AMINOPYRIDINE COMPOUNDS AND THEIR USES

1 . An aminopyridine or a pharmaceutically-acceptable salt thereof, wherein the aminopyridine is represented by formula (I):

wherein:

X 1 is selected from H, NH 2 , NHR 1 , N═NR 2 , N═R 3 , or NHCOOCH 3 ,

X 2 is selected from H, NH 2 , NHR 1 , N═NR 2 , or N═R 3 ,

X 3 is selected from NH 2 , NHR 1 , N═NR 2 , or N═CR 3 , wherein X 2 and X 3 are not both NH 2 ;

R 1 is selected from:

COR 4 , wherein R 4 is an amino acid attached at the carbonyl carbon;

COOR 5 , wherein R 5 is a C 2 or higher alkyl group;

COR 6 , wherein R 6 is a branched chain alkyl optionally substituted with a phenyl group, wherein the phenyl group is optionally substituted with a phosphonooxy group and optionally substituted with one or more alkyl groups;

a pyrone; and

SO 3 Na;

R 2 is a heterocycloalkenyl optionally substituted with one or more amino groups;

R 3 is a phenyl group optionally substituted with one or more halogens; or

R 3 is selected from the group consisting of formulas (II), (III), (IV), (V), (VI), (VII), (VIII), and (IX):

with the proviso that when X 3 is COOR 5 , R 5 is not an ethyl group, tert-butyl group, or n-dodecyl group.

2 . The aminopyridine of claim 1 , wherein R 4 is alanine, lysine, or phenylalanine.

3 . The aminopyridine of claim 2 , represented by a formula selected from the group consisting of (X), (XI), (XII), (XIII), (XIV), (XV), (XVI), (XVII), and (XVIII):

or a pharmaceutically acceptable salt thereof.

4 . The aminopyridine of claim 1 , represented by formula (XIX):

wherein R 5 is an n-propyl group; an n-butyl group; a sec-butyl group, or a straight or branched C 5 or higher alkyl chain, with the proviso that R 5 is not an n-dodecyl group;

or a pharmaceutically acceptable salt thereof.

5 . The aminopyridine of claim 1 , represented by a formula selected from the group consisting of (XX), (XXI), (XXII), and (XXIII):

wherein R 5 is a C 2 or higher alkyl group; or

or a pharmaceutically acceptable salt thereof.

6 . The aminopyridine of claim 5 , represented by formula (XXV):

or a pharmaceutically acceptable salt thereof.

7 . The aminopyridine of claim 5 , represented by formula (XXVI):

or a pharmaceutically acceptable salt thereof.

8 . The aminopyridine of claim 5 , represented by formula (XXVII):

or a pharmaceutically acceptable salt thereof.

9 . The aminopyridine of claim 5 , represented by formula (XXVIII):

or a pharmaceutically acceptable salt thereof.

10 . The aminopyridine of claim 1 , represented by the a formula selected from the group consisting of (XXIX), (XXX), and (XXXI):

wherein R 7 is a alkyl chain;

or a pharmaceutically acceptable salt thereof.

11 . The aminopyridine of claim 10 , wherein R 7 is a C 1 -C 6 straight or branched-chain alkyl.

12 . The aminopyridine of claim 1 , wherein R 6 is represented by formula (XXXII):

or a pharmaceutically acceptable salt thereof.

13 . The aminopyridine of claim 15 represented by the formula (XXXIII):

or a pharmaceutically acceptable salt thereof.

14 . The aminopyridine of claim 1 , wherein:

X 3 is NH 2 ,

X 1 is H, and

X 2 is N═R 3 .

15 . The aminopyridine of claim 14 , represented by formula (XXXIV):

wherein X 4 is a halogen;

or a pharmaceutically acceptable salt thereof.

16 . The aminopyridine of claim 1 , represented by formula (XXXV):

or a pharmaceutically acceptable salt thereof.

17 . The aminopyridine of claim 1 , represented by formula (XXXVI):

or a pharmaceutically acceptable salt thereof.

18 . The aminopyridine of claim 1 , represented by formula (XXXVII):

or a pharmaceutically acceptable salt thereof.

19 . A method of treating a neural disorder, the method comprising administering an effective dose of an aminopyridine, or a pharmaceutically acceptable salt thereof, wherein the aminopyridine is represented by formula (I):

wherein:

X 1 is selected from H, NH 2 , NHR 1 , N═NR 2 , N═R 3 , or NHCOOCH 3 ,

X 2 is selected from H, NH 2 , NHR 1 , N═NR 2 , or N═R 3 ,

X 3 is selected from NH 2 , NHR 1 , N═NR 2 , or N═CR 3 , wherein X 2 and X 3 are not both NH 2 ;

R 1 is selected from:

COR 4 , wherein R 4 is an amino acid attached at the carbonyl carbon;

COOR 5 , wherein R 5 is a C 2 or higher alkyl group;

COR 6 , wherein R 6 is a branched chain alkyl optionally substituted with a phenyl group, wherein the phenyl group is optionally substituted with a phosphonooxy group and optionally substituted with one or more alkyl groups;

a pyrone; and

SO 3 Na;

R 2 is a heterocycloalkenyl optionally substituted with one or more amino groups;

R 3 is a phenyl group optionally substituted with one or more halogens; or

R 3 is selected from the group consisting of formulas (II), (III), (IV), (V), (VI), (VII), (VIII), and (IX):

with the proviso that when X 3 is COOR 5 , R 5 is not an ethyl group, tert-butyl group, or n-dodecyl group.

20 . The method of claim 19 , wherein R 4 is alanine, lysine, or phenylalanine.

21 . The method of claim 20 , wherein the aminopyridine is represented by a formula selected from the group consisting of (XI), (XII), (XIII), (XIV), (XV), (XVI), (XVII), and (XVIII):

or a pharmaceutically acceptable salt thereof.

22 . The method of claim 19 , wherein the aminopyridine is represented by formula (XIX):

wherein R 5 is an n-propyl group; an n-butyl group; a sec-butyl group, or a straight or branched C 5 or higher alkyl chain, with the proviso that R 5 is not an n-dodecyl group;

or a pharmaceutically acceptable salt thereof.

23 . The method of claim 19 , wherein the aminopyridine is represented by a formula selected from the group consisting of (XX), (XXI), (XXII), and (XXIII):

wherein R 5 is a C 2 or higher alkyl group; or

a pharmaceutically acceptable salt thereof.

24 . The method of claim 23 , wherein the aminopyridine is represented by formula (XXV):

or a pharmaceutically acceptable salt thereof.

25 . The method of claim 23 , wherein the aminopyridine is represented by formula (XXVI):

or a pharmaceutically acceptable salt thereof.

26 . The method of claim 23 , wherein the aminopyridine is represented by formula (XXVII):

or a pharmaceutically acceptable salt thereof.

27 . The method of claim 23 , wherein the aminopyridine is represented by formula (XXVIII):

or a pharmaceutically acceptable salt thereof.

28 . The method of claim 19 , wherein the aminopyridine is represented by the a formula selected from the group consisting of (XXIX), (XXX), and (XXXI):

wherein R 7 is a alkyl chain;

or a pharmaceutically acceptable salt thereof.

29 . The method of claim 28 , wherein R 7 is a C 1 -C 6 straight or branched-chain alkyl.

30 . The method of claim 19 , wherein R 6 is represented by formula (XXXII):

or a pharmaceutically acceptable salt thereof.

31 . The method of claim 30 , wherein the aminopyridine is represented by the formula (XXXIII):

or a pharmaceutically acceptable salt thereof.

32 . The method of claim 19 , wherein:

X 3 is NH 2 ,

X 1 is H, and

X 2 is N═R 3 .

33 . The method of claim 32 , wherein the aminopyridine is represented by formula (XXXIV):

wherein X 4 is a halogen;

or a pharmaceutically acceptable salt thereof.

34 . The method of claim 19 , wherein the aminopyridine is represented by formula (XXXV):

or a pharmaceutically acceptable salt thereof.

35 . The method of claim 19 , wherein the aminopyridine is represented by formula (XXXVI):

or a pharmaceutically acceptable salt thereof.

36 . The method of claim 19 , wherein the aminopyridine is represented by formula (XXXVII):

or a pharmaceutically acceptable salt thereof.