Table 3.

In vitro inhibition of human histone deacetylases (HDACs) with the free thiols of largazole and its two analogs.

			IC50 (nM) a			Selectivity (HDAC1/6)
	HDAC1	HDAC2	HDAC3	HDAC8	HDAC6
15a b	4.39 ± 0.17	21.0 ± 0.3	39.2 ± 2.3	8.38 ± 2.46	300 ± 5	68
15b b	4.24 ± 0.38	16.3 ± 0.4	37.1 ± 0.8	17.5 ± 4.2	338 ± 17	80
15c	0.27 ± 0.02	1.33 ± 0.02	2.33 ± 0.15	0.44 ± 0.16	23.9 ± 0.2	89
largazole thiol	2.01 ± 0.01	9.49 ± 0.19	14.4 ± 0.2	3.75 ± 0.20	121 ± 5	60

^a Compounds were tested in 10-dose IC₅₀ mode in duplicate with three-fold serial dilution. ^b The data were previously reported by us in [23].