N'-Phenylacetohydrazide Derivatives as Potent Ebola Virus Entry Inhibitors with an Improved Pharmacokinetic Profile.

Ebola virus (EBOV) is a single-strand RNA virus belonging to the Filoviridae family, which has been associated to most Ebola virus disease outbreaks to date, including the West African and the North Kivu epidemics between 2013 and 2022. This unprecedented health emergency prompted the search for effective medical countermeasures. Following up on the carbazole hit identified in our previous studies, we synthetized a new series of compounds, which demonstrated to prevent EBOV infection in cells by acting as virus entry inhibitors. The in vitro inhibitory activity was evaluated through the screening against surrogate models based on viral pseudotypes and further confirmed using replicative EBOV. Docking and molecular dynamics simulations joined to saturation transfer difference-nuclear magnetic resonance (STD-NMR) and mutagenesis experiments to elucidate the biological target of the most potent compounds. Finally, in vitro metabolic stability and in vivo pharmacokinetic studies were performed to confirm their therapeutic potential.

Multitarget Hybrid Fasudil Derivatives as a New Approach to the Potential Treatment of Amyotrophic Lateral Sclerosis.

Hybrid compounds containing structural fragments of the Rho kinase inhibitor fasudil and the NRF2 inducers caffeic and ferulic acids were designed with the aid of docking and molecular mechanics studies. Following the synthesis of the compounds using a peptide-coupling methodology, they were characterized for their ROCK2 inhibition, radical scavenging, effects on cell viability (MTT assay), and NRF2 induction (luciferase assay). One of the compounds (1d) was selected in view of its good multitarget profile and good tolerability. It was able to induce the NRF2 signature, promoting the expression of the antioxidant response enzymes HO-1 and NQO1, via a KEAP1-dependent mechanism. Analysis of mRNA and protein levels of the NRF2 pathway showed that 1d induced the NRF2 signature in control and SOD1-ALS lymphoblasts but not in sALS, where it was already increased in the basal state. These results show the therapeutic potential of this compound, especially for ALS patients with a SOD1 mutation.

Potential pharmacological strategies targeting the Niemann-Pick C1 receptor and Ebola virus glycoprotein interaction.

Niemann-Pick C1 (NPC1) receptor is an intracellular protein located in late endosomes and lysosomes whose main function is to regulate intracellular cholesterol trafficking. Besides being postulated as necessary for the infection of highly pathogenic viruses in which the integrity of cholesterol transport is required, this protein also allows the entry of the Ebola virus (EBOV) into the host cells acting as an intracellular receptor. EBOV glycoprotein (EBOV-GP) interaction with NPC1 at the endosomal membrane triggers the release of the viral material into the host cell, starting the infective cycle. Disruption of the NPC1/EBOV-GP interaction could represent an attractive strategy for the development of drugs aimed at inhibiting viral entry and thus infection. Some of the today available EBOV inhibitors were proposed to interrupt this interaction, but molecular and structural details about their mode of action are still preliminary thus more efforts are needed to properly address these points. Here, we provide a critical discussion of the potential of NPC1 and its interaction with EBOV-GP as a therapeutic target for viral infections.

Determination of polyamines and related compounds in saliva via in situ derivatization and microextraction by packed sorbents coupled to GC-MS.

Here we show the determination of different polyamines (putrescine, cadaverine, spermidine) and related compounds (gamma-aminobutyric acid and l-ornithine) in saliva samples. These compounds are known to be biomarkers for several diseases. We have optimised an in situ derivatization process using ethyl chloroformate, an automated microextraction by packed sorbent and the determination of the corresponding products using a programmed temperature vaporizer coupled to a gas chromatograph - mass spectrometer. After finding that saliva matrix has an effect on the analysis, quantitation was performed using the one-point standard additions method and normalization to IS. This allows the detection of the analytes in the range of µg/L within a matrix obtained by a non-invasive procedure. The method has been successfully validated and it has been used in the determination of these compounds in six saliva samples finding that putrescine and cadaverine present the highest concentrations in the subject diagnosed with rheumatoid arthritis. For ornithine and spermidine, the highest concentrations were found for male subjects, especially heavy smokers. All concentrations found for the compounds were in good agreement with data found in bibliography.