Activator of human deacetylase SIRT1. Anti-inflammatory, immunomodulatory and antiproliferative agent that inhibits p56lck and syk protein tyrosine kinases and inhibits TNF-induced NF-kB activation and gene expression. Piceatannol is a resveratrol analog formed by the cytochrome P450-catalyzed hydroxylation of resveratrol. Piceatannol exhibits potent anticancer properties by inducing apoptosis in BJAB Burkitt-like lymphoma cells with an ED50 value of 25 uM. Piceatannol also exhibits anti-proliferative and anti-inflammatory effects by inhibiting the activity of a wide range of tyrosine and serine/threonine protein kinases and suppressing NF-kB activation through inhibition of IkBa kinase.