RESUMO
The self-assembly of 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine (tpt) triangular panels with p-cymene (pPr(i)C(6)H(4)Me) ruthenium building blocks and 2,5-dioxydo-1,4-benzoquinonato (dobq) or 5,8-dioxydo-1,4-naphthoquinonato (donq) bridges, in the presence of a pyrenyl-nucleoside derivatives (pyreneR), affords the triangular prismatic host-guest compounds [(pyrene-R)âRu(6)(pPr(i)C(6)H(4)Me)(6)(tpt)(2)(dobq)(3)](6+) ([(pyrene-R)â1](6+)) and [(pyrene-R)âRu(6)(pPr(i)C(6)H(4)Me)(6)(tpt)(2)(donq)(3)](6+) ([(pyrene-R)â2](6+)), respectively. The inclusion of six monosubstitutedpyrenyl-nucleosides (pyrene-R1 = 5'-(1-pyrenyl butanoate)-2'-deoxyuridine, pyrene-R2 = 5-fluoro-5'-(1-pyrenyl butanoate)-2'-deoxyuridine, pyrene-R3 = 5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-glycyl}-2'-deoxyuridine, pyrene-R4 = 5-fluoro-5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-glycyl}-2'-deoxyuridine, pyrene-R5 = 5-fluoro-5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-phenylalanyl}-2'-deoxyvuridine, pyrene-R6 = 5-fluoro-5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-phenylalanyl}-2'-deoxyuridine) has been accomplished. The carceplex nature of [(pyrene-R)â1](6+) with the pyrenyl moiety firmly encapsulated in the hydrophobic cavity of the cage with the nucleoside groups pointing outward was confirmed by NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS), while the host-guest nature of [(pyrene-R)â2](6+) was studied in solution by NMR techniques. In contrast to the floxuridine compounds used in the clinic, the host-guest complexes are highly water-soluble. Consequently, the cytotoxicities of these water-soluble compounds have been established using human ovarian A2780 and A2780cisR cancer cells. All the host-guest systems are more cytotoxic than the empty cages alone [1][CF(3)SO(3)](6) (IC(50) = 23 µM) and [2][CF(3)SO(3)](6) (IC(50) = 10 µM), the most active compound [pyrene-R4â1][CF(3)SO(3)](6)being 2 orders of magnitude more cytotoxic (IC(50) = 0.3 µM) on these human ovarian cancer cell lines (A2780 and A2780cisR).
Assuntos
Antineoplásicos/administração & dosagem , Floxuridina/administração & dosagem , Neoplasias/tratamento farmacológico , Antineoplásicos/uso terapêutico , Floxuridina/uso terapêutico , Humanos , Espectroscopia de Ressonância Magnética , Neoplasias/patologia , Solubilidade , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Água/químicaRESUMO
In this paper, we demonstrated a highly discriminated and reliable molecular switch based on the interaction between the self-duplex of (Py)A-substituted oligodeoxyadenylate and graphene oxide in aqueous solution. This system showed a clear on/off state through the association and dissociation of (Py)A-modified oligodeoxynucleotide with graphene oxide in manipulated pH conditions, high amplitude efficiency for at least 50 cycles, and rapid response within seconds. Our molecular switch system has high reproducibility and simple operation by using pH stimulus.
Assuntos
Desoxiadenosinas/química , Grafite/química , Óxidos/química , Pirenos/química , Fluorescência , Concentração de Íons de Hidrogênio , Soluções , Água/químicaRESUMO
We report the highly improved version of quencher-free molecular beacon (QF-MB) system by using graphene oxide (GO) as an external quencher. This QF-MB/GO system provided a higher S/B ratio (31.0) relative to that (2.2) of the same system in the absence of GO, while retaining a high selectivity for fully matched over single-base-mismatched targets.
Assuntos
Corantes Fluorescentes/química , Grafite/química , Sondas de Oligonucleotídeos/química , Óxidos/química , Modelos Moleculares , Oligodesoxirribonucleotídeos/química , Espectrometria de FluorescênciaRESUMO
We synthesized five novel uridine-based cationic nucleolipids, introducing basic amino acid residues at the 5' position of uridine, through 1,3-dipolar cycloaddition, and hydrophobic alkyl moieties at the 2' and 3' positions, through carbamate linkages. Their lipoplexes delivered siRNAs efficiently to cells, in vitro, without any severe toxicity.
Assuntos
Lipídeos/química , RNA Interferente Pequeno/química , Cátions/química , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Lipídeos/farmacologia , Estrutura MolecularRESUMO
Homogeneous oligodeoxyguanylates incorporating small-molecule intercalator pyrene moieties in a 1,5 relationship form various structures of dimer, trimer, tetramer and internal hairpin form that are yellowish in color because of the intermolecular interactions between the pyrene units.
Assuntos
Substâncias Intercalantes/química , Oligodesoxirribonucleotídeos/química , Pirenos/química , Sequência de Bases , Modelos Moleculares , Estrutura Molecular , Conformação de Ácido Nucleico , Homologia de Sequência do Ácido Nucleico , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
We suggest a novel method for probing human i-motif structure based on a pi-stacking interaction between a base pair of two cytosines and a non-polar aromatic fluorophore, PyA, at the end position.
Assuntos
DNA/química , Corantes Fluorescentes/química , Sequência Rica em GC , Conformação de Ácido Nucleico , Dicroísmo Circular , DNA de Cadeia Simples/química , Desoxiadenosinas/síntese química , Desoxiadenosinas/química , Corantes Fluorescentes/síntese química , Humanos , Concentração de Íons de Hidrogênio , Oligodesoxirribonucleotídeos/química , Pirenos/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Telômero/química , Temperatura de TransiçãoRESUMO
Pyrene-modified adenosines in the dangling positions of G-rich oligodeoxynucleotides undergo pi-stacking in their G-quadruplex formation, but not in their single strands, which can be characterized by fluorescence lambda(max) changes that occur on stacking.
