4-thioribose nad analogues and methods of synthesizing and using the same

A method of synthesizing an analogue compound of formula VI:

• or a pharmaceutically acceptable salt or solvate thereof, the method comprising enzymatically converting a compound of formula VII:
• to the analogue compound of formula VI, wherein:
• X is S or O;
• R3 is selected from thymine, cytosine, adenine, uracil or guanine;
• and
• R1 and R2 are each independently selected from the group consisting of hydroxyl, thiol, optionally substituted C1-C8 alkyl, optionally substituted C1-C8 alkenyl, optionally substituted C1-C8 alkynyl, optionally substituted C1-C8 alkoxy, optionally substituted C1-C8 alkenyloxy, optionally substituted C1-C8 alkynyloxy, optionally substituted heteroaryloxy, optionally substituted aryloxy, acyl, acylamino, acyloxy, optionally substituted amino, halo, aminocarbonyl, aminothiocarbonyl, aminocarbonylamino, aminocarbonyloxy, aminosulfonyl, aminosulfonyloxy, aminosulfonylamino azidyl, cyano, nitro, oxo, amidino, arylthio, carboxylate, optionally substituted C1-C8 carboxyl ester, optionally substituted C1-C8 (carboxyl ester)amino, optionally substituted C1-C8 (carboxyl ester)oxy, optionally substituted C1-C8 cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted C1-C8 cycloalkenyl, optionally substituted C1-C8 cycloalkoxy, optionally substituted C1-C8 cycloalkylthio, optionally substituted C1-C8 cycloalkenyloxy, optionally substituted C1-C8 heterocyclyloxy, and OP wherein P is a protecting group.