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Estratégias fotocatalíticas para a síntese de miméticos de glicopeptídeos e síntese do fármaco anticâncer Carfilzomibe
(Universidade Federal de São Carlos, 2026-04-15) Chavarro Vélez, Jeimy Alejandra; Paixão, Márcio Weber; https://lattes.cnpq.br/3773908504964104; https://orcid.org/0000-0002-0421-2831; https://lattes.cnpq.br/4922446535555256; https://orcid.org/0009-0008-2233-0998; Brocksom, Timothy John; Trossini, Gustavo Henrique Goulart; Raminelli, Cristiano; Pastre, Julio Cesar; https://lattes.cnpq.br/7055452150201902; https://lattes.cnpq.br/1463048040306555; https://lattes.cnpq.br/3153931165773039; https://lattes.cnpq.br/2428327858391101; https://orcid.org/0000-0003-3634-2531; https://orcid.org/0000-0002-6920-5456
Peptide-based structures play a crucial role in biological recognition and contemporary drug development because of their structural versatility and functional significance. In this context, this thesis reports the development of photocatalytic methodologies for the synthesis of glycopeptide mimetics and sustainable synthetic routes for the peptide-based anticancer drug Carfilzomib. The work is divided into two chapters addressing methodological and applied challenges in peptide chemistry and pharmaceutical synthesis. In Chapter 1, visible-light-mediated photocatalytic strategies were developed for the diastereoselective synthesis of glycopeptide analogues. Although C-glycosides provide enhanced chemical and enzymatic stability, their synthesis typically requires complex multistep protocols and presents significant challenges in stereochemical control. To address these limitations, a photocatalytic radical addition strategy was investigated using glycosyl nitrones and 4-amido-1,4-dihydropyridines derived from amino acids and peptides. This approach enables stereoselective carbon–carbon bond formation under mild conditions, providing a robust platform for the construction of neoglycosylated peptide frameworks. Chapter 2 focuses on the development of an efficient and scalable synthetic route to Carfilzomib; a second-generation proteasome inhibitor used in the treatment of multiple myeloma. Considering the limited production of high-cost pharmaceuticals, this study proposes a sustainable and accessible synthetic strategy for this clinically relevant drug. The approach involves the visible-light photocatalytic synthesis of the unnatural amino acid L-homophenylalanine, followed by solid-phase peptide synthesis to assemble the peptide backbone and coupling of an epoxide fragment. An alternative route using a proline-functionalized resin enables controlled peptide elongation and cleavage via a Grignard reaction to generate a terminal alkene, followed by asymmetric epoxidation of α,β-unsaturated ketones as a late-stage functionalization step. According to the results obtained, photocatalysis and modern synthetic methodologies offer robust, stereocontrolled, and sustainable solutions for the synthesis of glycopeptide mimetics and complex peptide-based pharmaceuticals. Overall, this thesis demonstrates the applicability of visible-light-driven processes and strategic molecular design in addressing key challenges in glycopeptide chemistry and pharmaceutical manufacturing, contributing to advances in contemporary drug discovery and production.
Ecologia espacial como ferramenta para compreender os potenciais impactos de cães domésticos em uma unidade de conservação do Cerrado
(Universidade Federal de São Carlos, 2026-04-15) Gonçalves, Beatriz Garcia; Lima, Caio Filipe da Motta; http://lattes.cnpq.br/5833399072087947; http://lattes.cnpq.br/5148317135041568; Beisiegel, Beatriz de Mello; Dénes, Francisco Voeroes; http://lattes.cnpq.br/8143797535693714; https://lattes.cnpq.br/5139370160420533
The domestic dog (Canis lupus familiaris) is an invasive species of global significance, posing a potential threat to native wildlife and biodiversity. Introduced to virtually every region of the planet, dogs—when poorly managed—can cause serious disturbances to wildlife and ecological imbalances, especially stray dogs or those raised to roam freely. These impacts include predation, transmission of infectious diseases, harassment, competition for resources and territory, hybridization with native canids, and predation on livestock. In this context, understanding the spatial behavior of these animals is essential for assessing their potential ecological impacts. This study investigated the spatial patterns of semi-domesticated dogs in the vicinity of the Serra de Caldas Novas State Park (PESCaN—GO), as well as their potential to invade the conservation area.The dogs were classified into two groups based on their origin: rural and peri-urban. A total of 36 individuals (15 females and 21 males) were monitored using GPS collars programmed to record coordinates every 10 minutes for 21 to 28 days (June through December 2024). Analyses were performed using R software, including estimates of home range and foray range (areas of movement beyond the dogs’ homes) via Kernel Density Estimation (KDE), using 95% and 50% isopleths. The average foray range was 165.20 hectares (ha). On average, the dogs spent 57.25% of their time at their homes, 37.36% on forays, and 5.12% visiting neighboring homes. During these forays, the dogs traveled an average of 83.52 m from their homes, reaching a maximum distance of 10.85 km. Dogs in rural areas had an average foray range of 262.55 ha (1.62–2,602.22 ha), values 8.27 times greater than those observed for dogs in peri-urban areas, whose average foray range was 11.47 ha (0.58–41.09 ha). Rural dogs undertook more extensive forays, with routes 44% longer than those of peri-urban dogs, although they spent a smaller proportion of their time on these forays. Large dogs also exhibited larger foray ranges and longer movements than small and medium-sized dogs. It was observed that 25% of the monitored dogs entered the interior of the park, representing a potential threat to the Cerrado’s wildlife. Considering the total area of PESCaN (approximately 12,000 ha), estimates based on kernel density indicated that 45.22% of the park’s area (5,500 ha) is frequently used by dogs, while 13.14% (1,613 ha) is intensively used. The results highlight striking differences between the spatial behaviors of dogs in rural and peri-urban areas, indicating the need for distinct management strategies for each group. While peri-urban areas have a higher density of dogs, dogs in rural areas explore significantly larger areas, potentially exerting greater pressure on wildlife. Thus, this study provides relevant information on the spatial use patterns of semi-domesticated dogs in the region, contributing to the development of management strategies aimed at mitigating impacts on biodiversity and promoting conservation in Cerrado protected areas.