We have identified a series of diphenylmethylene hydroxamic acids as novel and selective HDAC class IIa inhibitors. The original hit, N-hydroxy-2,2-diphenylacetamide (6), has sub-micromolar class IIa HDAC inhibitory activity, while the rigidified oxygen analogue, N-hydroxy-9H-xanthene-9-carboxamide (13), is slightly more selective for HDAC7 with an IC₅₀ of 0.05 μM. Substitution of 6 allows for the modulation of selectivity and potency amongst the class IIa HDAC isotypes.

中文翻译：

---

二苯基亚甲基异羟肟酸作为选择性的IIa类组蛋白脱乙酰基酶抑制剂

我们已经鉴定出一系列二苯基亚甲基异羟肟酸作为新型和选择性的HDAC IIa类抑制剂。最初的产物N-羟基-2,2-二苯乙酰胺（6）具有亚微摩尔IIa类HDAC抑制活性，而刚性的氧类似物N-羟基9 H-并蒽9-羧酰胺（13）具有抑制作用。IC ₅₀为0.05μM时对HDAC7的选择性更高。取代6可在IIa类HDAC同种型之间调节选择性和效能。