The samples (HEDF, Mt-OH, and Ac-OEt) were diluted in ethanol and water (1: 1) and the standard substance, ascorbic acid, was diluted in water.
In 96-well microtiter plate, we added 9 [micro]L of the samples (HEDF, Mt-OH, and Ac-OEt); 27 [micro]L of water; and 270 [micro]L of the FRAP solution.
The samples (HEDF, Mt-OH, and Ac-OEt) were weighed and solubilized initially in dimethyl sulfoxide (DMSO) and diluted at 1024 [micro]g/mL using sterile distilled water (test solution).
The chromatographic profile of HEDF demonstrated the presence of caffeic acid and rutin as major compounds (33.17 [+ or -] 0.03 mg/g and 20.05 [+ or -] 0.01 mg/g, resp.) while gallic acid (5.29 [+ or -] 0.01 mg/g) and catechin (5.31 [+ or -] 0.01 mg/g) were the least abundant [6].
The content of total phenols and flavonoids was higher in Ac-OEt fraction (657.05 mg/EAG/g and 120.9 mg EQ/g, resp.), followed by Mt-OH fraction (289.33 mg/EAG/g and 76.26 mg EQ/g, resp.) and HEDF (231.26 mg EAG/g and 87.57 mg EQ/g, resp.).
The in vitro antioxidant potential of crude extract (HEDF) and fractions of D.
furfuracea (HEDF) and methanolic (Mt-OH) and ethyl acetate (Ac-OEt) fractions was tested against standard strains of C.
In a previously published study by our group, the crude extract (HEDF) was demonstrated to present alkaloids in its phytochemical constitution [6].
furfuracea (HEDF) and its methanolic (Mt-OH) and ethyl acetate (Ac-OEt) fractions have an important antioxidant activity (in vitro) when compared to other natural compounds.
Abbreviations HEDF: Hydroethanolic extract of Duguetia furfuracea Mt-OH: Methanolic fractions of Duguetia furfuracea Ac-OEt: Acetate fractions of Duguetia furfuracea HPLC DAD: High performance liquid chromatography with diode array DPPH: 2,2-Diphenyl-1-picrylhydrazyl FRAP: Ferric reducing antioxidant power.
Caption: Figure 1: Elution profiles of high performance liquid chromatography analysis: (a) HEDF (modified from [6]), (b) methanolic fraction (MtOH) and (c) ethyl acetate (Ac-OEt).
