PROBLEM TO BE SOLVED: To provide a new compound capable of improving a protein expression efficiency from exogenous genes.SOLUTION: A new compound is an SAHA (suberoylanilide hydroxamic acid) derivative modifying SAHA which is a histone deacetylase inhibitor as shown by reaction formula (A). Since the derivative has an effect of improving a gene expression efficiency, the compound is useful as a gene expression enhancer. Besides, the compound is also useful as a gene-transfer auxiliary agent used together with the exogenous gene transfer agent since the compound can effectively improve the expression of exogenous genes.COPYRIGHT: (C)2013,JPO&INPIT【課題】外来性遺伝子からのタンパク質発現効率を向上させることができる、新規化合物を提供。【解決手段】ヒストン脱アセチル化酵素阻害剤であるSAHA(suberoylanilide hydroxamic acid)を修飾したSAHA誘導体。遺伝子発現効率向上効果を有するため、遺伝子発現増強剤として有用である。また、該化合物は、外来性遺伝子の発現を効果的に向上させることができるため、外来性遺伝子導入剤と共に使用される遺伝子導入剤補助剤としても有用である。【選択図】なし