Pyrido [4,3-b] indole and pyrido [3,4-b] indole derivatives and methods of use

1. A compound of the formula (IA):

or a salt or solvate thereof;

wherein:

R 1 is H, hydroxyl, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted C 2 -C 8 alkenyl, substituted or unsubstituted C 2 -C 8 alkynyl, perhaloalkyl, acyl, acyloxy, carbonylalkoxy, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted aralkyl, C 1 -C 8 perhaloalkoxy, alkoxy, aryloxy, thiol, thioalkyl, substituted or unsubstituted amino, acylamino, aminoacyl, aminocarbonylamino, aminocarbonyloxy, aminosulfonyl, sulfonylamino, sulfonyl or carbonylalkylenealkoxy, or R 1 and R 2a are taken together to form a propylene (—CH 2 CH 2 CH 2 —) moiety or a butylene (—CH 2 CH 2 CH 2 CH 2 —) moiety, or R 1 and R 3a are taken together to form a propylene (—CH 2 CH 2 CH 2 —) moiety or a butylene (—CH 2 CH 2 CH 2 CH 2 —) moiety;

each R 2a and R 2b is independently H, substituted or unsubstituted C 1 -C 8 alkyl, halo, cyano, hydroxyl, alkoxy, nitro or R 2a and R 2b are taken together with the carbon to which they are attached to form a carbonyl moiety or a cycloalkyl moiety, or R 2a and R 1 are taken together to form a propylene (—CH 2 CH 2 CH 2 —) moiety or a butylene (—CH 2 CH 2 CH 2 CH 2 —) moiety;

each R 3a and R 3b is independently H, substituted or unsubstituted C 1 -C 8 alkyl, halo, cyano, hydroxyl, alkoxy, nitro or R 3a and R 3b are taken together with the carbon to which they are attached to form a carbonyl moiety or a cycloalkyl moiety, or R 3a and R 1 are taken together to form a propylene (—CH 2 CH 2 CH 2 —) moiety or a butylene (—CH 2 CH 2 CH 2 CH 2 —) moiety, or R 3a and R 4a are taken together to form a propylene (—CH 2 CH 2 CH 2 —) moiety or a butylene (—CH 2 CH 2 CH 2 CH 2 —) moiety;

each R 4a and R 4b is independently H, substituted or unsubstituted C 1 -C 8 alkyl, halo, cyano, nitro, substituted or unsubstituted amino, hydroxyl, alkoxy, acyloxy, acylamino, aryl, heteroaryl, cycloalkyl, heterocyclyl, or R 4a and R 4b are taken together with the carbon to which they are attached to form a carbonyl moiety or a cycloalkyl moiety, or R 4a and R 3a are taken together to form a propylene (—CH 2 CH 2 CH 2 —) moiety or a butylene (—CH 2 CH 2 CH 2 CH 2 —) moiety;

each X 1 , X 2 , X 3 and X 4 is independently N, CH or CR 6 ;

Q is a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted of unsubstituted aralkyl, wherein the aralkyl is a fused ring system where at least one cycloalkyl moiety is fused with at least one aryl moiety and wherein the aralkyl is attached to the parent structure via the cycloalkyl moiety or the aryl moiety; and

R 6 is hydroxyl, nitro, cyano, halo, C 1 -C 8 perhaloalkyl, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted C 2 -C 8 alkenyl, substituted or unsubstituted C 2 -C 8 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, C 1 -C 8 perhaloalkoxy, substituted or unsubstituted C 1 -C 8 alkoxy, substituted or unsubstituted aryloxy, carboxyl, carbonylalkoxy, thiol, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aralkyl, thioalkyl, substituted or unsubstituted amino, acylamino, aminoacyl, aminocarbonylamino, aminocarbonyloxy, aminosulfonyl, sulfonylamino, sulfonyl, carbonylalkylenealkoxy, alkylsulfonylamino or acyl,

provided that:

(1) at least one of X 1 , X 2 , X 3 and X 4 is CH or CR 6 ;

(2) when each X 1 , X 2 , X 3 and X 4 is independently CH or CR 6 , none of R 1 , R 2a , R 2b , R 3a , R 3b , R 4a and R 4b are taken together to form a ring and Q is an unsubstituted 6-membered aryl or an unsubstituted 6-membered heteroaryl, then Q is other than unsubstituted phenyl, unsubstituted pyridyl and unsubstituted pyrimidyl; and

(3) when each X 1 , X 2 , X 3 and X 4 is independently CH or CR 6 , none of R 1 , R 2a , R 2b , R 3a , R 3b , R 4a and R 4b are taken together to form a ring and Q is a substituted phenyl, then Q is a phenyl substituted with a substituent selected from the group consisting of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted heterocyclyl, and substituted or unsubstituted aralkyl.

2. The compound of claim 1 , wherein the compound is of the formula (IA4):

wherein:

either (i) one or more of X 1 , X 2 , X 3 and X 4 is N or (ii) X 1 and X 3 are CH, X 2 is CR 6 and X 4 is N, CH or CR 6 ; and

Q is an aromatic ring of the formula:

 where

Z is C, NH, N—CH 3 , O or S and the Z-containing aromatic ring is attached to the parent structure at any available ring position;

t is 0 or 1; and

W is: (i) a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl that is bound to the Z-containing ring via a single bond at any available ring position or is fused to the Z-containing ring at any available adjacent ring positions, (ii) a substituted amino, provided that when X 1 , X 2 , X 3 and X 4 are each independently CH or CR 6 , then R 1 is an unsubstituted C 1 -C 8 alkyl when W is a substituted amino, or (iii) H, provided that when X 1 , X 2 , X 3 and X 4 are each independently CH or CR 6 , then W is H only when the Z-containing ring is a 5-membered heteroaryl moiety.

3. The compound of claim 1 , wherein the compound is of the formula (IA5):

wherein:

Z is C, NH, N—CH 3 , O or S;

t is 0 or 1;

W is: (i) a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl that is bound to the Z-containing ring via a single bond at any available position or is fused to the Z-containing ring at two adjacent positions, (ii) a substituted amino, provided that R 1 is a C 1 -C 8 alkyl when W is a substituted amino, or (iii) H, provided that W is only H when the Z-containing ring is a 5-membered heteroaryl moiety; and

wherein the Z-containing ring is aromatic and is attached to the parent structure at any available ring position.

4. The compound of claim 1 , wherein the compound is of the formula (IA6):

wherein:

X 1 and X 3 are CH;

X 2 is CR 6 ; and

W is a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl that is bound to the parent structure via a single bond located at any available ring position.

5. The compound of claim 1 , wherein the compound is of the formula (IA6):

wherein:

one or more of X 1 , X 2 , X 3 and X 4 is N; and

W is a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl that is bound to the parent structure via a single bond located at any available ring position.

6. The compound of claim 1 , wherein the compound is of the formula (IA6):

wherein:

X 1 and X 3 are CH;

X 2 is CR 6 ;

W is a substituted amino that is bound to the parent structure via a single bond located at any available ring position; and

R 1 is an unsubstituted C 1 -C 8 alkyl.

7. The compound of claim 4 , wherein the compound is of the formula (A1) or (A2):

8. The compound of claim 1 , wherein the compound is of the formula (IA7):

wherein:

Z is NH, N—CH 3 , O or S; and

W is H, hydroxyl, halo, nitro, cyano, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted C 1 -C 8 alkoxy, C 1 -C 8 perhaloalkyl, C 1 -C 8 perhaloalkoxy, substituted or unsubstituted C 2 -C 8 alkenyl, substituted or unsubstituted C 2 -C 8 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aralkyl, substituted or unsubstituted amino, aminoacyl, acyl, acylamino, acyloxy, carbonylalkoxy, carboxyl, thiol, thioalkyl, aminocarbonylamino, aminocarbonylalkoxy, aminosulfonyl or sulfonylamino.

9. The compound of claim 8 , wherein one or more of X 1 , X 2 , X 3 and X 4 is N.

10. The compound of claim 8 , wherein X 1 and X 3 are CH and X 2 is CR 6 .

11. The compound of claim 8 , wherein the compound is of the formula (B1), (B2), (B3), (B4), (B5) or (B6):

12. The compound of claim 1 , wherein the compound is of the formula (IA8):

wherein:

W is H, hydroxyl, halo, nitro, cyano, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted C 1 -C 8 alkoxy, C 1 -C 8 perhaloalkyl, C 1 -C 8 perhaloalkoxy, substituted or unsubstituted C 2 -C 8 alkenyl, substituted or unsubstituted C 2 -C 8 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aralkyl, substituted or unsubstituted amino, aminoacyl, acyl, acylamino, acyloxy, carbonylalkoxy, carboxyl, thiol, thioalkyl, aminocarbonylamino, aminocarbonylalkoxy, aminosulfonyl or sulfonylamino.

13. The compound of claim 12 , wherein one or more of X 1 , X 2 , X 3 and X 4 is N.

14. The compound of claim 12 , wherein X 1 and X 3 are CH and X 2 is CR 6 .

15. The compound of claim 12 , wherein the compound is of the formula (C1), (C2) or (C3):

16. The compound of claim 1 , wherein the compound is of the formula (IA9):

wherein W is H, hydroxyl, halo, nitro, cyano, substituted or unsubstituted C 1 -C 8 alkyl, substituted or unsubstituted C 1 -C 8 alkoxy, C 1 -C 8 perhaloalkyl, C 1 -C 8 perhaloalkoxy, substituted or unsubstituted C 2 -C 8 alkenyl, substituted or unsubstituted C 2 -C 8 alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aralkyl, substituted or unsubstituted amino, aminoacyl, acyl, acylamino, acyloxy, carbonylalkoxy, carboxyl, thiol, thioalkyl, aminocarbonylamino, aminocarbonylalkoxy, aminosulfonyl or sulfonylamino.

17. The compound of claim 1 , wherein X 4 is N.

18. The compound of claim 1 wherein X 4 is CH or CR 6 .

19. A compound selected from the group consisting of compounds 2-114, 118-120, 127-172, 201, 203-206, 211, 212, 217-220, 223-226 and 231, or a pharmaceutically acceptable salt thereof.

20. A pharmaceutical composition comprising a compound of claim 1 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

21. A kit comprising a compound according to claim 1 or a pharmaceutically acceptable salt thereof and instructions for use in the treatment of a cognitive disorder, psychotic disorder, neurotransmitter-mediated disorder or a neuronal disorder.

22. A compound of claim 19 , wherein the compound is Compound No. 100:

or a pharmaceutically acceptable salt thereof.