Entecavir (SQ34676) is a guanosine nucleoside analogue used in the treatment of chronic hepatitis B virus (HBV) infection. Entecavir therapy can be associated with flares of the underlying hepatitis B during or after therapy, but has not been linked to cases of clinically apparent liver injury.

HBV (HepG2 cells):3.75 nM(ec50)

BMS-200475抑制HBV蛋白引物（EC50 值为 3.75 nM），抑制反转录酶的启动。与其他抗RNA和DNA病毒化合物相比，BMS-200475的抗病毒活性显著下降[1]。相对于其他脱氧鸟苷类似物（penciclovir、ganciclovir、lobucavir、aciclovir 或 lamivudine），BMS-200475更容易被磷酸化为其活性代谢物。BMS-200475 的细胞内半衰期为15小时[2]。

BMS-200475（p.o ,剂量自0.02至0.5 mg/kg体重，连续1至3个月治疗）能有效降低慢性感染土拨鼠中的土拨鼠乙型肝炎病毒（WHV）血症水平[3]。

BMS 200475 is prepared in phosphate-buffered saline (PBS) and diluted with appropriate medium containing 2% fetal bovine serum. HepG2 2.2.15 cells are plated at a density of 5×105 cells per well on 12-well Biocoat collagen-coated plates and are maintained in a confluent state for 2 to 3 days before being overlaid with 1 mL of medium spiked with BMS 200475. Quantification of HBV was performed on day 10[1].