Histone deacetylase inhibitor as well as preparation method and application thereof

The invention discloses a histone deacetylase inhibitor. The invention furthermore discloses a compound shown as a formula I and stereisomers thereof. The novel compound shown as the formula I disclosed by the invention shows excellent histone deacetylase inhibitory activity, and provides a novel medical probability for clinical treatment of histone deacetylase activity abnormality-related diseases. 本发明公开了一种组蛋白去乙酰化酶抑制剂，本发明公开了式I所示的化合物或其立体异构体。本发明公开的式I所示的新化合物，表现出了良好的去乙酰化酶抑制活性，为临床治疗与组蛋白去乙酰化酶活性异常相关的疾病提供了一种新的药用可能。