Cytotoxic benzodiazepine derivatives

1. A compound represented by the following formula:

or a pharmaceutically acceptable salt thereof, wherein:

the double line between N and C represents a single bond or a double bond, provided that when it is a double bond X is absent and Y is —H, or a linear or branched alkyl having 1 to 4 carbon atoms, and when it is a single bond, X is —H, a linking group, or an amine protecting moiety;

Y is —H or a leaving group selected from the group consisting of —OR, —OCOR′, —OCOOR′, —OCONR′R″, —NR′R″, —NR′COR″, —NR′NR′R″, an optionally substituted 5- or 6-membered nitrogen-containing heterocycle, —NR′(C═NH)NR′R″, an amino acid, and a peptide represented by —NRCOP′, wherein P′ is an amino acid or a polypeptide containing between 2 to 20 amino acid units, —SR, —SOR′, —SO 2 M, —SO 3 M, —OSO 3 M, halogen, cyano and an azido; or,

Y is HSO 3 , HSO 2 or a salt of HSO 3 − , SO 3 2− or HSO 2 − formed with a cation, H 2 S 2 O 5 or a salt of S 2 O 5 2− formed with a cation, PO 3 SH 3 , PO 2 S 2 H 2 , POS 3 H 2 , PS 4 H 2 or a salt of PO 3 S 3− , PO 2 S 2 3− , POS 3 3− or PS 4 3− formed with a cation, (R i O) 2 PS(OR i ), R i S—, R i SO, R i SO 2 , R i SO 3 , HS 2 O 3 or a salt of S 2 O 3 2− formed with a cation, HS 2 O 4 or a salt of S 2 O 4 2− formed with a cation, P(═S)(OR k′ )(S)(OH) or a salt thereof formed with a cation, R k′ C(═O)NOH or a salt formed with a cation, HOCH 2 SO 2 − or a salt of HOCH 2 SO 2 − formed with a cation or a mixture thereof, wherein R i is a linear or branched alkyl having 1 to 10 carbon atoms and is substituted with at least one substituent selected from the group consisting of —N(R j ) 2 , —CO 2 H, —SO 3 H, and —PO 3 H; R i can be further optionally substituted with a substituent for an alkyl described herein; R j is a linear or branched alkyl having 1 to 6 carbon atoms; R k′ is a linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, aryl, heterocyclyl or heteroaryl;

M is —H or a cation;

R, for each occurrence, is independently selected from the group consisting of —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(CH 2 CH 2 O) n —R c , an optionally substituted aryl having 6 to 18 carbon atoms, an optionally substituted 5- to 18-membered heteroaryl ring containing one or more heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an optionally substituted 3- to 18-membered heterocyclic ring containing 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P;

R′ and R″ are each independently selected from the group consisting of —H, —OH, —OR, —NHR, —NR 2 , —COR, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(CH 2 CH 2 O) n —R c , and an optionally substituted 3- to 18-membered heterocyclic ring having 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P;

R c is —H or a optionally substituted linear or branched alkyl having 1 to 4 carbon atoms, or the linking group;

n is an integer from 1 to 24;

W is C═O;

X′ is selected from the group consisting of —H, an amine-protecting group, the linking group, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(CH 2 CH 2 O) n —R c , an optionally substituted aryl having 6 to 18 carbon atoms, an optionally substituted 5- to 18-membered heteroaryl ring containing one or more heteroatoms independently selected from nitrogen, oxygen, and sulfur, and an optionally substituted 3- to 18-membered heterocyclic ring containing 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P;

Y′ is selected from the group consisting of —H, an oxo group, the linking group, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, an optionally substituted 6- to 18-membered aryl, an optionally substituted 5- to 18-membered heteroaryl ring containing one or more heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an optionally substituted 3- to 18-membered heterocyclic ring having 1 to 6 heteroatoms;

R 1 , R 2 , R 3 , R 4 , R 1 ′, R 2 ′, R 3 ′ and R 4 ′ are each independently selected from the group consisting of —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(OCH 2 CH 2 ) n —R c , halogen, —NH(C═NH)NH 2 , —OR, —NR′R″, —NO 2 , —NCO, —NR′COR″, —SR, —SOR′, —SO 2 R′, —SO 3 − M + , —OSO 3 − M + , —SO 2 NR′R″, cyano, an azido, —COR′, —OCOR′, —OCONR′R″, and the linking group;

R 6 is —H, —R, —OR, —SR, —NR′R″, —NO 2 , halogen or the linking group;

Z is —CH 2 —;

A and A′ are the same or different, and are independently selected from the group consisting of —O—, —C(═O)—, —CRR′O—, —CRR′—, —S—, —CRR′S—, —NR 5 and —CRR′N(R 5 )—,

R 5 for each occurrence is independently —H or an optionally substituted linear or branched alkyl having 1 to 10 carbon atoms;

D and D′ are the same or different, and are independently absent or selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, an amino acid, a peptide bearing 2 to 6 amino acids, and a polyethylene glycol unit (—OCH 2 CH 2 ) n —;

L is absent, the linking group, a polyethylene glycol unit (—OCH 2 CH 2 ) n —, a linear, branched or cyclic alkyl or alkenyl having 1 to 10 carbon atoms, a phenyl group, a 3 to 18-membered heterocyclic ring or a 5- to 18-membered heteroaryl ring having 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P, wherein the alkyl or alkenyl is optionally substituted with the linking group; phenyl or heterocyclic or heteroaryl ring can be optionally substituted, wherein the substituent can be the linking group;

provided that the compound is not any one of the following compounds:

wherein the linking group is a group having a reactive group capable of covalently linking the compound to a cell binding agent (CBA); and

the optional substituent described above is a linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, aryl, heteroaryl, heterocycyclyl, halogen, —NH(C═NH)NH 2 , —OR 100 , NR 101 R 102 , —NO 2 , —NR 101 COR 102 , —SR 100 , —SOR 101 , —SO 2 R 101 , —SO 3 M, —OSO 3 M, —SO 2 NR 101 R 102 , cyano, an azido, —COR 101 , —OCOR 101 , —OCONR 101 R 102 and a polyethylene glycol unit (—OCH 2 CH 2 ) n R 101 wherein M is H or a cation; R 100 , R 101 , R 102 and R 103 are each independently selected from the group consisting of H, linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit (—OCH 2 CH 2 ) n —R 104 , an aryl having from 6 to 10 carbon atoms, a heterocyclic ring having from 3 to 10 carbon atoms and a heteroaryl having 5 to 10 carbon atoms; n is an integer from 1 to 24, and R 104 is H or a linear or branched alkyl having 1 to 4 carbon atoms, wherein the alkyl, alkenyl, alkynyl, aryl, heteroaryl and heterocyclyl in the groups represented by R 100 , R 101 , R 102 , R 103 and R 104 are optionally substituted with one or more substituents independently selected from the group consisting of halogen, —OH, —CN, —NO 2 and unsubstituted linear or branched alkyl having 1 to 4 carbon atoms.

2. The compound of claim 1 , wherein the compound is represented by any one of the following formulas:

wherein:

L′, L″, and L′″ are the same or different, and are independently selected from the group consisting of —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(OCH 2 CH 2 ) n —R c , halogen, —NH(C═NH)NH 2 , —OR, —NR′R″, —NO 2 , —NR′COR″, —SR, —SOR′, —SO 2 R′, —SO 3 M, —OSO 3 M, —SO 2 NR′R″, cyano, an azido, —COR′, —OCOR′, —OCONR′R″ and the linking group, provided only one of L′, L″, and L′″ is the linking group; and

G is —CH— or —N—.

3. The compound of claim 2 , wherein L′ is the linking group, and L″ and L′″ are —H.

4. The compound of claim 3 , wherein L′ is represented by the following formula:

—W′—R x —V—R y -J,

wherein:

W′ and V are the same or different, and are each independently absent, —CR e R e′ —, —O—, —O—C(═O)—, —C(═O)—O—, —S—, —SO—, —SO 2 —, —CH 2 —S—, —CH 2 O—, —CH 2 NR e —, —O—(C═O)O—, —O—(C═O)N(R e )—, —N(R e )—, —N(R e )—C(═O)—, —C(═O)—N(R e )—, —N(R e )—C(═O)O—, —N(C(═O)R e )C(═O)—, —N(C(═O)R e )—, —(O—CH 2 —CH 2 ) n —, —SS—, or —C(═O)—, an amino acid, or a peptide having 2 to 8 amino acids;

R x and R y are the same or different, and are each independently absent or an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, an aryl bearing 6 to 10 carbon atoms or a 3- to 8-membered hetereocyclic ring bearing 1 to 3 heteroatoms selected from the group consisting of O, N, and S;

R e and R e′ are the same or different, and are —H, a linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms or —(CH 2 —CH 2 —O) n —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms, optionally bearing —NHR 101 or —NR 101 R 102 group or a 5- or 6-membered nitrogen containing heterocycle, wherein R 101 and R 102 are each independently a linear, branched, or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms;

n is an integer from 1 to 24;

J comprises the reactive group bonded thereto, and is selected from the group consisting of a maleimide, a haloacetamido, —SH, —SSR d , —CH 2 SH, —CH(Me)SH, —C(Me) 2 SH, —NHR c1 , —CH 2 NHR c1 , —NR c1 NH 2 , —COOH, and —COE, wherein —COE represents a reactive ester selected from the group consisting of N-hydroxysuccinimde ester, N-hydroxy sulfosuccinimide ester, nitrophenyl ester, dinitrophenyl ester, sulfo-tetrafluorophenyl ester, and pentafluorophenyl ester, and wherein R c1 is —H or an optionally substituted linear or branched alkyl having 1 to 4 carbon atoms, and,

R d is phenyl, nitrophenyl, dinitrophenyl, carboxynitrophenyl, pyridyl or nitropyridyl.

5. The compound of claim 4 , wherein J is —SH, —SSR d , a maleimide, or a N-hydroxysuccinimide ester.

6. The compound of claim 4 , wherein:

W′ is —O—, —N(R e )— or —N(R e )—C(═O)—;

R e is —H, -Me, or —(CH 2 —CH 2 —O) n -Me;

n is an integer from 2 to 6;

R x is linear or branched alkyl bearing 1 to 6 carbon atoms;

V and R y are absent; and

J is —COE.

7. The compound of claim 6 , wherein —COE is N-hydroxysuccinimide ester.

8. The compound of claim 4 , wherein L′ is represented by the following formula:

—W′—[CR 1″ R 2″ ] a —V-[Cy] 0-1 -[CR 3″ R 4″ ] b —COE,

wherein:

R 1″ , R 2″ , and R 3″ are each independently —H or -Me;

R 4″ is —H, -Me, —SO 3 H, or —SO 3 − M + , wherein M + is a pharmaceutically acceptable cation;

a is an integers from 0-2, b is an integer from 0-3; and,

Cy is an optionally substituted 5-membered heterocyclic ring bearing an N heteroatom.

9. The compound of claim 4 , wherein W′ is —N(R e )—; R e is —(CH 2 —CH 2 —O) 2-6 —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms; and V is —S— or —SS—.

10. The compound of claim 4 , wherein L′ is represented by the following formula:

—NR e —[CR 1″ R 2″ ] a —S—[CR 3″ R 4″ ] b —COE.

11. The compound to claim 4 , which is:

wherein Y is —H or —SO 3 M, and M is —H or a pharmaceutically acceptable cation.

12. The compound of claim 4 , wherein L′ is represented by the following formula:

—NR e —[CR 1″ R 2″ ] a —S-Cy-[CR 3″ R 4″ ] b —COE.

13. The compound of claim 4 , which is:

wherein Y is —H or —SO 3 M, and M is —H or a pharmaceutically acceptable cation.

14. The compound of claim 1 , wherein the compound is represented by any one of the following formulas:

wherein:

the double line between N and C represents a single bond or a double bond, provided that when it is a double bond, X is absent and Y is —H, and when it is a single bond, X is —H, the linking group, or an amine protecting group;

Y is —H, —OR, —OCOR′, —SR, —NR′R,″ —SO 3 M, —SO 2 M or —OSO 3 M, wherein M is —H or a cation;

R is —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms or a PEG group —(CH 2 CH 2 O) n —R c , wherein n is an integer from 1 to 24, and R c is a linear or branched alkyl having 1 to 4 carbon atoms;

R′ and R″ are the same or different, and are selected from the group consisting of —H, —OH, —OR, —NRR g′ , —COR, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, an optionally substituted aryl having from 6 to 18 carbon atoms, an optionally substituted 3- to 18-membered heterocyclic ring having 1 to 6 heteroatoms selected from O, S, N and P, and a PEG group —(CH 2 CH 2 O) n —R c , wherein n is an integer from 1 to 24; and R g′ is —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms or a PEG group —(CH 2 CH 2 O) n —R c ;

X′ is selected from the group consisting of —H, —OH, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, phenyl, and an amine-protecting group;

Y′ is selected from the group consisting of —H, an oxo group, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms;

A and A′ are —O— and or —S—;

W′ is absent, —O—, —N(R e )—, —N(R e )—C(═O)—, —N(C(═O)R e )—, —S—, —CH 2 —S—, or —CH 2 NR e —;

R x is absent or a linear, branched or cyclic alkyl having 1 to 10 carbon atoms;

R e is —H, a linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms or —(CH 2 —CH 2 —O) n —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms, optionally bearing a —NHR 101 or NR 101 R 102 group or a 5- or 6-membered nitrogen containing heterocycle, wherein R 101 and R 102 are each independently a linear, branched, or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms;

G is —CH— or —N—;

Z s is —H, or is selected from any one of the following formulas:

wherein:

q is an integer from 1 to 5;

n is an integer from 2 to 6;

D is —H or —SO 3 M;

M is —H or a cation.

15. The compound of claim 14 , wherein Z s is represented by any one of the following formulas:

16. The compound of claim 14 , wherein W′ is —N(R e )—; and R e is —(CH 2 —CH 2 —O) n —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms.

17. The compound of claim 16 , wherein R k is —H or -Me, n is 4, and q is 2.

18. The compound of claim 17 , wherein R x is a linear or branched alkyl having 1 to 6 carbon atoms.

19. The compound of claim 17 , wherein R x is —(CH 2 ) p —(CR f R g )—, wherein R f and R g are each independently —H or a linear or branched alkyl having 1 to 4 carbon atoms; and p is 0, 1, 2 or 3.

20. The compound of claim 19 , wherein R f and R g are the same or different, and are —H or -Me; and p is 1.

21. The compound of claim 14 , wherein:

the double line between N and C represents a single bond or a double bond, provided that when it is a double bond X is absent and Y is —H, and when it is a single bond, X is —H; Y is —OH or —SO 3 M;

M is —H or a pharmaceutically acceptable cation;

X′ and Y′ are both —H;

A and A′ are both —O—;

R 6 is —OMe; and

R x is a linear or branched alkyl having 1 to 6 carbon atoms.

22. The compound of claim 1 , wherein the double line between N and C represents a double bond.

23. The compound of claim 1 , wherein the double line between N and C represents a single bond, X is —H, the linking group thereto, or an amine protecting group; and Y is selected from the group consisting of —H, —OR, —OCOR′, —SR, —NR′R,″ an optionally substituted 5- or 6-membered nitrogen-containing heterocycle, —SO 3 M, —SO 2 M and OSO 3 M.

24. The compound of claim 23 , wherein Y is —H, —SO 3 M, —OH, —OMe, —OEt or —NHOH.

25. The compound of claim 11 , wherein M is —H, Na + or K + .

26. The compound of claim 1 , wherein:

the double line between N and C represents a double bond;

Y is —H;

W is C═O;

R 1 , R 2 , R 1 ′, R 2 ′, R 4 and R 4 ′ are —H;

one of R 3 , or R 3 ′ is optionally the linking group and the other is —H;

R 6 is —OMe;

Z and Z′ are —CH 2 ;

X′ is —H;

Y′ is —H; and

A and A′ are —O—.

27. A conjugate comprising: a compound and a cell binding agent (CBA), wherein the compound comprises a linking group which covalently links the compound to the CBA, and wherein said compound is represented by any one of the following formulas:

or a pharmaceutically acceptable salt thereof, wherein:

the double line between N and C represents a single bond or a double bond, provided that when it is a double bond X is absent and Y is —H, or a linear or branched alkyl having 1 to 4 carbon atoms, and when it is a single bond, X is —H, the linking group, or an amine protecting moiety;

Y is —H or a leaving group selected from the group consisting of —OR, —OCOR′, —OCOOR′, —OCONR′R″, —NR′R″, —NR′COR″, —NR′NR′R″, an optionally substituted 5- or 6-membered nitrogen-containing heterocycle, —NR′(C═NH)NR′R″, an amino acid, and a peptide represented by —NRCOP′, wherein P′ is an amino acid or a polypeptide containing between 2 to 20 amino acid units, —SR, —SOR′, —SO 2 M, —SO 3 M, —OSO 3 M, halogen, cyano and an azido; or,

Y is a HSO 3 , HSO 2 or a salt of HSO 3 − , SO 3 2− or HSO 2 − formed with a cation, H 2 S 2 O 5 or a salt of S 2 O 5 2− formed with a cation, PO 3 SH 3 , PO 2 S 2 H 2 , POS 3 H 2 , PS 4 H 2 or a salt of PO 3 S 3− , PO 2 S 2 3− , POS 3 3− or PS 4 3− formed with a cation, (R i O) 2 PS(OR i ), R i S—, R i SO, R i SO 2 , R i SO 3 , HS 2 O 3 or a salt of S 2 O 3 2− formed with a cation, HS 2 O 4 or a salt of S 2 O 4 2− formed with a cation, P(═S)(OR k′ )(S)(OH) or a salt thereof formed with a cation, R k′ C(═O)NOH or a salt formed with a cation, HOCH 2 SO 2 − or a salt of HOCH 2 SO 2 − formed with a cation or a mixture thereof, wherein R i is a linear or branched alkyl having 1 to 10 carbon atoms and is substituted with at least one substituent selected from the group consisting of —N(R j ) 2 , —CO 2 H, —SO 3 H, and —PO 3 H; R i can be further optionally substituted with a substituent for an alkyl described herein; R j is a linear or branched alkyl having 1 to 6 carbon atoms; R k′ is a linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, aryl, heterocyclyl or heteroaryl;

M is —H or a cation;

R, for each occurrence, is independently selected from the group consisting of —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(CH 2 CH 2 O) n —R c , an optionally substituted aryl having 6 to 18 carbon atoms, an optionally substituted 5- to 18-membered heteroaryl ring containing one or more heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an optionally substituted 3- to 18-membered heterocyclic ring containing 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P;

R′ and R″ are each independently selected from the group consisting of —H, —OH, —OR, —NHR, —NR 2 , —COR, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(CH 2 CH 2 O) n —R c , and an optionally substituted 3-18-membered heterocyclic ring having 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P;

R c is —H or an optionally substituted linear or branched alkyl having 1 to 4 carbon atoms, or the linking group;

n is an integer from 1 to 24;

W is C═O;

X′ is selected from the group consisting of —H, an amine-protecting group, the linking group, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(CH 2 CH 2 O) n —R c , an optionally substituted aryl having 6 to 18 carbon atoms, an optionally substituted 5- to 18-membered heteroaryl ring containing one or more heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an optionally substituted 3- to 18-membered heterocyclic ring containing 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P;

Y′ is selected from the group consisting of —H, an oxo group, the linking group, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, an optionally substituted 6- to 18-membered aryl, an optionally substituted 5- to 18-membered heteroaryl ring containing one or more heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an optionally substituted 3 to 18-membered heterocyclic ring having 1 to 6 heteroatoms;

R 1 , R 2 , R 3 , R 4 , R 1 ′, R 2 ′, R 3 ′ and R 4 ′ are each independently selected from the group consisting of —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(OCH 2 CH 2 ) n —R c , halogen, —NH(C═NH)NH 2 , —OR, —NR′R″, —NO 2 , —NCO, —NR′COR″, —SR, —SOR′, —SO 2 R′, —SO 3 − M + , —OSO 3 − M + , —SO 2 NR′R″, cyano, an azido, —COR′, —OCOR′, —OCONR′R″ and the linking group;

R 6 is —H, —R, —OR, —SR, —NR′R″, —NO 2 , halogen or the linking group;

Z is —CH 2 —;

A and A′ are the same or different, and are independently selected from the group consisting of —O—, —(—C(═O)—, —CRR′O—, —CRR′—, —S—, —CRR′S—, —N(R 5 )— and —CRR′N(R 5 )—,

R 5 for each occurrence is independently —H or an optionally substituted linear or branched alkyl having 1 to 10 carbon atoms;

D and D′ are the same or different, and are independently absent or selected from the group consisting of an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, an amino acid, a peptide bearing 2 to 6 amino acids, and a polyethylene glycol unit (—OCH 2 CH 2 ) n —;

L is absent, the linking group, a polyethylene glycol unit (—OCH 2 CH 2 ) n —, a linear, branched or cyclic alkyl or alkenyl having 1 to 10 carbon atoms, a phenyl group, a 3- to 18-membered heterocyclic ring or a 5- to 18-membered heteroaryl ring having 1 to 6 heteroatoms independently selected from the group consisting of O, S, N and P, wherein the alkyl or alkenyl is optionally substituted with the linking group; phenyl or heterocyclic or heteroaryl ring can be optionally substituted, wherein the substituent can be the linking group,

provided that the compound is not:

wherein the optional substituent described above is a linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, aryl, heteroaryl, heterocycyclyl, halogen, —NH(C═NH)NH 2 , —OR 100 , NR 101 R 102 , —NO 2 , —NR 101 COR 102 , —SR 100 , —SOR 101 , —SO 2 R 101 , —SO 3 M, —OSO 3 M, —SO 2 NR 101 R 102 , cyano, an azido, —COR 101 , —OCOR 101 , —OCONR 101 R 102 and a polyethylene glycol unit (—OCH 2 CH 2 ) n R 101 wherein M is H or a cation; R 100 , R 101 , R 102 and R 103 are each independently selected from the group consisting of H, linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit (—OCH 2 CH 2 ) n —R 104 , an aryl having from 6 to 10 carbon atoms, a heterocyclic ring having from 3 to 10 carbon atoms and a heteroaryl having 5 to 10 carbon atoms; n is an integer from 1 to 24, and R 104 is H or a linear or branched alkyl having 1 to 4 carbon atoms, wherein the alkyl, alkenyl, alkynyl, aryl, heteroaryl and heterocyclcyl in the groups represented by R 100 , R 101 , R 102 , R 103 and R 104 are optionally substituted with one or more substituents independently selected from the group consisting of halogen, —OH, —CN, —NO 2 and unsubstituted linear or branched alkyl having 1 to 4 carbon atoms.

28. A pharmaceutical composition comprising the conjugate of claim 27 and a pharmaceutically acceptable carrier.

29. A method of treating a cancer in a mammal comprising administering to said mammal a therapeutically effective amount of a conjugate of claim 27 and, optionally, a chemotherapeutic agent, wherein the cancer is selected from the group consisting of leukemia, lymphoma, multiple myeloma, cervical cancer, non-small cell lung cancer, small-cell lung cancer, head and neck cancer and colon cancer.

30. The conjugate of claim 27 , wherein the compound is represented by any one of the following formulas:

wherein:

L′, L″, and L′″ are the same or different, and are independently selected from the group consisting of —H, an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having from 1 to 10 carbon atoms, a polyethylene glycol unit —(OCH 2 CH 2 ) n —R c , halogen, NH(C═NH)NH 2 , —OR, —NR′R″, —NO 2 , —NR′COR″, —SR, —SOR′, —SO 2 R′, —SO 3 M, —OSO 3 M, —SO 2 NR′R″, cyano, an azido, —COR′, —OCOR′, —OCONR′R″ and the linking group, provided only one of L′, L″, and L′″ is the linking group; and

G is —CH— or —N—.

31. The conjugate of claim 30 , wherein L′ is the linking group, and L″ and L′″ are —H.

32. The conjugate of claim 31 , wherein L′ is represented by the following formula:

—W′—R x —V—R y -J,

wherein:

W′ and V are the same or different, and are each independently absent, or selected from the group consisting of —CR e R e′ —, —O—, —O—C(═O)—, —C(═O)—O—, —S—, —SO—, —SO 2 —, —CH 2 —S—, —CH 2 O—, —CH 2 NR e —, —O—(C═O)O—, —O—(C═O)N(R e )—, —N(R e )—, —N(R e )—C(═O)—, —C(═O)—N(R e )—, —N(R e )—C(═O)O—, —N(C(═O)R e )C(═O)—, —N(C(═O)R e )—, —(O—CH 2 —CH 2 ) n —, —SS—, —C(═O)—, an amino acid, and a peptide having 2 to 8 amino acids;

R x and R y are the same or different, and are each independently absent or an optionally substituted linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms, an aryl bearing 6 to 10 carbon atoms or a 3- to 8-membered hetereocyclic ring bearing 1 to 3 heteroatoms selected from the group consisting of O, N and S;

R e and R e′ are the same or different, and are selected from —H, a linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms or —(CH 2 —CH 2 —O) n —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms, optionally bearing NHR 101 or NR 101 R 102 group or a 5- or 6-membered nitrogen containing heterocycle, wherein R 101 and R 102 are each independently a linear, branched, or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms;

n is an integer from 1 to 24;

J comprises the reactive group bonded thereto, and is selected from the group consisting of a maleimide, a haloacetamido, —SH, —SSR d , —CH 2 SH, —CH(Me)SH, —C(Me) 2 SH, —NHR c1 , —CH 2 NHR c1 , —NR c1 NH 2 , —COOH, and —COE, wherein —COE represents a reactive ester selected from the group consisting of N-hydroxysuccinimde ester, N-hydroxy sulfosuccinimide ester, nitrophenyl ester, dinitrophenyl ester, sulfo-tetrafluorophenyl ester, and pentafluorophenyl ester, and wherein R c1 is —H or an optionally substituted linear or branched alkyl having 1 to 4 carbon atoms, and,

R d is selected from the group consisting of phenyl, nitrophenyl, dinitrophenyl, carboxynitrophenyl, pyridyl and nitropyridyl.

33. The conjugate of claim 32 , wherein J is —SS—, a succinimide, or —C(═O)—.

34. The conjugate of claim 32 , wherein:

W′ is —O—, —N(R e )— or —N(R e )—C(═O)—;

R e is —H, -Me, or —(CH 2 —CH 2 —O) n -Me;

n is an integer from 2 to 6;

R x is linear or branched alkyl bearing 1 to 6 carbon atoms;

V and R y are absent; and

J is —C(═O)—.

35. The conjugate of claim 32 , wherein L′ is represented by the following formula:

—W′—[CR 1″ R 2″ ] a —V-[Cy] 0-1 -[CR 3″ R 4″ ] b —C(═O)—,

wherein:

R 1″ , R 2″ , and R 3″ are each independently —H or -Me;

R 4″ is —H, -Me, —SO 3 H, or —SO 3 − M + , wherein M + is a pharmaceutically acceptable cation;

a is an integers from 0-2, b is an integer from 0-3; and,

Cy is an optionally substituted 5-membered heterocyclic ring bearing an N heteroatom.

36. The conjugate of claim 32 , wherein W′ is —N(R e )—; R e is —(CH 2 —CH 2 —O) 2-6 —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms; and V is —S— or —SS—.

37. The conjugate of claim 32 , wherein L′ is represented by the following formula:

—NR e —[CR 1″ R 2″ ] a —S—[CR 3″ R 4″ ] b —C(═O)—.

38. The conjugate of claim 32 , which is:

wherein r is an integer from 1 to 10, Y is —H or —SO 3 M, and M is —H or a pharmaceutically acceptable cation.

39. The conjugate of claim 38 , wherein the antibody is huMy9-6.

40. The conjugate of claim 32 , wherein L′ is represented by the following formula:

—NR e —[CR 1″ R 2″ ] a —S-Cy-[CR 3″ R 4″ ] b —C(═O)—.

41. The conjugate of claim 32 , which is:

wherein r is an integer from 1 to 10, Y is —H or —SO 3 M, and M is —H or a pharmaceutically acceptable cation.

42. The conjugate of claim 27 , wherein the compound is represented by any one of the following formulas:

W′ is absent, —O—, —N(R e )—, —N(R e )—C(═O)—, —N(C(═O)R e )—, —S—, —CH 2 —S—, or —CH 2 NR e —;

R x is absent or a linear, branched or cyclic alkyl having 1 to 10 carbon atoms;

R e is —H, a linear, branched or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms or —(CH 2 —CH 2 —O) n —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms, optionally bearing a —NHR 101 —NR 101 R 102 group or a 5 or 6-membered nitrogen containing heterocycle, wherein R 101 and R 102 are each independently a linear, branched, or cyclic alkyl, alkenyl or alkynyl having 1 to 10 carbon atoms;

n is an integer from 2 to 6;

Z s is linked to the CBA, and is selected from:

a bond;

wherein:

q is an integer from 1 to 5; and,

M is —H or a cation.

43. The conjugate of claim 42 , wherein Z s is represented by any one of the following formulas:

44. The conjugate of claim 42 , wherein W′ is —N(R e )—; and R e is —(CH 2 —CH 2 —O) n —R k , wherein R k is a —H, a linear, branched cyclic alkyl having 1 to 6 carbon atoms.

45. The conjugate of claim 44 , wherein R k is —H or -Me, n is 4, and q is 2.

46. The conjugate of claim 45 , wherein R x is a linear or branched alkyl having 1 to 6 carbon atoms.

47. The conjugate of claim 46 , wherein R x is —(CH 2 ) p —(CR f R g )—, wherein R f and R g are each independently —H or a linear or branched alkyl having 1 to 4 carbon atoms; and p is 0, 1, 2 or 3.

48. The conjugate of claim 47 , wherein R f and R g are the same or different, and are —H or -Me; and p is 1.

49. The conjugate of claim 42 , wherein:

the double line between N and C represents a single bond or a double bond, provided that when it is a double bond X is absent and Y is —H, and when it is a single bond, X is —H; Y is —OH or —SO 3 M;

M is —H or a pharmaceutically acceptable cation;

X′ and Y′ are both —H;

A and A′ are both —O—;

R 6 is —OMe; and

R x is a linear or branched alkyl having 1 to 6 carbon atoms.

50. The conjugate of claim 27 , wherein the double line between N and C represents a double bond.

51. The conjugate of claim 27 , wherein the double line between N and C represents a single bond, X is —H, the linking group, or an amine protecting group; and Y is selected from the group consisting of —H, —OR, —OCOR′, —SR, —NR′R,″ an optionally substituted 5- or 6-membered nitrogen-containing heterocycle, —SO 3 M, —SO 2 M and a sulfate —OSO 3 M.

52. The conjugate of claim 51 , wherein Y is —H, —SO 3 M, —OH, —OMe, —OEt or —NHOH.

53. The conjugate of claim 52 , wherein M is —H, Na + or K + .

54. The conjugate of claim 27 , wherein:

the double line between N and C represents a double bond;

Y is —H;

W is C═O;

R 1 , R 2 , R 1 ′, R 2 ′, R 4 and R 4 ′ are —H;

one of R 3 , or R 3 ′ is optionally the linking group and the other is —H;

R 6 is —OMe;

Z and Z′ are —CH 2 ;

X′ is —H;

Y′ is —H; and

A and A′ are —O—.

55. The conjugate of claim 27 , wherein the cell-binding agent is an antibody, a single chain antibody, an antibody fragment that specifically binds to the target cell, a monoclonal antibody, a single chain monoclonal antibody, or a monoclonal antibody fragment that specifically binds to a target cell, a chimeric antibody, a chimeric antibody fragment that specifically binds to the target cell, a domain antibody, a domain antibody fragment that specifically binds to the target cell, a lymphokine, a hormone, a vitamin, a growth factor, a colony stimulating factor, or a nutrient-transport molecule.

56. The conjugate of claim 55 , wherein the antibody is a resurfaced antibody, a resurfaced single chain antibody, or a resurfaced antibody fragment, a monoclonal antibody, a single chain monoclonal antibody, or a monoclonal antibody fragment thereof, a humanized antibody, a humanized single chain antibody, or a humanized antibody fragment.