Cephalosporin having catechol group

1. A compound of the formula:

wherein,

X is N, CH or C—Cl;

T is S, S═O, CH 2 or O;

A is lower alkylene, lower alkenylene or lower alkynylene;

G is optionally present, and when present is, —CH 2 —CH(CH 3 )—, —CH 2 —CH( i Pr)—, lower alkylene optionally substituted with a carbocyclic group, lower alkenylene, or lower alkynylene;

B is optionally present, and when present B is a 5- or 6-membered heterocyclic group containing at least 1 N atom(s);

D is optionally present, and when present D is, —CO—, —O—CO—, —CO—O—, —NR 7 —, —NR 7 —CO—, —CO—NR 7 —, —NR 7 —CO—NR 7 —, —O—, —S—, —SO—, —SO 2 —NR 7 —, —NR 7 —SO 2 —, —CH 2 —NR 7 —CO— or —SO 2 —;

E is of the formula:

wherein R 1 and R 2 are each independently hydrogen, halogen, lower alkyl optionally substituted with carbamoyl, lower alkylthio, or phenyl, R 11 and R 12 are each independently hydrogen, lower alkyl optionally substituted with carbamoyl or carboxyl, carboxyl, or a carbamoyl, and m refers to an integer of 1 to 5;

F is optionally present, and when present F is phenylene;

R 3 and R 4 are —OR 8 ;

R 5 and R 6 each is independently hydrogen, halogen, nitrile, or —OR 8 ;

R 7 each is independently hydrogen or lower alkyl;

R 8 each is independently hydrogen, lower alkyl, halo(lower)alkyl, lower alkylcarbonyl or carbamoyl;

the formula:

is an optionally substituted, saturated or unsaturated, monocyclic or condensed cyclic quaternary ammonium group containing one or more N atom(s);

wherein the substituents are at least one selected from the group consisting of halogen, hydroxy, lower alkyl, halo(lower)alkyl, lower alkoxy, and halo(lower)alkoxy;

the broken line represents the presence or absence of a bond between the cationic N atom and a ring-forming atom;

provided that

when G bonds to the cationic N atom, the broken line is absent;

when G does not bond to the cationic N atom, the broken line represents a single bond between the cationic N atom and a neighboring atom or represents lower alkylene between the cationic N atom and a ring-forming atom other than the neighboring atom; and

when G and B are not present, and D is —NH—CO— or —S—, then a group of the formula:

is not a group of the formula:

wherein a hydrogen atom(s) on the quaternary ring is(are) optionally substituted;

or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof.

2. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein said formula

is the following formula:

wherein n is an integer from 0 to 5, k is an integer from 0 to 5, q is an integer from 0 to 3, R 10 is halogen, hydroxy, lower alkyl, halo(lower)alkyl, lower alkoxy, or halo(lower)alkoxy, provided that R 10 may be identical or different at k or q occurrences, and A and G are as defined in claim 1 .

3. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein said formula

is the formula:

wherein n, k, q and R 10 are as defined in claim 2 , and A and G are as defined in claim 1 .

4. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein

the formula

is the formula:

wherein R 5 , R 6 and R 8 are as defined in claim 1 .

5. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein

the formula:

is the formula

6. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein A is —CH 2 —, —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH═CH—, —CH═CH—CH 2 — or —CH 2 —CH═CH—.

7. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein G is optionally present, and when present is —CH═CH—, —CH═CH—CH 2 —, —CH 2 —CH═CH—, —CH 2 —CH(CH 3 )—, —CH 2 —CH( i Pr)— or —CH 2 —CH(Ph)-, wherein iPr refers to isopropyl group, and Ph refers to a phenyl group.

8. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein B is optionally present, and when present is the formula:

9. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein D is absent, —CO—, —O—CO—, —CO—O—, —NR 7 —, —NR 7 —CO—NR 7 —, —NR 7 —CO— or —CO—NR 7 —, wherein R 7 is as defined in claim 1 .

10. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein D is optionally present, and when present is —CO—, —NR 7 —CO—NR 7 —, —NR 7 —CO— or —CO—NR 7 —, wherein R 7 is as defined in claim 1 .

11. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein R 8 is hydrogen or a lower alkyl.

12. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein X is N.

13. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein X is CH or C—Cl.

14. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein T is S.

15. The compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 , wherein

X is N, CH or C—Cl;

T is S;

A is a lower alkylene;

G is optionally present, and when present is a lower alkylene;

the formula:

is the formula:

B is absent;

n is an integer of 0-3;

D is —NH—CO— or —CO—NH—;

E is the formula:

wherein Me refers to a methyl group;

F is absent;

R 3 and R 4 are —OH, and R 5 is hydrogen or Cl, and R 6 is hydrogen.

16. A pharmaceutical composition comprising the compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 .

17. The pharmaceutical composition according to claim 16 , which has an antimicrobial activity.

18. The compound according to claim 1 , which is selected from the group consisting of:

or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof.

19. The compound according to claim 1 , which is of the formula:

or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof.

20. The compound according to claim 1 , which is of the formula:

or a pharmaceutically acceptable salt, or a solvate thereof.

21. A method for treating a bacterial infection, comprising administering to a subject in need thereof the compound, or an ester at the carboxyl at the 7-position side chain or at the 4-position, a protected compound at the amino on the ring in the 7-side chain, a pharmaceutically acceptable salt, or a solvate thereof according to claim 1 .