来源于马尾树树皮的化合物蜡果杨梅酸B抑制HIV进入的机制研究

目的：利用假病毒技术，研究来源于马尾树树皮的化合物蜡果杨梅酸B抑制HIV-1进入的活性及作用机制。方法：利用pHXB2和pVSV-G两个病毒包膜蛋白质粒，与pNL4-3.Luc.R-E-共转染，构建HIV-1 Env假病毒和VSV-G假病毒，检测化合物抑制假病毒感染的活性。采用针对包膜蛋白亚基gp41的ELISA方法，结合分子对接，研究活性化合物抗HIV-1的作用机制。结果：从马尾树树皮中来源的2个三萜类单体化合物蜡果杨梅酸B（myriceric acid B）和蜡果杨梅酸C（myriceric acid C）中，仅蜡果杨梅酸B能特异性地抑制HIV-1 Env假病毒感染，其半数抑制浓度（IC50）值为（8.3±0.2） mg·L^-1。此外，蜡果杨梅酸B在C-28位羧基的酯化产物蜡果杨梅酸B甲酯（myriceric acid B methyl ester）没有抑制HIV-1进入的活性。蜡果杨梅酸B的进入抑制活性与其抑制gp41六螺旋束结构形成的机制有关。分子对接表明，蜡果杨梅酸B能靶向gp41上N-螺旋三聚体的靶穴位置。结论：蜡果杨梅酸B是作用于gp41的HIV-1进入抑制剂，其分子结构中C-28位的羧基及C-3位羟基与抑制活性密切相关。蜡果杨梅酸B可作为先导化合物来研发新的HIV进入抑制剂类抗艾滋病药物。

Aim: To investigate the HIV-1 entry inhibitory activities of myriceric acid B and C isolated from Rhoiptelea chiliantha Diels et Hand-Mazz and their mechanism of action. Method: The plasmids encoding envelope proteins of HIV-1 (pHXB2) and VSV (pVSV-G) were cotransfected 293T cells with pNL4-3. Luc. R-E- to produce HIV-1 Env pseudovirus and VSV-G pseudovirus, respectively, which were used for testing the antiviral activities of these compounds. ELISA and molecular docking were used to study the mechanism of action of the active compounds. Results: Myriceric acid B could significantly inhibit the infection of HIV-1 Env pseudovirus with an IC₅₀ of (8.3 ± 0.2) mg·L^-1. The carbonoxyl group at C-28 position and the hydroxyl group at the C-3 position of myriceric acid B are important for its anti-HIV-1 activity. Like other HIV-1 entry inhibitors targeting gp41 (eg, ADS-J1 and NB-64), myriceric acid B could also block the gp41 six-helix bundle formation. Molecular docking analysis suggests that myriceric acid B may bind to the hydrophobic cavity of the gp41 N-trimeric coiled coil. Conclusion: Myriceric acid B is a potent HIV-1 entry inhibitor targeting gp41 and can serve as a lead compound for developing novel anti-HIV-1 drug.