Table 1:

Selected sirtuin ligands/inhibitors examined by means of FP-based binding assay using the TAMRA-labelled SirReal (4a) as well as the ZMAL- or FA-based activity assays. n.c. = no competition (inhibition of probe (4a) binding to Sirt2 < 10% at given concentration), n.i. = no inhibition (less than 10% inhibition at 50 µM). Chemical structures of the tested small-molecule ligands/inhibitors are given in figure 2 or electronic supplementary material, figure S6. The biological activity of the inhibitors/ligands used has been validated by cellular investigations in former studies.

ligands/inhibitors	IC50 (µM) or percentage inhibition
	binding assay	activity assays
	Sirt2	Sirt2			Sirt3
	FP-assay	ZMAL-assay	FA-assay		ZMAL-assay	FA-assay
			acetyl	myristoyl		acetyl	myristoyl
nicotinamide	n.c. at 400 µM	49.8 ± 4.6	56.8 ± 8.6	98.2 ± 28.6	67.9 ± 3.3	35.1 ± 3.8	122.7 ± 44.8
AEM2	20.9 ± 0.7	2.5 ± 0.2	1.1 ± 0.1	35.8% at 50 µM	n.i.	n.i.	n.i.
SirReal1 (1a)	2.8 ± 0.2	3.7 ± 0.8	13.3 ± 2.2	IC50 > 100 µM	IC50 > 100 µM	IC50 > 100 µM	IC50 > 100 µM
SirReal2 (2a)	0.95 ± 0.07	0.38 ± 0.11	0.472 ± 0.08	17.4% at 50 µM	n.i.	n.i.	24.8% at 50 µM
MZ242 (3b)	0.86 ± 0.09	0.12 ± 0.01	0.22 ± 0.10	18.1% at 50 µM	n.i.	n.i.	n.i.
EX-527	IC50 > 400 µM	10.6 ± 1.1	10.9 ± 1.6	n.i.	19.0% at 50 µM	20.4% at 50 µM	n.i.
SRT1720	13.8% at 50 µM	15.9% at 50 µM	24.6% at 50 µM	11.1% at 50 µM	4.5 ± 0.2	1.5 ± 0.1	8.1 ± 1.7
resveratrol	n.c. at 100 µM	11.4% at 50 µM	29.7% at 50 µM	14.9% at 50 µM	10.1% at 50 µM	23.8% at 50 µM	26.0% at 50 µM