A cell-permeable inhibitor of SIRT1 (IC₅₀ = 56 µM) and SIRT2 (IC₅₀ = 59 µM); less effectively inhibits SIRT5 (IC₅₀ >300 µM) and has no effect on class I and II HDACs; sensitizes H460 lung cancer cells to etoposide and paclitaxel; blocks a…