Diminutol is a cell-permeable purine derivative that inhibits the NADP-dependent oxidoreductase, NQO1 (Ki = 1.72 μM), to destabilize microtubules and disrupt mitosis. At 50 μM, it directly affects tubulin polymerization in Xenopus egg extracts without interfering with the activity of Cdk1, DNA replication, or actin polymerization.
