RESUMO
A new nor-cardenolide, named toxicarioside H (1), was isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Its structure was elucidated on the basis of HRFAB-MS and spectroscopic techniques (IR, UV, 1D and 2D NMR). Compound 1 showed significant cytotoxicity against K562, SGC-7901, SMMC-7721, and HeLa cell lines in vitro by MTT method.
Assuntos
Antiaris/química , Cardenolídeos/isolamento & purificação , Cardenolídeos/farmacologia , Glicosídeos Cardíacos/isolamento & purificação , Glicosídeos Cardíacos/farmacologia , Látex/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância MagnéticaRESUMO
A series of N-acylhydrazones were synthesised and found to be "turn-on" fluorescent chemodosimeters for Cu(2+). Among the tested transition metal ions such as Cu(2+), Pb(2+), Zn(2+), Cd(2+), Hg(2+), and Ni(2+), a prominent fluorescence enhancement of up to 1000-fold was only observed for Cu(2+) in acetonitrile (CH(3)CN). This was indicated by an onset of unprecedented structured emission. Detailed experiments established that the highly Cu(2+) selective fluorescence enhancement resulted from an oxidative cyclization by Cu(2+)of the originally nonfluorescent N-acylhydrazones into highly fluorescent rigid 1,3,4-oxadiazoles, n-dope type blocks in optoelectronic materials. The chemodosimeters can be applied to sense Cu(2+) at nM levels in CH(3)CN and sub-microM levels in neutral aqueous environments, despite a slower response in the latter case. It is expected that these redox-based chemodosimeters might be of general applicability.
RESUMO
Two new cardenolides, toxicarioside F (1) and toxicarioside G (2), were isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Their structures were elucidated on the basis of spectral data and chemical evidence. Compounds 1 and 2 showed significant cytotoxicity against K562, SGC-7901, SMMC-7721, and HeLa cell lines in vitro by the MTT method.
Assuntos
Antiaris/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Glicosídeos Cardíacos/isolamento & purificação , Glicosídeos Cardíacos/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Glicosídeos Cardíacos/química , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Células HeLa , Humanos , Células K562 , Látex/químicaRESUMO
N-Methyl-N-methoxycarbonylmethyl-1-aminonaphthalene (MMAN) and N,N-dimethoxycarbonylmethyl-1-aminonaphthalene (DCAN) were synthesized and their fluorescence and absorption spectra in solvents of varied polarity were investigated and compared to those of 1-dimethylaminonaphthylene (DMAN). The data were discussed in terms of the N-substitution effects on the internal conversion (IC). Results showed that the IC was enhanced when the N-methyl group in DMAN was replaced by N-CH2CO2CH3.
Assuntos
1-Naftilamina/análogos & derivados , 1-Naftilamina/síntese química , 1-Naftilamina/química , Estrutura Molecular , Teoria Quântica , Solventes , Espectrometria de Fluorescência , EspectrofotometriaRESUMO
A dual fluorescent charge transfer fluoroionophore (1) with its ionophore incorporated in the electron acceptor was developed and was found to show a highly selective fluorescent response to Cu2+ with a dramatic enhancement in its CT emission.
RESUMO
[structure: see text] A neutral receptor with a rigid hydrazine spacer, N-p-(dimethylamino)benzamido-N'-phenylthiourea, was prepared, and its dual fluorescence in acetonitrile was found to show response toward the presence of anions such as AcO(-), H(2)PO(4)(-), HSO(4)(-), Br(-), Cl(-), F(-), and ClO(4)(-) with high sensitivity and selectivity toward AcO(-).
