Table 1. Dual Sirt2/HDAC6 Inhibitors Tested by Means of Previously Reported Biochemical in Vitro Deacetylation Assays^44−46a.

compd	Sirt2	HDAC6	Sirt1	Sirt3	HDAC1	HDAC2	HDAC3
21	11.5 ± 0.04	0.15 ± 0.01	nib	nib	2.1 ± 0.2	nte	nte
22	15% @ 10 μM	0.011 ± 0.001	nib	nib	0.21 ± 0.03	nte	nte
31	0.56 ± 0.27	0.025 ± 0.001	nib	nib	0.62 ± 0.06	nte	nte
32	0.15 ± 0.01	0.042 ± 0.007	nib	17% @ 20 μM	1.2 ± 0.2	1.8 ± 0.1	0.71 ± 0.03
33	0.32 ± 0.11	0.043 ± 0.003	nib	nib	2.2 ± 0.2	6.0 ± 0.2	2.5 ± 0.2
44	0.48 ± 0.04	0.0096 ± 0.0003	nib	nib	0.60 ± 0.03	nte	nte
45	0.54 ± 0.01	0.017 ± 0.001	nib	nib	0.46 ± 0.05	nte	nte
46	0.48 ± 0.07	0.0050 ± 0.0005	nib	nib	0.21 ± 0.03	0.34 ± 0.02	0.14 ± 0.01
4	0.22 ± 0.01	18% @ 10 μM	nib	nib	10% @ 10 μM	nte	nte
5	0.12 ± 0.01c	nic,d	nic,d	nic,d	nic,d	nte	nte
55	nte	0.65 ± 0.04	nte	nte	17 ± 1	nte	nte
56	nte	0.018 ± 0.001	nte	nte	0.81 ± 0.05	nte	nte
57	nie	0.032 ± 0.004	nib	nib	3.2 ± 0.2	4.7 ± 0.1	4.8 ± 0.4
SAHA	nte	0.030 ± 0.008	nte	nte	0.12 ± 0.01	0.16 ± 0.01	0.11 ± 0.01

^aIC₅₀ values [μM, mean ± SD] or percentual inhibition at a given concentration of the dual Sirt2/HDAC6 inhibitors, as well as reference compounds for selective Sirt2 inhibition (4,5), HDAC6 inhibition (55–57), and SAHA as an nonselective inhibitor of Zn²⁺-dependent HDACs.

^bni = no inhibition (inhibition <15% @ 20 μM).

^cValues for 5 taken from Vogelmann et al.⁴⁷

^dni = no inhibition (IC₅₀ > 100 μM).

^ent = not tested.