Abstract:
The ribonuclease H (RNase H) active site of HIV-1 reverse transcriptase (RT) is the only viral enzyme not targeted by approved antiretroviral drugs. Using a fluorescence-based in vitro assay, we screened 65,239 compounds at a final concentration of 10 µM to identify inhibitors of RT RNase H activity. We identified 41 compounds that exhibited 50% inhibitory concentration (i.e., IC50) values < 1.0 µM. Two of these compounds, 2-(4-methyl-3-(piperidin-1-ylsulfonyl)phenyl)benzo[d]isothiazol-3(2H)-one (1) and ethyl 2-(2-(3-oxobenzo[d]isothiazol-2(3H)-yl)thiazol-4-yl)acetate (2), which both share the same benzisothiazolone pharmacophore, demonstrate robust antiviral activity (50% effective concentrations of 1.68 ± 0.94 µM and 2.68 ± 0.54, respectively) in the absence of cellular toxicity. A limited structure-activity relationship analysis identified two additional benzisothiazolone analogs, 2-methylbenzo[d]isothiazol-3(2H)-one (3) and N,N-diethyl-3-(3-oxobenzo[d]isothiazol-2(3H)-yl)benzenesulfonamide (4), which also resulted in the inhibition of RT RNase H activity and virus replication. Compounds 1, 2 and 4, but not 3, inhibited the DNA polymerase activity of RT (IC50 values~1 to 6 µM). In conclusion, benzisothiazolone derivatives represent a new class of multifunctional RT inhibitors that warrants further assessment for the treatment of HIV-1 infection.
摘要:
HIV-1逆转录酶(RT)的核糖核酸酶H(RNaseH)活性位点是唯一未被批准的抗逆转录病毒药物靶向的病毒酶。使用基于荧光的体外测定,我们筛选了最终浓度为10µM的65,239种化合物,以鉴定RTRNaseH活性的抑制剂。我们鉴定了41种表现出50%抑制浓度的化合物(即,IC50)值<1.0µM。其中两种化合物,2-(4-甲基-3-(哌啶-1-基磺酰基)苯基)苯并[d]异噻唑-3(2H)-酮(1)和2-(2-(3-氧代苯并[d]异噻唑-2(3H)-基)噻唑-4-基)乙酸乙酯(2),两者共享相同的苯并异噻唑酮药效团,在没有细胞毒性的情况下,表现出强大的抗病毒活性(分别为1.68±0.94µM和2.68±0.54的50%有效浓度)。有限的结构-活性关系分析确定了两个额外的苯并异噻唑酮类似物,2-甲基苯并[d]异噻唑-3(2H)-酮(3)和N,N-二乙基-3-(3-氧代苯并[d]异噻唑-2(3H)-基)苯磺酰胺(4),这也导致RTRNaseH活性和病毒复制的抑制。化合物1、2和4,而不是3,抑制RT的DNA聚合酶活性(IC50值~1至6μM)。总之,苯并异噻唑酮衍生物代表了一类新的多功能RT抑制剂,需要对HIV-1感染的治疗进行进一步评估。