Patent ID: 7897787

Claim:
A compound represented by the following general formula (I): wherein R 1 and R 2 independently represent hydrogen atom, or a group represented by the following formula (A): wherein X 1 and X 2 independently represent hydrogen atom, a C 1-6 alkyl group which may have a substituent, a C 1-6 alkoxy group which may have a substituent, or a halogen atom, provided that at least one of R 1 and R 2 represented by formula (A); R 3 and R 6 independently represent a C 1-6 alkyl group which may have a substituent; R 4 and R 7 independently represent hydrogen atom, a C 1-6 alkyl group which may have a substituent, carboxy group, a C 1-6 alkoxycarbonyl group, or sulfo group, or R 4 may combine with R 3 to form a condensed aryl ring together with two carbon atoms to which they bond, wherein the aryl ring may have a substituent, and/or R 7 may combine with R 6 to form a condensed aryl ring together with two carbon atoms to which they bond, wherein the aryl ring may have a substituent; and R 5 and R 8 independently represent a C 1-6 alkyl group which may have a substituent, an aryl group which may have a substituent, a C 1-6 alkoxycarbonyl group which may have a substituent, a vinyl group which may have a substituent, a thienyl group which may have a substituent, or a pyrrolyl group which may have a substituent, or a salt thereof.