RESUMO
Aspergillus flavus is a filamentous, saprophytic fungus, whose colonization occurs mainly in cereal grains and oilseeds once harvested. Under certain conditions, it could produce mycotoxins called aflatoxins, known as powerful human liver carcinogens. The aim of the present study was to describe the antifungal activity of extracts of Peltophorum dubium, a species from northern Argentina (Oriental Chaco), against A. flavus. The antifungal activities of different collection sites are reported. The extracts exhibited a minimum inhibitory concentration of 125 µg/mL, and the differences between the treatments and the inoculum control were 11 mm of P. dubium A and 10 mm of P. dubium F in colony growth. Moreover, hyphae treated with the extracts stained blue with Evans blue showed alterations in the membrane and/or cell wall, allowing the dye income. Bio-guided fractionation, High Performance Liquid Chromatography diode array ultraviolet/visible (HPLC UV/VIS DAD), and Ultra-High Performance Liquid Chromatography Electrospray Ionization Mass Spectrometry (UPLC ESI-MS) analyses were conducted to characterize the extracts and their active fractions. The HPLC UV/VIS DAD analysis allowed the determination of the presence of flavonoids (flavonols and flavones), coumarins, terpenes, and steroids. UPLC ESI/MS analysis of active fractions revealed the presence of Kaempferol, Apigenin, Naringenin, Chrysin and Daidzein.
RESUMO
The present work deals with the development and validation of a novel dual CD-MEKC system for the systematic flavonoid fingerprinting of Ligaria cuneifolia (R. et P.) Tiegh.-Loranthaceae-extracts. The BGE consisted of 20 mM pH 8.3 borate buffer, 50 mM SDS, a dual CD system based on the combination of 5 mM ß-CD and 2% w/v S-ß-CD, and 10% v/v methanol. The proposed method has been successfully applied to the comparative analysis of extracts from aerial parts and different hosts, geographical areas, and extraction procedures in order to establish the flavonoid fingerprint of L. cuneifolia. The method was validated according to international guidelines. LOD and LOQ, intra and interday precision, and linearity were determined for catechin, epicatechin, procyanidin B2, rutin, quercetin-3-O-glucoside, quercetin-3-O-xyloside, quercetin-3-O-rhamnoside, quercetin-3-O-arabinofuranoside, quercetin-3-O-arabinopyranoside, and quercetin. The CD-MEKC methodology emerges as a suitable alternative to the traditional HPLC for quality control, fingerprinting, and standardization of L. cuneifolia extracts from different sources.
