Broad spectrum viral inhibitor

1. A compound or pharmaceutical salt thereof, wherein the compound is selected from the group consisting of Formula I, Formula II, Formula III, Formula IV, Formula V, Formula VI, Formula VII, Formula VIII, and Formula IX;

wherein, in Formula I, R 1 is a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl; and

R 2 is an adenine, guanosine, cytosine, uridine, or thymidine; and

R 3 is a hydrogen, hydroxyl, thiol, halide, or alkyl,

provided that when R 1 is a hydrogen and R 2 is cytosine, guanosine, uridine, thymidine or adenine,

R 3 is not hydrogen;

and

wherein, in Formula II, R 1 and R 2 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl; and

R 3 is a hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula III, R 1 and R 2 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl; and

R 3 is hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula IV, R 1 and R 2 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl;

R 3 is adenine, guanosine, cytosine, uridine, or thymidine; and

R 4 is hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula V, R 1 and R 2 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl;

R 3 is adenine, guanosine, cytosine, uridine, or thymidine; and

R 4 is hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula VI, R 1 , R 2 , and R 3 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl; and

R 4 is hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula VII, R 1 , R 2 , and R 3 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl; and

R 4 =hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula VIII, R 1 , R 2 , and R 3 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl;

R 5 is adenine, guanosine, cytosine, uridine, or thymidine; and

R 4 is hydrogen, hydroxyl, thiol, halide, or alkyl,

and

wherein, in Formula IX, R 1 , R 2 , and R 3 are each, independently, a hydrogen, alkyl, benzyl, aryl, acycloxyalkyl, alkoxycarbonyloxy alkyl, or S-acylthioalkyl;

R 5 is adenine, guanosine, cytosine, uridine, or thymidine; and

R 4 is hydrogen, hydroxyl, thiol, halide, or alkyl.

2. A non-naturally occurring compound or pharmaceutical salt thereof, wherein the compound has the following formula:

3. The compound or pharmaceutical salt thereof of claim 1 , wherein the compound is represented by Formula II.

4. The compound or pharmaceutical salt thereof of claim 1 , wherein the compound is represented by Formula III.

5. The compound or pharmaceutical salt thereof of claim 1 , wherein the compound is represented by Formula VI.

6. The compound or pharmaceutical salt thereof of claim 1 , wherein the compound is represented by Formula VII.

7. A pharmaceutical composition comprising the compound or pharmaceutical salt thereof of claim 1 .

8. The pharmaceutical composition of claim 7 , comprising a pharmaceutically acceptable carrier.

9. A pharmaceutical composition comprising the compound or pharmaceutical salt thereof of claim 2 .

10. A method of treating a flavivirus infection in a subject comprising administering to the subject an effective amount of the compound or pharmaceutical salt thereof of claim 1 ,

or a compound of Formula I′ or a pharmaceutical salt thereof,

wherein R 1 is a hydrogen and R 2 is cytosine, guanosine, uridine, thymidine or adenine, and R 3 is hydrogen;

or

in an effective amount to treat a flavivirus infection.

11. The method of claim 10 , wherein the flavivirus infection is a Dengue virus infection, Zika virus infection, or West Nile virus infection.

12. A method of treating a viral infection in a subject comprising administering to the subject an effective amount of the compound or pharmaceutical salt thereof of claim 1 ,

or a compound of Formula I′ or a pharmaceutical salt thereof,

wherein R 1 is a hydrogen and R 2 is cytosine, guanosine, uridine, thymidine or adenine, and R 3 is hydrogen;

or

in an effective amount to treat a viral infection.

13. The method of claim 12 , wherein the viral infection is an influenza virus infection or a hepatitis C virus infection or an HIV infection.

14. A method of inhibiting a viral RNA-dependent RNA-polymerase comprising contacting the viral RNA-dependent RNA-polymerase in a cell with an effective amount of the compound or pharmaceutical salt thereof of claim 1 ,

or a compound of Formula I′ or a pharmaceutical salt thereof,

wherein R 1 is a hydrogen and R 2 is cytosine, guanosine, uridine, thymidine or adenine, and R 3 is hydrogen;

or

in an effective amount to inhibit a viral RNA-dependent RNA-polymerase.

15. A method of inhibiting multiplication of a virus, which virus uses or expresses a viral RNA-dependent RNA-polymerase, comprising contacting the virus with an effective amount of the compound or pharmaceutical salt thereof of claim 1 ,

or a compound of Formula I′ or a pharmaceutical salt thereof,

wherein R 1 is a hydrogen and R 2 is cytosine, guanosine, uridine, thymidine or adenine, and R 3 is hydrogen;

or

in an effective amount to inhibit viral multiplication.

16. The method of claim 15 , wherein the compound is represented by Formula II.

17. The method of claim 15 , wherein the compound is represented by Formula III.

18. The method of claim 15 , wherein the compound is represented by Formula VI.

19. The method of claim 15 , wherein the compound is represented by Formula VII.