RESUMEN
Rosa canina L. (dog rose) is a rich source of phenolic compounds that offer great hope for the prevention of chronic human diseases. Herein, wild and commercial samples of dog rose were chemically characterized with respect to their phenolic composition by liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI/MS). Furthermore, in vitro antioxidant properties and antibacterial activity of dog rose fruits and leaves hydromethanolic extracts and infusions were also evaluated. The results revealed that wild and commercial fruits of dog rose are similar in terms of l(+)-ascorbic acid, total phenolics (TPC), total flavonoids (TFC) and total phenolic acids (TPAC) content, individual phenolic constituents and antioxidant activity. Moreover, the fruits had lower levels of phenolic compounds and also revealed lower biological activity than the leaves. On the other hands, the highest content of TPC, TFC, TPAC, individual phenolic constituents, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity and FRAP (ferric reducing antioxidant power) were found in the leaf's infusions. They were also the only ones to show antibacterial activity. Overall, these finding confirmed usefulness of R. canina L. leaves and fruits as a rich source of bioactive phenolic compounds with potential use in food, pharmaceutical, and cosmetic industries.
Asunto(s)
Antioxidantes/química , Frutas/química , Fenoles/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Rosa/química , Compuestos de Bifenilo/química , Cromatografía Liquida , Cosméticos , Escherichia coli/efectos de los fármacos , Flavonoides/química , Hidroxibenzoatos/química , Pruebas de Sensibilidad Microbiana , Picratos/química , Pseudomonas aeruginosa/efectos de los fármacos , Espectrometría de Masa por Ionización de Electrospray , Staphylococcus aureus/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Streptococcus pyogenes/efectos de los fármacosRESUMEN
A simple and reliable HPLC method was developed and validated for the quality consistency evaluation of Coffea arabica commercial samples through establishing chromatographic fingerprint and simultaneous determination of bioactive constituents. In the HPLC fingerprint, thirteen common peaks were selected to assess the similarities of coffee samples of different geographical origin. A similarity analysis showed values from 0.434 to 0.950 for the analyzed samples, while quantitation of selected bioactive compounds revealed the highest content of caffeine and the lowest of p-coumaric acid and theobromine in coffee samples. Since phenolic compounds and alkaloids are commonly recognized as natural antioxidants, the antioxidant activity of coffee extracts was also evaluated. The correlation analysis and principal component analysis indicated that the combination of HPLC fingerprint and quantitative analysis can be readily utilized as a quality assessment tool for coffee and other plant products.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Coffea/química , Análisis de los Alimentos/métodos , Alcaloides/análisis , Antioxidantes/química , Cafeína/análisis , Cromatografía Líquida de Alta Presión/estadística & datos numéricos , Análisis de los Alimentos/estadística & datos numéricos , Calidad de los Alimentos , Fenoles/análisis , Análisis de Componente Principal , Reproducibilidad de los Resultados , Semillas/química , Teobromina/análisisRESUMEN
Tannins, secondary plant metabolites, possess diverse biological activities and can interact with biopolymers such as lipids or proteins. Interactions between tannins and proteins depend on the structures of both and can result in changes in protein structure and activity. Because human serum albumin is the most abundant protein in plasma and responsible for interactions with important biological compounds (e.g. bilirubin) and proper blood pressure, therefore, it is very important to investigate reactions between HSA and tannins. This paper describes the interaction between human serum albumin (HSA) and two tannins: bihexahydroxydiphenoyl-trigalloylglucose (BDTG) and 1-O-galloyl-4,6-hexahydroxydiphenoyl-ß-d-glucose (OGßDG), isolated from Geranium sanguineum and Oenothera gigas leafs, respectively. Optical (spectrofluorimetric) and chiral optical (circular dichroism) methods were used in this study. Fluorescence analysis demonstrated that OGßDG quenched HSA fluorescence more strongly than BDTG. Both OGßDG and BDTG formed complexes with albumin and caused a red shift of the fluorescence spectra but did not significantly change the protein secondary structure. Our studies clearly demonstrate that the tested tannins interact very strongly with human serum albumin (quenching constant K=88,277.26±407.04 M(-1) and K=55,552.67±583.07 M(-1) respectively for OGßDG and BDTG) in a manner depending on their chemical structure.
