New potential antitumor compounds from the plant Aristolochia manshuriensis as inhibitors of the CDK2 enzyme

The 70% aqueous methanolic extract of the Chinese plant Aristolochia manshuriensis was found to contain two novel substituted phenanthrene compounds, SCH 546909 (1), and another phenanthrene glycoside (2). The structures of 1 and 2 were established based on NMR studies. They were identified as inhibitors of the CDK2 enzyme. Compound 1 was found to be a potent inhibitor of the CDK2 enzyme with an IC(50) of 140 nM, whereas compound 2 was found to be less active with an IC(50) of > 10 mu M. (C) 2010 Elsevier Ltd. All rights reserved.