Vitor Martins de Almeida

Background/Objectives: Human and canine leishmaniases are neglected diseases with limited therapeutic options. The nitrochalcone NAT22, a high-affinity inhibitor of the essential parasite enzyme tryparedoxin peroxidase (cTXNPx), has emerged as a promising antileishmanial candidate. Interestingly, NAT22 demonstrated superior efficacy when administered orally rather than intralesionally, suggesting a metabolism-driven activity enhancement. Since in vivo studies with chalcones have been conducted exclusively in mice, this study aimed to determine whether mice are suitable models for oral chalcone therapies for human and canine leishmaniases and to identify metabolites with potential antileishmanial activity. Methods: NAT22 hepatic metabolism was investigated using in silico prediction and in vitro liver microsomal assays from rats, mice, humans, and dogs. Metabolites were identified by LC-MS/MS and NMR, and docking studies were performed against cTXNPx. Results: In silico analysis predicted metabolism mainly by CYP1A2, CYP2A6, CYP2C8, and CYP3A4. Seven metabolites (M1–M7) were identified by LC-MS/MS and NMR in all species except mice, whose microsomes did not generate M6. Structural analyses indicated preservation of the α,β-enone system and nitro-substituted B ring in all metabolites. Docking studies showed that metabolites M2 and M4 displayed stronger predicted binding energies than NAT22. Conclusions: NAT22 undergoes hepatic phase I metabolism generating two metabolites with enhanced predicted interaction with cTXNPx. The similarity between human and canine metabolic profiles supports the translational relevance of oral NAT22 therapy in leishmaniasis, while metabolites M2 and M4 emerge as candidates for validation in local treatment of cutaneous leishmaniasis.

Background/Objectives: Human and canine leishmaniasis are neglected diseases with limited therapeutic options. The nitrochalcone NAT22, a high-affinity inhibitor of the essential parasite enzyme tryparedoxin peroxidase (cTXNPx), has emerged as a promising antileishmanial candidate. Interestingly, NAT22 demonstrated superior efficacy when administered orally rather than intralesionally, suggesting metabolism-driven enhancement of activity. Since in vivo studies with chalcones have been conducted exclusively in mice, this study aimed to evaluate whether mice are suitable models for oral chalcone therapies for human and canine leishmaniasis and to identify metabolites with potential antileishmanial activity. Methods: NAT22 hepatic metabolism was investigated using in silico prediction and in vitro liver microsomal assays from rats, mice, humans, and dogs. Metabolites were identified by LC-MS/MS and NMR, and docking studies were performed against cTXNPx. Results: In silico analysis predicted metabolism mainly by CYP1A2, CYP2A6, CYP2C8, and CYP3A4. Seven metabolites (M1–M7) were identified by LC-MS/MS and NMR in all species except mice, whose microsomes did not generate M6. Structural analyses indicated preservation of the α,β-enone system and nitro-substituted B ring in all metabolites. Docking studies showed that metabolites M2 and M4 displayed stronger predicted binding energies than NAT22. Conclusions: NAT22 undergoes hepatic phase I metabolism generating two metabolites with enhanced predicted interaction with cTXNPx. The similarity between human and canine metabolic profiles supports the translational relevance of oral NAT22 therapy in leishmaniasis, while metabolites M2 and M4 emerge as candidates for validation in local treatment of cutaneous leishmaniasis.

Background/Objectives: Antibody–drug conjugates are a rapidly evolving class of cancer therapeutics that combine the specificity of monoclonal antibodies with the potency of cytotoxic drugs. This review explores experimental and computational advances in ADC design, focusing on structural elements and optimization strategies. Methods: We examined recent developments in the mechanisms of action, antibody engineering, linker chemistries, and payload selection. Emphasis was placed on experimental strategies and computational tools, including molecular modeling and AI-driven structure prediction. Results: ADCs function through both internalization-dependent and -independent mechanisms, enabling targeted drug delivery and bystander effects. The therapeutic efficacy of ADCs depends on key factors: antigen specificity, linker stability, and payload potency. Linkers are categorized as cleavable or non-cleavable, each with distinct advantages. Payloads—mainly tubulin inhibitors and DNA-damaging agents—require extreme potency to be effective. Computational methods have become essential for antibody modeling, developability assessment, and in silico optimization of ADC components, accelerating candidate selection and reducing experimental labor. Conclusions: The integration of experimental and in silico approaches enhances ADC design by improving selectivity, stability, and efficacy. These strategies are critical for advancing next-generation ADCs with broader applicability and improved therapeutic indices.

Leishmaniasis is an emerging tropical infectious disease caused by a protozoan parasite of the genus Leishmania. In this work, the molecular hybridization between a trimethoxy chalcone and a sulfonamide group was used to generate a series of sulfonamide‐chalcones. A series of eight sulfonamide‐chalcone hybrids were made with good yields (up to 95%). These sulfonamide‐chalcones were tested against promastigotes of Leishmania amazonensis and cytotoxicity against mouse macrophages, which showed good antileishmanial activity with IC₅₀ = 1.72–3.19 µM. Three of them (10c, 10g, and 10h) were also highly active against intracellular amastigotes and had a good selectivity index (SI > 9). Thus, those three compounds were docked in the cytosolic tryparedoxin peroxidase (cTXNPx) enzyme of the parasite, and molecular dynamics simulations were carried out. This enzyme was selected as a target protein for the sulfonamide‐chalcones due to the fact of the anterior report, which identified a strong and stable interaction between the chalcone NAT22 (6) and the cTXNPx. In addition, a prediction of the drug‐likeness, and the pharmacokinetic profile of all compounds were made, demonstrating a good profile of those chalcones.