Table 1.

Selective HDAC inhibitors, subdivided by class and isoform selectivity

Inhibitor	HDAC Isoform	Selectivity
Class I-selective inhibitors
Trapoxin A and derivatives	HDAC1	640–570 000-fold vs. HDAC6
Apicidin	HDAC2–3	5–83-fold vs. HDAC1, 4–9
Romidepsin	HDAC1–2	10-fold vs. HDAC4
Azumamide E	HDAC1–3	37–500-fold vs. HDAC4–9
2	HDAC1–3	10-fold vs. HDAC6
		65-fold vs. HDAC4,5,7
3	HDAC3,6	4–135-fold vs.
		HDAC1,2,4,5,7,8
4	HDAC1,4	3–8-fold vs. HDAC6
MS-275	HDAC1,3	135-fold vs. HDAC6,8
CI-994	HDAC1,3	133-fold vs. HDAC6,8
MGCD0103	HDAC1,3	40-fold vs. HDAC6,8
13–15	HDAC1,2	100-fold vs. HDAC3,8
SK-7041	HDAC1,2	HDAC3–6
SK-7068	HDAC1,2	HDAC3–6
VPA	HDAC1–5,7	>20-fold vs. HDAC6, 10
Isoform-selective inhibitors within class I
1	HDAC1	4-fold vs. HDAC8
5	HDAC1	10-fold vs. HDAC2
		20-fold vs. HDAC3
6	HDAC1	4-fold vs. HDAC2
		13-fold vs. HDAC3
12	HDAC1	5–32-fold vs. HDAC2
		>145-fold vs. HDAC3,8
16–23	HDAC1	6–19-fold vs. HDAC2
SB-429201	HDAC1	20-fold vs. HDAC3,8
27	HDAC1	370-fold vs. HDAC4
		10-fold vs. HDAC2,3
25	HDAC8	140-fold vs. HDAC1
		115-fold vs. HDAC6
26	HDAC8	330-fold vs. HDAC1
		180-fold vs. HDAC6
PCI-34051	HDAC8	>290-fold vs.
		HDAC1–3,6,10
SB-379278A	HDAC8	60-fold vs. HDAC1,3
Class II-selective inhibitors
10	HD1-A	78-fold vs. HD1-B
11	HD1-A	176-fold vs. HD1-B
Tubacin	HDAC6	4-fold vs. HDAC1
9	HDAC6	14-fold vs. HDAC1
28	HDAC4	3-fold vs. HDAC1,2,3
Isoform-selective inhibitors within class II
8d	HDAC6	46-fold vs. HDAC1
		51-fold vs. HDAC4
24	HDAC4	4-fold vs. HDAC1
		15-fold vs. HDAC6