Some Hydrazones of 2‐Aroylamino‐3‐methylbutanohydrazide: Synthesis,Molecular Modeling Studies,and Identification as Stereoselective Inhibitors of HIV‐1

In accordance with our antiviral drug development attempt, acylhydrazone derivatives bearing amino acid side chains were synthesized for the evaluation of their antiviral activity against various types of viruses. Among these compounds, 8 _S , 11 _S , and 12 _S showed anti‐HIV‐1 activity with a 50% inhibitory concentration (IC₅₀) = 123.8 µM (selectivity index, SI > 3), IC₅₀ = 12.1 µM (SI > 29), IC₅₀ = 17.4 µM (SI > 19), respectively. Enantiomers 8 _R , 11 _R , and 12 _R were inactive against the HIV‐1 strain III_B. Hydrazones 8 _S , 11 _S , and 12 _S which were active against HIV‐1 wild type showed no inhibition against a double mutant NNRTI‐resistant strain (K103N;Y181C). Molecular docking calculations of R‐ and S‐enantiomers of 8 , 11 , and 12 were performed using the hydrazone‐bound novel site of HIV‐1 RT.     

HIV-1逆转录过程及应用PCR检测

人类免疫缺陷病毒(human immunodeficiency virus，HIV)作为逆转录病毒，在进入宿主细胞以后其正链RNA基因组就在逆转录酶的作用下开始逆转录合成双链的DNA。HIV-1逆转录的过程大致包括以下几个步骤：负链强力终止DNA的起始合成，负链强力终止DNA的链转移，正链DNA的合成起始，正链强力终止DNA的链转移和最终完整双链DNA的合成。逆转录是HIV-1复制的重要环节，现已成为抗HIV-1药物研究开发的重要靶标。聚合酶链反应(polymerase chain reaction，PCR)可用来检测HIV-1的逆转录过程，设计引物扩增HIV-1基因组R/U5序列、U3序列、U5/PBS序列和LTR与Gag之间的序列，根据PCR结果可相应判断出HIV-1的逆转录是否起始、是否进行了负链的链转移、正链的起始和双链DNA的完整合成。本文将主要介绍逆转录过程以及应用PCR的检测方法。     

A θ‐defensin composed exclusively of d‐amino acids is active against HIV‐1

Abstract: The ability of certain θ‐defensins, including retrocyclin‐1, to protect human cells from infection by HIV‐1 marks them as potentially useful molecules. θ‐Defensins composed of l ‐amino acids are likely to be unstable in environments that contain host and microbial proteases. This study compared the properties of two enantiomeric θ‐defensins, retrocyclin‐1, and RC‐112. Although these peptides have identical sequences, RC‐112 is composed exclusively of d ‐amino acids, whereas retrocyclin‐1 contains only l ‐amino acids. We compared the ability of these peptides to protect JC53‐BL human cells from infection by 30 primary HIV‐1 isolates. JC53‐BL cells are modified HeLa cells that express surface CD4, CXCR4, and CCR5. They also contain reporter cassettes that are driven by the HIV‐1 LTR, and express β‐galactosidase and luciferase. The HIV‐1 isolates varied in co‐receptor specificity and included subtypes A, B, C, D, CRF01‐AE, and G. RC‐112 was several fold more potent than retrocyclin‐1 across the entire HIV‐1 panel. Although RC‐112 bound immobilized gp120 and CD4 with lower affinity than did retrocyclin‐1, surface plasmon resonance experiments performed with 1 μg/mL of RC‐112 and retrocyclin‐1 revealed that both glycoproteins were bound to a similar extent. The superior antiviral performance of RC‐112 most likely reflected its resistance to degradation by surface‐associated or secreted proteases of the JC53‐BL target cells. θ‐Defensins composed exclusively of d ‐amino acids merit consideration as starting points for designing microbicides for topical application to the vagina or rectum.     

Synthesis and Anti‐HIV‐1 Integrase Activitiy of Cyano Pyrimidinones

A series of 2‐phenethyl/benzylthio‐6‐oxo‐4‐phenyl‐1,6‐dihydropyrimidine‐5‐carbonitrile were synthesized and tested against recombinant HIV‐1 integrase in an enzyme assay. 2‐(Phenethylthio)‐4‐(4‐chlorophenyl)‐6‐oxo‐1,6‐dihydropyrimidine‐5‐carbonitrile 4m and 2‐(phenethylthio)‐4‐(3‐chlorophenyl)‐6‐oxo‐1,6‐dihydropyrimidine‐5‐carbonitrile 4o showed significant inhibition against integrase in the assay (strand transfer: IC₅₀ values of 16 and 17 μM, respectively).     

Design of peptide mimetics of HIV‐1 gp120 for prevention and therapy of HIV disease

Abstract: It has been reported that the C‐terminus of the second conserved region (C2) of the envelope glycoprotein gp120, encompassing peptide RSANFTDNAKTIIVQLNESVEIN (NTM), is important for infectivity and neutralization of the human immunodeficiency virus type 1 (HIV‐1). It was also demonstrated that human natural anti‐vasoactive intestinal peptide (VIP) antibodies reactive with this gp120 region play an important role in control of HIV disease progression. The bioinformatic analysis based on the time‐frequency signal processing revealed non‐obvious similarities between NTM and VIP. When tested against a battery of sera from 46 AIDS patients, these peptides, in spite of a significant difference in their primary structures, showed a similar reactivity profiles (r = 0.83). Presented results point out that similarity in the periodical pattern of some physicochemical properties in primary structures of peptides plays a significant role in determination of their immunological crossreactivity. Based on these findings, we propose this bioinformatic criterion be used for design of VIP/NTM peptide mimetics for prevention and treatment of HIV disease.     

Structural Basis of Why Nelfinavir‐Resistant D30N Mutant of HIV‐1 Protease Remains Susceptible to Saquinavir

Although anti‐HIV‐1 protease drugs nelfinavir (NFV) and saquinavir (SQV) share common functional groups, D30N is a major resistance mutation against NFV but remains susceptible to SQV. We have determined the crystal structure of D30N mutant‐tethered HIV‐1 protease in complex with SQV to 1.79 Å resolution. Structural analysis showed that SQV forms two direct hydrogen bonds with the main chain atoms of the residues Asp29 and Asp30 that are not observed in the D30N–NFV complex. Apart from maintaining these two main chain hydrogen bonds, the P2‐asparagine of SQV forms an additional hydrogen bond to the mutated side chain of the residue 30. These could be the reasons why D30N is not a drug resistance mutation against SQV. This structure supports the previous studies showing that the interactions between a potential inhibitor and backbone atoms of the enzyme are important to maintain potency against drug‐resistant HIV‐1 protease.     

Quinoline antimalarials as investigational drugs for HIV‐1/AIDS: in vitro effects on HIV‐1 replication,HIV‐1 response to antiretroviral drugs,and intracellular antiretroviral drug concentrations

In this study, the effects of the quinoline antimalarials, chloroquine and mefloquine, were tested on: (1) HIV‐1 replication; (2) virus response to existing antiretrovirals; (3) functional activity of drug efflux pumps; and (4) intracellular accumulation of antiretrovirals. Antiretroviral activity was evaluated using cells acutely infected with drug‐sensitive/resistant HIV‐1 isolates or retroviral vectors, chronically infected cell lines, and syncytium assays. Drug interactions were assessed isobolographically. Activity of efflux pumps was tested using specific fluorochromes. Antitretroviral concentrations were quantitated by HPLC. Results indicated that: (1) the antimalarials (mefloquine > chloroquine) inhibited the replication of drug‐sensitive and drug‐resistant HIV‐1 at therapeutically achievable concentrations and specifically impaired the formation of fusion‐competent viral glycoproteins; (2) anti‐HIV‐1 effects were additive to those of zidovudine and nevirapine, and synergistic to those of lopinavir; (3) the antimalarials (mefloquine > chloroquine) inhibited the P‐glycoprotein, multidrug‐resistance‐associated proteins, and breast‐cancer resistance‐associated protein; (4) Chloroquine, but not mefloquine, increased lopinavir concentrations in peripheral blood mononuclear cells (PBMCs) by approximately 5 (five)‐fold. Thus quinoline antimalarials inhibited HIV‐1 replication by a novel mechanism, resulting in additive or synergistic effects in combination with known antiretrovirals. These drugs may also have an impact on the cellular pharmacokinetics of antiretrovirals. Drug Dev. Res. 67:806–817, 2006. © 2007 Wiley‐Liss, Inc.