Patent ID: 7186400

Claim:
A compound of general formula (I): in which: R 1 is hydrogen, C 1 –C 20 alkyl, C 3 –C 10 cycloalkyl, C 4 –C 20 cycloalkylalkyl, aryl, arylalkyl; or the two R 1 groups, taken together, form a straight or cyclic C 2 –C 10 alkylene group or an ortho-disubstituted arylene; R 2 is hydrogen, C 1 –C 20 alkyl, C 3 –C 10 cycloalkyl, C 4 –C 20 cycloalkylalkyl, aryl or arylalkyl optionally substituted with functional groups which allow conjugation with a suitable molecule able to interact with physiological systems; R 3 , R 4 and R 5 , which are the same or different, are hydrogen, C 1 –C 20 alkyl, C 3 –C 10 cycloalkyl, C 4 –C 20 cycloalkylalkyl, aryl, arylalkyl; FG, which are the same or different, are carboxy, —PO 3 H 2 or —RP(O)OH groups, wherein R is hydrogen, C 1 –C 20 alkyl, C 3 –C 10 cycloalkyl, C 4 –C 20 cycloalkylalkyl, aryl, arylalkyl; or their chelates with bi-trivalent ions of the metal elements having atomic numbers ranging between 20 and 31, 39, 42, 43, 44, 49, or between 57 and 83, and radioisotopes 203 Pb, 67 Ga, 68 Ga, 72 As, 111 In, 113 In, 90 Y, 97 Ru, 62 Cu, 64 Cu, 52 Fe, 52 Mn, 140 La, 175 Yb, 153 Sm, 166 Ho, 149 Pm, 177 Lu, 142 Pr, 159 Gd, 212 Bi, 47 Sc, 149 Pm, 67 Cu, 111 Ag, 199 Au, 161 Tb, and 51 Cr as well as salts thereof with physiologically compatible bases or acids.