A Highly Regioselective Esterase from Penicillium Frequentans IMI 92265

An esterase isolated from Penicillium frequentans IMI 92265 selectively hydrolyses the acetoxyethyl ester in preference to the acetoxymethyl esters in the triacetate substrate 1,4-diacetoxy-2-acetoxymethylbutane (1) which was converted to 4-acetoxy-3-acetoxymethylbutan-l-ol (2) in good yield. The enzyme gave no detectable hydrolysis of l,3-diacetoxy-2-acetoxymethylpropane (4). When immobilised to a cyanogen bromide activated Sepharose resin the enzyme was highly stable and showed no loss of regioselectivity in the hydrolysis of (1). A method is described for the elective isolation of microorganisms which have the ability to hydrolyse (1).