| abstract |
A near infrared fluorescent contrast agent which is excellent in permeability in a living tissue and enables specific imaging of tumor and/or blood vessel, comprising a compound represented by formula (I) or a pharmaceutically acceptable salt thereof, wherein R1, R2, R7, and R8 represent a C1-C10 alkyl group or the like; R3, R4, R5, R6, R9, R10, R11, and R12 represent a hydrogen atom, a C1-C6 alkyl group, an aryl group or the like; X1 and X2 represent a C1-C15 alkyl group or an aryl group and X1 and X2 in total have 0 to 4 carboxyl groups; m1, m2, and m3 represents 0 or 1; L1 to L7 independently represent a methine group; M represents a hydrogen atom, a metal, or a quaternary ammonium salt; and n represents an integer of 1 to 7 necessary for neutralizing charge. |