7-Methyl-6-mercaptopurine

7-Methyl-6-mercaptopurine (Compound 4) is a purine derivative and a substrate for thiopurine methyltransferase (TPMT) with Km and Vmax values of 231 μM and 2340 U/mg protein, respectively[1].

[1] Deininger M, et al. Purine substrates for human thiopurine methyltransferase. Biochem Pharmacol. 1994;48(11):2135-2138. DOI:10.1016/0006-2952(94)90515-0
[2] P. M. KOCHERGIN V S K E Aleksandrova. Chemical transformations of 6-[(1-methyl-4-nitro-5-imidazolyl)-thio]purine (azathioprine)[J]. Chemistry of Heterocyclic Compounds, 2000, 36 1: 311-318. DOI: 10.1007/bf02256869