RESUMO
This work describes the synthesis of three new ruthenium(ii) complexes with gallic acid and derivatives of the general formula [Ru(L)(dppb)(bipy)]PF6, where L = gallate (GAC), benzoate (BAC), and esterified-gallate (EGA), bipy = 2,2'-bipyridine and dppb = 1,4-bis(diphenylphosphino)butane. The complexes were characterized by elemental analysis, molar conductivity, NMR, cyclic voltammetry, UV-vis and IR spectroscopy, and two of them by X-ray crystallography. Cell viability assays show promising results, indicating higher cytotoxicity of the complexes in MDA-MB-231 cells, a triple-negative breast cancer (TNBC) cell line, compared with the hormone-dependent MCF-7 cell line. Studies in vitro with the MDA-MB-231 cell line showed that only Ru(BAC) and Ru(GAC) interacted with BSA. Besides that, the Ru(GAC) complex, which has a polyphenolic acid, interacted in an apo-Tf structure and function dependent manner and it was able to inhibit the formation of reactive oxygen species. Ru(GAC) was able to cause damage to the cellular cytoskeleton leading to inhibition of some cellular processes of TNBC cells, such as invasion, migration, and adhesion.
Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Ácido Gálico/farmacologia , Piridinas/farmacologia , Rutênio/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Citoesqueleto de Actina/efeitos dos fármacos , Animais , Apoproteínas/metabolismo , Compostos de Bifenilo/química , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/química , Ácido Gálico/química , Humanos , Camundongos , Picratos/química , Piridinas/química , Rutênio/química , Soroalbumina Bovina/metabolismo , Transferrina/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
Antimicrobial peptides (AMPs) are promising candidates for the development of future antibiotics. In an attempt to increase the efficacy of therapeutic AMPs, computer-based design methods appear as a reliable strategy. In this study, we evaluated the antimicrobial efficiency and mechanism of action of a novel designed AMP named PaDBS1R1, previously designed by means of the Joker algorithm, using a fragment of the ribosomal protein L39E from the archaeon Pyrobaculum aerophilum as a template. PaDBS1R1 displayed low micromolar broad-spectrum antimicrobial activity against Gram-negative (MIC of 1.5⯵M) and Gram-positive (MIC of 3⯵M) bacteria, including carbapenem-resistant Klebsiella pneumoniae (MIC of 6.25⯵M) and methicillin-resistant Staphylococcus aureus (MIC of 12.5⯵M), without cytotoxicity towards HEK-293 cells. In addition, membrane permeabilization and depolarization assays, combined with time-kill studies and FEG-SEM imaging, indicated a fast membrane permeation and further leakage of intracellular content. Biophysical studies with lipid vesicles show a preference of PaDBS1R1 for Gram-negative bacteria-like membranes. We investigated the three-dimensional structure of PaDBS1R1 by CD and NMR analyses. Our results suggest that PaDBS1R1 adopts an amphipathic α-helix upon interacting with hydrophobic environments, after an initial electrostatic interaction with negative charges, suggesting a membrane lytic effect. This study reveals that PaDBS1R1 has potential application in antibiotic therapy.
Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Membrana Celular/efeitos dos fármacos , Antibacterianos/farmacologia , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Dicroísmo Circular , Bactérias Gram-Negativas , Células HEK293 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Luz , Lipídeos/química , Espectroscopia de Ressonância Magnética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Micelas , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Conformação Proteica em alfa-Hélice , Espalhamento de RadiaçãoRESUMO
A comprehensive investigation of anhydrous form of 3,4,5-Triacetoxybenzoic acid (TABA) is reported. Single crystal X-ray diffraction, Thermal analysis, Fourier Transform Infrared spectroscopy (FTIR) and DFT calculations were applied for TABA characterization. This anhydrous phase crystallizes in the triclinic [Formula: see text] space group (Z' = 1) and its packing shows a supramolecular motif in a classical [Formula: see text] ring formed by acid-acid groups association. The phase stability is accounted in terms of supramolecular architecture and its thermal behaviour. Conformation search at B3LYP/6-311++G(2d,p) level of theory shows the existence of three stable conformers and the most stable conformation was found experimentally. The reactivity of TABA was investigated using the molecular orbital theory and molecular electrostatic potential. The calculation results were used to simulate the infrared spectrum. There is a good agreement between calculated and experimental IR spectrum, which allowed the assignment of the normal vibrational modes.