RESUMO
This work presents a simply new method for in situ synthesis of gold nanoparticles (AuNPs) using the biodegradable polysaccharides. A novel composite of lactose/alginate (Lac/Alg) could be prepared easily through ionotropic gelation mechanism which can reduce in situ gold ions into AuNPs. Lactose plays a crucial role as a reducing reagent which are demonstrated by FTIR analysis. The crystalline structure of AuNPs with a mean size of 10 nm has been confirmed by analysis techniques. The nanocomposite powder possesses highly catalytic performance for degradation of contaminants including 4-nitrophenol, methyl orange, rhodamine 6 G and rhodamine B. The dispersion solution of AuNPs@Lac/Alg was used as an effective probe for highly selective detection of Fe3+ ions. The detection mechanism replies on the aggregation of nanocomposite in the presence of Fe3+ ions. LOD value was found to be 0.8 µM in a linear range of 2.0-80.0 µM.
Assuntos
Alginatos/química , Compostos Férricos/análise , Lactose/química , Nanopartículas Metálicas/química , Nanocompostos/química , Biodegradação Ambiental , Catálise , Colorimetria/métodos , Corantes/isolamento & purificação , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica , Nanocompostos/ultraestrutura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
A series of O-alkyl and O-acyl flavonoid derivatives was synthesized in high efficiency. Alkylation and acylation of 5-hydroxyflavonoids showed that the low reactivity hydroxyl group, 5-OH, well reacted with strong reagents whereas with weaker reagents, the different products were obtained dependently on structural characteristic of ring C of respective flavonoid. In order to evaluate anti-inflammatory activity, all compounds were tested for in vitro inhibition of bovine serum albumin denaturation and in vivo inhibition of carrageenan-induced mouse paw edema. Among them, the compounds 3, 3b, 4b and 4c demonstrated more effective anti-inflammatory activity than standard drugs (diclofenac sodium and ketoprofen) in both tests. Meanwhile, the flavonoids 2, 2c, 3a and 4b displayed anti-proliferative activity against MCF-7 cell lines. Triacetyl derivative of hesperetin 4b inducing degradation of DNA in MCF-7 cells was observed.
