glucobrassicin and glucotropeolin

Glucosinolates (GLs) present in root, seed, and leaf extracts of Pentadiplandra brazzeana Baillon were characterized and quantified according to the ISO 9167-1 method based on the HPLC analysis of desulfo-GLs. The analyses were complemented by GC-MS analyses of the isothiocyanates (ITCs) generated from GL degradation by myrosinase. Glucotropaeolin (1a), glucolimnanthin (2a), and glucoaubrietin (3a) were shown to be present in the root extract, whereas the seed mainly contained 3a. 3,4-Dimethoxybenzyl GL (4a), glucobrassicin (5a) and traces of 1a were detected in the leaf extract. The products were fully characterized as their desulfo-counterparts by spectroscopic techniques.

Topics: Brassicaceae; Cameroon; Chromatography, High Pressure Liquid; Glucosinolates; Indoles; Isothiocyanates; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Plant Leaves; Plant Roots; Seeds

The aim of this study was to optimize by micellar electrokinetic chromatography the separation of four glucosinolates, i.e. sinigrin, glucobrassicin and methoxyglucobrassicin involved in Cruciferae resistance mechanisms and glucotropaeolin used as an internal standard. The separation borate buffer which contained sodium dodecyl sulphate, tetramethylammonium hydroxide and methanol was firstly optimized by using a three variable Doehlert experimental design. The optimum concentrations found enabled, for the first time, to obtain an acceptable resolution between the two indole glucosinolates, glucobrassicin and methoxyglucobrassicin. Modifications of the method such as a capillary pre-rinse with pure borate buffer and a step change in voltage during experiment were performed to improve the resolutions between glucosinolates and to reduce the analysis time. This method was validated by a statistical analysis and showed good linearity, repeatability and reproducibility.

Topics: Buffers; Chromatography, Micellar Electrokinetic Capillary; Glucosinolates; Hydroxamic Acids; Indoles; Isothiocyanates; Reproducibility of Results; Sensitivity and Specificity; Thioglucosides; Vegetables

Significant induction of mixed-function-oxidase (MFO) activity was observed in the small intestines of rats within 4-6 hr of ingestion of a single meal containing a Brassica vegetable (cabbage). Intact Brussels sprouts and a fractionated methanol-water extract of Brussels sprouts induced similar degrees of MFO activity in the livers, and small and large intestines of rats. However, the residue left after extraction of the polar compounds did not induce MFO activity. Different amounts of the various naturally-occurring thioglycosides and glucosinolates were found in the intact Brussels sprouts and in the extract, but virtually none were found in the extracted residue. When glucusinolates that were found in Brussels sprouts (sinigrin, progoitrin, glucobrassicin and glucotropaeolin) were fed separately to rats, only the indole glucosinolate, glucobrassicin, induced MFO activity (causing induction in the small intestines of the rats). This is consistent with the inducing activity of the various hydrolysis products of this glucosinolate. This is the first study in which an attempt has been made to define the inducing compounds in Brassica vegetables by feeding the individual purified glucosinolates.

Topics: Animals; Antithyroid Agents; Brassica; Enzyme Induction; Food Analysis; Glucosinolates; Hydroxamic Acids; Indoles; Intestine, Large; Intestine, Small; Intestines; Isothiocyanates; Liver; Male; Mixed Function Oxygenases; Rats; Rats, Inbred Strains; Thioglucosides; Thioglycosides