An extracellular alpha-L-rhamnosidase has been purified to electrophoretic homogeneity from the culture filtrate of Penicillium corylopholum MTCC-2011 using a simple procedure consisting of concentration by ultrafiltration and cation exchange column chromatography on carboxymethyl cellulose. The sodium dodesyl sulphate polyacrylamide gel electrophoresis analysis of the purified enzyme gave a single protein band corresponding to the molecular mass of 67.0 kDa. The native - polyacrylamide gel electrophoresis analysis also gave a single protein band confirming the purity of the enzyme and also showing that the enzyme is a monomer in the native state. The K-m and k(cat) values of the enzyme were 0.42 mM and 357 s(-1), respectively, using p-nitrophenyl alpha-L-rhamnopyranoside as the substrate. The pH and temperature optima of the enzyme were 6.5 and 57.0 degrees C, respectively. The purified enzyme preparation successfully hydrolyzed naringin and rutin to prunin and quercetin glucoside, respectively. Thus it can be used for the preparation of these pharmaceutically important compounds. (C) 2013 Elsevier Ltd. All rights reserved.