RESUMO
In the present work dual beam thermal lens technique is used for studying the solvent dependency on the quantum efficiency of a novel dye used for biomedical applications. The role of solvent in the absolute fluorescence quantum yield of 4-[(4-Aminophenyl)-(4-imino-1-cyclohexa-2, 5- dienylidene) methyl] aniline hydrochloride is studied using thermal lens technique. It is observed that the variation in solvents and its concentration results considerable variations in the fluorescence quantum yield. These variations are due to the non-radiative relaxation of the absorbed energy and because of the different solvent properties. The highest quantum yield of the dye is observed in the polar protic solvent-water.
Assuntos
Compostos de Anilina/química , Corantes Fluorescentes/química , Teoria Quântica , Solventes/química , Espectrometria de Fluorescência/métodos , Fluorescência , Água/químicaRESUMO
Nano structured noble metals have very important applications in diverse fields such as photovoltaics, catalysis, electronic and magnetic devices, etc. In the present work, the application of dual beam thermal lens technique is employed for the determination of the absolute fluorescence quantum yield of the triaminotriphenylmethane dye, basic fuchsin in the presence of silver sol is studied. Silver sol is prepared by femtosecond laser ablation. It is observed that the presence of silver sol decreases the fluorescence quantum efficiency. The observed results are in line with the conclusion that the reduction in quantum yield in the quenching region is essentially due to the non-radiative relaxation of the absorbed energy. It is also observed that the presence of silver sol enhances the thermal lens signal which makes its detection easier at any concentration.
Assuntos
Benzopiranos/química , Fluorescência , Lasers , Nanopartículas Metálicas/química , Prata/químicaRESUMO
Essential oil from Cymbopogon nardus was evaluated for activity against Trypanosoma brucei brucei BS221 (IC50 = 0.31 ± 0.03 µg/mL) and cytotoxic effect on normal kidney (Vero) cells (IC50 = >100 µg/mL). The crude essential oil was subjected to various chromatography techniques afforded active sub fractions with antitrypanosomal activity; F4 (IC50 = 0.61 ± 0.06 µg/mL), F6 (IC50= 0.73 ± 0.33 µg/mL), F7 (IC50 = 1.15 ± 0 µg/mL) and F8 (IC50 = 1.11 ± 0.01 µg/mL). These active fractions did not exhibit any toxic effects against Vero cell lines and the chemical profiles investigation indicated presence of α-and γ-eudesmol, elemol, α-cadinol and eugenol by GC/MS analysis.
Assuntos
Antiprotozoários/farmacologia , Cymbopogon/química , Óleos Voláteis/farmacologia , Extratos Vegetais/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Animais , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Antiprotozoários/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Cromatografia Gasosa-Espectrometria de Massas , Concentração Inibidora 50 , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/toxicidade , Testes de Sensibilidade Parasitária , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Células VeroRESUMO
Essential oil from Cymbopogon nardus was evaluated for activity against Trypanosoma brucei brucei BS221 (IC50 = 0.31 ± 0.03 μg/mL) and cytotoxic effect on normal kidney (Vero) cells (IC50 = >100 μg/mL). The crude essential oil was subjected to various chromatography techniques afforded active sub fractions with antitrypanosomal activity; F4 (IC50 = 0.61 ± 0.06 μg/mL), F6 (IC50= 0.73 ± 0.33 μg/mL), F7 (IC50 = 1.15 ± 0 μg/mL) and F8 (IC50 = 1.11 ± 0.01 μg/mL). These active fractions did not exhibit any toxic effects against Vero cell lines and the chemical profiles investigation indicated presence of α-and γ-eudesmol, elemol, α-cadinol and eugenol by GC/MS analysis.
