A versatile and practical synthesis toward the development of novel HIV-1 integrase inhibitors

Atom-economic Approach to the Synthesis of α-(Hetero)aryl-substituted Furan Derivatives from Biomass

An atom-economic ring construction approach to the synthesis of α-(hetero)arylfurans based on renewable furanic platform chemicals has been developed. Corresponding compounds have been prepared in good to excellent yields via [2+2+2] and [4+2] cycloaddition reactions using metal-catalyzed or photoredox protocols. Easily available HMF-based 2-hydroxymethyl-5-ethynylfuran and 2-hydroxymethyl-5-cyanofuran were used as starting materials. A synthetic route with an improved carbon economy factor has been implemented to achieve sustainability aim. The possible application of arylfurans as molecular conductors has been investigated by DFT calculations, which revealed excellent charge transfer properties. As a future perspective, integration of biomass processing strategy into manufacturing of molecular electronics was pointed out to achieve the aim of sustainability.

The Fellowship of Privileged Scaffolds-One Structure to Inhibit Them All

Over the past few years, the application of privileged structure has emerged as a powerful approach to the discovery of new biologically active molecules. Privileged structures are molecular scaffolds with binding properties to the range of different biological targets. Moreover, privileged structures typically exhibit good drug-like properties, thus assuring more drug-like properties of modified compound. Our main objective is to discuss the privileged structures used for the development of antiviral agents.

Multicomponent reactions in the synthesis of antiviral compounds

BACKGROUND

Multicomponent reactions are one-pot processes for the synthesis of highly functionalized hetero-cyclic and hetero-acyclic compounds, often endowed with biological activity.

OBJECTIVE

Multicomponent reactions are considered green processes with high atom economy. In addition, they present advantages compared to the classic synthetic methods such as high efficiency and low wastes production.

METHOD

In these reactions two or more reagents are combined together in the same flask to yield a product containing almost all the atoms of the starting materials.

RESULTS

The scope of this review is to present an overview of the application of multicomponent reactions in the synthesis of compounds endowed with antiviral activity. The syntheses are classified depending on the viral target.

CONCLUSION

Multicomponent reactions can be applied to all the stages of the drug discovery and development process making them very useful in the search for new agents active against emerging (viral) pathogens.

The Importance of Rhodanine Scaffold in Medicinal Chemistry: A Comprehensive Overview

After the clinical use of epalrestat that contains a rhodanine ring, in type II diabetes mellitus and diabetic complications, rhodanin-based compounds have become an important class of heterocyclic in the field of medicinal chemistry. Various modifications to the rhodanine ring have led to a broad spectrum of biological activity of these compounds. Synthesis of rhodanine derivatives, depended on advenced throughput scanning hits, frequently causes potent and selective modulators of targeted enzymes or receptors, which apply their pharmacological activities through different mechanisms of action. Rhodanine-based compounds will likely stay a privileged scaffold in drug discovery because of different probability of chemical modifications of the rhodanine ring. We have, therefore reviewed their biological activities and structure activity relationship.

Novel broad spectrum virucidal molecules against enveloped viruses

Viral infections are an important cause of death worldwide. Unfortunately, there is still a lack of antiviral drugs or vaccines for a large number of viruses, and this represents a remarkable challenge particularly for emerging and re-emerging viruses. For this reason, the identification of broad spectrum antiviral compounds provides a valuable opportunity for developing efficient antiviral therapies. Here we report on a class of rhodanine and thiobarbituric derivatives displaying a broad spectrum antiviral activity against seven different enveloped viruses including an HSV-2 acyclovir resistant strain with favorable selectivity indexes. Due to their selective action on enveloped viruses and to their lipid oxidation ability, we hypothesize a mechanism on the viral envelope that affects the fluidity of the lipid bilayer, thus compromising the efficiency of virus-cell fusion and preventing viral entry.

Rhodanine derivatives as potent anti-HIV and anti-HSV microbicides

Although highly active antiretroviral therapies (HAART) remarkably increased life expectancy of HIV positive people, the rate of novel HIV-1 infections worldwide still represent a major concern. In this context, pre-exposure prophylaxis (PrEP) approaches such as vaginal microbicide gels topically releasing antiretroviral drugs, showed to have a striking impact in limiting HIV-1 spread. Nevertheless, the co-presence of other genital infections, particularly those due to HSV-1 or 2, constitute a serious drawback that strongly limits the efficacy of PrEP approaches. For this reason, combinations of different compounds with mixed antiviral and antiretroviral activity are thoroughly investigated Here we report the synthesis and the biological evaluation of a novel series of rhodanine derivatives, which showed to inhibit both HIV-1 and HSV-1/2 replication at nanomolar concentration, and were found to be active also on acyclovir resistant HSV-2 strains. The compounds showed a considerable reduction of activity in presence of serum due to a high binding to serum albumin, as determined through in vitro ADME evaluations. However, the most promising compound of the series maintained a considerable activity in gel formulation, with an EC50 comparable to that obtained for the reference drug tenofovir. Moreover, the series of compounds showed pharmacokinetic properties suitable for topical formulation, thus suggesting that the novel rhodanine derivatives could represent effective agents to be used as dual anti HIV/HSV microbicides in PrEP approaches.

One drug for two targets: Biological evaluation of antiretroviral agents endowed with antiproliferative activity

AIDS-related cancer diseases are malignancies with low incidence on healthy people that affect mostly subjects already immunocompromised. The connection between HIV/AIDS and these cancers has not been established yet, but a weakened immune system is certainly the main cause. We envisaged the possibility to screen a small library of compounds synthesized in our laboratory against opportunistic tumors mainly due to HIV infection like Burkitt's Lymphoma. From cellular assays and gene expression analysis we identified two promising compounds. These derivatives have the dual action required inhibiting HIV replication in human TZM-bl cells infected with HIV-1 NL4.3 and showing cytotoxic activity on human colon HT-29 and breast adenocarcinoma MCF-7 cells. In addition, preclinical in vitro adsorption, distribution, metabolism, and excretion studies highlighted a satisfactory pharmacokinetic profile.

Synthetic Development of New 3-(4-Arylmethylamino)butyl-5-arylidene-rhodanines under Microwave Irradiation and Their Effects on Tumor Cell Lines and against Protein Kinases

A new route to 3-(4-arylmethylamino)butyl-5-arylidene-2-thioxo-1,3-thiazolidine-4-one 9 was developed in six steps from commercial 1,4-diaminobutane 1 as starting material. The key step of this multi-step synthesis involved a solution phase “one-pot two-steps” approach assisted by microwave dielectric from N-(arylmethyl)butane-1,4-diamine hydrochloride 6a–f (as source of the first point diversity) and commercial bis-(carboxymethyl)-trithiocarbonate reagent 7 for construction of the rhodanine platform. This platform was immediately functionalized by Knoevenagel condensation under microwave irradiation with a series of aromatic aldehydes 3 as second point of diversity. These new compounds were prepared in moderate to good yields and the fourteen synthetic products 9a–n have been obtained with a Z-geometry about their exocyclic double bond. These new 5-arylidene rhodanines derivatives 9a–n were tested for their kinase inhibitory potencies against four protein kinases: Human cyclin-dependent kinase 5-p25, HsCDK5-p25; porcine Glycogen Synthase Kinase-3, GSK-3α/β; porcine Casein Kinase 1, SsCK1 and human HsHaspin. They have also been evaluated for their in vitro inhibition of cell proliferation (HuH7 D12, Caco 2, MDA-MB 231, HCT 116, PC3, NCI-H727, HaCat and fibroblasts). Among of all these compounds, 9j presented selective micromolar inhibition activity on SsCK1 and 9i exhibited antitumor activities in the HuH7 D12, MDA-MBD231 cell lines.

2-Aminothiazolones as anti-HIV agents that act as gp120-CD4 inhibitors

We report here the synthesis of 2-aminothiazolones along with their biological properties as novel anti-HIV agents. Such compounds have proven to act through the inhibition of the gp120-CD4 protein-protein interaction that occurs at the very early stage of the HIV-1 entry process. No cytotoxicity was found for these compounds, and broad antiviral activities against laboratory strains and pseudotyped viruses were documented. Docking simulations have also been applied to predict the mechanism, at the molecular level, by which the inhibitors were able to interact within the Phe43 cavity of HIV-1 gp120. Furthermore, a preliminary absorption, distribution, metabolism, and excretion (ADME) evaluation was performed. Overall, this study led the basis for the development of more potent HIV entry inhibitors.

Discovery of small molecule HIV-1 integrase dimerization inhibitors

Human immunodeficiency virus-1 integrase (HIV-1 IN) inserts the viral DNA into host cell chromatin in a multistep process. This enzyme exists in equilibrium between monomeric, dimeric, tetrameric and high order oligomeric states. However, monomers of IN are not capable of supporting its catalytic functions and the active form has been shown to be at least a dimer. As a consequence, the development of inhibitors targeting IN dimerization constitutes a promising novel antiviral strategy. In this work, we successfully combined different computational techniques in order to identify small molecule inhibitors of IN dimerization. Additionally, a novel AlphaScreen-based IN dimerization assay was used to evaluate the inhibitory activities of the selected compounds. To the best of our knowledge, this study represents the first successful virtual screening and evaluation of small molecule HIV-1 IN dimerization inhibitors, which may serve as attractive hit compounds for the development of novel anti-HIV.