sinigrin and allyl-isothiocyanate

In this study an active antimicrobial packaging based on the controlled release of Allyl isothiocyanate (AITC) from mustard seed was designed. The effect of fat content and particle size of ground mustard seeds on formation and release of AITC was investigated and the underlying mechanisms were highlighted. A smaller size of mustard particles resulted in more sinigrin conversion to AITC and a higher release of AITC in the headspace. The fat content has an important role on AITC release, a decreased fat content decreased AITC levels in the particles and increased the amount of AITC in the headspace. Based on the results of the sinigrin hydrolysis, the AITC surface exchange rate and the AITC fat solubility, an overall picture of the factors influencing the AITC release from the particles is proposed, which describes formation of AITC and its partitioning between the compartments of the particles and the headspace.

Topics: Anti-Bacterial Agents; Fats; Glucosinolates; Isothiocyanates; Mustard Plant; Particle Size; Product Packaging; Seeds

The functional food Cruciferous vegetables contain glucosinolates which are decomposed by the myrosinase enzyme upon tissue damage. The isothiocyanates are the most frequent decomposition products. Because of their various bioactivities, these compounds and the myrosinase is of high interest to many scientific fields.. Development of a capillary electrophoresis method capable of myrosinase-compatible, simultaneous quantification of glucosinolates and isothiocyanates.. Capillary electrochromatography parameters were optimised, followed by optimisation of a myrosinase-compatible derivatisation procedure for isothiocyanates. Vegetable extracts (Brussels sprouts, horseradish, radish and watercress) were tested for myrosinase activity, glucosinolate content and isothiocyanate conversion rate. Allyl isothiocyanate was quantified in some food products.. The method allows quantification of sinigrin, gluonasturtiin and allyl isothiocyanate after myrosinase compatible derivatisation in-vial by mercaptoacetic acid. The chromatograhpic separation takes 2.5 min (short-end injection) or 15 min (long-end injection). For the tested vegetables, measured myrosinase activity was between 0.960-27.694 and 0.461-26.322 µmol/min/mg protein, glucosinolate content was between 0-2291.8 and 0-248.5 µg/g fresh weight for sinigrin and gluconastrutiin, respectively. The possible specificity of plants to different glucosinolates was also shown. Allyl isothiocyanate release rate was different in different vegetables (73.13 - 102.13%). The method could also be used for quantification of allyl isothiocyanate from food products.. The presented capillary electrophoresis method requires a minimal amount of sample and contains only a few sample preparation steps, and can be used in several applications (glucosinolate determination, myrosinase activity measurement, isothiocyanate release estimation). Copyright © 2016 John Wiley & Sons, Ltd.

Topics: Armoracia; Brassica; Chromatography, Micellar Electrokinetic Capillary; Electrophoresis, Capillary; Glucosinolates; Glycoside Hydrolases; Isothiocyanates; Molecular Structure; Nasturtium; Plant Extracts; Raphanus; Sensitivity and Specificity; Time Factors; Vegetables

In this study, the effect of myrosinase-treated glucoerucin (GER+MYR), which releases the isothiocyanate (ITC) erucin, on heme oxygenase 1 (HO-1) gene expression and Nrf2 signaling was investigated in vitro in cultured cells and in vivo in mice. Treatment of HT-29 cells with GER+MYR resulted in a significant increase in the mRNA and protein levels of nuclear Nrf2 and HO-1. GER+MYR was more potent at enhancing the nuclear Nrf2 levels than were the following myrosinase-treated glucosinolates: sinigrin, glucoraphanin and gluconasturtiin, which are the precursors of allyl-ITC, R-sulforaphane and 2-phenylethyl ITC, respectively. GER+MYR also significantly induced HO-1 gene expression in the mouse intestinal mucosae and liver but not in the brain. Mechanistic studies suggest that GER+MYR induces Nrf2 via ERK1/2-, p38- and JNK-dependent signal transduction pathways. The GER+MYR-mediated increase in HO-1 expression is primarily attributable to p38 signaling.

Topics: Animals; Brain; Diet, High-Fat; Female; Glucose; Glucosinolates; Glycoside Hydrolases; Heme Oxygenase-1; HT29 Cells; Humans; Imidoesters; Intestinal Mucosa; Intestines; Isothiocyanates; Liver; Membrane Proteins; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 3; Mustard Plant; NF-E2-Related Factor 2; Oximes; p38 Mitogen-Activated Protein Kinases; Plant Extracts; RNA, Messenger; Signal Transduction; Sulfoxides; Up-Regulation

This study was aimed to identify sinigrin-induced bacterial proteins potentially involved in the metabolism of glucosinolate in two glucosinolate-metabolising bacteria Lactobacillus agilis R16 and Escherichia coli VL8. Sinigrin (2 mM) was used to induce the proteins in both bacteria under anaerobic incubation for 8 h at 30 °C for L. agilis R16 and 37 °C for E. coli VL8 and the controls without sinigrin were performed. Allyl isothiocyanate and allyl nitrile as two degradation products of sinigrin were detected in sinigrin-induced cultures of L. agilis R16 (27% total products) and E. coli VL8 (38% total products) from a complete sinigrin degradation in 8 h for both bacteria. 2D gel electrophoresis was conducted to identify induced proteins with at least twofold increased abundance. Sinigrin-induced L. agilis R16 and the control produced 1561 and 1543 protein spots, respectively. For E. coli VL8, 1363 spots were detected in sinigrin-induced and 1354 spots in the control. A combination of distinct proteins and upregulated proteins of 32 and 35 spots in L. agilis R16 and E. coli VL8, respectively were detected upon sinigrin induction. Of these, 12 and 16 spots from each bacterium respectively were identified by LC-MS/MS. In both bacteria most of the identified proteins are involved in carbohydrate metabolism, oxidoreduction system and sugar transport while the minority belong to purine metabolism, hydrolysis, and proteolysis. This indicated that sinigrin induction led to the expressions of proteins with similar functions in both bacteria and these proteins may play a role in bacterial glucosinolate metabolism.

Topics: Bacterial Proteins; Chromatography, High Pressure Liquid; Electrophoresis, Gel, Two-Dimensional; Escherichia coli; Glucosinolates; Glycoside Hydrolases; Hydrolysis; Isothiocyanates; Lactobacillus; Nitriles; Tandem Mass Spectrometry

Members of the Brassicaceae are known for their contents of nutrients and health-promoting phytochemicals, including glucosinolates. The concentrations of these chemopreventive compounds (glucosinolate-degradation products, the bioactive isothiocyanates) may be modified under salinity. In this work, the effect of the aliphatic glucosinolate sinigrin (2-propenyl-glucosinolate) on plant water balance, involving aquaporins, was explored under salt stress. For this purpose, water uptake and its transport through the plasma membrane were determined in plants after NaCl addition, when sinigrin was also supplied. We found higher hydraulic conductance (L0 ) and water permeability (Pf ) and increased abundance of PIP2 aquaporins after the direct administration of sinigrin, showing the ability of the roots to promote cellular water transport across the plasma membrane in spite of the stress conditions imposed. The higher content of the allyl-isothiocyanate and the absence of sinigrin in the plant tissues suggest that the isothiocyanate is related to water balance; in fact, a direct effect of this nitro-sulphate compound on water uptake is proposed. This work provides the first evidence that the addition of a glucosinolate can regulate aquaporins and water transport: this effect and the mechanism(s) involved merit further investigation.

Topics: Amino Acids; Aquaporins; Biological Transport; Brassica; Cell Membrane Permeability; Gene Expression Regulation, Plant; Glucosinolates; Isothiocyanates; Osmosis; Plant Roots; Sodium Chloride; Solutions; Stress, Physiological; Sulfates; Time Factors; Water

The antimicrobial activities of oriental mustard extract alone or combined with malic acid and EDTA were investigated against Salmonella spp. or Listeria monocytogenes at different temperatures. Five strain Salmonella or L. monocytogenes cocktails were separately inoculated in Brain Heart Infusion broth containing 0.5% (w/v) aqueous oriental mustard extract and incubated at 4 °C to 21 °C for 21 d. For inhibitor combination tests, Salmonella Typhimurium 02:8423 and L. monocytogenes 2-243 were individually inoculated in Mueller Hinton broth containing the mustard extract with either or both 0.2% (w/v) malic acid and 0.2% (w/v) EDTA and incubated at 10 °C or 21 °C for 10 to 14 d. Mustard extract inhibited growth of the L. monocytogenes cocktail at 4 °C up to 21 d (2.3 log10 CFU/mL inhibition) or at 10 °C for 7 d (2.4 log10 CFU/mL inhibition). Salmonella spp. viability was slightly, but significantly reduced by mustard extract at 4 °C by 21 d. Although hydrolysis of sinigrin in mustard extract by both pathogens was 2 to 6 times higher at 21 °C than at 4 °C to 10 °C, mustard was not inhibitory at 21 °C, perhaps because of the instability of its hydrolysis product (allyl isothiocyanate). At 21 °C, additive inhibitory effects of mustard extract with EDTA or malic acid led to undetectable levels of S. Typhimurium and L. monocytogenes by 7 d and 10 d, respectively. At 10 °C, S. Typhimurium was similarly susceptible, but combinations of antimicrobials were not more inhibitory to L. monocytogenes than the individual agents.

Topics: Animals; Anti-Bacterial Agents; Culture Media; Edetic Acid; Food Microbiology; Glucosinolates; Humans; Isothiocyanates; Listeria monocytogenes; Malates; Mustard Plant; Plant Preparations; Salmonella; Salmonella typhimurium

Factors, including pH, temperature, glucose concentration, and iron compounds, affect the activity of plant myrosinase and, consequently, endogenous glucosinolate degradation. These factors also may affect glucosinolate degradation by bacterial myrosinase. Therefore, this study examined the effect of temperature (4 to 21°C), glucose (0.05 to 1.0%), and iron (10 mM ferrous or ferric) on sinigrin degradation by Salmonella or Listeria monocytogenes cocktails in Mueller-Hinton broth and the effect of sinigrin degradation on bacterial viability. The degradation of sinigrin by both pathogens increased with higher temperatures (21 > 10 > 4°C). Salmonella and L. monocytogenes cocktails hydrolyzed 59.1 and 53.2% of sinigrin, respectively, at 21°C up to 21 days. Both iron compounds significantly enhanced sinigrin degradation by the pathogens. On day 7, sinigrin was not detected when the Salmonella cocktail was cultured with ferrous iron or when the L. monocytogenes cocktail was cultured in Mueller-Hinton broth containing ferric iron. In contrast, ferric and ferrous iron inhibited the activity of 0.002 U/ml myrosinase from white mustard by 63 and 35%, respectively, on day 1. Salmonella and L. monocytogenes cocktails were able to degrade >80% of sinigrin at 0.05 and 0.1% glucose; however, 0.25 to 1.0% glucose significantly reduced sinigrin degradation. Although both pathogens significantly degraded sinigrin, the allyl isothiocyanate (AITC) recoverable was ≤6.2 ppm, which is not inhibitory to Salmonella or L. monocytogenes. It is probable that the gradual hydrolysis of sinigrin to form AITC either did not produce an inhibitory level of AITC or the AITC formed was unstable in the aqueous medium and rapidly decomposed to new compounds that were less bactericidal against the pathogens.

Topics: Glucose; Glucosinolates; Glycoside Hydrolases; Hydrolysis; Iron; Isothiocyanates; Listeria monocytogenes; Microbial Viability; Mustard Plant; Salmonella; Temperature

The glucosinolate sinigrin (SNG) is converted by endogenous plant myrosinase or by bacterial myrosinase-like activity to form the potent antimicrobial allyl isothiocyanate. In order to use SNG as a natural antimicrobial precursor in food, it became important to better understand the ability of bacteria to synthesize the enzyme(s) and understand factors influencing this synthesis at a constant SNG concentration. Eight spoilage, pathogenic, or starter culture bacteria were grown separately in medium containing individual or combined salts with SNG. SNG degradation by the bacteria and the formation of its major degradation product, allyl isothiocyanate, were followed for 12 days at 30 or 35°C. The bacterial strains varied in their ability to metabolize SNG, and this was enhanced by NaCl and/or NaNO(3). SNG hydrolysis took place after 4 days, and the greatest amount occurred by day 12. At 12 days, Escherichia coli O157:H7 showed the greatest capacity to hydrolyze SNG (45.3% degradation), followed by Staphylococcus carnosus (44.57%), while Pseudomonas fluorescens was not active against SNG. The ability of tested strains to metabolize SNG, in decreasing order, was as follows: Escherichia coli O157:H7 > Staphylococcus carnosus > Staphylococcus aureus > Pediococcus pentosaceus > Salmonella Typhimurium > Listeria monocytogenes > Enterococcus faecalis > Pseudomonas fluorescens.

Topics: Bacteria; Food Microbiology; Food Preservatives; Food Safety; Glucosinolates; Humans; Hydrolysis; Isothiocyanates; Sodium Chloride; Sodium Nitrite; Temperature; Time Factors

Sinigrin (SIN) and allyl isothiocyanate (AITC) are compounds found in high concentrations in Brassica family vegetables, especially in Brussels sprouts. Recently, they have been used as a nutrition supplement for their preventive and medicinal effect on some types of cancer and other diseases. In this research, nutritional significance of parent glucosinolate sinigrin 50 μmol/kg b. w./day and its degradation product allyl isothiocyanate 25 μmol/kg b. w./day and 50 μmol/kg b. w./day was studied by the evaluation of their influence on some parameters of carbohydrate and lipid metabolism in an animal rat model in vivo after their single (4 h) and 2 weeks oral administration. Additionally, the aim of this trial was to evaluate the direct action of AITC on basal and epinephrine-induced lipolysis in isolated rat adipocytes at concentration 1 μM, 10 μM and 100 μM in vitro. Sole AITC after 4 h of its ingestion caused liver triacylglycerols increment at both doses and glycaemia only at the higher dose. Multiple SIN treatment showed its putative bioconversion into AITC. It was found that SIN and AITC multiple administration in the same way strongly disturbed lipid and carbohydrate homeostasis, increasing esterified and total cholesterol, free fatty acids and lowering tracylglycerols in the blood serum. Additionally, AITC at both doses elevated insulinaemia and liver glycogen enhancement. The in vitro experiment revealed that AITC potentiated basal lipolysis process at 10 μM, and had stimulatory effect on epinephrine action at 1 μM and 10 μM. The results of this study demonstrated that the effect of SIN and AITC is multidirectional, indicating its impact on many organs like liver as well as pancreas, intestine in vivo action and rat adipocytes in vitro. Whilst consumption of cruciferous vegetables at levels currently considered "normal" seems to be beneficial to human health, this data suggest that any large increase in intake could conceivably lead to undesirable effect. This effect is potentiated with time of action of the examined compounds, whose influence is rather adverse for the majority of metabolic pathways (liver steatosis at short duration and insulinaemia, cholesterolaemia at long time treatment). Beneficial action of AITC concerned intensified hydrolysis of TG in the blood serum with a simultaneous lipolysis in adipocytes.

Topics: Adipocytes; Animals; Brassica; Carbohydrate Metabolism; Cholesterol; Dose-Response Relationship, Drug; Epinephrine; Esterification; Fatty Acids, Nonesterified; Fatty Liver; Glucosinolates; Glycogen; Homeostasis; Hydrolysis; Hyperinsulinism; Isothiocyanates; Lipid Metabolism; Lipolysis; Liver; Male; Models, Animal; Pancreas; Rats; Rats, Wistar; Time Factors; Triglycerides

Allyl isothiocyanate (AITC), which occurs in many common cruciferous vegetables, was recently shown to be selectively delivered to bladder cancer tissues through urinary excretion and to inhibit bladder cancer development in rats. The present investigation was designed to test the hypothesis that AITC-containing cruciferous vegetables also inhibit bladder cancer development. We focused on an AITC-rich mustard seed powder (MSP-1). AITC was stably stored as its glucosinolate precursor (sinigrin) in MSP-1. Upon addition of water, however, sinigrin was readily hydrolyzed by the accompanying endogenous myrosinase. This myrosinase was also required for full conversion of sinigrin to AITC in vivo, but the matrix of MSP-1 had no effect on AITC bioavailability. Sinigrin itself was not bioactive, whereas hydrated MSP-1 caused apoptosis and G(2)/M phase arrest in bladder cancer cell lines in vitro. Comparison between hydrated MSP-1 and pure sinigrin with added myrosinase suggested that the anticancer effect of MSP-1 was derived principally, if not entirely, from the AITC generated from sinigrin. In an orthotopic rat bladder cancer model, oral MSP-1 at 71.5 mg/kg (sinigrin dose of 9 μmol/kg) inhibited bladder cancer growth by 34.5% (P < 0.05) and blocked muscle invasion by 100%. Moreover, the anticancer activity was associated with significant modulation of key cancer therapeutic targets, including vascular endothelial growth factor, cyclin B1 and caspase 3. On an equimolar basis, the anticancer activity of AITC delivered as MSP-1 appears to be more robust than that of pure AITC. MSP-1 is thus an attractive delivery vehicle for AITC and it strongly inhibits bladder cancer development and progression.

Topics: Animals; Antineoplastic Agents, Phytogenic; Caspase 3; Cell Line, Tumor; Cyclin B1; Female; Glucosinolates; Humans; Isothiocyanates; Mustard Plant; Neoplasm Invasiveness; Poly(ADP-ribose) Polymerases; Rats; Rats, Inbred F344; Seeds; Urinary Bladder Neoplasms; Vascular Endothelial Growth Factor A

Food derived from Brassica species is rich in glucosinolates. Hydrolysis of these compounds by myrosinase yields isothiocyanates and other breakdown products, which due to their pungency represent the primary purpose of Indian mustard cultivation. Strong interactive effects of S (0.0, 0.2, and 0.6 g pot(-1)) and N (1, 2, and 4 g pot(-1)) supply on growth, seed yield, and the concentrations of glucosinolates and isothiocyanates in seeds were observed in growth experiments, reflecting the involvement of S-containing amino acids in both protein and glucosinolate synthesis. At intermediate S supply, a strong N-induced S limitation was apparent, resulting in high concentrations of sinigrin (12 micromol g(-1) of DM) and allyl isothiocyanate (213 micromol kg(-1) of DM) at low N supply only. Myrosinase activity in seeds increased under low N and low S supply, but the results do not suggest that sinigrin functions as a transient reservoir for S.

Topics: Drug Interactions; Fertilizers; Glucosinolates; Glycoside Hydrolases; Isothiocyanates; Mustard Plant; Nitrogen; Seeds; Sulfur

Isothiocyanates have been implicated in the cancer-protective effects of brassica vegetables. When cabbage is consumed, sinigrin is hydrolysed by plant or microbial myrosinase partly to allyl isothiocyanate (AITC), which is mainly excreted as N-acetylcysteine conjugates (NAC) of AITC in urine. The effect of cooking cabbage on the excretion of NAC of AITC, and glutathione-S-transferase (GST) and uridine 5'-diphospho-glucuronosyl transferase (UGT) activity in rat liver and colon was investigated. Germ-free (GF) and human faecal microbiota-associated (HFM) rats were fed a control diet containing 20 % raw, lightly cooked, or fully cooked cabbage for 14 d. When plant myrosinase was present, excretion of NAC of AITC/24 h was increased by 1.4 and 2.5 times by the additional presence of microbial myrosinase after consumption of raw and lightly cooked cabbage respectively. When plant myrosinase was absent, as after consumption of fully cooked cabbage, excretion of the AITC conjugate was almost zero in GF and HFM rats. None of the cabbage diets modified hepatic GST activity. When microbiota was absent, colonic GST was 1.3-fold higher after fully cooked cabbage, and hepatic UGT was increased by 1.4-1.8-fold after all cabbage diets, compared with the control feed. There were no differences in GST or UGT following cabbage consumption when microbiota was present. It is possible that other constituents of cabbage, rather than metabolites of glucosinolates per se, may be responsible for changes in phase 2 enzyme activity. The main effect of cooking cabbage and altering colonic microbiota was on excretion of NAC of AITC.

Topics: Acetylcysteine; Animals; Bacteria; Brassica; Colon; Cooking; Diet; Female; Germ-Free Life; Glucosinolates; Glucuronosyltransferase; Glutathione Transferase; Glycoside Hydrolases; Humans; Isothiocyanates; Liver; Male; Models, Animal; Rats; Rats, Inbred F344; Time Factors

The consumption of cauliflower consumers has been related to the olfactory and gustatory sensitivities to potentially objectionable flavor compounds in this vegetable. Based on the ascending concentration series method of limits, a first experiment was designed to develop rapid tests dedicated to estimate individuals' olfactory thresholds for allyl isothiocyanate (AITC) and dimethyl trisulfide (DMTS) and gustatory thresholds for sinigrin (SIN). The best compromise between rapidity and reliability was obtained with two replications of a four-alternative forced choice (AFC) at six ascending concentrations (6x2x4-AFC) for both AITC and DMTS, and with a 6x1x4-AFC for SIN. In a second experiment, sensitivity to SIN, AITC and DMTS was determined on 267 participants divided into three cauliflower consumer target groups: non-, medium- or high consumers. The non-consumers were significantly more sensitive to SIN and AITC than were the medium and high consumers. No effect of consumer's sensitivity to DMTS was observed.

Topics: Adolescent; Adult; Aged; Brassica; Consumer Behavior; Cooking; Female; Food Preferences; Glucosinolates; Humans; Isothiocyanates; Male; Middle Aged; Smell; Sulfides; Taste

Three strains of Bifidobacterium sp., B. pseudocatenulatum, B. adolescentis, and B. longum were studied for their ability to digest glucosinolates, sinigrin (SNG) and glucotropaeolin (GTL), in vitro. All strains digested both glucosinolates during 24-48 h cultivation, accompanied by a decline in the medium pH from 7.1 to 5.2. The digestion of glucosinolates by a cell-free extract prepared from sonicated cells of B. adolescentis, but not cultivated broth, increased in the presence of 0.5 mM l-ascorbic acid. Also, a time-dependent formation of allyl isothiocyanate (AITC) was observed when the cell-free extract was incubated with 0.25 mM SNG for 120 min at pH 7.0. These reaction features suggest that the digestive activity may have been due to an enzyme similar to myrosinase, an enzyme of plant origin. GC-MS analysis of the Bifidobacterial cultured broth showed that the major products were 3-butenenitrile (BCN) and phenylacetonitrile (PhACN), from SNG and GTL, respectively and nitriles, probably due to a decrease in the pH of the media. AITC and benzyl isothiocyanate (BzITC) were barely detectable in the broth. It was concluded that the three species of Bifidobacteria could be involved in digestive degradation of glucosinolates in the human intestinal tract.

Topics: Acetonitriles; Ascorbic Acid; Bifidobacterium; Biotransformation; Culture Media, Conditioned; Digestive System; Gas Chromatography-Mass Spectrometry; Glucosinolates; Hydroxamic Acids; Isothiocyanates; Nitriles; Thioglucosides

A reversed-phase HPLC method for the simultaneous determination of the glucosinolate sinigrin and its major degradation product allyl isothiocyanate (AITC) was developed and used for direct analysis of aqueous extracts from Oriental mustard (Brassica juncea L.) related materials (ground and cracked seeds, powders, and bran) and from soil samples. The lowest detection limit was 0.1 microg/mL for both sinigrin and AITC). The developed method was used to trace the degradation of sinigrin to AITC in aqueous extracts. One of the major advantages of this method is the complete estimation of sinigrin content. The simultaneous analysis of both sinigrin and AITC in a single run avoided the underestimation caused by separate analyses.

Topics: Acetates; Buffers; Chromatography, High Pressure Liquid; Glucosinolates; Isothiocyanates; Mustard Plant; Soil

A human digestive strain of Bacteroides thetaiotaomicron was tested for its ability to metabolise sinigrin, a glucosinolate commonly found in Brassica vegetables. Gnotobiotic rats harbouring the bacterial strain were orally dosed with 50 micromol sinigrin. HPLC analysis of the digestive contents showed that sinigrin was degraded in the large bowel, where B. thetaiotaomicron was established at a high level. Concurrently, a hydrolysis product of sinigrin, allyl isothiocyanate, was identified by GC-MS analysis, following headspace solid-phase microextraction of the digestive contents; its production peaked at ca. 200 nmol, 12 h after dosing. This is the first study to demonstrate in vivo the involvement of a human colonic predominant bacterium in the bioconversion of a dietary glucosinolate to a potentially anticarcinogenic isothiocyanate.

Topics: Animals; Bacteroides; Colon; Digestive System; Germ-Free Life; Glucosinolates; Humans; Isothiocyanates; Rats

Sinigrin, the predominant glucosinolate in the oriental mustard Brassica juncea, is mainly degraded upon the enzymatic action of myrosinase under normal conditions to give allyl isothiocyanate (AITC) in an aqueous media. Because AITC is considered to be the principal nematicidal ingredient in B. juncea, its stability in aqueous media is an important issue in achieving efficient nematode control. Pure sinigrin and AITC were found to be relatively stable in buffered water in the pH range of 5.00-7.00 but less stable at pH 9.00. Both sinigrin and AITC were more stable in soil water (supernatant of a 1:1 water/air-dried soil mixture) than in buffered water at the same pH range of 5.00-9.00. Sinigrin dissolved from the mustard bran or ground seed into water very quickly and was degraded by codissolved myrosinase to AITC. The AITC that formed from the degradation of sinigrin was found to be more stable in the soil water than in the buffered water. Buffer capacity was considered to be one of the factors that contributed to the stabilization of AITC in the soil water, but other unknown factors from both bran or seed and soil may also have contributed to the stabilization.

Topics: Glucosinolates; Hydrolysis; Isothiocyanates; Solubility; Solutions; Water

Four compounds commonly found in the human diet, allyl isothiocyanate (AITC), phenethyl isothiocyanate (PEITC) and their parent glucosinolates sinigrin and gluconasturtiin, were tested for cytotoxic and genotoxic effects in a Chinese hamster ovary cell line (CHO). The isothiocyanates were found to be more than one thousand times more cytotoxic than the glucosinolates, showing significant cytotoxic activity at concentrations below 1.0 microgram/ml. AITC was unable to induce either chromosome aberrations or sister chromatid exchanges (SCEs) even at highly cytotoxic doses. In contrast, PEITC was found to induce both aberrations and SCE at concentrations of 0.9-1.2 micrograms/ml whilst sinigrin and gluconasturtiin induced aberrations at concentrations above 2 mg/ml.

Topics: Animals; Cell Death; CHO Cells; Chromosome Aberrations; Cricetinae; Glucosinolates; Isothiocyanates; Mitotic Index; Mutagens; Sister Chromatid Exchange

Forty-two lactobacilli were screened for their potential to degrade glucosinolate sinigrin. One of them, strain R16, demonstrated a high level of sinigrin degradation; it was identified as Lactobacillus agilis. The sinigrin degrading activity of L. agilis R16 could only be demonstrated when intact cells were used. The products of sinigrin degradation are allyl-isothiocyanate (AITC) and glucose (which is further fermented to DL-lactic acid), suggesting that myrosinase activity is involved. The activity was induced by the presence of sinigrin. Glucose inhibited the myrosinase activity, even in induced cells. Lactobacillus agilis R16 was able to grow on an extract of brown mustard seed and caused glucosinolate degradation.

Topics: Biodegradation, Environmental; Glucosinolates; Glycoside Hydrolases; Isothiocyanates; Lactobacillus; Mustard Plant; Plant Extracts; Plants, Medicinal; Species Specificity