RESUMO
Two new triterpenes mayteneri A (1), mayteneri B (2), and seven known compounds (3-9) were isolated from stems of Maytenus hookeri Loes. The chemical structures of compounds 1 and 2 were established by 1D, 2D NMR, HRESIMS analysis, and calculating electronic circular dichroism (ECD). The structures of known compounds 3-9 were determined by comparison of their spectral with those reported. Compounds 4-7 showed significant inhibitory activity for NLRP3 inflammasome, with the IC50 values of 2.36-3.44 µM.
Assuntos
Maytenus , Ácido Oleanólico , Estrutura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Maytenus/química , Triterpenos/química , Triterpenos/farmacologia , Triterpenos/isolamento & purificação , Caules de Planta/química , Animais , Camundongos , Inflamassomos/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidoresRESUMO
A new ruthenium(II) complex [Ru(Happip)(3)](ClO(4))(2) {Happip=2-(4-(ß-D-allopyranoside)phenyl)imidazo[4,5-f][1,10]phenanthroline} was synthesized and characterized by elemental analysis, (1)H NMR and matrix-assisted laser desorption ionization mass spectrometry. Calf-thymus DNA-binding properties were studied by DNA viscosity measurements and spectroscopic methods of UV-visible (UV-vis) absorption and luminescence titrations, steady-state emission quenching, DNA competitive binding with ethidium bromide and DNA melting experiments, indicating that the complex partially intercalates into the DNA with a large binding constant greater than 10(6)M(-1). The pH effects on UV-vis absorption and emission spectra of the complex were studied, demonstrating that the complex acted as an excellent pH-induced "on-off-on" luminescence switch with large on-off intensity ratios of 88 and 50 with one of luminescence on/off switching actions occurring in near-physiological pH region (pK(a2)=7.33). The DNA photocleaving properties of [Ru(Happip)(3)](2+) were also studied and compared with those of [Ru(bpy)(2)(Happip)](2+) and [Ru(bpy)(2)(Hpip)](2+){bpy=2,2'-bipyridine, Hpip=2-(4-phenyl)imidazo[4,5-f][1,10]phenanthroline}.
Assuntos
Complexos de Coordenação/síntese química , Glicosídeos/química , Substâncias Intercalantes/síntese química , Rutênio/química , 2,2'-Dipiridil/análogos & derivados , Ligação Competitiva , DNA/química , Etídio/química , Concentração de Íons de Hidrogênio , Cinética , Medições Luminescentes , Espectroscopia de Ressonância Magnética , Fenantrolinas/química , Fotólise , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Raios UltravioletaRESUMO
A new ruthenium(II) complex grafted with beta-d-allopyranoside, Ru(bpy)(2)(Happip)(ClO(4))(2) (where bpy = 2,2'-bipyridine; Happip = 2-(4-(beta-d-allopyranoside)phenyl)imidazo[4,5-f][1,10]phenanthroline), has been synthesized and characterized by elemental analysis, (1)H NMR spectroscopy, and mass spectrometry. The acid-base properties of the complex have been studied by UV-visible and luminescence spectrophotometric pH titrations, and ground- and excited-state ionization constants have been derived. The Ru(II) complex functions as a DNA intercalator as revealed by UV-visible and emission titrations, salt effects, steady-state emission quenching by [Fe(CN)(6)](4-), DNA competitive binding with ethidium bromide, DNA melting experiment, and viscosity measurements.
