Tyrosinase catalyzed production of 3,4-dihydroxyphenylacetic acid using immobilized mushroom (Agaricus bisporus) cells and in situ adsorption

• Immobilized mushroom cells were able to produce 3,4-dihydroxyphenylacetic acid.
• The selectivity of the reaction system was almost 100%.
• The product yield could be increased by in situ adsorption onto aluminum oxide.
• The results could be also useful for purification of 3,4-dihydroxyphenylacetic acid.

3,4-Dihydroxyphenylacetic acid (DHPAA), a catechol derivative with proposed beneficial human health applications, was synthesized in this work from 4-hydroxyphenylacetic acid (HPAA) using an unpurified, tyrosinase-containing, cell preparation from the fruiting body of the edible mushroom Agaricus bisporus which were immobilized in silica alginate matrix capsules. The formation of DHPAA was equimolar to the conversion of HPAA, as long as ascorbic acid was present in amounts sufficient for reduction of o-quinones generated by oxidation of DHPAA. With a concentration of 5 mM HPAA and 5, 10, or 25 mM ascorbic acid, the maximum yields of DHPAA were 26, 36, or 56%, respectively. When aluminum oxide, pretreated with ammonium acetate, was added for an in situ adsorption of DHPAA, the yield obtained with 5 or 10 mM ascorbic acid was increased to 42 or 52%, respectively, with a reaction time reduced by ∼25%. In contrast to experiments without in situ adsorption, the yield remained almost constant after depletion of ascorbic acid. After desorption, the concentration of DHPAA in the eluent was up to 32 times higher than the concentration of HPAA. The results presented here will be useful for the design of production and purification processes for DHPAA.

Figure optionsDownload as PowerPoint slide