ABSTRACT
Agaricus bisporus, commonly known as the button mushroom, has attracted attention for its biological properties, including antimicrobial activities. Here, we evaluated the efficacy of ethanolic and acetonic extracts from white and brown A. bisporus against different bacterial strains, including antibiotic-resistant strains. Bioautography and principal component analysis identified the most active antibacterial compounds for each of the tested bacteria and indicated the main markers responsible for the strain-specific effects. In addition, the mushroom extracts demonstrated a synergistic impact when combined with the antistaphylococcal antibiotic AFN-1252.
ABSTRACT
High-Performance Thin-Layer Chromatography (HPTLC)-radical scavenging capacity (RSC) assays are standard techniques for the separation and identification of antioxidants from complex mixtures. HPTLC coupled with DPPH· visualization of chromatograms allows for the detection of individual antioxidants. However, other HPTLC-RSC assays that recognize compounds exhibiting different mechanisms of radical-scavenging activity are rarely reported. In this study, we developed an integrated approach that combines five HPTLC-RSC assays, principal component analysis (PCA) and quantum chemical calculations to assess the antioxidant capacity of Sempervivum tectorum L. leaf extracts. Two HPTLC assays - potassium hexacyanoferrate(III) total reducing power assay (TRP) and total antioxidant capacity by phosphomolybdenum method (TAC) - were developed for the first time. The method supports a more in-depth study of the RSC of natural products, as it compares the radical scavenging fingerprints of S. tectorum leaf extracts and recognizes differences in their individual bioactive constituents. Kaempferol, kaempferol 3-O-glucoside, quercetin 3-O-glucoside, caffeic acid, and gallic acid were identified as the compounds that discriminate HPTLC-RSC assays according to their mechanism of action and capture the similarities between 20 S. tectorum samples. Additionally, DFT calculations on M06-2X/6-31+G(d,p) level were applied to map thermodynamic feasibility of hydrogen atom transfer (HAT) and single electron transfer (SET) mechanisms of the identified compounds. Based on experimental and theoretical results, a combination of HPTLC-ABTS and HPTLC-TAC assays were proposed as the optimal method for mapping the antioxidants from S. tectorum. This study represents a step forward in identifying and quantifying individual antioxidants from complex food and natural product matrices in a more rational manner.
Subject(s)
Antioxidants , Crassulaceae , Antioxidants/chemistry , Kaempferols , Chromatography, Thin Layer/methods , Plant Extracts/chemistry , ChemometricsABSTRACT
To replace common organic solvents that present inherent toxicity and have high volatility and to improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) were evaluated for the extraction of phenolic compounds from Agrimonia eupatoria. Screening of NADES efficiency was carried out based on the total phenolic and flavonoid content and radical-scavenging activity, determined by spectrophotometry, as well as phenolic compounds quantified, obtained using ultra-high-performance liquid chromatography with a diode array detector and a triple-quadrupole mass spectrometer. Increased extraction efficiency when compared with organic solvent was achieved using NADES mixtures choline chloride (ChCl):urea 1:2 and choline chloride:glycerol 1:1. Flavonol glycosides were the most abundant compounds in all extracts. The COSMO-RS model provided insights into the most important intermolecular interactions that drive the extraction process. Moreover, it could explain the extraction efficiency of flavonol glycosides using ChCl:glycerol NADES. The current article offers experimental evidence and mechanistic insights for the selection of optimal NADES to extract bioactive components from Agrimonia eupatoria.
