Virtual Screen for Repurposing of Drugs for Candidate Influenza a M2 Ion-Channel Inhibitors.

Influenza A virus (IAV) matrix protein 2 (M2), an ion channel, is crucial for virus infection, and therefore, an important anti-influenza drug target. Adamantanes, also known as M2 channel blockers, are one of the two classes of Food and Drug Administration-approved anti-influenza drugs, although their use was discontinued due to prevalent drug resistance. Fast emergence of resistance to current anti-influenza drugs have raised an urgent need for developing new anti-influenza drugs against resistant forms of circulating viruses. Here we propose a simple theoretical criterion for fast virtual screening of molecular libraries for candidate anti-influenza ion channel inhibitors both for wild type and adamantane-resistant influenza A viruses. After in silico screening of drug space using the EIIP/AQVN filter and further filtering of drugs by ligand based virtual screening and molecular docking we propose the best candidate drugs as potential dual inhibitors of wild type and adamantane-resistant influenza A viruses. Finally, guanethidine, the best ranked drug selected from ligand-based virtual screening, was experimentally tested. The experimental results show measurable anti-influenza activity of guanethidine in cell culture.

Preclinical discovery and development of maraviroc for the treatment of HIV.

INTRODUCTION: Maraviroc is a first-in-class antiretroviral (ARV) drug acting on a host cell target (CCR5), which blocks the entry of the HIV virus into the cell. Maraviroc is currently indicated for combination ARV treatment in adults infected only with CCR5-tropic HIV-1. AREAS COVERED: This drug discovery case history focuses on the key studies that led to the discovery and approval of maraviroc, as well as on post-launch clinical reports. The article is based on the data reported in published preclinical and clinical studies, conference posters and on drug package data. EXPERT OPINION: The profound understanding of HIV's entry mechanisms has provided a strong biological rationale for targeting the chemokine receptor CCR5. The CCR5-antagonist mariviroc, with its unique mode of action and excellent safety profile, is an important therapeutic option for HIV patients. In general, the authors believe that targeting host factors is a useful approach for combating new and re-emerging transmissible diseases, as well as pathogens that easily become resistant to common antiviral drugs. Maraviroc, offering a potent and safe cellular receptor-mediated pharmacological response to HIV, has paved the way for the development of a new generation of host-targeting antivirals.

Simple and general criterion for "in silico" screening of candidate HIV drugs.

Highly active antiretroviral therapy (HAART) dramatically has changed the course of HIV infection. Currently, this therapy involves the use of agents from at least two distinct classes of antivirals: a protease inhibitor in combination with two nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs), or a non-nucleoside reverse transcriptase inhibitor (NNRTI) in combination with NRTIs. Recently, the third family of antivirals started to be used clinically, with the advent of enfuvirtide, the first fusion inhibitor. This broad spectrum of anti-HIV agents recently was extended with compounds inhibiting HIV integrase and vital entry. But these advances did not come without a cost: there were the short- and long-term drug toxicities, emergence of drug resistance, and persistence of viral reservoirs. For these reasons, there is a pressing need for novel anti-HIV drugs, particularly those that have a novel action mechanism, as these might be less likely to show cross-resistance with current therapies. The field of bioinformatics has become a major part of the drug discovery pipeline playing a key role in improvement and acceleration of the time and money consuming process of the drug development. Here we review the application of the EIIP/AQVN (Electron-Ion Interaction Potential, EIIP; Average Quasi Valence Number, AQVN) bioinformatics concept in the development of new anti-HIV drugs and propose a simple theoretical criterion for a virtual screening of molecular libraries for promising lead anti-HIV compounds and refinement of selected lead compounds in order to increase their biological activity.

Toward novel HIV-1 integrase binding inhibitors: molecular modeling, synthesis, and biological studies.

The identification of a novel hit compound as integrase binding inhibitor has been accomplished by means of virtual screening techniques. A small family of structurally related molecules has been synthesized and biologically evaluated with one of the compounds showing an IC(50)=12 microM.