Synthesis of aromatic-linked polyamine macrocyclic derivatives as HIV-1 entry inhibitors

A series of novel aromatic-linked polyamine macrocyclic derivatives have been synthesized. Their structures were confirmed by MS and ^1H NMR. These compounds exhibited potent anti-HIV-1 activities.

Mechanism of inhibitor ADS-J1 and ADS-J2 binding to HIV-1 gp41

In order to analyze and explain the mechanism of the two small inhibitors （ADS-JI and ADS-J2） binding to HIV-1 gp41, a computational study is carried out to help identifying possible binding modes by docking these compounds onto the hydrophobic pocket on gp41 and characterize structures of binding complexes. The binding interactions of gp41-molecule and free energies of binding are obtained through molecular dynamics simulation and molecular mechanic/Poisson- Boitzmann surface area （ MM/PBSA ） calculation. Specific molecular interactions in the gp41-inhibitor complexes are identified. The present computational study complements the corresponding experimental investigation and helps establish a good starting point tbr further refinement of small molecular gp41 inhibitors.

Building the Pharmacophore Model of HIV-1 Integrase Strand Transfer Inhibitors and Studying Their Inhibition Mechanism

The replication of HIV-1 requires the integration of its cyclic DNA into host DNA by HIV-1 integrase （IN）, which includes two important reactions, 3＇-processing and strand transfer, both catalyzed by HIV-1 IN. Disrupting either of the reactions will fulfill the purpose of inhibiting the replication of HIV-1. In this paper, pharmacophore modeling and molecular docking are employed to investigate the inhibition mechanism of the HIV-1 IN strand transfer inhibitors （INSTIs）. Based on the results, we suggest that the inhibition mechanism of INSTIs involves the inhibitor chelating the cofactors Mg2＋ and its forming hydrogen bonds with some crucial residues adjacent to the DDE active center.

Peptide Inhibitors of HIV-1 Virus Infection Based on Cullin-5

Virion infectivity factor（Vif） is one of the six accessory proteins of HIV-1 and is necessary for viral infectivity. Human Apolipoprotein B editing complex protein 3G（h-APOBEC3G） is a cytidine deaminase only expressed in ＂nonpermissive＂ cells and exhibits virus suppressive activity. With the aid of a Cullin-5 E3 ligase, Vif induces h-APOBEC3G degradation and with the destruction of this ligase, Vif is functionally inactive. Therefore, it is expected that blocking this E3 pathway would be a new therapeutic strategy against HIV-1 infection. In this article, the authors＇ took sequence alignment of the N-termini of Cullin-5 and three other members of the Cullin protein family, respectively. A set of small peptides has been synthesized based on the sequence comparison results and possible Vif-Cullin-5 interaction domains. Moreover, it has been demonstrated that several peptides can reduce virus infectivity in ＂nonpermissive＂ cells with a dose-responsive manner, but not in ＂permissive＂ cells. The results also indicate that the loss of viral infectivity may be because of the increase of APOBEC3G amount in the peptide-treated cells. It is concluded that peptides derived from Cullin-5 can block the APOBEC3G degradation induced by Vif and suppress HIV-1 infectivity. Therefore this study starts a novel strategy for the development of a new HIV-1 inhibitor.

A Mechanism-based 3D-QSAR and DFT Approach for the Prediction of H5N1 Entry Inhibitory Potency of 3-O-β-chacotriosyl Ursolic Acid Derivatives

In this work, 25 3-O-β-chacotriosyl ursolic acid derivatives were employed to achieve the highly reliable and predictive 3 D-QSAR models by Co MFA and Co MSIA methods, respectively. The predictive capabilities of two constructed CoMFA and CoMSIA models were verified by the leave-one-out cross-validation method. The results showed that the cross-validated coefficient（q2） and non-cross-validated coefficient（R2） were 0.559, 0.981 in the CoMFA model and 0.696, 0.978 in the CoM SIA model, respectively, which suggests that these two models are robust and have good exterior predictive capabilities. Furthermore, based on the contour maps information of two models, ten novel inhibitors with higher inhibitory potency were designed, and the quantum chemical calculation of density functional theory（DFT） was performed to investigate the mechanism why the designed molecules have stronger inhibitory activity than the lead compound. The calculations show that the C-50 position of lead compound is a key active site for the enhancement of inhibitory activity, and it should be introduced into the large electron withdrawing group, which would result in generating potent and selective H5 N1 entry inhibitors. We expect that the results in this paper could provide important information to develop new potent H5 N1 entry inhibitors.

Investigation of formation of dimeric G-quadruplex of HIV-1 integrase inhibitor by nuclear magnetic resonance

In this research, an unusually dimeric G-quadruplex of d（GGGTGGGTGGGTGGGT） （SI）, the potent nanomolar HIV-1 integrase inhibitor, was detected by nuclear magnetic resonance （NMR）. This result has been confirmed by electrospray ionization mass spectrometry （ESI-MS） and circular dichroism （CD）.

HIV-1 fusion inhibitor VIR576 interferes with T-cell activation by targeting TCR

Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were estalished to investigate the potential effect of FP16, VIR576 on the proliferation of A2b cells in response to MOG35-55. A fluorescence-based binding assay using Rhodamine （Rho）-conjugated VIR576 was estalished to e- valuate the potential interaction between VIR576 and TCR-TMD. Fluorescence confocal microscopy was used to to study whether VIR576 could colocalize with CD4 molecule in the CD4 ＋ T cell membrane to interact with TCR. Re- suits The effects of VIR576 on the proliferation of MOG-specific A2b T cells in response to the stimulation of MOG 35 -55 peptide wasevaluated. VIR576 itself could directly inhibit antigen-specific T-cell activation. Further studies confirmed that VIR576 also inhibited the proliferation of splenocytes and primary CD4 ＋ CD25- T cells iso- lated from the spleens of DOll. 10 OVA Tg mice in response to OVA stimulation in vitro. However, VIR576 had no effect on the proliferation of normal mouse splenocytes and T lymphocytes stimulated with Con A or anti-CD3 anti- body. The FRET assay confirmed that VIR576 effectively binds to the core peptide （CP） , corresponding to the N- terminal 9-residue region of TCR-TMD. Confocal microscopy revealed that VIR576 colocalizes with CD4 on the ac- tivated CD4 ＋ T-cell membrane, particularly within the activation cluster including re-assembled CD4 and TCR mol- ecules. Conclusion These results suggest that VIR576 is effective in suppressing antigen-specific T-cell activa- tion, but it has no effect on non-specific T-cell proliferation, and VIR576 has the ability to down-regulate antigen- specific T-cell activation by interaction with TCR transmembrane domain.

Structure-Based Pharmacophore Modeling to Discover Novel CCR5 Inhibitors for HIV-1/Cancers Therapy

CC chemokine receptor 5 (CCR5), a member of G protein-coupled receptors (GPCRs), not only plays a significant role in inflammatory responses, but also correlates with HIV-1 infection and cancer progression. Recently, blocking of CCR5 has been considered as an effective strategy in HIV-1/cancers therapy. So far, only Maraviroc has been approved by FDA in 2007, while the other CCR5 inhibitors have failed in their clinical trials. In this study, a highly selective structure-based pharmacophore model was constructed, validated, and applied for virtual screening to retrieve novel CCR5 inhibitors from NCI database. Finally, one potential CCR5 inhibitor candidate, NSC13165, was identified after molecular docking, molecular dynamics (MD) simulations, binding free energy analyses and ADMET prediction. Docking and MD simulation results not only suggested that NSC13165 reserves the common binding mode of the most known CCR5 inhibitors, but also provided important insights toward the allosteric inhibition mechanism of CCR5. The results of binding free energy analyses indicated that the binding affinity of NSC13165 is much better than that of Maraviroc and that van der Waals interaction is the key driving force during the binding process. ADMET prediction suggested that NSC13165 exhibits very low risk of causing lethal side effects. Altogether, our results strongly suggest that NSC13165 has great potential to serve as a novel CCR5 inhibitor, which may be further tested in vitro/in vivo as a drug target for HIV-1/cancers therapy or be used as a lead compound for improving its efficacy through chemical modifications.

日本蛇菰中咖啡酰基葡萄糖类化合物抑制HIV-1进入的机制

目的研究从日本蛇菰中分离的咖啡酰基葡萄糖类化合物抑制HIV-1进入的作用机制。方法利用HIV-1假病毒体系,并结合针对gp41包膜蛋白的ELISA以及分子对接方法,对日本蛇菰分离的咖啡酰基葡萄糖类化合物抑制HIV-1进入机制进行研究。结果我们首先用HIV-1 Env假病毒来检测六个咖啡酰基葡萄糖类化合物(终浓度:25μg·ml-1)的抑制活性,发现1,2,6-三-O-咖啡酰基-β-D-吡喃葡萄糖(TCGP)和1,3-双-O-咖啡酰基-4-O-没食子酰-β-D-吡喃葡萄糖(DCGGP)具有较好的抑制病毒进入靶细胞的作用。进一步量效关系研究表明,两个化合物的病毒抑制活性呈剂量依赖性,它们的IC50值分别是(5.5±0.2)和(5.3±0.1)μg·ml-1。这两个化合物的抑制活性与其抑制gp41六螺旋束结构形成的机制有关。分子对接表明,它们均能靶向gp41上N-螺旋三聚体的靶穴位置。结论1,2,6-三-O-咖啡酰基-β-D-吡喃葡萄糖(TCGP)和1,3-双-O-咖啡酰基-4-O-没食子酰-β-D-吡喃葡萄糖(DCGGP)可以较好的抑制HIV-1 Env假病毒感染靶细胞,可作为先导化合物来研发抗HIV-1新药。

槐花提取化合物K3体外抗HIV-1活性的研究

目的:研究槐花提取化合物K3的体外抗H IV-1活性,并对其抗H IV-1机制进行初步探讨。方法:采用MTT比色法检测化合物对各种细胞的毒性。用合胞体形成计数法,p24抗原捕获ELISA法及RT-PCR等多种方法研究化合物体外抗H IV-1活性。结论:槐花提取化合物K3体外有较好的抗H IV-1活性,能够抑制病毒实验株(H IV-1ⅢB,耐药株(H IV-174V)和临床分离株(H IV-1KM018)等多种病毒株的复制,且其作用机制是多靶点的,不仅可以抑制病毒的进入,还可以抑制H IV-1逆转录酶活性。

阻断HIV-1进入细胞的抑制剂研究

为了解决HlV-1病毒耐药的难题，研究阻断病毒进入细胞的抑制剂是一个重要途径，通过对近年来国内外学者在阻断HIV-1病毒进入宿主细胞的抑制剂方面所发表的文献进行分析，概述了阻断HIV-1病毒进入宿主细胞的抑制剂的研究进展．阻断病毒进入细胞的抑制剂具有强大的抗逆转录病毒作用，它的优势在于可以对抗目前所有的HIV-1耐药毒株，它分为阻断病毒与细胞吸附的抑制剂、阻断病毒进入的抑制剂及阻断病毒与细胞融合的抑制剂．提出了研究抑制剂时可考虑的几个不同靶点．

作用于HIV-1gp120小分子HIV进入抑制剂NC-2的虚拟筛选及其作用机制

目的基于中和抗体VRC01与HIV-1 gp120的结合模式,利用计算机虚拟筛选,从IBS天然产物数据库中筛选靶向HIV-1gp120的小分子HIV-1进入抑制剂,并对其抗病毒活性和机制进行研究。方法运用MM-PBSA方法计算候选化合物与HIV-1gp120结合后自由能的变化;利用HIV-1假病毒、活病毒技术及细胞融合实验,检测化合物抑制HIV-1感染的活性;XTT比色法检测化合物对细胞的毒性;采用酶联免疫吸附测定法(ELISA)研究化合物体外抗病毒活性的机理。结果利用计算机从40 000个化合物中虚拟筛选出19个与gp120结合后自由能降低较大的小分子化合物,其中NC-2具有抑制HIV-1感染和细胞融合的活性,其抑制HIV-1实验株IIIB的IC50是1.95±0.44μmol/L,抑制HIV-1JRFL假病毒的IC50是10.58±0.13μmol/L。酶联免疫吸附法结果表明NC-2体外能抑制HIV-1 gp120与CD4的结合,但不抑制HIV-1 gp41六螺旋的形成。结论该计算机虚拟筛选的方法可为开发作用于HIV-1 gp120的小分子进入抑制剂提供参考。同时,通过计算机辅助设计加病毒活性筛选的方法,得到一个新颖结构的HIV进入抑制剂NC-2。

HIV-1进入抑制剂的研究进展

高效抗逆转录病毒治疗法(HAART)是目前用于抗人免疫缺陷病毒(HIV)感染的主要方法,随着HAART的广泛应用,诸如药物交互作用、不良反应和耐药毒株等问题也相继出现,因此人们致力于其他抗HIV药物的研究。HIV-1进入抑制剂是颇具前景的抗艾滋病药物,该类药物作用于病毒黏附、辅助受体结合和膜融合的过程,能有效阻断HIV-1侵入细胞,抑制病毒感染。具有作用于细胞外,毒性较低,不易产生耐药性等诸多优点,目前已有多种HIV-1进入抑制剂上市或进入临床研究,本文综述近年来HIV-1进入抑制剂的研究进展。

HIV-1进入抑制剂的研究近况

分类综述靶向病毒进入宿主细胞过程各环节的HIV-1进入抑制剂,包括HIV-1附着抑制剂、HIV-1辅助受体抑制剂、HIV-1融合抑制剂以及氧化还原酶蛋白二硫化物异构酶抑制剂的作用机制和疗效研究及其开发。

靶向gp120或gp41的小分子HIV进入抑制剂的研究进展

人免疫缺陷病毒Ⅰ型(HIV-1)包膜糖蛋白表面亚基gp120和跨膜亚基gp41在HIV-1进入靶细胞的过程中具有重要作用,是HIV-1进入抑制剂的关键靶位点。肽类HIV进入抑制剂(如T20)由于不能口服,导致其临床应用受限。小分子化合物具有可口服、生物利用度高等优点,是HIV进入抑制剂的重要研究方向之一。本文综述了近年来小分子HIV-1进入抑制剂的研究进展,如靶向gp120的小分子抑制剂NBD系列、BMS系列等,以及靶向gp41的小分子抑制剂NB-206、ADS-J1等,这些都是很有前景和研究价值的化合物,为设计更高效、更合理的小分子抑制剂奠定了结构基础,并发挥重要指导性作用。

Novel Antiviral Agents Targeting HIV Entry and Transmission

Studies of the mechanism of HIV entry and transmission have identified multiple new targets for drug development. A range of inhibitors have demonstrated potent antiretroviral activity by interfering with CD4-gp120 interaction,coreceptor binding or viral-cell fusion in preclinical and clinical studies. One of these agents,fusion inhibitor enfuvirtide,is already in clinical use. Here we review the progress in the development of specific entry inhibitors as novel therapeutics. The potential of entry inhibitors as topical microbicides to block HIV transmission is also discussed.

Synthesis and anti-HIV-1 activity evaluation of N-1-alkyl-5-halogeno-6-alkylamino uracils as novel non-nucleoside HIV-1 reverse transcriptase inhibitors

N-1-alkyl-5-halogeno-6-alkylamino uracils,which are novel 1-[(2-hydroxyethoxy) methyl]-6-(phenylthio) thymine (HEPT) analogues,were synthesized as the selective and potent non-nucleoside human immunodeficiency virus(HIV)-1 reverse transcriptase inhibitors.Some of the compounds showed potent inhibitory activity against HIV-1 reverse transcriptase.For instance,compounds 1d,1m and 1n exhibited potent anti-HTV-1 activity with the IC_(50) values of 13.3,11.7 and 3.15μM,respectively, which are comparable to that of nevirapine(IC_(50) 8.38μM).

Synthesis and biological evaluation of novel 1-aryl-5-iodo-6-benzyluracils as potent HIV-1 non-nucleoside reverse transcriptase inhibitors

We have synthesized the novel compounds 1a-1i,which are a series of hybrid analogues to 6-benzyl-1-（benzyloxymethyl）- 5-iodouracil,a compound showing strong activity against HIV-1.We also evaluated the activity of these compounds as the inhibitors of HIV-1 reverse transcriptase（HIV-1 RT）,and they have demonstrated moderate activity.

From design to biological mechanism evaluation of phenylalanine-bearing HIV-1 capsid inhibitors targeting a vital assembly interface

HIV-1 capsid protein(CA) has emerged as a promising target for antiviral treatment considering its structural and regulatory roles in HIV-1 replication. Here, we disclose the design, synthesis, biological assessment, and mechanism investigation of a novel series of phenylalanine derivatives gained by further structural modification of PF74. The newly synthesized compounds demonstrated potent anti-HIV activity, represented by 7n displayed anti-HIV-1 activity 6.25-fold better than PF74, and 7h showed anti-HIV-2activity with nearly 139 times improved efficacy over PF74. Surface plasmon resonance(SPR) studies of representative compounds proved that HIV-1 CA was the binding target. Competitive SPR studies using CPSF6 and NUP153 peptides identified that 7n binds to a vital CA assembly interface between the Nterminal and C-terminal domain(NTD-CTD interface). Action stage determination assay revealed that the newly synthesized compounds were antiviral with a dual-stage inhibitory profile. Molecular dynamics(MD) simulations offered the crucial foundation for the hopeful antiviral potency of 7n. Besides, 7m and7n modestly increased metabolic stabilities in human liver microsome(HLM) and human plasma compared to PF74. Overall, these studies offer valuable insights and can regard as the beginning for succedent medicinal chemistry endeavors to discover promising HIV capsid inhibitors with improved efficacy and better drug-like characteristics.

Design, synthesis and activity evaluation of novel pyridinone derivatives as anti-HIV-1 dual(RT/IN) inhibitors

Three series of novel anti-immunodeficiency virus 1 （HIV-1） dual （RT/1N） inhibitors were rationally designed by introducing a functioning diketo acid （DKA） into pyridin-2-one scaffold. To efficiently analyze inhibitory activity, these compounds were screened against HIV-1 RT and IN respectively via surface plasmon resonance （SPR）, and active compounds were subsequently evaluated by enzyme assay. It was noteworthy that compound A2 exhibited moderate activity against both HIV-1 RT and IN. This result provided information for further development of pyridinone analogues as potent dual HIV-1 inhibitors.