for the four indoles: indole-3-carbinol (I3C), indole-3-acetonitrile (I3A), indole-3-acetic acid (IAA), and 3,3'-diindolylmethane (DIM). For direct analysis suitable dilution of the extract with the running buffer was required. The linear range of the quantitation is 0.75-25.0 μg/mL, limit of detection (LOD) of 0.14-0.52 μg/mL and r² > 0.998. The amount of indole in the Brassica vegetables are in the order I3C > > IAA, I3A > DIM.

CONCLUSION

A rapid method for extraction and quantitation of four indoles in four Brassica vegetables using CE with UV detection was developed. It has the potential as an efficient technique for generating data for use in agricultural and nutritional studies.

Extraction and Quantification of Sulforaphane and Indole-3-Carbinol from Rapeseed Tissues Using QuEChERS Coupled with UHPLC-MS/MS

Rapeseed (Brassica napus L.) is rich in phenols, vitamins, carotenoids, and mineral elements, such as selenium. Additionally, it contains the active ingredients sulforaphane and indole-3-carbinol, which have been demonstrated to have pharmacological effects. In this study, sulforaphane and indole-3-carbinol were extracted and quantified from rapeseeds using quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with ultra high performance liquid chromarography tandem mass spectrometry (UHPLC-MS/MS). The major parameters for extraction and purification efficiency were optimized, including the hydrolysis reaction, extraction condition and type and amount of purification adsorbents. The limit of detection (LOD) and the limit of quantification (LOQ) for sulforaphane were 0.05 μg/kg and 0.15 μg/kg, and for indole-3-carbinol were 5 μg/kg and 15 μg/kg, respectively. The developed method was used to successfully analyze fifty rapeseed samples. The QuEChERS coupled with UHPLC-MS/MS simultaneously detect sulforaphane and indole-3-carbinol in vegetable matrix and evaluate the quality and nutrition of rapeseed samples.

Profiling glucosinolate metabolites in human urine and plasma after broccoli consumption using non-targeted and targeted metabolomic analyses

Broccoli is a popular brassica vegetable and its consumption may decrease the occurrence of cancer in certain populations. To gain insight into the metabolites that may induce physiological responses to broccoli intake, a non-targeted metabolomic approach and a targeted approach for analysis of glucosinolate metabolites were developed using high resolution accurate mass spectrometry. A human study was conducted in which 6 subjects consumed a single meal of 200 g of uncooked broccoli florets. The metabolomic analysis revealed changes in endogenous metabolites and a decrease in hippuric acid after broccoli consumption. Targeted analysis using high-resolution, accurate mass-mass spectrometry (HRAM-MS) enabled detection of low concentrations (nM) of glucosinolate metabolites in human urine and plasma. Glucosinolate metabolites were found in human urine (13) and plasma (8), respectively. Metabolites from methoxyl-indole glucosinolates, arising from broccoli consumption, are reported for the first time. Most glucosinolate metabolites reached their peak concentration in urine 2-4 h after consumption while, in plasma, peak maxima were achieved 2 h after intake. The results suggest that glucoraphanin metabolites (sulforaphane, sulforaphane cysteine, sulforaphane N-acetyl cysteine) and indole metabolites (ascorbigen and methoxyl ascorbigen from indole glucosinolates) may serve as marker compounds for the intake of broccoli.

Identification of Auxin Metabolites in Brassicaceae by Ultra-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry

Auxins are signaling molecules involved in multiple stages of plant growth and development. The levels of the most important auxin, indole-3-acetic acid (IAA), are regulated by the formation of amide and ester conjugates with amino acids and sugars. In this work, IAA and IAA amide conjugates with amino acids bearing a free carboxylic group or a methyl ester group, along with some selected IAA metabolites, were studied in positive and negative electrospray ionization (ESI) modes, utilizing high-resolution mass spectrometry (HRMS) as a tool for their structural analysis. HRMS/MS spectra revealed the fragmentation patterns that enable us to identify IAA metabolites in plant extracts from eight vegetables of the Brassicaceae family using a fast and reliable ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) method. The accurate m/z (mass to charge) ratio and abundance of the molecular and fragment ions of the studied compounds in plant extracts matched those obtained from commercially available or synthesized compounds and confirmed the presence of IAA metabolites.

SMYD3-associated pathway is involved in the anti-tumor effects of sulforaphane on gastric carcinoma cells

Sulforaphane (SFN), a natural compound derived from cruciferous vegetables, has been proved to possess potent anti-cancer activity. SMYD3 is a histone methyltransferase which is closely related to the proliferation and migration of cancer cells. This study showed that SFN could dose-dependently induce cell cycle arrest, stimulate apoptosis, and inhibit proliferation and migration of gastric carcinoma cells. Accompanied with these anti-cancer effects, SMYD3 and its downstream genes, myosin regulatory light chain 9, and cysteine-rich angiogenic inducer 61, was downregulated by SFN. Furthermore, overexpression of SMYD3 via transfection could abolish the effects of SFN, suggesting that SMYD3 might be an important mediator of SFN. To the best of our knowledge, this is the first report describing the role of SMYD3 in the anti-cancer of SFN. These findings might throw light on the development of novel anti-cancer drugs and functional food using SFN-rich cruciferous vegetables.