NAD zwitterion is a NAD. It has a role as a geroprotector. It is functionally related to a deamido-NAD zwitterion. It is a conjugate base of a NAD(+).
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TR is a prodrug that requires metabolic activation into its active form, tiazofurin adenine dinucleotide (TAD, Figure 1), a mimic of nicotinamide adenine dinucleotide (NAD).