Scope
Epithionitriles can be main glucosinolate hydrolysis products in Brassica vegetables such as cabbage or pak choi. Here, for the first time, the bioavailability and metabolism of longer‐chain ...epithionitriles (C4–C5) is studied in a human intervention study.
Methods and results
After consumption of a white cabbage or pak choi sprouts beverage, rich in either 1‐cyano‐2,3‐epithiopropane (CETP) or 1‐cyano‐3,4‐epithiobutane (CETB) and 1‐cyano‐4,5‐epithiopentane (CETPent), blood and urine samples of nine participants are taken and the metabolites are analyzed. The corresponding N‐acetyl‐S‐(cyano‐(methylthio)alkyl)‐l‐cysteine metabolites are identified and quantified by isotope dilution method using UHPLC‐TOF‐MS. The standards for N‐acetyl‐S‐(cyano‐(methylthio)alkyl)‐l‐cysteine metabolites from CETB and CETPent are synthesized for the first time and their structure confirmed by NMR spectroscopy. In contrast to the metabolites of CETP and CETPent, the expected metabolite of CETB is not detectable. The recoveries of the CETP and CETPent metabolites are 28 ± 9% for CETP and 12 ± 3% for CETPent in urine within 24 h.
Conclusion
CETP and CETPent are quickly uptaken, metabolized via the mercapturic acid pathway, and excreted via urine, while for CETB the corresponding metabolite is not detectable. Therefore, an additional metabolization pathway seems to exist.
Epithionitriles can be main glucosinolate hydrolysis products in Brassica vegetables. In the human intervention study uptake and metabolism of three epithionitriles is investigated. Depending on their structure, after consumption epithionitriles in humans are quickly uptaken, metabolized, and excreted. Up to 28% are recovered as urinary S‐methylated mercapturic acid within 24 h.
vegetables such as cabbage or pak choi contain alkenyl glucosinolates which can release epithionitriles and to a lesser degree isothiocyanates upon enzymatic hydrolysis. Here, for the first time, the ...metabolism of an epithionitrile was investigated in humans, namely 1-cyano-2,3-epithiopropane (CETP). After consumption of
var.
f.
and
sprouts, the main urinary metabolite of CETP was identified as
-acetyl-
-(3-cyano-2-(methylsulfanyl)propyl-cysteine using an UHPLC-ESI-QToF-MS approach and synthesis of the metabolite. This urinary epithionitrile metabolite is an
-methylated mercapturic acid. No other metabolites were detected. Then, in a preliminary pilot experiment the excretion kinetics of CETP were investigated in three volunteers. After consumption of a
sprout preparation containing 50.8 µmol of CETP, urinary
-acetyl-
-(3-cyano-2-(methylsulfanyl)propyl-cysteine concentrations were the highest three hours after consumption, ranging from 23.9 to 37.2 µM, and declined thereafter. Thus, epithionitriles are bioavailable compounds that are metabolized similarly to isothiocyanates by the mercapturic acid pathway. In the future, more epithionitrile metabolites should be identified and the pharmacokinetics of these important class of dietary compounds should be assessed in more detail.
Selenium (Se) is an essential micronutrient for human health. Se deficiency affects hundreds of millions of people worldwide, particularly in developing countries, and there is increasing awareness ...that suboptimal supply of Se can also negatively affect human health. Selenium enters the diet primarily through the ingestion of plant and animal products. Although, plants are not dependent on Se they take it up from the soil through the sulphur (S) uptake and assimilation pathways. Therefore, geographic differences in the availability of soil Se and agricultural practices have a profound influence on the Se content of many foods, and there are increasing efforts to biofortify crop plants with Se. Plants from the Brassicales are of particular interest as they accumulate and synthesize Se into forms with additional health benefits, such as methylselenocysteine (MeSeCys). The Brassicaceae are also well-known to produce the glucosinolates; S-containing compounds with demonstrated human health value. Furthermore, the recent discovery of the selenoglucosinolates in the Brassicaceae raises questions regarding their potential bioefficacy. In this review we focus on Se uptake and metabolism in the Brassicaceae in the context of human health, particularly cancer prevention and immunity. We investigate the close relationship between Se and S metabolism in this plant family, with particular emphasis on the selenoglucosinolates, and consider the methodologies available for identifying and quantifying further novel Se-containing compounds in plants. Finally, we summarize the research of multiple groups investigating biofortification of the Brassicaceae and discuss which approaches might be most successful for supplying Se deficient populations in the future.
Nowadays the importance of selenium for human health is widely known, but most of the plants are poor in terms of selenium storage and accumulation because of the low selenium mineralization ...potential of the soil. For this purpose, foliar application of different sodium selenate concentrations (0, 5, 10, 15, 20 mg/L) was used to treat the cauliflower cultivars “Clapton” and “Graffiti”. Higher yields and other related vegetative attributes were improved at 10 and 15 mg/L sodium selenate application. At a concentration of 10 mg/L sodium selenate, photosynthetic pigments, total phenolic compounds and antioxidant capacity were enhanced in both cultivars, but the “Graffiti” cultivar responded stronger than the “Clapton” cultivar. The glucosinolates were accumulated in response to selenium fortification and the highest amounts were found in the “Graffiti” cultivar at 10 mg/L. Selenium accumulated concentration-dependently and rose with higher fertilization levels. In general, foliar application of selenium at 10 mg/L led to an accumulation of secondary metabolites and also positively affected the growth and yield of florets.
Brassicales include many vegetables of nutritional interest because the hydrolysis products of their phytochemicals, the glucosinolates, have health-promoting properties. So far, the impact of rising ...CO2 concentrations on glucosinolates and their hydrolysis is unclear. Applying a modified atmosphere, we exposed two Arabidopsis thaliana accessions that differ in their glucosinolate hydrolysis behavior, namely Hi-0 and Bur-0, to elevated CO2 concentrations. Glucosinolates and their hydrolysis products were analyzed using UHPLC-DAD-MS and GC-MS. CO2 treatment increased indicators of primary production, such as biomass, leaf area and electron transport rate, and increased gluco-sinolate levels in Bur-0, but not Hi-0. Significantly, released glucosinolate hydrolysis product levels increased by up to 122% in Bur-0 due to increased epithionitrile formation. Likewise, in Hi-0 glucosinolate hydrolysis product levels increased after CO2 treatment by up to 67%, caused by enhanced nitrile and to some extent isothiocyanate formation. In addition, more alkenyl rather than alkyl glucosinolates were formed in Bur-0 under elevated CO2, thus changing the glucosinolate profile compositions. As CO2 treatment enhanced primary production but also overall glucosinolate hydrolysis pro-duct formation, it is conceivable to recycle excess CO2 by using it as supplement greenhouse gas to produce high-quality food.
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•Tropaeolum majusL. is a plant rich in bioactive compounds such as glucosinolates and their secondary metabolites isothiocyanates.•Nasturtium intervention reduces lipid metabolism ...biomarkers in prediabetic subjects.•The edible plant nasturtium reduces oxidized LDL and cardiovascular risk indexes.•Benzyl isothiocyanate reduces cardiovascular risk indexes and oxidized LDL.
Nasturtium (Tropaeolum majus L.) is a plant rich in bioactive compounds such as phenolic compounds, glucosinolates (GLS) and their hydrolyzed metabolites isothiocyanates (ITCs), which modulate signaling pathways related to lipid and carbohydrate metabolism. This randomized crossover trial explored the effect of intervention with a freeze-dried nasturtium drink on insulin response and lipid profile in prediabetic subjects. Ten (10) patients were randomly assigned to the following treatments: NT (nasturtium) and PLC (placebo) for 4 weeks and after this time the treatments were crossed for another 4 weeks. Biomarkers related to insulin resistance and lipid profile were measured at the beginning and the end of the intervention with each treatment. The consumption of 15 g NT (681 μmol of benzyl glucosinolate)/dose week for four (4) weeks resulted in a significant decrease in the concentration of LDL cholesterol (LDLc), Oxidized LDL (ox-LDL), Castelli's risk index I and II (TC/HDLc, and LDLc/HDLc) and Atherogenic Coefficient (non-HDLc)/HDLc). The results suggest that the nasturtium consumption might have a modulating effect on biomarkers related to cardiovascular disease, altered in subjects with chronic diseases, including type 2 diabetes. This study is the first in vivo study to explore the chronic effect of T. majus consumption in patients with prediabetes and shows the importance of continuing to explore this effect in studies with a larger number of participants.
Large quantities of biological waste are generated at various steps within the food production chain and a great utilization potential for this solid biological waste exists apart from the current ...main usage for the feedstuff sector. It remains unclear how the usage of biological waste as compost modulates plant metabolites. We investigated the effect of biological waste of the processing of coffee, aronia, and hop added to soil on the plant metabolite profile by means of liquid chromatography in pak choi sprouts. Here we demonstrate that the solid biological waste composts induced specific changes in the metabolite profiles and the changes are depending on the type of the organic residues and its concentration in soil. The targeted analysis of selected plant metabolites, associated with health beneficial properties of the Brassicaceae family, revealed increased concentrations of carotenoids (up to 3.2-fold) and decreased amounts of glucosinolates (up to 4.7-fold) as well as phenolic compounds (up to 1.5-fold).
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•Secondary metabolites remarkably affect the quality of brassicaceous vegetables.•Genetic factor is most influential on intrinsic quality of brassicaceaous vegetables.•Environmental ...and agronomic factors change secondary plant metabolites enormously.•Secondary metabolite diversity is essential for the plant-environment interactions.
From the order Brassicales, different plant organs, such as inflorescences (e.g. broccoli and cauliflower), leaves (e.g. kale and pak choi), heads (e.g. white and red cabbage), as well as roots and bulbs (e.g. radish and turnip), are frequently consumed brassicaceaous vegetables. The order Brassicales is characterized by a specific group of secondary plant metabolites, namely the glucosinolates. Glucosinolates and their breakdown products the isothiocyanates are linked to conferring beneficial health effects. In addition, some studies have also highlighted the beneficial health effects of phenolic compounds and carotenoids, both well-known as antioxidants. Of interest is that the profiles and concentrations of secondary plant metabolites vary enormously between the species, and genetic factors are thought to affect this the most. Further, environmental and agronomical factors are also known to change concentrations of secondary plant metabolites enormously. The main physiological mechanism to produce secondary plant metabolites is defense. Thus, the intrinsic quality, including color, aroma, taste, and beneficial health properties of brassicaceous vegetables, is remarkably affected by secondary plant metabolite profiles and concentrations.
Pak choi (Brassica rapa subsp. chinensis) is rich in secondary metabolites and contains numerous antioxidants, including flavonoids; hydroxycinnamic acids; carotenoids; chlorophylls; and ...glucosinolates, which can be hydrolyzed to epithionitriles, nitriles, or isothiocyanates. Here, we investigate the effect of reduced exposure to ultraviolet B (UVB) and UV (UVA and UVB) light at four different developmental stages of pak choi. We found that both the plant morphology and secondary metabolite profiles were affected by reduced exposure to UVB and UV, depending on the plant’s developmental stage. In detail, mature 15- and 30-leaf plants had higher concentrations of flavonoids, hydroxycinnamic acids, carotenoids, and chlorophylls, whereas sprouts contained high concentrations of glucosinolates and their hydrolysis products. Dry weights and leaf areas increased as a result of reduced UVB and low UV. For the flavonoids and hydroxycinnamic acids in 30-leaf plants, less complex compounds were favored, for example, sinapic acid acylated kaempferol triglycoside instead of the corresponding tetraglycoside. Moreover, also in 30-leaf plants, zeaxanthin, a carotenoid linked to protection during photosynthesis, was increased under low UV conditions. Interestingly, most glucosinolates were not affected by reduced UVB and low UV conditions. However, this study underlines the importance of 4-(methylsulfinyl)butyl glucosinolate in response to UVA and UVB exposure. Further, reduced UVB and low UV conditions resulted in higher concentrations of glucosinolate-derived nitriles. In conclusion, exposure to low doses of UVB and UV from the early to late developmental stages did not result in overall lower concentrations of plant secondary metabolites.
UV radiation is an underrated radiation currently missing in many horticultural production systems of vegetables in protected cultivation. It can be added e.g., in LED light sources. Using lettuce as ...a model plant, this study determined whether the use of UVB LEDs is suitable (1) for use in consistent systems (indoor farming) or (2) inconsistent systems (greenhouse). Blue and red LEDs were selected as additional artificial lighting to UVB LEDs. Both approaches led to a reproducible increase of desired flavonol glycosides, such as quercetin-3-
O
-(6′′-
O
-malonyl)-glucoside or quercetin-3-
O
-glucuronide and the anthocyanin cyanidin-3-
O
-(6′′-
O
-malonyl)-glucoside in lettuce. The impact of the consistent UVB treatment is higher with up to tenfold changes than that of the inconsistent UVB treatment in the greenhouse. Varying natural light and temperature conditions in greenhouses might affect the efficiency of the artificial UVB treatment. Here, UVB LEDs have been tested and can be recommended for further development of lighting systems in indoor farming and greenhouse approaches.
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