7 documents found, page 1 of 1
Is silver a precious metal for G-Quadruplex stabilization mediated by porphyrins?
Moura, Nuno M. M.; Guedes, Sofia; Salvador, Diana; Oliveira, Helena; Neves, M. Graça P. M. S.; Ramos, Catarina I. V.Cancer is a leading cause of death, so continuous efforts into cancer therapy are imperative. In tumor cells, telomerase and oncogene activity are key points for uncontrolled cell growth. Targeting these processes with ligands that inhibit telomerase and/or reduce oncogene expression has been identified as a promising cancer therapy. This study evaluated the selectivity and affinity of the silverII complex of 5...
Arrays of graphene-quantum dots-supported DNA oligonucleotides as self-indicati...
Monteiro, Ana R.; Ramos, Catarina I. V.; Fateixa, Sara; Neves, Maria G. P. M. S.; Trindade, TitoThe functionalization of deoxyribonucleic acid (DNA) with nanomaterials is a promising strategy to optimize the loading and efficiency of drugs in targeted clinical therapies. Herein we report a novel approach to construct arrays comprising blue- (B) or aqua green- (AG) emitting ethylenediamine-modified graphene quantum dots (GQDs) and DNA oligonucleotides that are able to fold into different structures, namely...
Interfacial assembly of zinc(II) phthalocyanines on graphene oxide (GO): stable...
Monteiro, Ana R.; Ramos, Catarina I. V.; Lourenço, Leandro M. O.; Fateixa, Sara; Rodrigues, Joana catarina; Neves, Maria G. P. M. S.; Trindade, TitoHypothesis The aggregation of phthalocyanines (Pcs) enfeebles their suitability as G-quadruplex (G4) ligands over time. It is hypothesized that the interfacial assembly of Pcs on graphene oxide (GO) influences intermolecular interactions, thereby affecting their physicochemical properties and inducing stabilization of Pcs in solution. Hence, the stacking of Pcs on GO could be tuned to create nanosystems with th...
Multicharged Phthalocyanines as Selective Ligands for G-Quadruplex DNA Structures
Ramos, Catarina I. V.; Almeida, Susana P.; Lourenço, Leandro M. O.; Pereira, Patrícia M. R.; Fernandes, Rosa; Faustino, M. Amparo F.; Tomé, João P. C.The stabilization of G-Quadruplex DNA structures by ligands is a promising strategy for telomerase inhibition in cancer therapy since this enzyme is responsible for the unlimited proliferation of cancer cells. To assess the potential of a compound as a telomerase inhibitor, selectivity for quadruplex over duplex DNA is a fundamental attribute, as the drug must be able to recognize quadruplex DNA in the presence...
Hybrids based on graphene oxide and porphyrin as tools for detection and stabil...
Monteiro, Ana R.; Ramos, Catarina I. V.; Fateixa, Sara; Moura, Nuno M. M.; Neves, Maria G. P. M. S.; Trindade, TitoTelomerase inhibition has been an important strategy in cancer therapies, but for which effective drugs are still required. Here, noncovalent hybrid nanoplatforms containing the tetracationic 5,10,15,20-tetrakis(1-methyl-pyridinium-4-yl)porphyrin (TMPyP) and graphene oxide (GO) were prepared for promoting telomerase inhibition through the selective detection and stabilization of DNA guanine-quadruplex (G-Q) str...
Synthesis, characterization and biological evaluation of cationic porphyrin-ter...
Moura, Nuno M. M.; Ramos, Catarina I. V.; Linhares, Ines; Santos, Sergio M.; Faustino, M. Amparo F.; Almeida, Adelaide; Cavaleiro, Jose A. S.A simple access to a new series of cationic porphyrin-terpyridine derivatives is described. The key step to obtain the required neutral precursors as major products involved a Krohnke type approach. The methodology allowed also the isolation of the respective benzoporphyrins and porphyrin-chalcone type derivatives, and in one case a new 2-(2,4-terpyridin-6-yl)-porphyrin. The quaternization of the pyridyl groups...
An insight into the gas-phase fragmentations of potential molecular sensors wit...
Ramos, Catarina I. V.; Moura, Nuno M. M.; Santos, Sergio M. F.; Amparo Faustino, M.; Tome, Joao P. C.; Amado, Francisco M. L.; Neves, M. Graca P. M. S.Porphyrin-chalcone derivatives with potential cation sensing ability have been studied by ESI-MS and multistage ESI-MS. The presence of conjugated C=C and C=O double bonds in the chalcone moiety is responsible for the formation of diagnostic fragment ions common to all the studied meta and para chalcones. The ortho isomers show different fragmentation patterns that can be explained by different electronic charg...