Brassicaceae glucosinolates

Matthaus B, Luftmann H (2000) Glucosinolates in members of the family Brassicaceae separation and identification by LC/ESI-MS-MS. J Agric Food Chem 48 2234-2239... 

State produces 95% of the broccoli grown commercially in the United States ( ) and it has been reported that residues of broccoli are phytotoxic and inhibit the establishment of other crops ( ). Both species, campestris and oleracea var. italica, belong to the Brassicaceae, which contain as a characteristic chemical compounds the glucosinolates , . Species from the Brassicaceae family have... 

A major proportion of the glucosinolate hydrolysis products formed upon myrosinase cleavage in some plants are nitriles. In vitro, nitrile formation associated with myrosinase-catalyzed hydrolysis is enhanced at low pH (pH<3) and in the presence of ferrous ions. In vivo, protein factors in addition to myrosinase may be responsible for nitrile formation. If the glucosinolate side chain has a terminal double bond, the sulfur released from the thioglucosidic bond may be captured by the double bond and an epithionitrile is formed.9 This reaction takes place only in plants that possess a protein factor known as epithiospecifier protein (ESP). ESP activities have been identified in several species of the Brassicaceae and shown to influence the outcome of the myrosinase-catalvzed hydrolysis reaction although they have no hydrolytic activity by themselves.10 12 The mechanism by which ESPs promote epithionitrile formation is not known. 

Table 5.2 Examples of studies showing attraction of insects specialized on Brassicaceae by isolated glucosinolate hydrolysis products. NCS, isothiocyanate CN, cyanide (= nitrile).

BOREK, V., ELBERSON, L.R., MCCAFFREY, J.P., MORRA, M.J., Toxicity of isothiocyanates produced by glucosinolates in Brassicaceae species to black vine weevil eggs., J. Agric. FoodChem., 1998, 46, 5318-5323. 

Glucosinolates from Brassicaceae (Cruciferae) e.g. Brassica napus, Brassica oleraceae (Brussels sprouts)... 

Xue, J., Lenman, M., Falk, A. and Rask, L. (1992) The glucosinolate-degrading enzyme myrosinase in Brassicaceae is encoded by a gene family. Plant Mol. Biol, 18,387-98. 

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