The parent 5′-guanidino N7 -linked nucleoside 11 was shown to inhibit this cholinesterase with a Ki value that is ca. 2-fold higher than that of the N9-counterpart, while it showed higher cytotoxicity to hepatocytes (IC50 = 24.08 μM) and to the neuroblastoma cells (IC50 = 12.14 μM). Here, BCHE is linked to neuroblastoma.