Glucoraphenin

Effect of aliphatic diamine spacer length on enzymatic performance of myrosinase immobilized on chitosan microsphere and its application for sulforaphene production.[Pubmed:31042585]

J Biotechnol. 2019 Jun 20;299:79-85.

Glucosinolates can be hydrolyzed by the enzyme commonly known as myrosinase (E.C. 3.2.1.147) to a variety of biological compounds. Myrosinase (MYR) has been immobilized through the flexible spacers of different length on cross-linked chitosan resin (CCR). Ethylene diamine, hexamethylenediamine and decamethylene-diamine have been separately used as spacers. The influence of the flexible spacer length on the immobilized MYR (IMYR) properties were evaluated. The optimum pH and Vmax of IMYR linearly increase with the flexible spacer length, and the optimum temperature and Km of IMYR show an opposite trend. The recyclability of IMYR was good, with 90% recovery of activity after 10 cycles and 80% recovery after 30 cycles. IMYR was highly stable under storage conditions, with 95% recovery of activity after one year storage at 4 degrees C. The IMYR with the longest flexible spacer, decamethylene-diamine, was used as a biocatalyst for sulforaphene production. The overall hydrolysis ratio of Glucoraphenin was 93.25 +/- 0.91% and the activity of DDMCCR-IMYR remained 95% after 10 days of continuous use.

Bunias erucago L.: Glucosinolate Profile and In Vitro Biological Potential.[Pubmed:30791395]

Molecules. 2019 Feb 19;24(4). pii: molecules24040741.

Bunias erucago belongs to the Brassicaceae family, which represents a forgotten crop of the Euro-Mediterranean area. The aim of the present study was to determine the glucosinolate profile in different plant parts and biological properties (antioxidant, anticholinesterase, and cytotoxic activities) of the isolates containing glucosinolate breakdown products. The chemical profiles were determined by using HPLC-PDA-MS/MS of desulfoglucosinolates and GC-MS of glucosinolate degradation products. The analysis of B. erucago showed the presence of seven glucosinolates: gluconapin (1), glucoraphasatin (2), Glucoraphenin (3), glucoerucin (4), glucoraphanin (5), glucotropaeolin (6), and glucosinalbin (7). The total glucosinolate content ranged from 7.0 to 14.6 micromol/g of dry weight, with the major glucosinolate glucosinalbin in all parts. The antioxidant activity of all volatile isolates was not notable. At a tested concentration of 227 mug/mL, flower hydro-distillate (FH) showed good AChE inhibition, i.e., 40.9%, while root hydro-distillate (RH) had good activity against BChE, i.e., 54.3%. FH showed the best activity against both tested human bladder cancer cell lines, i.e., against T24 after 72 h, which have IC50 of 16.0 mug/mL, and against TCCSUP after 48 h with IC50 of 7.8 mug/mL, and can be considered as highly active. On the other hand, RH showed weak activity against tested cancer cells.

The mechanism of deterioration of the glucosinolate-myrosynase system in radish roots during cold storage after harvest.[Pubmed:28530612]

Food Chem. 2017 Oct 15;233:60-68.

The hydrolysis of glucosinolates (GSLs) by myrosinase yields varieties of degradation products including isothiocyanates (ITCs). This process is controlled by the glucosinolate-myrosinase (G-M) system. The major ITCs in radish roots are raphasatin and sulforaphene (SFE), and the levels of these compounds decrease during storage after harvest. We investigated the G-M system to understand the mechanism behind the decrease in the ITCs in radish roots. Six varieties of radish roots were stored for 8weeks at 0-1.5 degrees C. The concentrations of GSLs (glucoraphasatin and Glucoraphenin) were maintained at harvest levels without significant changes during the storage period. However, SFE concentration and myrosinase activity remarkably decreased for 8weeks. Pearson correlation analysis between ITCs, GSLs, and myrosinase activity showed that a decrease of SFE during storage had a positive correlation with a decrease in myrosinase activity, which resulted from a decrease of ascorbic acid but also a decrease of myrosinase activity-related gene expressions.

Development of an efficient glucosinolate extraction method.[Pubmed:28344636]

Plant Methods. 2017 Mar 21;13:17.

BACKGROUND: Glucosinolates, anionic sulfur rich secondary metabolites, have been extensively studied because of their occurrence in the agriculturally important brassicaceae and their impact on human and animal health. There is also increasing interest in the biofumigant properties of toxic glucosinolate hydrolysis products as a method to control agricultural pests. Evaluating biofumigation potential requires rapid and accurate quantification of glucosinolates, but current commonly used methods of extraction prior to analysis involve a number of time consuming and hazardous steps; this study aimed to develop an improved method for glucosinolate extraction. RESULTS: Three methods previously used to extract glucosinolates from brassicaceae tissues, namely extraction in cold methanol, extraction in boiling methanol, and extraction in boiling water were compared across tissue type (root, stem leaf) and four brassicaceae species (B. juncea, S. alba, R. sativus, and E. sativa). Cold methanol extraction was shown to perform as well or better than all other tested methods for extraction of glucosinolates with the exception of glucoraphasatin in R. sativus shoots. It was also demonstrated that lyophilisation methods, routinely used during extraction to allow tissue disruption, can reduce final glucosinolate concentrations and that extracting from frozen wet tissue samples in cold 80% methanol is more effective. CONCLUSIONS: We present a simplified method for extracting glucosinolates from plant tissues which does not require the use of a freeze drier or boiling methanol, and is therefore less hazardous, and more time and cost effective. The presented method has been shown to have comparable or improved glucosinolate extraction efficiency relative to the commonly used ISO method for major glucosinolates in the Brassicaceae species studied: sinigrin and gluconasturtiin in B. juncea; sinalbin, glucotropaeolin, and gluconasturtiin in S. alba; Glucoraphenin and glucoraphasatin in R. sativus; and glucosatavin, glucoerucin and glucoraphanin in E. sativa.

Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster.[Pubmed:26901196]

Int J Mol Sci. 2016 Feb 18;17(2):251.

We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of Glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARgamma-coactivator 1 alpha, as well as the inhibition of alpha-amylase and alpha-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus.

Methyl Jasmonate- and Light-Induced Glucosinolate and Anthocyanin Biosynthesis in Radish Seedlings.[Pubmed:26411013]

Nat Prod Commun. 2015 Jul;10(7):1211-4.

Radish sprouts and young seedlings are considered important dietary vegetables in Asian countries. In this study, we investigated the levels of glucosinolate and anthocyanin accumulation in radish seedlings in response to light and methyl jasmonate (MeJA) treatments. MeJA facilitated the accumulation of glucosinolate and anthocyanins under light conditions. The glucosinolate and anthocyanin contents in the radish seedlings that were exposed to light after MeJA treatment were higher than those of the seedlings that were grown in the dark without MeJA. At a concentration of 100 muM, MeJA led to the greatest accumulation of the most glucosinolates under both light and dark conditions. Under light conditions, the levels of Glucoraphenin, glucoerucin, and glucotropaeolin accumulation were 1.53-, 1.60-, and 1.30-fold higher, respectively, than those of the control. Remarkable accumulations of glucobrassicin were observed under light conditions (4.4-, 6.7-, and 7.8-fold higher than that of the control following the application of 100, 300, and 500 muM MeJA, respectively). The level of cyanidin in the 300 muM MeJA-treated seedlings was double of that in the control without MeJA treatment. The highest level of pelargonidin was observed after treatment with 500 muM MeJA under light conditions; this level was 1.73 times higher than that in the control. A similar trend of anthocyaninaccumulation was observed in the radish seedlings following MeJA treatment under dark conditions, but the levels of anthocyanins were considerably lower in the seedlings that were grown in the dark. Our findings suggest that light and low concentrations of MeJA enhance the accumulations of glucosinolates and anthocyanins during the development of radish seedlings.

Inhibitory effect of Raphanobrassica on Helicobacter pylori-induced gastritis in Mongolian gerbils.[Pubmed:24835035]

Food Chem Toxicol. 2014 Aug;70:107-13.

Helicobacter pylori (H. pylori) infection is well known to be associated with chronic gastritis and also development of gastric cancer. Raphanobrassica (RB) is an intergeneric hybrid of the genera Raphanus (radish) and Brassica (cabbages) containing appreciable amounts of glucoraphanin (GR) and Glucoraphenin (GRe), which are actively hydrolyzed by the enzyme myrosinase to sulforaphane and sulforaphene, respectively. Both of these metabolites exert antimicrobial and anti-inflammatory activity. The purpose of the present study was to investigate the effect of two freeze-dried products of RB (RB1 and RB2) on H. pylori-induced gastritis in Mongolian gerbils. Six-week-old male Mongolian gerbils were inoculated orally with H. pylori (ATCC 43504), and 2weeks later were fed diets containing no additives or diets supplemented with 2% RB1 (containing both GR and GRe) or 2% RB2 (containing GR only) for 10weeks. In the RB1, but not the RB2 group, mononuclear cell infiltration, mRNA expression of IL-6, and cell proliferation in the gastric mucosa were significantly suppressed. These results indicate that RB1 containing both GR and GRe exerted significant inhibitory effects on H. pylori-induced gastritis in Mongolian gerbils apparently mediated via suppression of IL-6 expression and chronic inflammation.

Biotic elicitors effectively increase the glucosinolates content in Brassicaceae sprouts.[Pubmed:24484436]

J Agric Food Chem. 2014 Feb 26;62(8):1881-9.

Several biotic elicitors have been used in Brassicaceae species to enhance their phytochemical quality. However, there is no comparison between elicitors under controlled growth conditions. In order to draw general conclusions about the use of elicitors to enrich ready-to-eat sprouts in health-promoting glucosinolates, the aim of this study was to unveil the effect of the phytohormones methyl jasmonate (25 muM), jasmonic acid (150 muM), and salicylic acid (100 muM), the oligosaccharides glucose (277 mM) and sucrose (146 mM), and the amino acid dl-methionine (5 mM) as elicitors over 8-day sprouting Brassica oleraceae (broccoli), Brassica napus (rutabaga cabbage), Brassica rapa (turnip), and Raphanus sativus (China rose radish and red radish), representative species high in glucosinolates previously studied. Results indicated that the phytohormones methyl jasmonate and jasmonic acid and the sugars acted as effective elicitors, increasing the total glucosinolate contents of the sprouts, particularly, glucoraphanin (from 183 to 294 mg.100 g(-1) in MeJA-treated broccoli sprouts), Glucoraphenin (from 33 to 124 mg.100 g(-1) and from 167 to 227 mg.100 g(-1) in MeJA-treated China rose radish and red radish, respectively), and glucobrassicin (from 23.4 to 91.0 mg.100 g(-1) and from 29.6 to 186 mg.100 g(-1) in MeJA-treated turnip and rutabaga sprouts, respectively).

Removal of off-flavours from radish (Raphanus sativus L.) anthocyanin-rich pigments using chitosan and its mechanism(s).[Pubmed:24176362]

Food Chem. 2014 Mar 1;146:423-8.

In this paper, we examined the role of chitosan in the removal of off-flavours from radish anthocyanin-rich pigments and studied the mechanisms of the process. Four radish glucosinolates (Glucoraphenin, dehydroerucin, glucobrassicin, and glucoerucin) were identified by LC-MSn from root extracts and dehydroerucin was found to be the major glucosinolate in red radish roots. Application of chitosan with 76%, 83% or 89% deacetylation in radish extracts attributed to 26%, 35% or 43% adsorption rate for glucosinolates, and 28%, 26% or 22% for anthocyanins, respectively. HS-SPME/GC-MS analysis demonstrated that the concentration of volatile compounds decreased by 70%, resulting in the loss of odorous compounds. The changes in chitosan spectra before/after adsorption and after desorption at 1590 and 3360cm(-1) and at broad bands from 2600 to 2000cm(-1) suggest that the dominant adsorption mechanisms of glucosinolates on chitosan may be electrostatic attractions, including hydrogen bonds and charge neutralisation.

Instability and Structural Change of 4-Methylsulfinyl-3-butenyl Isothiocyanate in the Hydrolytic Process.[Pubmed:23688308]

J Agric Food Chem. 2013 May 29;61(21):5097-102.

Sulforaphene (4-methylsulfinyl-3-butenyl isothiocyanate), which has significant chemopreventive activities, is an important phytochemical ingredient produced by myrosinase hydrolysis of Glucoraphenin (4-methylsulfinyl-3-butenyl glucosinolate) found in radish seeds. In this research, we found that sulforaphene was unstable and converted rapidly to a water-soluble degradation product in the hydrolytic process. The degradation product was successfully purified by preparative high-performance liquid chromatography on a C18 column using 10% methanol in water as the mobile phase. On the basis of MS and NMR spectroscopy data, the degradation product was identified to be 6-[(methylsulfinyl)methyl]-1,3-thiazinan-2-thione. The degradation pathway of sulforaphene was proposed in our study. Furthermore, low pH and metal ions were also found to have an effective inhibition to the degradation reaction of sulforaphene. Through adjusting the pH value of the system or adding metal ions after the content of sulforaphene has reached its maximum, the yield of sulforaphene increased significantly compared with that of the control.