Treatment of EBV and KHSV infection and associated abnormal cellular proliferation

1. A method for treating a host infected with Epstein-Barr virus or KHSV comprising administering an effective amount of a compound of the general formula (III)

or a pharmaceutically acceptable salt or prodrug thereof,

wherein

i) X is O, S, NR 4 , CH 2 , CHF, or CF 2 ,

ii) R 1 is chosen from haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, cycloalkyl, CN, CF 3 , N 3 , NO 2 , aryl, heteroaryl, heteroaryl, acyl or COR 5 where R 5 is chosen from one of H, OH, SH, alkyl, aminoalkyl, alkoxy, or thioalkyl;

iii) R 2 and R 2′ are independently H; carbonyl substituted with an alkyl, alkenyl, alkynyl, or aryl; benzyl, wherein the phenyl group is optionally substituted with one or more substituents; phosphate; phosphate ester; sulfonate ester; lipid; amino acid; peptide; cholesterol; or other pharmaceutically acceptable leaving group which, when administered in vivo, is capable of providing a compound wherein one or both of R 2 and R 2′ is H; and

R 4 is independently H, acyl, alkyl, alkenyl, alkynyl or cycloalkyl.

2. The method of claim 1 wherein the compound administered is a 13-L isomer and is at least 95% pure.

3. The method of claim 1 wherein the compound administered is a 13-D isomer and is at least 95% pure.

4. The method of claim 1 wherein the host is a human.

5. The method of claim 1 wherein the host exhibits acute mononucleosis or oral hairy leukoplakia.

6. A method for treating a host infected with Epstein-Barr virus or KHSV comprising administering an effective amount of a compound of the general formula (II):

or a pharmaceutically acceptable salt or prodrug thereof, wherein

i) X is O, S, NR 4 , CH 2 , CHF or CF 2 ;

ii) R 1 is haloalkynyl, cycloalkyl, CN, N 3 , NO 2 , aryl, heteroaryl, acyl or COR 5 , where R 5 is chosen from one of H, OH, SH, alkyl, aminoalkyl, alkoxy, or thioalkyl;

iii) R 2 is H, carbonyl substituted with an alkyl, alkenyl, alkynyl, or aryl; benzyl, wherein the phenyl group is optionally substituted with one or more substituents; phosphate; phosphate ester; sulfonate ester; lipid; amino acid; peptide; cholesterol; or other pharmaceutically acceptable leaving group which, when administered in vivo, is capable of providing a compound wherein R 2 is H;

iv) R 4 is H, acyl, alkyl, alkenyl, alkynyl or cycloalkyl; and

v) Z is O or S.

7. The method of claim 6 wherein X is O and Z is O.

8. The method of claim 7 wherein R 2 is H or R 1 is heteroaryl, or R 2 is H and R 1 is heteroaryl.

9. The method of claim 6 wherein the compound administered is a β-L isomer and is at least 95% pure.

10. The method of claim 6 wherein the compound administered is a β-D isomer and is at least 95% pure.

11. The method of claim 6 wherein the host is a human.