Production of o
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- 作者：Marí ; a Elisa Marí ; n-Zamora ; Francisco Rojas-Melgarejo ; Francisco Garcí ; a-Cá ; novas ; Pedro Antonio Garcí ; a-Ruiz
- 关键词：Tyrosinase ; Agaricus bisporus ; Immobilization ; Cinnamic carbohydrate esters ; Tyrosinase extraction ; o-Diphenols production
- 刊名：Journal of Biotechnology
- 出版年：2009
- 出版时间：15 January 2009
- 年：2009
- 卷：139
- 期：2
- 页码：163-168
- 全文大小：417 K
文摘
The o-diphenols 4-tert-butyl-catechol, 4-methyl-catechol, 4-methoxy-catechol, 3,4-dihydroxyphenylpropionic acid and 3,4-dihydroxyphenylacetic acid were produced from the corresponding monophenols (4-tert-butyl-phenol, 4-methyl-phenol, 4-methoxy-phenol, p-hydroxyphenylpropionic acid and p-hydroxyphenylacetic acid) using immobilized mushroom tyrosinase from Agaricus bisporus. In all cases the yield was Rdiphenol ≥ 88–96 % , which, according to the literature, is the highest yield so far, obtained using tyrosinase. The reaction was carried out in 0.5 M borate buffer pH 9.0 which was used to minimize the diphenolase activity of tyrosinase by complexing the o-diphenols generated. Hydroxylamine and ascorbic acid were also present in the reaction medium, the former being used to reduce mettyrosinase to deoxytyrosinase, closing the catalytic cycle, and the latter to reduce the o-quinone produced to o-diphenol. Inactivation of the tyrosinase by ascorbic acid was also minimized due to the formation of an ascorbic acid–borate complex. Concentrations of the o-diphenolic compounds obtained at several reaction times were determined by gas chromatography–mass spectrometry (GC–MS) and UV–vis spectroscopy. The experimental results are discussed.