Fluorescent probes for reactive sulfur species

1. A compound selected from:

wherein

R a and R b are independently selected from H, —C(O)OR 4 , —C(O)NR 5 R 6 , substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, halogen, —OR 11 , —SR 11 , —NR 12 R 13 , — C(O)OR 11 , —CHO, —OSO 3 R 11 , and —C(O)NR 12 R 13 ;

wherein at least one of R a or R b is not H;

wherein R 4 , R 5 , R 6 , R 11 , R 12 and R 13 are independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

wherein R 5 and R 6 are optionally joined to form, along with the atom to which they are attached, a substituted or unsubstituted heterocycloalkyl; and

R 12 and R 13 are optionally joined to form, along with the atom to which they are attached, a substituted or unsubstituted heterocycloalkyl;

R c , R d , R e , R f , R g , R h , R i , R j , and R k are independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, halogen, —OR 11 , —SR 11 , —NR 12 R 13 , —C(O)OR 11 , —CHO, —OSO 3 R 11 , and —C(O)NR 12 R 13 ;

R r is heteroalkyl substituted with OC(O)R 14 , wherein R 14 is C 1 -C 6 substituted or unsubstituted alkyl;

R z1 is a member selected from —OR 3 , —SR 3 , —NR 1 R 2 , -L 1 R L , —N 3 , —N(H)C(O)OR 3 and —N(H)C(O)NR 1 R 2 ;

wherein R 1 , R 2 and R 3 are independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

wherein R 1 and R 2 are optionally joined to form, along with the atom to which they are attached, a substituted or unsubstituted heterocycloalkyl;

L 1 is a linker which is a member selected from a bond, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

R L is a member selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

R z2 is a member selected from O, S, NR 1 , N + R 1 R 2 , and L 1 R L ;

W is a member selected from O, NR 7 , S, and Se;

wherein R 7 is a member selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl;

X is a member selected from O, S, Se, CR 8 R 9 , and SiR 8 R 9 ;

wherein R 8 and R 9 are independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl;

Y is a member selected from O, NR 10 , S, and Se;

wherein R 10 is a member selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl.

2. The compound according to claim 1 , selected from:

wherein

R c , R d , R e , R f , R g , R h , R i , and R j are each H; and

W, X and Y are each O.

3. The compound according to claim 2 , wherein

R a and R b are independently selected from H, —C(O)OR 4 , and —C(O)NR 5 R 6 , wherein at least one of R a or R b is not H; and

R z1 is a member selected from —NR 1 R 2 , —N 3 , —N(H)C(O)OR 3 and —N(H)C(O)NR 1 R 2 .

4. The compound according to claim 3 , selected from:

wherein

R z1 is a member selected from —N(H)C(O)OR 3 and —N(H)C(O)NR 1 R 2 ;

R a and R b are independently selected from H, —C(O)OR 4 and —C(O)NR 5 R 6 , wherein at least one of R a or R b is not H; and

R r is heteroalkyl substituted with —OC(O)R 14 ,

wherein R 14 is a member selected from unsubstituted C 1 , C 2 , C 3 , C 4 , C 5 or C 6 alkyl.

5. The compound according to claim 4 , wherein R a is H.

6. The compound according to claim 4 , wherein R 5 and R 6 are alkyl substituted with —C(O)OR 4 .

7. The compound according to claim 4 , selected from:

8. The compound according to claim 1 , wherein said compound is a probe for a reactive sulfur species; wherein the azide moiety undergoes a reduction upon contact with the reactive sulfur species, forming a reaction product, thereby generating a detectable signal.

9. The compound according to claim 8 , wherein said reactive sulfur species is H 2 S.

10. An assay mixture comprising a compound according to claim 1 ; and a suitable solvent for the compound.

11. A method of detecting a reactive sulfur species in a sample comprising:

(a) contacting the sample with the probe according to claim 8 ; and

(b) detecting the reaction product emitting the detectable signal.

12. The method according to claim 11 , wherein said reactive sulfur species is H 2 S.

13. The method according to claim 11 , wherein said sample comprises a cell, and the reaction product is formed within said cell.

14. The method according to claim 13 , wherein said cell is a living cell.

15. The method according to claim 11 , wherein said reaction product is detected in real-time.

16. A compound of the structure:

wherein

R z1 is a member select from —N(H)C(O)OR 3 and —N(H)C(O)NR 1 R 2

wherein R 1 and R 2 are independently selected from H, substituted or

unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl and R 1 and R 2 ′ together with the atom to which they are attached are optionally joined to form a substituted or unsubstituted heterocycloalkyl ring; and

wherein R 3 is independently selected from H, substituted alkyl, substituted or

unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl.

17. The compound according to claim 16 which is: