Season-dependent variation in the contents of glucosinolates and S-methyl-l-cysteine sulfoxide and their hydrolysis in Brassica oleracea.

Brassica vegetables contain glucosinolates and S-methyl-l-cysteine sulfoxide, which can be enzymatically hydrolyzed to form bioactive compounds. Glucosinolate hydrolysis can result in formation of health-promoting isothiocyanates, however, often less desirable nitriles and epithionitriles are formed due to presence of specifier proteins. Also, S-methyl-l-cysteine sulfoxide yields beneficial volatile organosulfur compounds (VOSC), such as S-methyl methanethiosulfinate.

Glucosinolate profile and specifier protein activity determine the glucosinolate hydrolysis product formation in kohlrabi (Brassica oleracea var. gongylodes) in a tissue-specific way.

Glucosinolates, commonly found in Brassica vegetables, are hydrolyzed by myrosinase to form bioactive isothiocyanates, unless specifier proteins redirect the degradation to less bioactive nitriles and epithionitriles. Here, the tissue-specific impact of specifier proteins on the outcome of glucosinolate hydrolysis in nine kohlrabi tissues was investigated. Glucosinolates and their hydrolysis product profiles, epithiospecifier protein and myrosinase activity, and protein abundance patterns of key glucosinolate biosynthesis, transport and hydrolysis enzymes were determined and correlated to the metabolites in the kohlrabi tissues.

Non-enzymatic degradation of aliphatic Brassicaceae isothiocyanates during aqueous heat treatment.

Glucosinolate-derived isothiocyanates are valuable for human health as they exert health promoting effects. As thermal food processing could affect their levels in a structure dependent way, the stability and reactivity of 12 Brassicaceae isothiocyanates during aqueous heating at 100 °C and pH 5-8 were investigated. The formation of their corresponding amines and N,N'-dialk(en)yl thioureas was quantified.

Essentials in the acquisition, interpretation, and reporting of plant metabolite profiles.

Plant metabolite profiling reveals the diversity of secondary or specialized metabolites in the plant kingdom with its hundreds of thousands of species. Specialized plant metabolites constitute a vast class of chemicals posing significant challenges in analytical chemistry. In order to be of maximum scientific relevance, reports dealing with these compounds and their source species must be transparent, make use of standards and reference materials, and be based on correctly and traceably identified plant material.

Acidification and tissue disruption affect glucosinolate and S-methyl-l-cysteine sulfoxide hydrolysis and formation of amines, isothiocyanates and other organosulfur compounds in red cabbage (Brassica oleracea var. capitata f. rubra).

Cabbages are rich in sulfur-containing metabolites like glucosinolates (GLSs) and S-methyl-l-cysteine sulfoxide (SMCSO). Tissue disruption initiates hydrolysis of these compounds and bioactive volatile hydrolysis products such as isothiocyanates (ITCs), sulfides, and thiosulfinates are formed. However, nitriles, epithionitriles, or amines can also result from GLSs.

Degradation of glucosinolates and formation of isothiocyanates, nitriles, amines, and N,N'-dialk(en)yl thioureas during domestic boiling of red cabbage.

Red cabbage is a popular vegetable in Central Europe and a rich source of glucosinolates (GLSs). Upon hydrolysis, GLSs form health-promoting isothiocyanates (ITCs), but also nitriles and epithionitriles. Recently, ITCs were shown to undergo further hydrolysis, yielding amines.

A monocentric, randomized, double-blind, controlled crossover trial of nasturtium () on the lipid regulator prostaglandin E.

Scope: As prostaglandin E2 (PGE) has important roles in physiological and inflammatory functions, a double-blind randomized controlled crossover study to investigate the potential of nasturtium () for modulating PGE was conducted, aiming at clarifying the role of benzyl isothiocyanate (BITC). As secondary parameters leukotriene 4 (LTB), and cytokine release (tumor necrosis factor alpha, TNF-α; interleukins IL-1β, IL-10, and IL-12) were quantified.

Methods And Results: Thirty-four healthy female participants consumed 1.

Thermal degradation and oxidation of glucosinolates in model systems and Brassica vegetable broth is mediated by redox-active compounds.

Glucosinolates (GLSs) are secondary plant metabolites with health-promoting effects found in Brassica vegetables. Recently, next to non-enzymatic degradation yielding nitriles, 4-(methylthio)butyl GLS (4MTB-GLS) was shown to undergo side chain oxidation during thermal treatment, forming 4-(methylsulfinyl)butyl GLS (4MSOB-GLS). Here, we investigated natural plant components and artificial analogs on their capability of altering the thermal reactivity of 4MTB-GLS in vegetable broths and model systems using buffers.

Effect of long-term storage on glucosinolate and S-methyl-l-cysteine sulfoxide hydrolysis in cabbage (Brassica oleracea var. capitata).

Cabbages are good sources for glucosinolates and S-methyl-l-cysteine sulfoxide (SMCSO), precursors to bioactive volatile hydrolysis products such as isothiocyanates, sulfides and thiosulfinates. Often, white and red cabbages are stored at 0 °C for many months before being sold. Here, we investigated the effect of storage for up to eight months on glucosinolates, SMCSO and the formation of isothiocyanates and derived amines, (epithio)nitriles and volatile organosulfur compounds (VOSCs) in white and red cabbages.

Glucosinolate Accumulation and Hydrolysis in Leafy Vegetables Are Influenced by Leaf Age.

The health-beneficial effects of vegetables are mainly attributed to their high contents of glucosinolates and the products of their hydrolysis, especially isothiocyanates. Distribution of glucosinolates across plant organs can strongly vary. Here, we investigated the effect of leaf age on glucosinolate accumulation and hydrolysis in two leafy vegetables, pak choi and giant red mustard.

Glucosinolate-derived amine formation in Brassica oleracea vegetables.

Glucosinolates are precursors of bioactive and health-promoting isothiocyanates (ITCs). Upon enzymatic hydrolysis, Brassica vegetables, such as cabbage, also often yield nitriles and epithionitriles as main products next to ITCs. Here, we show that amines can be additional main enzymatic hydrolysis products of glucosinolates in Brassica vegetables.

Metabolism and Recovery of Epithionitriles from Glucosinolates-A Human Intervention Study.

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.

Plant matrix concentration and redox status influence thermal glucosinolate stability and formation of nitriles in selected Brassica vegetable broths.

Brassica vegetables are frequently consumed foods of nutritional interest, because they are rich in glucosinolates (GLSs). Among GLS breakdown products, especially isothiocyanates are known for their health-beneficial effects, while nitriles are less beneficial. To increase the understanding of the plant matrix's influence on GLS degradation, differently concentrated vegetable broths were prepared from selected Brassica vegetables (kohlrabi and red cabbage) and subsequently boiled.

Assessing Bioavailability and Bioactivity of 4-Hydroxythiazolidine-2-Thiones, Newly Discovered Glucosinolate Degradation Products Formed During Domestic Boiling of Cabbage.

Glucosinolates are plant secondary metabolites found in cruciferous vegetables (Brassicaceae) that are valued for their potential health benefits. Frequently consumed representatives of these vegetables, for example, are white or red cabbage, which are typically boiled before consumption. Recently, 3-alk(en)yl-4-hydroxythiazolidine-2-thiones were identified as a class of thermal glucosinolate degradation products that are formed during the boiling of cabbage.

Formation and stability of isothiocyanate protein conjugates at different pH values and bread types enriched with nasturtium (Tropaeolum majus L.).

Brassicaceae vegetables are rich in glucosinolates (GLS), which degrade into various breakdown products, including isothiocyanates (ITC), during food processing. ITC are associated with health-promoting properties; therefore, producing food products enriched with a high content of these compounds is of interest for improving and maintaining human health. The present study aimed at evaluating a potential increase in ITC formation in Brassicaceae-enriched bread while minimizing ITC-protein conjugates.

Novel transformation products from glucosinolate-derived thioglucose and isothiocyanates formed during cooking.

Glucosinolates are plant secondary metabolites occurring in Brassicaceae plants. Upon tissue disruption, these compounds can be enzymatically hydrolyzed into isothiocyanates, which are very reactive and can react with nucleophiles during thermal processes such as boiling. Here, a novel type of glucosinolate degradation product was identified resulting from the reaction of thioglucose with the isothiocyanates sulforaphane or allyl isothiocyanate during aqueous heating.

Formation of volatile sulfur compounds and S-methyl-l-cysteine sulfoxide in Brassica oleracea vegetables.

Besides glucosinolates, Brassica vegetables accumulate sulfur-containing (+)-S-methyl-l-cysteine sulfoxide (SMCSO, methiin), mainly known from Allium vegetables. Such (+)-S-alk(en)yl-l-cysteine sulfoxides can degrade to volatile organosulfur compounds (VOSCs), which have been linked to health beneficial effects. In the present study, the accumulation of SMCSO and the formation of VOSCs was investigated in Brassica oleracea vegetables.

Advanced Research on Glucosinolates in Food Products.

Glucosinolate-containing foods, such as vegetables from the plant order Brassicales and its derivative products, are valued for their health-beneficial properties [...

Determination of Isothiocyanate-Protein Conjugates in a Vegetable-Enriched Bread.

Vegetables of the plant order Brassicales are believed to have health-promoting properties, as they provide high contents of glucosinolates (GLS) and deriving from these, enzymatically and heat-induced breakdown products, such as isothiocyanates (ITC). Besides their positive physiological effects, ITC are electrophilic and can undergo reactions with food components such as proteins. Following the trend of improving traditional food products with GLS-rich ingredients, interactions of ITC with proteins can diminish the properties of both components-protein's value and functionality as well as ITC's bioactivity.

Allyl Isothiocyanate: A TAS2R38 Receptor-Dependent Immune Modulator at the Interface Between Personalized Medicine and Nutrition.

Understanding individual responses to nutrition and medicine is of growing interest and importance. There is evidence that differences in bitter taste receptor (TAS2R) genes which give rise to two frequent haplotypes, TAS2R38-PAV (functional) and TAS2R38-AVI (non-functional), may impact inter-individual differences in health status. We here analyzed the relevance of the TAS2R38 receptor in the regulation of the human immune response using the TAS2R38 agonist allyl isothiocyanate (AITC) from plants.

Seasonal Variation of Glucosinolate Hydrolysis Products in Commercial White and Red Cabbages ( var. ).

vegetables contain glucosinolates, which are well-known for their potential to form health-promoting isothiocyanates. Among those crucifers, white and red cabbage are commonly consumed vegetables, exhibiting different glucosinolate and hydrolysis profiles thereof. Regarding the health beneficial effects from these vegetables, more information, especially concerning the seasonal variation of glucosinolate profiles and the formation of their bioactive hydrolysis products in commercial cabbages, is needed.

Corrigendum: Identification and Characterization of Three Epithiospecifier Protein Isoforms in .

[This corrects the article on p. 1552 in vol. 10, PMID: 31921230.

Domestic boiling and salad preparation habits affect glucosinolate degradation in red cabbage (Brassica oleracea var. capitata f. rubra).

Red cabbage contains glucosinolates, precursors to health-promoting isothiocyanates. However, raw cabbage often releases mainly epithionitriles and nitriles from glucosinolates. To increase isothiocyanate formation, the effect of acid usage in the preparation of red cabbage was evaluated.

Identification and Characterization of Three Epithiospecifier Protein Isoforms in .

Glucosinolates present in play a major role in herbivory defense. Upon tissue disruption, glucosinolates come into contact with myrosinase, which initiates their breakdown to biologically active compounds. Among these, the formation of epithionitriles is triggered by the presence of epithiospecifier protein (ESP) and a terminal double bond in the glucosinolate side chain.

Brassica-enriched wheat bread: Unraveling the impact of ontogeny and breadmaking on bioactive secondary plant metabolites of pak choi and kale.

Consumption of Brassica vegetables is linked to health benefits, as they contain high concentrations of the following secondary plant metabolites (SPMs): glucosinolate breakdown products, carotenoids, chlorophylls, and phenolic compounds. Especially Brassica vegetables are consumed as microgreens (developed cotyledons). It was investigated how different ontogenetic stages (microgreens or leaves) of pak choi (Brassica rapa subsp.