Glucosinolates mustard oil glycosides

These are pungent-tasting compounds fonnd mainly in the Brassi-caceae family. More than 70 individual glucosinolate compounds are known, varying only in the character of their side chain. These glycosides are formed by decarboxylation on amino acids snch as tyrosine, phenylalanine and tryptophan (see Table 4.1). 

At least 300 species of Brassicas have been studied for their glucosinolate content. The compounds are mainly concentrated in the seeds, although they can be found anywhere in the plants. They can 

Sinigrin Allyl isothiocyanate Homome- thionine Brassica nigra, B. juncea, B. oleracea 

Sinalbin p-hydroxybenzyl isothiocyanate Tyrosine Brassica alba 

Gluconasturtiin Phenylethyl isothiocyanate Phenylalanine Armoracia rusticana Nasturtium officinalis 

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Bialy, Z., Oleszek, W., Lewis, J. and Fenwick, G.R. (1990) Allelopathic potential of glucosinolates (mustard oil glycosides) and their degradation products against wheat. Plant Soil, 129,277-82. 

Carbohydrate derivatives with anomeric sulfur are not very common in nature, the only examples found are the various glucosinolates ( mustard oil glycosides ) mainly from the Bras-sicaceae family [1,2,3], the simple alkyl thioglycosides of lincomycin and structurally relat-... 

Keywords cyanogenic glycosides glucosinolates non-protein amino acids cytochrome P450 cyanogenesis fj-glucosidase myrosinase mustard oil... 

Mustard oils. Name for organic isothiocyanates, R-N=C=S, occurring in the essential oils of plants, mainly Brassicaceae, as the components responsible for sharp odors and pungent tastes. They exist in the plant in glycosidically bound form (see glucosinolates) and are released from the latter by tbioglycosidases (myrosinases) and subsequent rearrangements. 

One example is the formation by phenol oxidases of quinoid compounds from phloridzin in Malus sp. after microbial infections. The quinones built are able to bind to proteins and may inactivate in this way exoenzymes of the invading microorganisms. A similar function may be attributed to hydrocyanic acid and mustard oils set free by degrading enzymes from cyanogenic glycosides and glucosinolates after the infection of several other plant species. 

Two small but distinctive groups of natural products found in higher plants which show a clear and definite relationship to their biosynthetic precursors, the a-L-amino acids, are the cyanogenic glycosides (128)162,163 jjjg mustard oil glucosides or glucosinolates... 

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