Preparation of validoxylamine A by biotransformation of validamycin A using resting cells of a recombinant Escherichia coli

A gene encoding beta-glucosidase was cloned and over-expressed in Escherichia coli. Validamycin A was then biotransformed into validoxylamine A by using the resting recombinant cells. The biotransformation yield reached 92% when the reaction was performed at 37 degrees C for 1 h in the presence of 100 ml sodium phosphate buffer (0.1 M, pH 7.0), 32 mM validamycin A and 0.71 mg dry cell w/ml.