Resumo em Inglês:

Leishmaniasis is an infectious disease caused by protozoan parasites of the Leishmania genus and affects more than 90 countries, especially in tropical and subtropical regions. The first treatment for these diseases involves pentavalent antimonial derivatives, which are very toxic and cause severe side effects. The other chemotherapeutic drugs used as second-line agents include different organic compound classes, such as pentamidine, which also cause severe side effects. Thus, new, safer, and efficient antileishmaniasis agents are urgently needed to control and treat these diseases. This mini review, which considered the last two decades of related research, highlighted the principal synthetic methodologies used to access amidine derivatives, focusing on more eco-friendly methods. Furthermore, the results obtained from evaluations of the anti-Leishmania activity and several molecular targets of the amidine derivatives are highlighted.

Resumo em Inglês:

Modified flavonoids of the sub-group of pterocarpans, 5-carba-pterocarpans, 5-carbapterocarpens, 1-carba-isoflavanones, coumestans, and aurones were synthesized and evaluated as antiproliferative, antileishmanial and antiviral. A new scaffold, called pterocarpanquinone, was discovered and LQB-118, the prototypical scaffold of its series, showed consistent antileishmanial (mice and hamster in vivo) and antineoplastic (respectively, human and mice tumors ex vivo and in vivo) activity. 5-Carpa-pterocarpan LQB-485 is potent towards SF-295 cancer cells (CNS). LQB-262 and LQB-34 are new inhibitors of NB5S RdRp polymerase of hepatitis C virus (HCV) while LQB-314 and LQB-360 demonstrated potent activity and selectivity against HCV replicon reporter cells. LQB-454 and LQB-501 were evaluated for their in vitro anti-proliferative effects against human breast cancer and leukemia cell lines with diverse profiles of drug resistance. In breast cancer they present higher toxicity on multidrug resistant cells (collateral sensitivity). Aurone LQB-814, featuring a “lipophilic phenol” at A-ring”, was a very potent and selective inhibitor of SARS-CoV-2 in Calu-3 cells. Other four aurones bearing EC50 (concentration required to inhibit 50% of cell growth) < 1 were also discovered.

Resumo em Inglês:

This account describes the analysis of the Laboratory of Evaluation and Synthesis of Bioactive Substances (LASSBio) chemical library as a valuable resource for early drug discovery studies. LASSBio has been using medicinal chemistry strategies for almost 30 years to design new prototype compounds with a focus on pharmacological activity. The LASSBio Chemical Library (LCL) is a collection of more than 2000 compounds, and the aim of this work was to characterize its chemical diversity and to perform a molecular repositioning study to identify ligands of feline McDonough sarcoma (FMS)-like tyrosine kinase 3 (FLT3), a validated target for leukemia treatment. To achieve this, cheminformatic tools were utilized to analyze the chemical diversity of the LCL. The analysis allowed the identification of the most representative compounds of this collection, showing that the N-acylhydrazone chemotype is present in approximately 50% of the compounds. Furthermore, the compounds in this chemical library demonstrated remarkable compliance with both the Lipinski’s (93% of the compounds) and Veber’s (96% of the compounds) rules. In the study on molecular repositioning, 10 compounds were selected through virtual screening to test their enzymatic inhibition of FLT3 kinase. Among them, 4-((6,7-dimethoxyquinazolin-4-yl)amino) benzamide (LASSBio-2166) (31) showed a half-maximal inhibitory concentration (IC50) = 194 nM. Optimization of the identified hit and further studies to compare the diversity of the LCL with other libraries are perspectives of this work.

Resumo em Inglês:

The interactive profile between four 1,4-naphthoquinone derivatives (1-4) and human serum albumin (HSA) was studied by spectroscopic techniques and in silico calculations. The bimolecular quenching rate constant (kq ca. 1012 L mol-1 s-1) and the time-resolved fluorescence decays indicated a static fluorescence quenching mechanism. Thus, there is a spontaneous ground-state association, and based on both Stern-Volmer, modified Stern-Volmer, and van’t Hoff approaches, the association is moderate mainly driven by hydrophobic forces. The circular dichroism (CD) analysis indicated that until the proportion albumin:compound of 1:8 there is a weak perturbation on the structural content of albumin, while molecular docking results suggested subdomain IIA (site I), a positive electrostatic pocket, as the main binding site. Overall, even though the hydrogen atom replacement by methyl, fluorine, or chlorine atoms in the para position of the aromatic ring in the benzo[g]chromene-5,10-dione moiety changes the lipophilicity, it does not change the binding profile to HSA.