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RECENT work by Gmelin and Virtanen1, concerning the isolation and elucidation of the structure of glucobrassicin, and its reaction with ascorbic acid in the presence of myrosinase to give rise to ascorbigen, prompted us to investigate some biochemical interrelations of indole derivatives in Brassica oleracea L. by means of labelled (radioactive) compounds. The main question in this connexion was why, in our previous communication2, we were not able to prove the presence of glucobrassicin in our material. According to Gmelin3, our method of working up the plant material was not suitable for demonstrating the presence of glucobrassicin in it. The reaction of glucobrassicin with ascorbic acid in the presence of enzymes (myrosinase) set free in the damaged plant tissue is so rapid as to make impossible the proof of the presence of glucobrassicin in the fresh juice.

The isolation and characterization of progoitrin obtained from Brassica seed are described. Progoitrin is converted to goitrin during enzymic, but not acid, hydrolysis.

We designed a pot experiment to study the changes of growth parameters, accumulation of Cd in cabbage and kale, during a prolonged exposure period with two harvests (after 45 and 75 days of plant growth). Simultaneously, we monitored changes of total S and GSL contents in different plant organs. Both Brassica species showed tolerance to Cd, since no obvious symptoms of metal toxicity were displayed and no significantly reduced of plant biomass were recorded. Moreover, a trend of root biomass enhancement was noticed. In general, the Cd concentration in roots was higher than in other organs. Data indicate that the transport system from roots to shoots was already saturated after the first growing period, while root continued to accumulate Cd during the second growing period. Regardless of differences in the GSL content between cabbage and kale, both Brassica species had a similar response to Cd exposure, indicating that the Brassicacea plant family could have unique features for the regulation of GSL content in order to balance the roles of GSLs as defence compounds and as S reservoirs. During the first growing period, GSLs in leaves and root could be more involved in ameliorating S deficiency rather than plant defence. After long-term Cd exposure, we found differences between GSL patterns in leaves and root. Furthermore, we found increased total GSL levels in the stem during whole experiment which indicates that stem could serve as a GSLs storage organ under Cd stress. This paper provides new insight into the possible roles of GSL in Cd stress.

SummaryMyrosinase activity could be demonstrated in a variety of bacteria, particularly Paracolobactrum, which commonly inhabit the intestinal tract of man. Intact cells and sonicates were equally active. Ascorbate inhibited rather than potentiated this bacterial myrosinase activity.

Full-fat canola seed (FFCS) is a locally produced alternative protein source that has potential for inclusion in the diet of ostriches. Chicks aged 84 days and weighing 24.7 ± 0.36 kg were fed five iso-nutritional diets with varying levels of FFCS. Birds were fed until slaughter at 309 days old (93.2 ± 1.82 kg). In each feeding phase, FFCS replaced soybean oilcake meal incrementally (0%, 25%, 50%, 75% and 100% of protein source). Dry matter intake (DMI) during the grower phase was lowest (1.52 kg/bird/day) for the 100%FFCS diet. Birds on the 100%FFCS also showed a 34% slower growth rate (average daily gain of 152.0 g/bird/day) compared to the other four diets (average growth rate of 230 g/bird/day) during the grower phase. The 0%FFCS (236.2 g/bird/day) and 50%FFCS (267.8 g/bird/day) diets resulted in a higher ADG. End weights during the grower phase for 0%FFCS, 25%FFCS, 50%FFCS and 75%FFCS (74.8, 72.2, 76.8, and 72.5 kg, respectively) did not differ significantly. The 100%FFCS resulted in a lower end weight (67.4 kg) for the growth phase, when compared to the 0%FFCS and 50%FFCS diets. For the overall trial period, the only differences were in ADG, with the 0%, 50% and 75%FFCS replacement diets showing the fastest growth. Fat pad weight was the only slaughter trait that revealed differences between diets, with 50%FFCS resulting in the heaviest fat pad weight. A maximum of 20.6% inclusion of FFCS should be used in diets in the grower phase, although in the other phases, FFCS could be included up to the maximum level evaluated (100% replacement of soybean oilcake meal) without detrimental effects on production parameters.Keywords: Average daily gain, Brassica napus, dressing percentage, dry matter intake, feed conversion ratio, glucosinolates, Struthio camelus

The role glucosinolates play in defending plants against phloem feeders such as aphids and whiteflies is currently not clear as these herbivores may avoid bringing glucosinolates from the phloem sap into contact with myrosinase enzymes. Here, we investigated the effects of high levels of aliphatic and indolic glucosinolates on life history traits and detoxification gene expression in two sibling species, B and Q, of the whitefly Bemisia tabaci. High levels of aliphatic glucosinolates decreased the average oviposition rate of both species and reduced the survival and developmental rate of Q nymphs. High levels of indolic glucosinolates decreased the oviposition rate and survival of nymphal stages of the B species and the developmental rate of both species. Molecular analyses revealed two major asymmetries between the B and Q species. First, specific GST genes (BtGST1 and BtGST2) were significantly induced during exposure to indolic glucosinolates only in Q. This may reflect the genes putative involvement in indolic glucosinolates detoxification and explain the species' good performance on plants accumulating indolic glucosinolates. Second, the constitutive expression of eight of the 10 detoxification genes analysed was higher in the Q species than in the B species. Interestingly, four of these genes were induced in B in response to high levels of glucosinolates. It seems, therefore, that the B and Q species differ in their 'optimal defence strategy'. B utilizes inducible defences that are profitable if the probability of experiencing the stress is small and its severity is low, while Q invests significant resources in being always 'ready' for a challenge.

Meal prepared from unheated rapeseed (Brassica napus cv. Zephyr) showed the presence of thiocyanate ion, while meal from heated seed of the same cultivar did not show detectable amounts. Unheated seed meal on autolysis, and heated seed meal on incubation with thioglucosidase, yielded increased amounts of thiocyanate ion. Various commercial rapeseed meals showed the presence of thiocyanate ion only after enzyme incubation. Low glucosinolate, cv. Bronowski, and higher glucosinolate, cv. Zephyr on enzymic incubation yielded comparable amounts of thiocyanate ion, suggesting that the precursor responsible in the two varieties was the same and present in similar quantities. No formation of thiocyanate ion was observed on incubation of sinigrin with thioglucosidase. Rats dosed with heated meal, containing intact glucosinolate, showed a slight increase of thiocyanate ion in the urine as compared with control rats dosed with water, while a relatively large increase followed dosing with sinigrin. Rats dosed with meal containing free thiocyanate ion excreted the ingested thiocyanate ion almost quantitatively.

Two experiments were conducted with Hyline Leghorn hens to study the metabolism and detrimental effects of rapeseed meal (RSM) glucosinolates. Raw Target RSM was force fed to 12 hens which were killed after varying time intervals (15 min., 30 min., 60 min.) and the contents of areas of the digestive tract (crop; proventriculus and gizzard; duodenum and ileum) were analyzed for the presence of hydrolysis products of progoitrin. Nitrile compounds were found to be present in all areas of the digestive tract in much larger relative amounts than was oxazolidinethione. When commercially prepared RSMs of varying glucosinolate content were fed to laying hens at a 50% level of dietary inclusion, high glucosinolate-content RSM depressed egg production (P less than 0.05) more than low glucosinolate-content RSM but did not cause a greater frequency of liver hemorrhage. Histological examination of liver tissues from hens suffering liver hemorrhage revealed a severe reticulolysis.

Faba beans may be effectively used as a partial replacement for other protein supplements in swine diets. Breeding swine appear to be particularly sensitive to the level of faba beans in their diets. The lack of response to autoclaving faba beans suggests that the trypsin inhibitor level and condensed tannin content of faba beans do not significantly influence the performance of growing-finishing swine. Supplementation of diets containing faba beans with lysine and/or methionine has not improved pig performance. The scientific selection and commercial production of low glucosinolate varieties of rape constitutes a major advance for swine nutrition. All swine experiments that have compared low glucosinolate rapessed meal with regular rapeseed meal have demonstrated the superiority of the low glucosinolate material as a protein source. Substantially larger proportions of the low glucosinolate material may be fed to all classes of swine without any significant depression in performance.

Epidemiological and pharmacological studies have shown that colorectal cancer development could be reduced by consuming vegetables that contain glucosinolates. In view of this the effect of some glucosinolates and their isothiocyanate (ITC)-derived products on in vitro cell growth was studied. We report the isolation and characterization of ITCs derived from glucosinolates by using HPLC, GC-MS, and NMR techniques. The in vitro activity of ITCs on human erythroleukemic K562 cells has been investigated by using two alternative approaches: the in situ and pre-mix methods. No differences in antiproliferative activity were found comparing the effect of ITCs produced either of these methods. In the experimental conditions used, the production of ITCs from glucosinolates is almost quantitative as confirmed by HPLC or GC-MS analysis. The ITCs' inhibitory activity on K562 cells growth is particularly evident in the cases of ITCs derived from sinigrin, progoitrin, epi-progoitrin, glucotropaeolin and glucocheirolin. Finally, the antiproliferative activity of the ITCs obtained from glucoraphenin, taken as an example, was determined on other tumor cell lines with a different origin and hystotype. Considering the antiproliferative activity found for ITCs these compounds could be considered potentially responsible for the reduction of colorectal cancer associated with diets rich in cruciferous vegetables. Further studies will be aimed at the possible application of glucosinolate-derived products as chemopreventive cancer agents.

Defatted meals were prepared from two new varieties of rapeseed, the ‘high-glucosinolate’ variety, Brassica napus, Lesira, and the ‘low-glucosinolate’ variety, Brassica napus, Erglu, by each of the following processes: (1) defatting of the ground seed with hexane; (2) extraction of the myrosinase-deactivated ground seed with 70% aqueous acetone for the removal of glucosinolates followed by defatting with pure acetone, and (3) autolysis of the ground seed for the decomposition of glucosinolates followed by defatting and simultaneous removal of the decomposition products with hexane. The defatted meals obtained after extraction with aqueous acetone or autolysis contain very little glucosinolates and their degradation products as compared to those obtained by defatting with hexane only. The contents of available lysine and of phytates in the meals are, to some extent, affected by the treatment for the removal of glucosinolates. The rapeseed meals were fed at different levels to protein-depleted chicks and weanling rats. The animals fed low-glucosinolate meals prepared both from high-glucosinolate and low-glucosinolate varieties of rapeseed gave superior performance with regard to the feed conversion and protein efficiency ratio as compared to the animals fed the corresponding meals which were obtained simply by defatting the seeds with hexane. The levels of thyroxine (T4)and triiodothyronine (T3) in the serum of rats fed low-glucosinolate meals indicated normal function of the thyroid, whereas those in rats fed high-glucosinolate meals revealed hypo-thyroidism of the animals.

Industrial and laboratory-scale studies showed that the combined silage fermentation of rape-seed flakes with half sugar mangels leds to a very beneficial reduction in the content of glucosinolate derivatives, especially during the first week of fermentation and storage processes on the qualitative and quantitative fatty-acid parameters were but significant.

Studies were conducted with the aim to upgrade the nutritional quality of high glucosinolate rapeseed meals, via heat treatment and aqueous leaching of the glucosinolates, under various conditions of temperature and pH. Conditions for thermal pretreatment of the seeds were sought which ensured complete inactivation of the enzyme myrosinase, no reduction in available lysine, and minimal losses of soluble protein during subsequent leaching processes. This was achieved by 30 min steaming at 100°C, although kinetic studies showed that complete inactivation of the enzyme took place within 5 min. Leaching experiments were performed with full-fat flakes and with defatted meal. The rate as well as the total amount of leached glucosinolates was higher in defatted meal compared to full-fat flakes. Protein losses were similar with both types of rapeseed raw material and were only slightly affected by changing the pH. Oil losses from full-fat flakes during the leaching process were significant. Raising the leaching temperature from 25 to 50°C increased substantially the rate and the total amount of leached glucosinolates, but resulted in higher losses of protein. Generally, raising the pH of the leaching medium in the range of 4–8, resulted in an increase in the rate as well as in the total amount of leached glucosinolates. Rat feeding tests (PER) of leached meals indicated that raising the leaching temperature from 25 to 50°C lowered the protein quality of the meals. On the other hand, meals leached under the same temperature conditions, in the pH range of 4–8, were not found significantly different in their protein nutritive value. Substantial heat treatment was also found necessary for improving the nutritive quality of low glucosinolate rapeseed.

The cruciferous glucosinolates (epiprogoitrin, sinigrin and sinalbin), nine of their derivatives (nitriles, isothiocyanates, R-goitrin) and vitamin U were not teratogenic to the rat foetus when administered sc to the dams on days 8 and/or 9 of gestation. However, 1-cyano-3,4-epithiobutane, 3-methylsulphinylpropyl isothiocyanate and allyl isothiocyanate caused embryonal death and decreased foetal weight, whereas five other derivatives only decreased foetal weight. Under identical conditions, the reference teratogen, trypan blue, caused a significant incidence of malformations and resorptions. 3-Methylsulphinylpropyl isothiocyanate was the most toxic compound, followed by allyl isothiocyanate, 1-cyano-3,4-epithiobutane (nephrotoxic) and S-1-cyano-2-hydroxy-3-butene. Some nitriles caused hyperplasia of the thyroid, an effect which often was more pronounced in nonpregnant than in pregnant rats.

The stimulatory effect of feeding sucrose and sinigrin was studied with Vth instar larvae of Schistocera gregaria (Orthoptera). The food consisted of filter paper impregnated with the phagostimulant dissolved at different concentrations in water. We studied the intake of filter paper and phagostimulant simultaneously and separately. The intake of sucrose or sinigrin-impregnated paper gradually increased up to a limit, depending on the concentration of the phagostimulant, then decreased. When the intakes of paper and of phagostimulant were studied separately, they evolved differently: phagostimulant intake remained constant at the highest concentrations as filter paper intake decreased. The stability of phagostimulant intake suggested regulatory processes whose nature has been discussed. The results with the two phagostimulants were comparable; however, they were obtained with lower amounts of sinigrin than of saccharose. There was no dissuasive or toxic effect even at every high concentrations.

Summary A novel indole glucosinolate has been identified as a major constituent of cabbage seed and rapeseed. It was purified as the corresponding desulpho derivative by reversed-phase high-performance liquid chromatography and subjected to analysis by thin layer chromatography, nuclear magnetic resonance and ultraviolet spectroscopy, and gas chromatography/mass spectrometry. These studies indicate that the new glucosinolate is 4-hydroxy-3-indolylmethyl glucosinolate.

Summary The edible portions of cabbage, cauliflower and brussels sprouts were found to contain a previously unreported glucosinolate. The compound was purified as the desulfo derivative by reversed-phase high-performance liquid chromatography and subjected to analysis by thin layer chromatography, ultra-violet and nuclear magnetic resonance spectroscopy, and gas chromatography/mass spectrometry. The results of these investigations indicate that the new component is 4-methoxy-3-indolylmethyl glucosinolate.

This review surveys the occurrence, analysis, and properties of glucosinolates and derived compounds in plants and products intended for humans and animal consumption. The paper, which includes references published in 1981, is also intended to compliment existing reviews on the chemistry of these sulfur‐containing natural products. Particular emphasis is placed upon members of the Brassica family because of their importance as vegetables, condiments, oilseeds, and animal feedingstuffs. Since much of the work considered here relates to glucosinolate decomposition products, biochemical information concerning the nature, occurrence, and properties of the glucosinolate‐degrading enzyme, myrosinase, is considered in Section III. The methods available for the chemical analysis of glucosinolates and their various breakdown products are discussed critically. Factors affecting the glucosinolate content of plants and plant products arc outlined in Section VII. Particular emphasis is placed upon the effect of proces...

During the degradation of thioglucosides in defatted rape seed meal (RES) microorganisms were found, whose ability to degrade glucosinolates (GSL) and vinyl thio-oxazolidone (VTO) was not known so far. The isolated microorganisms are two strains of bacteria of the species Bacillus cereus and the yeast Trichosporon cutaneum. The degradation of GSL and VTO in the cultural broths by the Bacillus cereus strains was the more complete the more other Gram-negative bacteria from RES were additionally present. Drinking tests with Wistar rats showed that here is a relation between the watersoluble and mainly bitter toxin substances of rape and their influence on the increase of the animals body weight.