Mustard myrosinase

Formation of the thiocyanate (94) is believed to be caused by enzymatic rearrangement (E) of the isothiocyanate (54) although direct formation from the glucosinolate has not been excluded (95). It occurs in homogenized Eruca sativa plants but not seed (95), and in Lepidium sativum seed powder but not T. majus (54, 96). The isothiocyanate is initially (10-15 sec) formed in substantial quantities but immediately decreases to a low level (97, 98). Addition of mustard myrosinase to heated Lepidium seed powder produces only isothiocyanate (56). 

Glucobrassicin is a mustard oil glucoside found in various Bras-sica spp. (50). 3-Indoleacetonitrile (IAN) is released from glucobrassicin by the action of the enzyme myrosinase at pH 4.0. How-... 

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...

The water-soluble extracts of wild mustard and broccoli plants were species specific, as shown by the results obtained by other authors (22, 31, 32). The greater insensitivity of crucifers is apparently related to the presence of specific myrosinases which are capable of transforming the breakdown products of the glucosinolates (33). 

Sinapis alba L. Bai Jie (Mustard) (leaf) Arachidic acid, erucic acid, lignoceric acid, linoleic acid, myrosinase, phosphatase, sinalbine.50 Carminative, toothache, seal eruptions and ulcers. 

Figure 4.1 The mustard oil bomb in flower stalks of Arabidopsis thaliana consists of S-cells (with glucosinolates) and adjacent myrosin cells (with myrosinase). This is illustrated by transverse (A,C) and longitudinal (B) sections of a pedicel, analyzed by light microscopy (A,B) and transmission electron microscopy (C). The myrosin cells (m) are in contact with the S-cells (S-c), situated inside the starch sheath ( ) (A,B,C). The myrosin cells are located peripherally in the phloem tissue other cells of the phloem include sieve elements (s) and companion cells (cc, in (C) only).

LUTHY, B., MATILE, P., The mustard oil bomb Rectified analysis of the subcellular organisation of the myrosinase system., Biochem. Physiol. Pflanzen, 1984,179,5-12. 

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

When tissues of glucosinolate-containing plants are injured and cells are disrupted, myrosinases and glucosinolates come into contact and mustard... 

Tsuruo, I. and Hata, T. (1968) Studies on myrosinase in mustard seeds. Part. 4. Sugars and glucosides as competitive inhibitors. Agric. Biol. Chem., 32, 1420-24. 

Advantages and disadvantages of using enzymes are summarized in Tab. 3.13. The stability of enzymes can be increased by immobilization. Fig. 3.7 shows as an example the formation of mustard oils through immobilized myrosinase. Mustard seeds contain myrosinase naturally. The higher yields resulting from the use of additional, immobilized enzyme make the process more economical. Immobilized lipase has... 

Fig. 3. 7 Formation of mustard oils from mustard seeds with the aid of immobilized myrosinase [30, 40]...

A bienzyme electrode comprising GOD and myrosinase coimmobilized on platinized carbon paper for the determination of the glycosino-lates progvitrin and sinigrin has been described by Koshy et al. (1988). The substrates, otherwise known as mustard oil glycosides, were deter-... 

Myrosinase Origin Senapis alba (white mustard seed) Biocatalysts Pilot... 

The properties of myrosinase purified from mustard seed 14, IS) and wasabi 16) were studied. The pH and temperature activity, and the pH and temperature stability of wasabi myrosinase were examined in detail. However, the effects of pH and temperature on the yields of the isothiocyanates have not yet been reported. 

Glucosinolates are p-S-glucosides of isothiocyanates (ITC). They are non-volatile, water-soluble compounds, cleaved by the enzyme myrosinase, a P-thioglucosidase, when plant tissues are damaged to form isothiocyanates (mustard oils). 

H. insolans EGV of glycogen debranching Wlule mustard seed myrosinase... 

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