Tubercidin (Sparsomycin A), an adenosine analogue, is a nucleoside antibiotic. It is incorporated into DNA and inhibits polymerases, thereby inhibiting DNA replication and RNA and protein synthesis. This agent also exhibits antifungal and antiviral activities.

连续暴露于tubercidin 14天对人类CFU-GM和BFU-E极为毒性。tubercidin的IC50分别为CFU-GM的3.4±1.7 nM和BFU-E的3.7±0.2 nM。tubercidin还对人类骨髓中的髓系和红系祖细胞在体外呈剂量依赖性抑制效果[1]。

Tubercidin在剂量方案（每天5 mg/kg，连续4天）单独使用时是致命的。部分研究表明，tubercidin引起的死亡主要是由于肝脏和肾脏损伤，其次是胰腺损伤。与NBMPR-P联合给药，每天25 mg/kg，能完全保护小鼠（100%存活）免受tubercidin的致命剂量方案[1]。

Human bone marrow cells were obtained from healthy volunteers. In the protection studies, cells are exposed to 10 nM of tubercidin in the presence or absence of various doses of NBMPR-P. Cells are continuously exposed to drugs for 14 days in a humidified atmosphere of 5% C02-95% air at 37°C. Colonies of CFU-GM (250 cells) and BFU-E (>30 hemoglobinized cells) are counted with an inverted microscope. (Only for Reference)