In nature, the flavonolignan silybin (1) occurs as a mixture of two diastereomers, silybin A and silybin B, which in a number of biological assays exhibit different activities. A library of hydrolases (lipases, esterases, and proteases) was tested for separating the silybin A and B diastereomers by selective transesterification or by stereoselective alcoholysis of 23-O- acetylsilybin (2). Novozym 435 proved to be the most suitable enzyme for the preparative ...
