The present invention provides orally administrable novel proteasome inhibitor. A the following general formula (1): [Formula 1] Wherein, Y and Y 'are the same or different, a single bond, -O -, - NH -, - CH = CH →, -CO-CH = CH →, -O-CONH →, -S-CO →, -CONH →, -NHCO → or NHSO 2 → [where → indicates the bond of the phenyl group side] indicates； R 1, R 2, R 3, R 4, R 5, R 6, R 7 and R 8 are the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a carboxyl group, C 1-6 alkyl group, a C 1-6 alkoxy group or a C 1-6 alkoxycarbonyl group； R 9 and R 10 are the same or different, or a hydrogen atom or a C 1-6 alkyl group, or R 9 and R 10 are taken together, -CH 2 CH 2 - or -CH 2 CH (R 11) CH 2 - [wherein, R 11 is a hydrogen atom, C 1-6 an alkoxy group or a C 1-6 alkylsulfonyloxy group] indicates； m and n are the same or different, an integer from 2 to 4 proteasome inhibitor as an active ingredient compound, or a salt thereof or solvate thereof, which is represented in the show]. .BACKGROUND【課題】経口投与可能な新規プロテアソーム阻害剤の提供。【解決手段】次の一般式(1)：【化１】〔式中、Y及びY’は、同一又は異なって、単結合、－O－、－NH－、－CH＝CH→、－CO－CH=CH→、－O－CONH→、－S－CO→、－CONH→、－NHCO→又はNHSO2→[ここで→は、フェニル基側の結合を示す]を示し；R1、R2、R3、R4、R5、R6、R7及びR8は、同一又は異なって、水素原子、ハロゲン原子、水酸基、アミノ基、カルボキシル基、C1-6アルキル基、C1-6アルコキシ基又はC1-6アルコキシカルボニル基を示し；R9及びR10は、同一又は異なって、水素原子又はC1-6アルキル基を示すか、又はR9及びR10が一緒になって、－CH2CH2－又は－CH2CH(R11)CH2－[ここで、R11は水素原子、C1-6アルコキシ基又はC1-6アルキルスルホニルオキシ基を示す]を示し；m及びnは、同一又は異なって、２～４の整数を示す〕で表される化合物、若しくはその塩又はそれらの溶媒和物を有効成分とするプロテアソーム阻害剤。【選択図】なし
