Insights into SARS-CoV-2: Small-Molecule Hybrids for COVID-19 Treatment.

The advantages of a treatment modality that combines two or more therapeutic agents with different mechanisms of action encourage the study of hybrid functional compounds for pharmacological applications. Molecular hybridization, resulting from a covalent combination of two or more pharmacophore units, has emerged as a promising approach to overcome several issues and has also been explored for the design of new drugs for COVID-19 treatment. In this review, we presented an overview of small-molecule hybrids from both natural products and synthetic sources reported in the literature to date with potential antiviral -SARS-CoV-2 activity.

In Vitro Studies to Evaluate the Intestinal Permeation of an Ursodeoxycholic Acid-Conjugated Oligonucleotide for Duchenne Muscular Dystrophy Treatment.

Delivery represents a major hurdle to the clinical advancement of oligonucleotide therapeutics for the treatment of disorders such as Duchenne muscular dystrophy (DMD). In this preliminary study, we explored the ability of 2'--methyl-phosphorothioate antisense oligonucleotides (ASOs) conjugated with lipophilic ursodeoxycholic acid (UDCA) to permeate across intestinal barriers in vitro by a co-culture system of non-contacting IEC-6 cells and DMD myotubes, either alone or encapsulated in exosomes. UDCA was used to enhance the lipophilicity and membrane permeability of ASOs, potentially improving oral bioavailability.

Evaluation of Anticancer Activity of Nucleoside-Nitric Oxide Photo-Donor Hybrids.

Herein, we report the synthesis of a new hybrid compound based on a 2'-deoxyuridine nucleoside conjugated with a NO photo-donor moiety (dU-t-NO) via CuAAC click chemistry. Hybrid dU-t-NO, as well as two previously reported 2'-deoxyadenosine based hybrids (dAdo-S-NO and dAdo-t-NO), were evaluated for their cytotoxic and cytostatic activities in selected cancer cell lines. dAdo-S-NO and dAdo-t-NO hybrids displayed higher activity with respect to dU-t-NO.

Enzymatic Synthesis of New Acetoacetate-Ursodeoxycholic Acid Hybrids as Potential Therapeutic Agents and Useful Synthetic Scaffolds as Well.

Ursodeoxycholic acid (UDCA) and acetoacetate are natural compounds present in the human intestine and blood, respectively. A number of studies highlighted that besides their well-known primary biological roles, both compounds possess the ability to influence a variety of cellular processes involved in the etiology of various diseases. These reasons suggested the potential of acetoacetate-UDCA hybrids as possible therapeutic agents and prompted us to develop a synthetic strategy to selectively derivatize the hydroxyl groups of the bile acid with acetoacetyl moieties.

Dihydroartemisinin-Ursodeoxycholic Bile Acid Hybrids in the Fight against SARS-CoV-2.

Here, we propose the molecular hybridization of dihydroartemisinin (DHA) and ursodeoxycholic bile acid (UDCA), approved drugs, for the preparation of antiviral agents against SARS-CoV-2. DHA and UDCA were selected on the basis of their recently demonstrated activity against SARS-CoV-2. A selection of DHA-UDCA-based hybrids obtained by varying the nature of the linkage and the bile acid conjugation point as well as unconjugated DHA and UDCA were tested for cytotoxicity and anti-SARS-CoV-2 activity on Vero E6 and Calu-3 human lung cells.

Molecular Hybridization as a Strategy for Developing Artemisinin-Derived Anticancer Candidates.

Artemisinin is a natural compound extracted from Artemisia species belonging to the Asteraceae family. Currently, artemisinin and its derivatives are considered among the most significant small-molecule antimalarial drugs. Artemisinin and its derivatives have also been shown to possess selective anticancer properties, however, there are several limitations and gaps in knowledge that retard their repurposing as effective anticancer agents.

Anticancer Activity and Molecular Mechanisms of an Ursodeoxycholic Acid Methyl Ester-Dihydroartemisinin Hybrid via a Triazole Linkage in Hepatocellular Carcinoma Cells.

Hepatocellular carcinoma is the third most common cause of cancer-related death according to the International Agency for Research on Cancer. Dihydroartemisinin (DHA), an antimalarial drug, has been reported to exhibit anticancer activity but with a short half-life. We synthesized a series of bile acid-dihydroartemisinin hybrids to improve its stability and anticancer activity and demonstrated that an ursodeoxycholic-DHA (UDC-DHA) hybrid was 10-fold more potent than DHA against HepG2 hepatocellular carcinoma cells.

Antisense Oligonucleotides Conjugated with Lipophilic Compounds: Synthesis and In Vitro Evaluation of Exon Skipping in Duchenne Muscular Dystrophy.

Our groups previously reported that conjugation at 3'-end with ursodeoxycholic acid (UDCA) significantly enhanced in vitro exon skipping properties of ASO 51 oligonucleotide targeting the human DMD exon 51. In this study, we designed a series of lipophilic conjugates of ASO 51, to explore the influence of the lipophilic moiety on exon skipping efficiency. To this end, three bile acids and two fatty acids have been derivatized and/or modified and conjugated to ASO 51 by automatized solid phase synthesis.

Synthesis of 2,6-Dimethyltyrosine-Like Amino Acids through Pinacolinamide-Enabled C-H Dimethylation of 4-Dibenzylamino Phenylalanine.

The synthesis of a small library of -Boc- or -Fmoc-protected l-phenylalanines carrying methyl groups at positions 2 and 6 and diverse functionalities at position 4 has been achieved. The approach, which took advantage of a Pd-catalyzed directed C-H dimethylation of picolinamide derivatives, allowed the electronic and steric properties of the resulting amino acid derivatives to be altered by appending a variety of electron-withdrawing, electron-donating, or bulky groups.

Synthesis and Biological Investigation of Bile Acid-Paclitaxel Hybrids.

Chenodeoxycholic acid and ursodeoxycholic acid (CDCA and UDCA, respectively) have been conjugated with paclitaxel (PTX) anticancer drugs through a high-yield condensation reaction. Bile acid-PTX hybrids (BA-PTX) have been investigated for their pro-apoptotic activity towards a selection of cancer cell lines as well as healthy fibroblast cells. Chenodeoxycholic-PTX hybrid (CDC-PTX) displayed cytotoxicity and cytoselectivity similar to PTX, whereas ursodeoxycholic-PTX hybrid (UDC-PTX) displayed some anticancer activity only towards HCT116 colon carcinoma cells.

Synthesis and Exon-Skipping Properties of a 3'-Ursodeoxycholic Acid-Conjugated Oligonucleotide Targeting Pre-mRNA: Pre-Synthetic versus Post-Synthetic Approach.

Steric blocking antisense oligonucleotides (ASO) are promising tools for splice modulation such as exon-skipping, although their therapeutic effect may be compromised by insufficient delivery. To address this issue, we investigated the synthesis of a 20-mer 2'-OMe PS oligonucleotide conjugated at 3'-end with ursodeoxycholic acid (UDCA) involved in the targeting of human exon 51, by exploiting both a pre-synthetic and a solution phase approach. The two approaches have been compared.

Modified Nucleosides, Nucleotides and Nucleic Acids via Click Azide-Alkyne Cycloaddition for Pharmacological Applications.

The click azide = alkyne 1,3-dipolar cycloaddition (click chemistry) has become the approach of choice for bioconjugations in medicinal chemistry, providing facile reaction conditions amenable to both small and biological molecules. Many nucleoside analogs are known for their marked impact in cancer therapy and for the treatment of virus diseases and new targeted oligonucleotides have been developed for different purposes. The click chemistry allowing the tolerated union between units with a wide diversity of functional groups represents a robust means of designing new hybrid compounds with an extraordinary diversity of applications.

Bile Acid Conjugates with Anticancer Activity: Most Recent Research.

The advantages of a treatment modality that combines two or more therapeutic agents in cancer therapy encourages the study of hybrid functional compounds for pharmacological applications. In light of this, we reviewed recent works on hybrid molecules based on bile acids. Due to their biological properties, as well as their different chemical/biochemical reactive moieties, bile acids can be considered very interesting starting molecules for conjugation with natural or synthetic bioactive molecules.

Evaluation of the Anticancer Activity of a Bile Acid-Dihydroartemisinin Hybrid Ursodeoxycholic-Dihydroartemisinin in Hepatocellular Carcinoma Cells.

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy in adults and accounts for 85-90% of all primary liver cancer. Based on the estimation by the International Agency for Research on Cancer in 2018, liver cancer is the fourth leading cause of cancer death globally. Dihydroartemisinin (DHA), the main active metabolite of artemisinin derivatives, is a well-known drug for the treatment of malaria.

Attitude Towards Drug Therapy in a Community Mental Health Center Evaluated by the Drug Attitude Inventory.

Introduction: Negative attitude towards drug therapy can foster limited adherence to treatment, which remains one of the biggest obstacles for implementing effective treatments, especially long term.

Purposes: The purposes of the study were 1) to evaluate the attitude towards drug therapy among a representative sample of patients treated in a community psychiatric service using 30-item Drug Attitude Inventory (DAI-30); 2) to evaluate the DAI-30 dimensions, applying factorial analysis; and 3) to highlight the socio-demographic and clinical variables correlated to DAI-30 score and factors.

Methods: The DAI was administered, over a 7-month period, to all patients treated in our psychiatric outpatient services who agreed to participate in this study and provided their informed consent.

Oligonucleotides: Current Trends and Innovative Applications in the Synthesis, Characterization, and Purification.

Oligonucleotides (ONs) are gaining increasing importance as a promising novel class of biopharmaceuticals. Thanks to their fundamental role in gene regulation, they can be used to develop custom-made drugs (also called N-to-1) able to act on the gene expression at pre-translational level. With recent approvals of ON-based therapeutics by the Food and Drug Administration (FDA), a growing demand for high-quality chemically modified ONs is emerging and their market is expected to impressively prosper in the near future.

Dihydroartemisinin-Bile Acid Hybridization as an Effective Approach to Enhance Dihydroartemisinin Anticancer Activity.

A series of hybrid compounds based on natural products-bile acids and dihydroartemisinin-were prepared by different synthetic methodologies and investigated for their in vitro biological activity against HL-60 leukemia and HepG2 hepatocellular carcinoma cell lines. Most of these hybrids presented significantly improved antiproliferative activities with respect to dihydroartemisinin and the parent bile acid. The two most potent hybrids of the series exhibited a 10.

A New Drug Delivery System Based on Tauroursodeoxycholic Acid and PEDOT.

Localized drug delivery represents one of the most challenging uses of systems based on conductive polymer films. Typically, anionic drugs are incorporated within conductive polymers through electrostatic interaction with the positively charged polymer. Following this approach, the synthetic glucocorticoid dexamethasone phosphate is often delivered from neural probes to reduce the inflammation of the surrounding tissue.

UDP-GlcNAc Analogues as Inhibitors of O-GlcNAc Transferase (OGT): Spectroscopic, Computational, and Biological Studies.

A series of glycomimetics of UDP-GlcNAc, in which the β-phosphate has been replaced by either an alkyl chain or a triazolyl ring and the sugar moiety has been replaced by a pyrrolidine ring, has been synthesized by the application of different click-chemistry procedures. Their affinities for human O-GlcNAc transferase (hOGT) have been evaluated and studied both spectroscopically and computationally. The binding epitopes of the best ligands have been determined in solution by means of saturation transfer difference (STD) NMR spectroscopy.

Rational Design of Nucleoside-Bile Acid Conjugates Incorporating a Triazole Moiety for Anticancer Evaluation and SAR Exploration.

Herein we report a study on the synthesis and biological evaluation of a library of nucleoside-bile acid conjugates prepared by combining 2'-deoxyadenosine, 2'-deoxyguanosine, 2'-deoxyuridine as well as adenosine and guanosine derivatives with cheno-, urso-, -cheno-, -urso- and taurourso-desoxycholic acid derivatives by means of the click reaction. The new nucleoside-bile acid conjugates incorporating a triazole moiety were tested in vitro against leukemic K562 and HCT116 colon carcinoma, as well as on normal fibroblast cells. Six compounds displayed interesting anti-proliferative activity against the selected cancer lines and no cytotoxic effects against normal fibroblasts.

Fluorous-tag assisted synthesis of bile acid-bisphosphonate conjugates via orthogonal click reactions: an access to potential anti-resorption bone drugs.

The synthesis of a small collection of novel bile acid-bisphosphonate (BA-BP) conjugates as potential drug candidates is reported. The disclosed methodology relied on the installation of azide and thiol functionalities at the head and tail positions, respectively, of the BA scaffold and its subsequent decoration by orthogonal click reactions (copper-catalyzed azide-alkyne cycloaddition, thiol-ene or thiol-yne coupling) to introduce BP units and a fluorophore. Because of the troublesome isolation of the target conjugates by standard procedures, the methodology culminated with the functionalization of the BA scaffold with a light fluorous tag to rapidly and efficiently purify intermediates and final products by fluorous solid-phase extraction.

N-acetylcysteine in the treatment of psychiatric disorders: current status and future prospects.

N-acetylcysteine (NAC) is widely known for its role as a mucolytic and as an antidote to paracetamol overdose. There is increasing interest in the use of NAC in the treatment of several psychiatric disorders. The rationale for the administration of NAC in psychiatric conditions is based on its role as a precursor to the antioxidant glutathione, and its action as a modulating agent of glutamatergic, dopaminergic, neurotropic and inflammatory pathways.

NO Photoreleaser-Deoxyadenosine and -Bile Acid Derivative Bioconjugates as Novel Potential Photochemotherapeutics.

This contribution reports the synthesis of some novel bioconjugates with anticancer activity and able to release nitric oxide (NO) under visible light excitation. The 4-nitro-2-(trifluoromethyl)aniline derivative, a suitable NO photodonor, was conjugated with 2'-deoxyadenosine and urso- and cheno-deoxycholic acid derivatives, through a thioalkylic chain or the 4-alkyl-1,2,3-triazole moiety. Photochemical experiments demonstrated the effective release of NO from 2'-deoxyadenosine and ursodeoxycholic acid conjugates under the exclusive control of visible light inputs.

Exploring Splicing-Switching Molecules For Seckel Syndrome Therapy.

The c.2101A>G synonymous change (p.G674G) in the gene for ATR, a key player in the DNA-damage response, has been the first identified genetic cause of Seckel Syndrome (SS), an orphan disease characterized by growth and mental retardation.

Mcl-1 involvement in mitochondrial dynamics is associated with apoptotic cell death.

The B-cell lymphoma-2 (Bcl-2) family proteins are critical regulators of apoptosis and consist of both proapoptotic and antiapoptotic factors. Within this family, the myeloid cell leukemia factor 1 (Mcl-1) protein exists in two forms as the result of alternative splicing. The long variant (Mcl-1L) acts as an antiapoptotic factor, whereas the short isoform (Mcl-1S) displays proapoptotic activity.