Cell-permeable, selective sirtuin deacetylase inhibitor (IC50 values are 38, 68 and 131 uM for SIRT2, Sir2p and SIRT1 respectively) that has no effect on HDAC1 activity. Significantly decreases growth and viability of PCa and HEK293T cells in vitro. Sirtinol inhibits yeast Sir2p transcriptional silencing activity in vivo, yeast Sir2p and human SIRT2 deacetylase activity in vitro.