- Glucobrassicin
Glucobrassicin (indol-3-ylmethylglucosinolate) is a type of
glucosinolate that can be found in almost all cruciferous plants, such as cabbages (e.g.broccoli ), mustards, cress andwoad . As for other glucosinolates, degradation by the enzyme myrosinase is expected to produce an isothiocyanate, indol-3-ylmethylisothiocyanate. Hovever, this specific isothiocyanate is expected to be highly unstable, and has indeed never been detected. The expected hydrolysis products, in addition to glucose, sulphate, and hydrogen ion, areIndole-3-carbinol and thiocyanate ion, which are envisioned to result from a rapid reaction of the unstable isothiocyanate with water. Indole-3-carbinol and/or products of additional reactions such asdiindolylmethane ) may help preventcancer , but the effect is still not completely understood. Some adverse effects may in fact be expected, at least at high doses (probably higher than you would get by eating vegetables).Glucobrassicin is also known to be a highly active egg-laying stimulant of cabbage white butterflies such as the small white (
Pieris rapae ) and the large white (Pieris brassicae ).Several derivatives of glucobrassicin are known.The compound itself was first isolated from Brassica plants, hence the ending of the name.When a second, similar natural produt was discovered, it was named neoglucobrassicin. When further derivatives were discovered, a more systematic nomenclature was used.
Currently, the following five derivatives are known from plants:1-methoxyglucobrassicin (=neoglucobrassicin),4-hydroxyglucobrassicin,4-methoxyglucobrassicin,1,4-dimethoxyglucobrassicin, and 1-sulphoglucobrassicin.The existence of a sixth derivative, 1-acetylglucobrassicin, has been suggested, but the data were insufficient so whether this compound exists or not in nature is not known (by 2008).
The three first mentioned derivatives are as frequent in crucifers as glucobrassicin itself. The additional two derivatives appear to be rare in nature.
External links
* [http://www3.interscience.wiley.com/cgi-bin/abstract/112730122 "Glucobrassicin enhancement in woad (Isatis tinctoria) leaves by chemical and physical treatments" ("Journal of the Science of Food and Agriculture")]
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