Bifunctional chelating agents

1. A bifunctional chelating agent of the formula (I):

wherein:

-M- is

Q 1 , Q 2 and Q 4 are independently H or R;

Q 5 is H, R or R 1 ″;

Q 6 is H or R 1 ″;

Q 7 is H or R;

A 1 and A 2 form together with the atoms to which they are attached a C 6 -C 10 -aryl, C 6 —C 1-10 -heteroaryl, C 3 -C 5 -cycloalkyl, C 7 -C 10 -cycloalkyl or C 3 -C 10 -heterocyclyl group;

R is —C(O)-L,

—(CHR 2 ) p COR 3 or —(CHR 2 ) p PO 2 R 4 R 5 ;

Q 3 is H, —(CHR 2 ) w COR 3 or —(CHR 2 ) w PO 2 R 4 R 5 ;

R 1 , R 1 ′ and R 1 ″ are independently

each R 2 is independently hydrogen; C 1 -C 4 alkyl or (C 1 -C 2 alkyl)phenyl; each R 3 , R 4 and R 5 are independently OH, an —O-protecting group or a leaving group;

R 6 is H; OH; an alkyl-LG or alkoxy-LG, wherein LG is a leaving group; a boronate ester or a leaving group;

X and Y are each independently hydrogen or may be taken with an adjacent X and Y to form an additional carbon—carbon bond;

Z 1 and Z 2 are independently CH or N;

m is an integer from 0 to 10 inclusive;

n is 0 or 1;

p is 1 or 2;

r is 0 or 1;

w is 0 or 1;

z is 1 or 2;

L is a linker/spacer group covalently bonded to, and replacing one hydrogen atom of the carbon atom to which it is joined, said linker/spacer group being represented by the formula (II):

wherein:

s is an integer of 0 or 1;

t is an integer of 0 to 20 inclusive;

R 7 , R 8 and R 9 are independently H; an electrophilic, nucleophilic or electron-rich moiety that allows for covalent attachment to a carrier comprising a biotargeting group, a lipophilic moiety or a biosensor; a protected form or a precursor of the electrophilic, nucleophilic or electron-rich moiety; or a synthetic linker having an electrophilic, nucleophilic or electron-rich moiety that allows for covalent attachment to the carrier comprising a biotargeting group, a lipophilic moiety or a biosensor, or a protected form or a precursor of the electrophilic, nucleophilic or electron-rich moiety of the synthetic linker, and

Cyc represents a cyclic aliphatic moiety, aromatic moiety, aliphatic heterocyclic moiety, or aromatic heterocyclic moiety, each of said moieties optionally substituted with one or more groups, which do not interfere with binding to a carrier comprising a biotargeting group, a lipophilic moiety or a biosensor;

or a pharmaceutically acceptable salt thereof,

provided that the chelating agent is not 6,6′,6″,6′″-((ethane-1,2-diylbis(azanetriyl))tetrakis(methylene))tetrapicolinic acid, 6,6′-((ethane-1,2-diylbis((phosphonomethyl)azanediyl))bis(methylene))dipicolinic acid, 6,6′-((ethane-1,2-diylbis((carboxymethyl)azanediyl))bis(methylene))dipicolinic acid or 6,6′-((ethane-1,2-diylbis((pyridin-2-ylmethyl)azanediyl))bis(methylene))dipicolinic acid, and

provided that the bifunctional chelating agent comprises at least one covalently attached moiety that allows for covalent attachment to the carrier comprising a biotargeting group, a lipophilic moiety or a biosensor.

2. The bifunctional chelating agent according to claim 1 , wherein the bifunctional chelating agent is of formula (Ia):

wherein Q 1 , Q 2 , Q 4 and z are as defined in claim 1 .

3. The bifunctional chelating agent according to claim 1 , wherein Q 1 and Q 2

are each H and Q 4 is

wherein L, X, Y, Q 3 , m, n and r are as defined in claim 1 .

4. The bifunctional chelating agent according to claim 3 , wherein Q 1 and Q 2 are each H and Q 4 is

wherein L, X, Y, m, n and r are as defined in claim 1 .

5. The bifunctional chelating agent according to claim 4 , wherein Q 1 and Q 2 are each H and Q 4 is

wherein R 8 is as defined in claim 1 .

6. The bifunctional chelating agent according to claim 1 , wherein at least one of Q 1 and Q 2 is

and Q 4 is H,

wherein L, X, Y, Q 3 , m, n and r are as defined in claim 1 .

7. The bifunctional chelating agent according to claim 6 , wherein at least one of Q 1 and Q 2 is

and Q 4 is H,

wherein L, X, Y, m, n and r are as defined in claim 1 .

8. The bifunctional chelating agent according to claim 7 , wherein at least one of Q 1 and Q 2 is

and Q 4 is H,

wherein R 8 is as defined in claim 1 .

9. The bifunctional chelating agent according to claim 1 , wherein at least one of Q 1 and Q 2 is —(CHR 2 ) p COR 3 and Q 4 is H, wherein R 3 and p are as defined in claim 1 .

10. The bifunctional chelating agent according to claim 1 , wherein at least one of Q 1 and Q 2 is —(CHR 2 ) p COR 3 and Q 4 is H, wherein R 3 is a leaving group and p is as defined in claim 1 .

11. The bifunctional chelating agent according to claim 1 , wherein at least one of Q 1 and Q 2 is —CH 2 COR 3 and Q 4 is H, wherein R 3 is as defined in claim 1 .

12. The bifunctional chelating agent according to claim 1 , wherein at least one of Q 1 and Q 2 is —CH 2 COR 3 and Q 4 is H, wherein R 3 is a leaving group.

13. The bifunctional chelating agent according to claim 1 , wherein at least one of Q 1 and Q 2 is —CH 2 C≡CH and Q 4 is H.

14. The bifunctional chelating agent according to claim 1 , wherein Q 1 and Q 2 are —(CHR 2 ) p COR 3 and Q 4 is R, wherein R 2 , R 3 , and R are as defined in claim 1 .

15. The bifunctional chelating agent according to claim 1 , wherein R 6 is NO 2 , NH 2 , isothiocyanato, semicarbazido, thiosemicarbazido, maleimido, bromoacetamido or carboxyl.

16. A complex comprising the bifunctional chelating agent defined in claim 1 or a pharmaceutically acceptable salt thereof, and an ion of a stable or radioactive form of a metal selected from a group consisting of Ga, In, TI, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y, Ti, Zr, Cr, Mn, Tc, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Zn, Cd, Hg, Al, Ge, Sn, Pb, Sb, Bi, Te, Po, Mg, Ca, Sr, Ba, Ra, Ac, Th and U.

17. The complex according to claim 16 , wherein the ion is an ion of a radioactive metal selected from a group consisting of 66 Ga, 67 Ga, 68 , 111 In, 201 Tl, 142 Pr, 149 Pm, 153 Sm, 153 Gd, 159 Gd, 166 Ho, 175 Yb, 177 Lu, 47 Sc, 90 Y, 89 Zr, 51 Cr, 99m Tc, 188 Re, 186 Re, 57 Co, 101m Rh, 62 Cu, 64 Cu, 67 Cu, 117m Sn, 203 Pb, 212 Pb, 212 Bi, 213 Bi, 223 Ra, and 225 Ac.