http://hdl.handle.net/11422/116 2026-04-08T11:37:15Z 2026-04-08T11:37:15Z Salgado, Leonardo Tavares Tomazetto, Rodrigo Cinelli, Leonardo Paes Farina, Marcos Amado Filho, Gilberto Menezes http://hdl.handle.net/11422/27698 2025-11-17T01:38:44Z 2007-06-01T00:00:00Z

Title: The influence of brown algae alginates on phenolic compounds capability of ultraviolet radiation absorption in vitro Author(s)/Inventor(s): Salgado, Leonardo Tavares; Tomazetto, Rodrigo; Cinelli, Leonardo Paes; Farina, Marcos; Amado Filho, Gilberto Menezes Abstract: Brown algae phenolic compounds (PC) are secondary metabolites that participate in many biological processes, such as ultraviolet radiation (UV) protection, polyspermy blocking and trace metals bounding. Recently, PC has also been studied due to possible interactions with cell wall polysaccharides. However, there are few evidences of these interactions and their influence in physiological processes. The interactions between PC from the brown alga Padina gymnospora and alginates and the influence of these interactions on the UV absorption properties of PC were investigated in this work. Chromatography and spectrophotometry techniques were used to isolate, characterize and determine UV absorption capacity of studied compounds. Even after the P. gymnospora polysaccharide extraction and isolating methods, the PC was maintained linked to the alginate. The interaction of alginates with PC did not cause modifications on absorbance pattern of electromagnetic spectrum (UV-VIS-IR). The UV absorbance capability of PC linked to alginate was maintained for a longer period of time if compared with the purified PC. The obtained results reveal the strong linkage between PC and alginates and that these linkages preserve the UV absorption capability of PC along time. Publisher: Universidade de São Paulo Type: Artigo

2007-06-01T00:00:00Z Sodero, Ana Carolina Rennó Romeiro, Nelilma Correia Cunha, Elaine Fontes Ferreira da Magalhães, Uiaran de Oliveira Alencastro, Ricardo Bicca de Rodrigues, Carlos Rangel Cabral, Lúcio Mendes Castro, Helena Carla Albuquerque, Magaly Girão http://hdl.handle.net/11422/27633 2025-11-12T08:03:11Z 2012-06-05T00:00:00Z

Title: Application of 4D-QSAR studies to a series of raloxifene analogs and design of potential selective estrogen receptor modulators Author(s)/Inventor(s): Sodero, Ana Carolina Rennó; Romeiro, Nelilma Correia; Cunha, Elaine Fontes Ferreira da; Magalhães, Uiaran de Oliveira; Alencastro, Ricardo Bicca de; Rodrigues, Carlos Rangel; Cabral, Lúcio Mendes; Castro, Helena Carla; Albuquerque, Magaly Girão Abstract: Four-dimensional quantitative structure-activity relationship (4D-QSAR) analysis was applied on a series of 54 2-arylbenzothiophene derivatives, synthesized by Grese and coworkers, based on raloxifene (an estrogen receptor-alpha antagonist), and evaluated as ERα ligands and as inhibitors of estrogen-stimulated proliferation of MCF-7 breast cancer cells. The conformations of each analogue, sampled from a molecular dynamics simulation, were placed in a grid cell lattice according to three trial alignments, considering two grid cell sizes (1.0 and 2.0 Å). The QSAR equations, generated by a combined scheme of genetic algorithms (GA) and partial least squares (PLS) regression, were evaluated by “leave-one-out” cross-validation, using a training set of 41 compounds. External validation was performed using a test set of 13 compounds. The obtained 4D-QSAR models are in agreement with the proposed mechanism of action for raloxifene. This study allowed a quantitative prediction of compounds’ potency and supported the design of new raloxifene analogs. Publisher: Multidisciplinary Digital Publishing Institute Type: Artigo

2012-06-05T00:00:00Z Danuello, Amanda Romeiro, Nelilma Correia Giesel, Guilherme Menegon Pivatto, Marcos Viegas Junior, Cláudio Verli, Hugo Barreiro, Eliezer Jesus de Lacerda Fraga, Carlos Alberto Manssour Castro, Newton Gonçalves de Bolzani, Vanderlan da Silva http://hdl.handle.net/11422/27632 2025-11-12T08:00:50Z 2012-01-01T00:00:00Z

Title: Molecular docking and molecular dynamic studies of semi-synthetic piperidine alkaloids as acetylcholinesterase inhibitors Author(s)/Inventor(s): Danuello, Amanda; Romeiro, Nelilma Correia; Giesel, Guilherme Menegon; Pivatto, Marcos; Viegas Junior, Cláudio; Verli, Hugo; Barreiro, Eliezer Jesus de Lacerda; Fraga, Carlos Alberto Manssour; Castro, Newton Gonçalves de; Bolzani, Vanderlan da Silva Abstract: The mixture of semi-synthetic derivatives ( )-3-O-acetyl-cassine hydrochloride and ( )-3-O-acetyl-spectaline hydrochloride, prepared from the mixture of natural alkaloids ( )-cassine and ( )-spectaline (4:1) isolated from Senna spectabilis, has been shown to be a potent acetylcholinesterase (AChE) inhibitor, thereby prompting further molecular studies. In this sense, docking and dynamic molecular studies were carried out in this work, aiming to acquire a deeper understanding about all the structural aspects of molecules ( )-3-O-acetyl-cassine and ( )-3-O-acetyl-spectaline hydrochlorides, which differ with respect to their AChE inhibitory potentials. Both molecules establish important interactions with the peripheral anionic site within the catalytic gorge of Torpedo californica AChE. However, only the major compound ( )-3-O-acetyl-cassine hydrochloride significantly interacts with the catalytic triad. Explicit-solvent molecular dynamic simulations were conducted in order to gain better understanding about the hypothetical interactions taking place between the semi-synthetic alkaloid molecules ( )-3-O-acetyl-cassine and ( )-3-O-acetyl-spectaline hydrochlorides and AChE. The data obtained in this study indicated that ( )-3-O-acetyl-cassine hydrochloride is the most potent inhibitor of AChE possibly due to the favorable interactions of this molecule with the target protein, with lower desolvation cost. These results suggested that the size of the side chain has an effect on the inhibitory potential of the evaluated molecules and may represent the starting point for the development of new derivatives of ( )-3-O-acetyl-cassine hydrochloride, with a view to the discovery of new effective AChE inhibitors. Publisher: Sociedade Brasileira de Química Type: Artigo

2012-01-01T00:00:00Z Nunes, Rodrigo Dutra Romeiro, Nelilma Correia Carvalho, Hugo Tremonte de Moreira, Jean Ribeiro Sola-Penna, Mauro Silva Neto, Mário Alberto Cardoso da Braz, Glória Regina Cardoso http://hdl.handle.net/11422/27631 2025-11-12T07:57:38Z 2016-02-25T00:00:00Z

Title: Unique PFK regulatory property from some mosquito vectors of disease, and from Drosophila melanogaster Author(s)/Inventor(s): Nunes, Rodrigo Dutra; Romeiro, Nelilma Correia; Carvalho, Hugo Tremonte de; Moreira, Jean Ribeiro; Sola-Penna, Mauro; Silva Neto, Mário Alberto Cardoso da; Braz, Glória Regina Cardoso Abstract: Background: Arthropod-borne diseases are some of the most rapidly spreading diseases. Reducing the vector population is currently the only effective way to reduce case numbers. Central metabolic pathways are potential targets to control vector populations, but have not been well explored to this aim. The information available on energy metabolism, as a way to control lifespan and dispersion through flight of dipteran vectors, is inadequate. Methods: Phosphofructokinase (PFK) activity was measured in the presence of both of its substrates, fructose 6-phosphate (F6P) and ATP, as well as some allosteric effectors: Fructose- 2,6 – bisphosphate (F2, 6BP), citrate and AMP. Aedes aegypti phosphofructokinase sequence (AaPFK) was aligned with many other insects and also vertebrate sequences. A 3D AaPFK model was produced and docking experiments were performed with AMP and citrate. Results: The kinetic parameters of AaPFK were determined for both substrates: F6P (V = 4.47 ± 0.15 μmol of F1, 6BP/min, K0.5 = 1.48 ± 0.22 mM) and ATP (V = 4.73 ± 0.57 μmol of F1, 6BP/min, K0.5 = 0.43 ± 0.10 mM). F2,6P was a powerful activator of AaPFK, even at low ATP concentrations. AaPFK inhibition by ATP was not enhanced by citrate, consistent with observations in other insects. After examining the sequence alignment of insect and non-insect PFKs, the hypothesis is that a modification of the citrate binding site is responsible for this unique behavior. AMP, a well-known positive effector of PFK, was not capable of reverting ATP inhibition. Aedes, Anopheles and Culex are dengue, malaria and filariasis vectors, respectively, and are shown to have this distinct characteristic in phosphofructokinase control. The alignment of several insect PFKs suggested a difference in the AMP binding site and a significant change in local charges, which introduces a highly negative charge in this part of the protein, making the binding of AMP unlikely. This hypothesis was supported by 3D modeling of PFK with AMP docking, which suggested that the AMP molecule binds in a reverse orientation due to the electrostatic environment. The present findings imply a potential new way to control PFK activity and are a unique feature of these Diptera. Conclusions: The present findings provide the first molecular explanation for citrate insensitivity in insect PFKs, as well as demonstrating for the first time AMP insensitivity in dipterans. It also identified a potential target for novel insecticides for the control of arthropod-borne diseases. Publisher: BioMed Type: Artigo

2016-02-25T00:00:00Z