RESUMO
Adsorption has been explored to minimize the pollution caused by dyes. This work relates the preparation of diethylenetriamine-modified cellulose (DetaCel) by reacting phthalic anhydride-modified cellulose (PhCel) with diethylenetriamine (Deta). Materials were characterized by Elemental Analysis and results showed a degree of incorporation of 5.55⯱â¯0.02â¯mmol of nitrogen per gram of modified material. The main bands observed for DetaCel by Fourier-Transform Infrared Spectroscospy (FTIR) were attributed to CN deformation (1330â¯cm-1) and NH stretching of amide (3400â¯cm-1), while Solid State Nuclear Magnetic Resonance of 13C (13C{1H}CP-MAS NMR) showed a signal at 164.6â¯ppm characteristic of amide group. Crystallinity index (CrI) obtained by X-Ray Diffraction (XRD) was 74.99 (Cel), 58.64 (PhCel) and 46.12% (DetaCel). Adsorbent matrices were employed to remove methyl orange (MO) and eosin (EY) dyes in aqueous medium. Data obtained experimentally from kinetic study had a better fit to the pseudo-first order, thus the adsorption process occurs in monolayer, with MO adsorption capacity by Cel and DetaCel of 2.19 and 65.45â¯mgâ¯g-1, respectively. For EY adsorption by Cel and DetaCel was 1.30 and 56.69â¯mgâ¯g-1, respectively. These results suggest that DetaCel can be used as an alternative potential for removal dyes in aqueous solution.
Assuntos
Compostos Azo/química , Celulose/química , Amarelo de Eosina-(YS)/química , Purificação da Água/métodos , AdsorçãoRESUMO
An ethanol extract and different partition fractions obtained from Lippia origanoides H.B.K. were assayed for light-mediated activity against strains of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Identical assays were conducted with and without exposure to UV-A (400-315 nm) light to test for light enhanced activity. The ethanol extract and dichloromethane fraction showed light-mediated activity against the S. aureus strain, but not against the E. coli strain. The dichloromethane fraction was more active than the ethanol extract. Naringenin did not display light-mediated activity against the tested bacteria, indicating that the light-mediated antimicrobial activity of the dichloromethane fraction is not due to its major component. The results represent the first report of light-mediated antimicrobial activity of Lippia origanoides and show that its phytochemicals could be used as light-mediated antimicrobial agents.
Assuntos
Antibacterianos/química , Lippia/química , Fármacos Fotossensibilizantes/química , Extratos Vegetais/química , Raios Ultravioleta , Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Flavanonas/química , Cloreto de Metileno/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiaçãoRESUMO
Propolis is a complex matrix of chemical constituents extracted from plants and produced by bees which is used in folk medicine due to its several pharmacological properties. Its chemical composition varies according to the region where it is produced. This work has studied the antileishmanial activity and cytotoxicity of brown propolis (BP) originating from the semi-arid region of Piauí, Brazil. The BP showed significant inhibition of the Leishmania amazonensis promastigotes growth as well as being effective in reducing infection of murine macrophages and the number of internalised amastigotes in these cells. The dichloromethane fraction was the most active and showed the best selectivity index. The studied samples presented good activity and the fractioning improved the antileishmanial activity without an increase in the cytotoxicity against mammalian cells. Therefore, BP is a potential source for development of apitherapeutic products for the treatment of leishmaniasis.
Assuntos
Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Própole/química , Própole/farmacologia , Animais , Antiprotozoários/química , Brasil , Cromatografia Gasosa-Espectrometria de Massas , Concentração Inibidora 50 , Macrófagos Peritoneais/efeitos dos fármacosRESUMO
Platonia insignis Mart., a native species of the Brazilian Amazon more commonly known as bacuri, is a member of the Clusiaceae family. In this study, we evaluated the chemical composition and the antioxidant and toxicity activities of the dichloromethane and ethyl acetate fractions from P. insignis seed ethanolic extract using different experimental models. Our results demonstrate in vitro antioxidant effects, by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt and 1,1-diphenyl-2-picryl-hydrazyl assays, as well as in vivo effects in antioxidant-defective Saccharomyces cerevisiae strains to both fractions. Toxicity was evaluated against the micro-crustaceous Artemia salina Leach. and promastigote Leishmania amazonensis. The dichloromethane fraction was the most active fraction evaluated on A. salina and promastigote L. amazonensis (IC(50) = 24.89 µg/mL and 2.84 µg/mL, respectively). In addition, a slight cytotoxicity was observed in mammalian V79 cells using ethyl acetate and dichloromethane fractions with MTT assays. Both fractions displayed genotoxicity up to 25 µg/mL (dichloromethane) and 10 µg/mL (ethyl acetate) in V79 cells, as evaluated by the alkaline comet assay. Thus, in this study, we demonstrate for the first time that ethyl acetate and dichloromethane fractions from P. insignis seeds display antioxidant effects, a toxic effect against A. salina and L. amazonensis and induce genotoxicity in V79 mammalian cells. The observed activities can be attributed to the phenolic compounds present in these fractions and to the presence of xanthones (alpha- and gamma-mangostin).