Recently, an interest in the development of new vancomycin derivatives has been demonstrated. Here, the feasibility of using lipases, particularly those from Pseudomonas sp., for the hydrolysis of vancomycin alkyl esters is demonstrated. Benzyl ester derivatives were more easily cleavable than methyl ester derivatives, resulting in good yields of vancomycin acids without degradation. (C) 1998 Elsevier Science Ltd. All rights reserved.