Synthesis and antiviral evaluation of cytisine derivatives against dengue virus types 1 and 2.
Bioorg Med Chem Lett 2021;
54:128437. [PMID:
34737087 DOI:
10.1016/j.bmcl.2021.128437]
[Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/22/2022]
Abstract
Dengue virus (DENV) causes about 50-100 million cases per year worldwide. However, there is still a big challenge in developing antiviral drugs against DENV infection. Some derivatives of alkaloid (-)-cytisine, like other alkaloid analogs, have been proposed for their antiviral potential. This study investigated antiviral activity and mechanisms of the cytisine derivatives, and discovered the structure-activity relationship against DENV. The antiviral assays were performed using one strain of DENV1 and DENV2, and two cell lines Vero E6 and A549. The structure-activity relationship of the effective compounds was also evaluated using combination of time-of-addition/removal assay and molecular docking. Compounds 3, 4, 12 (N-allylcytisine-3-thiocarbamide), 16, and 20 exhibited the high antiviral activity with IC50 values of lower than 3 μM against DENV1 and DENV2. Of them, the derivative 12 showed the highest antiviral activities against DENV1 (IC50 = 0.14 μM) and DENV-2 (IC50 = <0.1 μM), exhibiting the potent inhibition on virus attachment and entry stages. Meanwhile, the compounds 4 and 20 had a strong inhibition at the post-entry stage (IC50 = <0.1 μM). A correlation between the experimental pIC50 values and predicted pKi calculated by docking of compounds into DENV E protein was significant, correlating with the impact of compound 12 on the attachment stage, but compounds 4, and 20 on post-entry stage. The results provided the insight into the directions of synthetic modifications of starting (-)-cytisine as the inhibitors of DENV E protein at attachment and entry stages of DENV life cycle.
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