Catechol: oxygen 2,3-oxidoreductase

Systematic name Catechol oxygen 1,2-oxidoreductase (decycling)... 

The shell precursors in the vitelline cells - proteins, phenols and phenol oxidase (EC 1.14.18.1, monophenol o-diphenol oxygen oxidoreductase) - can all be stained specifically with cytochemical reagents although the reactions are not as intense as in trematodes (810). The most useful of these reagents are probably (a) Fast Red Salt B, which stains phenolic materials orange/purple, and (b) catechol, which can be used for detecting the phenol oxidase. Details of these techniques are given by Smyth (789). 

Ripe grapes contain an orthophenol oxygen oxidoreductase, also known as cresolase, catechol oxidase and tyrosinase. Its activity is extremely variable, depending on the grape variety and degree of ripeness. (Dubemet, 1974). Tyrosinase consists of a group of isoenzymes differing in inductor nature and catalyzed activities (Mayer and Harel, 1979). 

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