Patent ID: 8772297

Claim:
A compound represented by the following formula (I): wherein Y is a hydrogen atom, a carboxyl group or wherein L is an oxygen atom or a bond, and R 1 is optionally substituted C 1-6 alkyl; R 2 is R 3 is —NR 8 —R 9 — or a bond, wherein R 8 is a hydrogen atom or C 1-6 alkyl, and R 9 is C 1-6 alkylene; R 4 , R 5 , R 6 and R 7 are the same or different and each is a hydrogen atom or C 1-6 alkyl; and X is wherein R 10 is a hydrogen atom or C 1-6 alkyl; and R 11 is optionally substituted phenyl, optionally substituted C 1-6 alkyl or a hydrogen atom, or R 10 and R 11 form, together with the nitrogen atom bonded thereto, an optionally substituted 5- to 7-membered cyclic amino group, or a physiologically acceptable salt thereof.