Synthesis and antinociceptive activity of pyrrolidinylnaphthalenes

Structural Insights into the Ligand–LsrK Kinase Binding Mode: A Step Forward in the Discovery of Novel Antimicrobial Agents

LsrK is a bacterial kinase that triggers the quorum sensing, and it represents a druggable target for the identification of new agents for fighting antimicrobial resistance. Herein, we exploited tryptophan fluorescence spectroscopy (TFS) as a suitable technique for the identification of potential LsrK ligands from an in-house library of chemicals comprising synthetic compounds as well as secondary metabolites. Three secondary metabolites (Hib-ester, Hib-carbaldehyde and (R)-ASME) showed effective binding to LsrK, with KD values in the sub-micromolar range. The conformational changes were confirmed via circular dichroism and molecular docking results further validated the findings and displayed the specific mode of interaction. The activity of the identified compounds on the biofilm formation by some Staphylococcus spp. was investigated. Hib-carbaldehyde and (R)-ASME were able to reduce the production of biofilm, with (R)-ASME resulting in the most effective compound with an EC50 of 14 mg/well. The successful application of TFS highlights its usefulness in searching for promising LsrK inhibitor candidates with inhibitor efficacy against biofilm formation.

A step forward in the sigma enigma: a role for chirality in the sigma1 receptor–ligand interaction?

To investigate the role of chirality in the ligand–σ₁ receptor interaction, a series of enantiomeric arylalkylaminoalcohols and arylpyrrolidinols was evaluated by means of both in silico and in vitro studies.

Chiral arylpyrrolidinols: preparation and biological profile

The preparation and biological evaluation of a new class of arylpyrrolidinols is reported. The antinociceptive activity was evaluated in vivo with the hot plate test (HPT) and formalin test (FT), excluding any involvement on motor coordination with the rota-rod test (RRT). The nociceptive behavior in the late phase of FT (representative of chronic pain) suggests an involvement of the antiinflammatory process and it is clearly influenced by the stereochemical features, being the eutomer of phenylpyrrolidinols, the (2R,3S) enantiomer. Despite this, a specific mechanism of action is not yet clarified.

Synthesis and pharmacological evaluation of new N-methyl-arylpyrrolidinols with analgesic activity

In the present paper, we report on the synthesis and antinociceptive activity of a new series of N-methyl-arylpyrrolidinols that we designed for a rational structure-activity relationship (SAR) study. The antinociceptive properties were investigated in vivo by the hot plate and formalin tests in mice and control on the locomotory activity was also monitored by the rota rod test. With this aim, the evaluation of the lipophilicity of all compounds was performed by the Daylight computational method in order to better understand the SAR. Interesting properties were proven for the compounds of the entire series.

Synthesis of pyrrolinylnaphthalenes and evaluation of their antinociceptive activity

In this paper the regioselective preparation of (R/S)-1,2-dimethyl-3-[2-(6-substituted naphthyl)]-2H,5H-pyrrolines 2a-d is reported. These compounds were prepared by thermal dehydration of the corresponding alcohols (2R,3S/2S,3R)-1,2-dimethyl-3-[2-(6-substituted naphthyl)]-3-hydroxy-pyrrolidines (2R,3S/2S,3R)-1a-d with anhydrous FeCl3-SiO2, under vacuum. Pharmacological properties of (R/S)-2a-d are also described. Analgesic activity was investigated by the hot plate test, also in the presence of selective antagonists of mu, delta and kappa opioid receptors. Preliminary analysis of the side-effects was also accomplished using the rota-rod test. Interesting antinociceptive activity was shown by all compounds and in particular by (R/S)-2a (AD50 = 0.31 mg/kg); delta opioid receptors were found to be mainly involved in the pharmacological process and, in general, it was found that the compounds influenced locomotory activity to a much lesser extent than did morphine.