RESUMO
Cytotoxicity-guided phytochemical analysis on the extract of Lysimachia heterogenea Klatt led to the isolation of 3beta,16beta-12-oleanene-3,16,23,28-tetrol (1) and its four new oligosaccharidic derivatives heterogenosides A, B, C, and D (2-5). Their structural elucidation was mainly based on NMR and mass spectral data. The time course experimental results indicated that unlike the likely lysis activity of heterogenosides B-D, heterogenoside A showed a significantly time-dependent cytotoxicity.
Assuntos
Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/toxicidade , Primulaceae/química , Saponinas/toxicidade , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ácido Oleanólico/química , Ácido Oleanólico/isolamento & purificação , Saponinas/química , Saponinas/isolamento & purificação , Relação Estrutura-AtividadeRESUMO
Gram-scale synthesis of a silver-triazolato framework - {[Ag8(tz)6](NO3)2·6H2O}n (1-NO3; tz-=3,5-diphenyl-1,2,4-triazolate) - has been achieved, enabling the systematic investigation of its anion-exchange properties. Our experimental results show that the anion-exchange pattern of 1-NO3 conforms to the so-called Hofmeister bias, which has been correlated to the hydrophobic nature of the MOF pores, and can be understood by considering the difference between the hydration energies of the exchanging anions. Furthermore, 1-NO3 displays a fast, efficient, and reversible adsorption of HCrO4- (via anion-exchange) from Cr(VI)-containing aqueous solution (Qmax=37.0 Cr mg/g, 303K), rendering it a promising prototype of a recyclable MOF for Cr(VI) removal.