http://www.bdtd.uerj.br/handle/1/3538 2026-08-09T04:42:02Z 2026-08-09T04:42:02Z Novellino, Kátia Viviane Alves http://www.bdtd.uerj.br/handle/1/24467 2026-03-02T18:59:52Z 2021-03-12T00:00:00Z

Título: Análise direcionada de lignanas em espécies do gênero Phyllanthus (quebra pedra) Autor: Novellino, Kátia Viviane Alves Primeiro orientador: Moreira, Davyson de Lima Abstract: Stonebreaker is a medicinal plant commonly used in the treatment of urinary lithiasis, diabetes and hepatitis. Several species of the genus Phyllanthus are recognized in Brazil as stonebreaker such as: P. niruri, P. amarus, P. urinaria e P. tenellus. Lignans is a group of substances produced by Phyllanthus species that have several pharmacological properties. The goal of this study is to assess the differences in the production of lignans by Phyllanthus genus focusing on extracts standardization and therapeutic application. To that end, specimens from six species ‒ P. niruri, P. amarus, P. urinaria, P. tenellus, P. stipulatus e P. caroliniensis ‒ were collected from different locations in Brazil. To that end a GC-MS analytical method was developed, with which 99 samples of the Phyllanthus genus were analyzed. Phyllanthin and hypophyllanthin were quantified and the presence of other lignans were investigated. According to the experimental design the optimized method for GC-MS analysis employed DB-17ht collumn and 120 °C initial oven temperature, 6 °C/min heating rate and 2.0 mL/min carrier gas flow. This new unpublished method presents better resolution than any published methods. Only 27 samples had amounts of phyllanthin and hypophyllanthin over the limit of quantification. Other lignans such as lintetralin, urinaligran, filtetralin, nirtetralin, niranthin, dextrobursehernin, hinokinin, 5-demetoxiniranthin e urinatetralin were identified as well. A multivariate analysis correlating the amount of these lignans with abiotic factors, was performed. No correlation between the amount of lignans and environmental factors were found. P. amarus presented the higher amounts of lignans as well as the greater variability in their production. Therefore, it is suggested the establishment of a producing lineage rich in lignans to be used in the brazilian public health system (SUS). Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese

2021-03-12T00:00:00Z Arruda, Renan Silva http://www.bdtd.uerj.br/handle/1/23802 2025-05-16T15:45:59Z 2023-12-15T00:00:00Z

Título: Avaliação dos efeitos da aplicação de técnicas para mitigação de florações de cianobactérias na liberação e destino de cianotoxinas em dois sistemas eutróficos tropicais Autor: Arruda, Renan Silva Primeiro orientador: Marinho, Marcelo Manzi Abstract: As a result of intense eutrophication, frequent blooms of potentially toxic cyanobacteria affect the water quality in continental and coastal aquatic systems. In this study, using a deep eutrophic reservoir and a hypertrophic shallow coastal lagoon, both tropical aquatic systems, and scenarios of recurrent cyanobacterial bloom events as models, we investigated the occurrence and diversity of microcystins, other cyanopeptides, and their potential producers as well as flocculation and sedimentation techniques aiming for efficient and safe removal of cyanobacterial biomass. Through LC-MS analyses, we identified compounds belonging to microcystins, aeruginosins, microginins, cianopeptolins, and microviridins classes in both environments, many of which exhibit seasonality between dry and rainy seasons. During the study, Microcystis aeruginosa, Dolichospermum circinalis, and Planktothrix isothrix were the most representative potential microcystins producers. In biomass removal tests using the Floc & Sink technique, we employed combinations of polyaluminum chloride (PAC) as a flocculant, lanthanum Phoslock® (LMB) alone or combined with local red soil (LRS) as ballast, and the algaecide hydrogen peroxide (H2O2). In the reservoir, testing the PAC+LMB and PAC+LMB+LRS combinations, we obtained similar results for cyanobacteria removal between microcosms and mesocosms, with removal rates of 92-100% of biomass and 94-100% of intracellular microcystins. No signs of cell lysis were observed in any of these experiments. In tests where extracellular microcystins (MCs) were measured, a significant reduction in toxin concentrations was recorded due to the ballast used. In the lagoon, the results of biomass removal were less pronounced in the microcosm, ranging from 78-85%. The integrated Kill, Floc & Sink method achieved the best removal result, where H2O2 was applied prior to PAC and LMB. In this experiment, we did not identify dissolved MCs in the water, either before or after treatments. Furthermore, the tested treatments reduced intracellular MC concentrations below the detection limit. In mesocosm tests, both variations of treatments removed similar amounts of biomass, ranging from 92-97%, and intracellular MCs with a 95-100% reduction, with no MCs release into the water column. At the end of the experiments, we concluded that flocculation and sedimentation techniques effectively remove cyanobacterial biomass and MCs, with a low risk of cell lysis. However, their effectiveness depends on the appropriate combination of flocculant and ballast, their respective dosages, intrinsic characteristics of the environment (e.g., depth, pH), and, finally, the morphophysiological characteristics of the dominant cyanobacterial species. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese

2023-12-15T00:00:00Z Ramos, Carlos Henrique http://www.bdtd.uerj.br/handle/1/23711 2025-05-16T15:38:56Z 2024-06-07T00:00:00Z

Título: Estudo da Interferência de Neolignanas Bioativas Isoladas e do Extrato Hidroalcoólico de Piper rivinoides Kunth (Piperaceae) na atividade do CYP1A Autor: Ramos, Carlos Henrique Primeiro orientador: Moreira, Davyson de Lima Abstract: The Piperaceae family, with around 3,600-3,700 species, is one of the most diverse plant lineages, with emphasis on the genus Piper L., with approximately 2,000 species. Phytochemical studies in Piperaceae have revealed several classes of metabolites, including lignans and neolignans, which are known for their rich structural diversity and biological activities such as antiparasitic and antitumor. Neolignans extracted from the leaves of Piper rivinoides Kunth exhibited multiple biological activities, such as leishmanicidal, antifungal, antibacterial and antitumor. Cytochrome P450 (CYP450) enzymes form an extensive family of hemeproteins essential in the metabolism of xenobiotics and endogenous agents. The CYP1, CYP2 and CYP3 families are predominant in oxidative biotransformation, capable of catalyzing different reactions on different substrates. This work investigated the interference of neolignans isolated from Piper rivinoides and its hydroalcoholic extract on the human recombinant enzymes rhCYP1A1 and rhCYP1A2. In vitro tests, Eupomatenoid-5 stood out for its potent inhibitory activity, with an IC50 of 39.5 μM. In vivo assays were carried out in mice of the DBA/2 and Swiss strains. In silico analyzes were conducted on the SwissADME platform and molecular docking was performed using the GOLD© 2022.1 for Windows program with the Hermes viewer. The in vitro results showed that both the isolated neolignans and the hydroalcoholic extract inhibited the activity of rhCYP1A1 and rhCYP1A2. In vivo assays indicated induction of CYP1A in mice subjected to chronic treatment with Eupomatenoid-5. Molecular docking revealed that the fragments in the CYP1A1/A2 cavity are crucial for the interactions of neolignans, especially with eupomatenoid-5 and eupomatenoid-6, which presented the best scores and the highest number of interactions with key residues, such as Phe123, Phe224 and Phe258 (CYP1A1) and Phe125, Phe226, Gly316, Ala317, Ile386 and Leu497 (CYP1A2). These interactions favor aromatic π-π contacts, providing superior docking at the active sites compared to conocarpan. Such results are relevant to understand the pharmacokinetic interactions between benzofuran neolignans and commercialized drugs. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese

2024-06-07T00:00:00Z Ferreira, Gabriel do Amaral http://www.bdtd.uerj.br/handle/1/23468 2025-03-13T19:38:53Z 2024-02-23T00:00:00Z

Título: Respostas anatômicas da madeira às variações fitofisionômicas da Mata Atlântica Autor: Ferreira, Gabriel do Amaral Primeiro orientador: Cunha, Maura da Abstract: The analysis of functional attributes of wood plays a fundamental role in assessing future strategies for tropical forest preservation. Understanding how wood anatomy contributes to species resilience becomes crucial for predicting the effects of climate change on the structure of trees in different phytophysiognomies of the Atlantic Forest. Dense Ombrophilous Forests (DOF), Seasonal Semideciduous Forests (SSF), and Restingas (RES) are phytophysiognomies that make up the vegetation mosaic of the Atlantic Forest. However, environmental conditions related to water availability and irradiance in these phytophysiognomies vary. In this sense, it is possible to observe a water and irradiance gradient, with DOF being the wettest phytophysiognomy, with lower irradiance and clayey soil, RES being the driest, with higher irradiance and sandy soil, and SSF having intermediate conditions. These microclimatic differences among these phytophysiognomies can directly influence species distribution, reflecting in their anatomical characteristics and functional wood attributes. Species occurring in drier phytophysiognomies, such as SSF and RES, need to invest in strategies to restrict water loss and increase water storage. In contrast, species living in wetter phytophysiognomies, such as DOF, do not need to expend energy on attributes restrictive to water loss and only concern themselves with their growth. Thus, the present study aims to description the anatomy and identify the functional attributes of wood in the most abundant species, relating them to variations in soil water availability and irradiance among these phytophysiognomies. For this purpose, 15 species were selected for wood collection. Anatomical characteristics of the species were described, and morphoanatomical parameters of wood were evaluated (vessel frequency, diameter, and lumen; fiber length and thickness; and length of pits, total parenchyma, and rays; and tissue percentages). Additionally, soil characteristics (chemical and granulometric) were assessed. Results indicated that species have distinct anatomical traits; in DOF, they exhibit an architecture geared towards efficient water transport, with higher theoretical hydraulic conductivity and lower wood density. On the other hand, species from SSF and RES show more conservative attributes, reflecting a secure hydraulic architecture adapted to conditions of lower water availability. These results highlight species adaptation to the specific conditions of each phytophysiognomy. Plants in humid phytophysiognomies, such as DOF, are more vulnerable to climate change due to higher water demand, while plants in dry phytophysiognomies, like RES, have strategies that offer greater survival security. In addition to the anatomical description of wood from uncataloged species, their anatomical attributes provide important insights into understanding species responses to variations in water availability, assisting in predicting the effects of climate change on plant communities, and implementing appropriate conservation strategies in the Atlantic Forest. Instituição: Universidade do Estado do Rio de Janeiro Tipo do documento: Tese

2024-02-23T00:00:00Z