Compounds and compositions for differential modulation of nicotinamide adenine dinucleotide

A compound having the structure of Formula 2c:

• or a salt thereof, wherein
• X is H or a phosphate group;
• R2 is selected from H, a halogen, a carboxylic acid, a substituted or unsubstituted C1-C6 carboxy ester, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C1-C6 alkoxy group, a substituted or unsubstituted C1-C6 alkenyl group, and a substituted or unsubstituted C1-C6 alkynyl group;
• R3 is selected from H, a halogen, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C1-C6 alkenyl group, a substituted or unsubstituted C1-C6 alkynyl group, a substituted or unsubstituted C1-C6 alkoxy group, a carboxylic acid, a substituted or unsubstituted C1-C6 carboxy ester, and a substituted or unsubstituted carboxamide;
• and
• R4 is selected from H, a substituted or unsubstituted C1-C6 alkyl group, a substituted or unsubstituted C1-C6 alkenyl group, a substituted or unsubstituted C1-C6 alkynyl group, a substituted or unsubstituted C1-C6 alkoxy group, a carboxylic acid, a substituted or unsubstituted C1-C6 carboxy ester, and a substituted or unsubstituted carboxamide;
• and further wherein at least one of R2 and R3 is not H.