Figure 1.
Structures of SIRT1-activating compounds (STACs). Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a naturally occurring STAC identified in the AMC-based assay that lowers the Km for the substrate. STACs subsequently identified using the TAMRA-based assay also work by lowering the Km for substrates but with potency up to three orders of magnitude greater than that of resveratrol. Abbreviations: AMC, aminomethylcoumarin; Km, Michaelis constant; TAMRA, tetramethylrhodamine.