sinigrin and allyl-cyanide

Allyl nitrile (3-butenenitrile) occurs naturally in the environment, in particular, in cruciferous vegetables, indicating a possible daily intake of the compound. There is no report on actual health effects of allyl nitrile in humans, although it is possible that individuals in the environment are at a risk of exposure to allyl nitrile. However, little is known about its quantitative assessment for the environment and bioactivity in the body. This study provides a review of previous accumulated studies on allyl nitrile.. Published literature on allyl nitrile was examined for findings on toxicity, metabolism, risk of various cancers, generation, intake estimates, and low-dose effects in the body.. High doses of allyl nitrile produce toxicity characterized by behavioral abnormalities, which are considered to be produced by an active metabolite, 3,4-epoxybutyronitrile. Cruciferous vegetables have been shown to have a potential role in reducing various cancers. Hydrolysis of the glucosinolate sinigrin, rich in cruciferous vegetables, results in the generation of allyl nitrile. An intake of allyl nitrile is estimated at 0.12 μmol/kg body weight in Japan. Repeated exposure to low doses of allyl nitrile upregulates antioxidant/phase II enzymes in various tissues; this may contribute to a reduction in neurotoxicity and skin inflammation. These high and low doses are far more than the intake estimate.. Allyl nitrile in the environment is a compound with diverse bioactivities in the body, characterized by inducing behavioral abnormalities at high doses and some antioxidant/phase II enzymes at low doses.

Topics: Animals; Antioxidants; Disease Models, Animal; Glucosinolates; Humans; Mental Disorders; Mice; Neoplasms; Nitriles; Rats; Vegetables

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

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