Definition

A synthetic nucleoside analogue with antineoplastic activity. Tiazofurin (TR) is anabolized intracellularly to an analogue of NAD, tiazole-4-carboxamide adenine dinucleotide (TAD), a potent inhibitor of IMP dehydrogenase (IMPDH); IMPDH is the rate-limiting enzyme for de novo purine synthesis. Inhibition of IMPDH results in reduced levels of guanylates, resulting in the inhibition tumor cell growth in vitro and in vivo.