Glucosinolates myrosinase activity

As pro-bioherbicides, glucosinolates can be utilized to control weeds but the success depends on their conversion into active principles. Agricultural use of untreated seed meal may elicit varying degrees of weed control because environmental factors determine the extent of glucosinolate bio-activation in the field [39, 42 5]. Our approach to ferment seed meal using myrosinase (and possibly other enzymes) in... 

Cooking also inactivates two key enzymes. The first is myrosinase, which hydrolyses glucosinolates into oil-soluble sulfur-containing compounds. The second is phospholipase, which hydrolyses phospholipids into nonhydratable phosphatides. Myrosinase activity has been extensively studied and is carefully controlled during the cooking operation that minimizes hydrolysis of glucosinolates and reduces... 

Dunford, N.T. and Temelli, F. (1996) Effect of supercritical CO2 on myrosinase activity and glucosinolate degradation in canola, J. Agric. Food Chem. 44, 2372-2376. 

The first phosphate isostere, 76, of a naturally occurring glucosinolate has been prepared in connection with studies of myrosinase activity. ... 

Li Q, Eigenbrode SD, Stringam GR, Thiagarajah MR (2000) Feeding and Growth of Plutella xylostella and Spodoptera eridania on Brassica juncea with Varying Glucosinolate Concentrations and Myrosinase Activities. J Chem Ecol 26 2291-2305... 

Rouzaud, G. et al. (2003) Influence of plant and bacterial myrosinase activity on the metabolic fate of glucosinolates in gnotobiotic rats. Brit J Nutri 90, 395 04... 

Crushing canola disrupts cell membranes and brings the glucosinolates in close proximity with myrosinase enzyme, and some hydrolysis occurs until the enzyme is inactivated by heat during commercial oil extraction operations. The effect of SC-CO2 extraction conditions (temperature, pressure, extraction time and moisture content) on the myrosinase activity and glucosinolate hydrolysis in flaked and whole canola seeds was studied (Dunford and Temelli, 1996). 

Fig. 4.1 Sinigrin is an aliphatic glucosinolate that occurs at significant levels in the human diet, notably in mustard and Brussels sprouts. When brought into contact with myrosinase, derived either from plant cells or from colonic bacteria, it is broken down to yield a variety of products including the acrid, volatile, biologically active compoimd...

NASTRUZZI C, CORTESI R, ESPOSITO E, MENEGATTI E, LEONI O, lORI R and PALMIERI S (2000) In vitro antiproliferative activity of isothiocyanates and nitriles generated hy myrosinase-mediated hydrolysis of glucosinolates from seeds of cruciferous vegetables , JAgric Food Chem, 48 3572-5. 

It is very likely that the inhibitors are breakdown products of glucosinolates, which are considered nontoxic in themselves (23) but can yield physiologically active products upon hydrolysis by the enzyme myrosinase. Through hydrolysis glucosinolates can yield isothiocyanates (24-28). Ju et al. (29) demonstrated the capacity of thiocyanates as allelopathic agents, and isothiocyanates also have allelopathic activity (30). 

---