吡喃香豆素衍生物对HIV-1的抑制作用及其构效关系

研究香豆素衍生物对人类免疫缺陷病毒1型逆转录酶 (HIV-1 RT)、蛋白酶 (HIV-1 PR) 和细胞内复制的抑制作用及其构效关系。不同香豆素衍生物具有抑制HIV-1 RT、HIV-1 PR活性, 且在细胞内显示出抑制HIV-1复制的作用已见报道。本课题根据国内传统药学的特点, 考察以天然产物为先导化合物、结合HIV-1蛋白酶三维结构计算机辅助药物设计、合成的四环双吡喃香豆素及其类似物。以HIV-1 RT及HIV-1 PR以及细胞内病毒复制为靶点, 利用酶学模型和细胞培养模型进行药物筛选及其构效关系研究, 设计合成的7个化合物的药效学实验结果显示, 部分化合物显示了不同程度的抗HIV-1活性。其中V0201作用最强, 它对HIV-1 PR和HIV-1 RT的IC₅₀分别为3.56和0.78 μmol?L⁻¹; 在PBMC培养实验中, V0201对HIV-1复制的IC₅₀为0.036 μmol?L⁻¹。这些结果表明, 化合物V0201具有全新结构, 可能成为新的先导化合物。     

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-1Env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。     

蒿属植物Artemisiacaruifolia中三-对香豆酰亚精胺等对HIV-1蛋白酶的抑制作用

作者从蒿属植物 A.caruifolia 中分得具抗人免疫缺陷病毒蛋白酶(HIV-1 PR)活性的 N~1,N~5,N~(10)-三-p-香豆酰亚精胺(1),并研究了相关化合物抑制 HIV-1 PR 的活性。该植物地上部分用甲醇回流提取,将提取物悬于水中,分别用氯仿、乙酸乙酯、正丁醇萃取。乙酸乙酯部位经柱层析,用甲醇-水     

一株南沙群岛柳珊瑚来源真菌 Aspergillus terreus 中化合物及 mPTPB 酶抑制活性研究

目的 从1株南沙群岛柳珊瑚来源真菌 Aspergillus terreus (NS02-09)中分离鉴定海洋天然产物,对所得化合物进行结核分枝杆菌酪氨酸磷酸激酶 (mPTPB) 抑制活性评价。方法 运用多种色谱手段分离纯化化合物,利用NMR、CD等现代波谱分析方法,对化合物进行结构鉴定、,通过衍生物制备获得两个乙酰化衍生物(2a和2b);并对化合物2及其衍生物2a和2b进行mPTPB酶抑制活性测试。结果 鉴定了1个土曲霉酮(1)和1个丁烯酸内酯 (2) 的结构; 2具有较强的mPTPB酶抑制活性,而其乙酰化产物(2a和2b)的mPTPB 酶抑制活性显著降低。运用Sybyl X 1.3 软件,对2与mPTPB酶的模拟对接计算发现,丁烯酸内酯环及环上的羟基是化合物2发挥酶抑制活性的重要作用基团。结论 从柳珊瑚来源真菌 A. terreus (NS02-09) 中发现了具有mPTPB 酶抑制活性的丁烯酸内酯类化合物,并对其作用机制进行了计算研究,该类化合物的相关研究对抗结核药物先导化合物发现具有借鉴作用。     

抗病毒药

二、核苷类逆转录酶抑制药(NNRTI)属于NNRTI的抗艾滋病毒药物共有3个药物,即奈韦拉平、地拉韦啶及依非韦伦(结构式见图1)。它们抑制HIV-1作用很强,但对HIV-2,猴艾滋病毒(SIV)均无抑制活性。它们的作用机制与NRTI不同,它们不需要磷酸化,不直接掺入新生的病毒DNA链,直接与病毒RT催化活性位点的P66疏水区结合,使酶蛋白构象改变,导致酶失活,抑制病毒复制。它们只作用于HIV-1RT,不抑制细胞DNA聚合酶,故毒性小。这类药物易产生耐药性,只需一个核苷酸变异,即可产生耐药,且对其它NNR-TIs产生交叉耐药。由于抑制HIV-1作用强,依非韦…     

红厚壳属植物中的香豆素类和呫吨酮类化合物对HIV-1逆转录酶和HIV-1复制 的抑制

作者从斯里兰卡红厚壳属植物中分得多种香豆素类、呫吨酮类和色烯酸类化合物,并用其绿色荧光蛋白报道基因的细胞(HOG.R5)实验测试了这些化合物对 HIV-1和HIV-1逆转录酶(HIV-1RT)的抑制活性。试验以绵毛胡桐内酯 A(calanolide A)为阳性对照药(IC_(50) 0.067μmol/L)。结果显示,cordatolide A(1)和 B(2)抑制 HIV-1的复制,IC_(50)分别为19.3和11.7μmol/L。Corda-     

格尔德霉素衍生物TC-GM的合成及体外抗病毒活性研究

本文以发现新型抗病毒结构化合物为目的,将不同作用机制的抗病毒活性化合物格尔德霉素和拉米夫定化学偶联得到新结构化合物TC-GM。分别采用p24抗原、斑点杂交法以及细胞病变法(CPE)测定了TC-GM对HIV-1、HBV、HSV和CoxB病毒的抑制活性。结果显示,TC-GM具有与格尔德霉素相似的广谱抗病毒特性,对HIV-1、HBV、HSV 1型和2型、CoxB6等病毒的复制均具有抑制作用,并且抗HIV-1和HBV的活性较强。     

三个非核苷类逆转录酶抑制剂S-DABO类衍生物的体外抗HIV作用

本文对3个新S-DABO类衍合物 (RZK-4、RZK-5、RZK-6) 的体外抗HIV活性进行了研究。化合物RZK-4、RZK-5和RZK-6在200 µg·mL⁻¹的浓度下均能完全抑制HIV-1逆转录酶的活性。3个化合物对多种细胞均呈现出低毒性, 且均在较低浓度下具有抑制HIV-1病毒实验株、临床株和耐药株的作用, 治疗指数为3 704～38 462。其中, 化合物RZK-6对HIV-1耐药株HIV-1_IIIB A17具有非常显著的抑制作用。结果表明, 这3种S-DABO类衍生物有良好的体外抗HIV-1作用, 具有开发成为抗HIV-1药物的前景。     

对天然产物抑制HIV-1逆转录酶的评价

对HIV-1逆转录酶的抑制是目前被认为是预防爱滋病有益的新进展。天然产物已广泛用作HIV-1逆转录酶(HIV-1RT)的抑制剂。作者开发的在病毒粒子中检测HIV-1的方法,可作为天然产物对HIV-1RT的抑制作用的筛选方法,作者筛选了156种纯天然产物。鸟成髓细咆血症病毒逆转录酶的抑制剂苯并菲啶生物碱氯化崖椒宁(fagarnoninechloride)和氯化两面针碱(nitidine chloride)对HIV-1RT具有显著活性,因此以这两个化合物作为筛选时的阳性对照。作者发现非洲汉防己碱(columbamine)和另一些原小檗碱异奎宁碱(如o-methyl psychotrine sulfate和iri-doid fulvo plumierin)具有抑制作用。而一些吲哚类等其它类型的生物碱却无活性。作者筛     

咖啡酸衍生物的合成及其抑制HIV整合酶活性

目的合成新型咖啡酸衍生物并测定其抑制HIV-1整合酶活性.方法化学合成一系列N-取代咖啡酰萘磺胺类化合物,采用32p标记法体外测定化合物抑制HIV-1整合酶活性.结果合成了20个咖啡酸衍生物,其结构经红外光谱、核磁共振氢谱及质谱确定.其中化合物I 2、I 3、I 4抑制HIV-1整合酶活性高于L-巨菊酸(IG50=11.8 μg·mL-1),3个化合物的IC50分别为(8.6±4.8)、(4.5±3.4)、(7.9±4.9)μg·mL-1.结论 N-取代咖啡酰萘磺胺类化合物对HIV-1整合酶有较高抑制活性,值得深入研究.     

Synthesis, stability, antiviral activity, and protease-bound structures of substrate-mimicking constrained macrocyclic inhibitors of HIV-1 protease

Three new peptidomimetics (1-3) have been developed with highly stable and conformationally constrained macrocyclic components that replace tripeptide segments of protease substrates. Each compound inhibits both HIV-1 protease and viral replication (HIV-1, HIV-2) at nanomolar concentrations without cytotoxicity to uninfected cells below 10 microM. Their activities against HIV-1 protease (K(i) 1.7 nM (1), 0.6 nM (2), 0.3 nM (3)) are 1-2 orders of magnitude greater than their antiviral potencies against HIV-1-infected primary peripheral blood mononuclear cells (IC(50) 45 nM (1), 56 nM (2), 95 nM (3)) or HIV-1-infected MT2 cells (IC(50) 90 nM (1), 60 nM (2)), suggesting suboptimal cellular uptake. However their antiviral potencies are similar to those of indinavir and amprenavir under identical conditions. There were significant differences in their capacities to inhibit the replication of HIV-1 and HIV-2 in infected MT2 cells, 1 being ineffective against HIV-2 while 2 was equally effective against both virus types. Evidence is presented that 1 and 2 inhibit cleavage of the HIV-1 structural protein precursor Pr55(gag) to p24 in virions derived from chronically infected cells, consistent with inhibition of the viral protease in cells. Crystal structures refined to 1.75 A (1) and 1.85 A (2) for two of the macrocyclic inhibitors bound to HIV-1 protease establish structural mimicry of the tripeptides that the cycles were designed to imitate. Structural comparisons between protease-bound macrocyclic inhibitors, VX478 (amprenavir), and L-735,524 (indinavir) show that their common acyclic components share the same space in the active site of the enzyme and make identical interactions with enzyme residues. This substrate-mimicking minimalist approach to drug design could have benefits in the context of viral resistance, since mutations which induce inhibitor resistance may also be those which prevent substrate processing.     

白藜芦醇衍生物体外抗HIV-1活性的初步研究

目的:检测白藜芦醇衍生物IFB-1和IFB-9的体外抗HIV-1活性,并对其进行抗HIV-1作用机制的初步研究。方法:采用MTT比色法检测白藜芦醇衍生物IFB-1和IFB-9的细胞毒性;细胞病变法检测化合物对HIV-1急性感染的抑制活性;采用HIV-1 p24抗原ELISA方法检测临床分离株HIV-1KM018在PBMC中复制的抑制实验;采用细胞病变法检测HIV-1感染和未感染细胞之间的融合;采用HIV-1重组逆转录酶活性抑制实验,HIV-1重组蛋白酶活性抑制实验以及直接杀病毒实验来研究化合物体外抗HIV-1机制。结果:白藜芦醇衍生物IFB-1和IFB-9对HIV-1IIIB诱导的合胞体形成抑制的选择指数分别为16.16和230.27;IFB-1和IFB-9均能抑制p24抗原的产生,EC50s分别为14.51和0.23μg.mL-1,也能抑制HIV-1KM018在PBMC中的复制。IFB-1和IFB-9对感染细胞与未感染细胞融合有较好的抑制,但对病毒逆转录酶和蛋白酶体外活性没有抑制作用,也不能直接杀死HIV-1病毒。结论:白藜芦醇衍生物IFB-1和IFB-9具有抗HIV-1活性,其作用机制可能为抑制病毒进入细胞。     

两种AZT-氟喹诺酮偶联物体外抗HIV-1及抗菌活性的研究

目的体外测定两种AZT-氟喹诺酮偶联物SRLZ和SROZ的抗HIV-1活性及抗菌活性。方法通过合胞体抑制、HIV-1感染细胞保护、HIV-1 p24抗原测定等方法检测急性感染中化合物对HIV-1实验株、临床分离株的抑制作用和对慢性感染细胞中的病毒复制影响;通过体外金黄色葡萄球菌的抑制实验检测化合物的抗菌活性。结果AZT-氟喹诺酮偶联物SRLZ和SROZ能抑制HIV-1实验株诱导的合胞体形成,减少病毒感染细胞的死亡和抑制病毒在细胞内的复制;SRLZ和SROZ对HIV-1临床分离株也有较好的抑制作用;SRLZ和SROZ对HIV-1的抑制活性与AZT相近;AZT-氟喹诺酮偶联物也能抑制金黄色葡萄球菌,其MIC值与其相应的阳性药物相近。结论SRLZ和SROZ有很好的抗HIV-1活性和抗菌活性。     

Three new derivatives of anti-HIV-1 polyphenols isolated from Salvia yunnanensis

During the study of anti-HIV-1 active components of the aqueous extracts of the roots of Salvia yunnanensis, three new derivatives of polyphenols, namely: methyl salvianolate A (2), ethyl salvianolate A (3) and cis-lithospermic acid (5) were isolated along with two known polyphenols, salvianolic acid A (1) and lithospermic acid (4) their structures were elucidated on the basis of NMR and MS spectral analyses. The anti-HIV-1 activities of the 5 polyphenols were tested for the inhibition of P24 antigen in HIV-1 infected MT-4 cell cultures and HIV-1 replicative enzymes in vitro.     

The Vif protein of human immunodeficiency virus type 1 (HIV-1): enigmas and solutions

HIV-1 and other complex retroviruses express six auxiliary genes in addition to the canonical retroviral genes, gag, pol and env. Vif (virion infectivity factor) protein is absolutely essential for productive HIV-1 infection of peripheral blood lymphocytes and macrophages, the two major HIV-1 target cells in vivo. However, Vif is not required for production of infectious particles in several human cell lines. In spite of the prominent phenotype of Vif mutations, the mechanism of its action remains unknown. During the last decade several models were suggested to explain the mechanism of Vif activity. One view holds that Vif is active in virions after budding or after entry into target cells during the early stages of HIV-1 replications. The second view places the action of Vif at the late stage of HIV-1 replication in virus producing cells, which affects the production of infectious virus. According to this view, Vif either compensates the cell factor required for production of infectious virus, or alternatively, it neutralizes a cell factor, which prevents the production of infectious particles in these cells. This review is addressed to summarize the models envisioned to explain Vif activities. The findings described here, that Vif interacts with viral and cellular components, elaborates the importance of Vif as a novel target for developing anti HIV-1 drugs.     

Modeling Deficits in Attention,Inhibition, and Flexibility in HAND

Nearly half of all HIV-1-positive individuals on combination antiretroviral therapy (cART) are afflicted with HIV-1-associated neurocognitive disorders (HAND). The most prevalent cognitive deficits observed in the cART era are those of attention and executive function. Presently, we sought to model deficits in attention and core components of executive function (inhibition, flexibility, and set-shifting) observed in HAND using the HIV-1 transgenic (Tg) rat, which expresses 7 of the 9 HIV-1 genes. Ovariectomized female Fischer HIV-1 Tg and non-transgenic control rats (ns?=?39–43) were tested in a series of operant tasks: signal detection, discrimination learning, reversal learning, and extradimensional set-shifting. The HIV-1 Tg animals attained the criterion of three sessions at 70 % accuracy at a significantly slower rate than the control animals on all tasks with the exception of the extradimensional set-shifting task. Of the animals that met the criteria, there was no significant difference in percent accuracy in any task. However, the HIV-1 Tg rats showed a lower overall response rate in signal detection and discrimination learning. A discriminant function analysis classified the animals by genotype with 90.4 % accuracy based on select measures of their performance. The functional consequences of chronic low-level expression of the HIV-1 proteins on attention, as well as inhibition and flexibility as core components of executive function, are apparent under conditions which resemble the brain proinflammatory immune responses and suppression of infection in HIV-1+ individuals under cART. Deficits in attention and core components of executive function may reflect an underlying impairment in temporal processing in HAND.