Patent ID: 8722730

Claim:
A compound represented by the following formula (I): [wherein R 1 and R 2 independently represent a C 3-10 alkyl group (the alkyl group may have a substituent selected from halogen atom, hydroxyl group, alkoxy group, amino group, and oxo group), X represents —O—, Y represents C, R 3 represents hydrogen atom or a C 1-10 alkyl group (the alkyl group may have a substituent selected from halogen atom, hydroxyl group, alkoxy group, amino group, and oxo group), Z represents —CO—N(R 5 )— (R 5 represents hydrogen atom or a C 1-6 alkyl group) or —C(R 6 )═C(R 7 )—CO—NH—(R 6 and R 7 independently represent hydrogen atom or a C 1-6 alkyl group), Ar represents an aryldiyl group (the aryldiyl group may have a substituent selected from halogen atom, hydroxyl group, alkoxy group, and alkyl group), and R 4 represents —COOH, —OCH 2 —COOH, —CH 2 —COOH, or —CH 2 —CH 2 —COOH], or a salt thereof.