Molecularly imprinted polymer-specific solid-phase extraction for the determination of 4-hydroxy-2(3H)benzoxazolone isolated from Acanthus ilicifolius Linnaeus using high-performance liquid chromatography-tandem mass spectrometry

Development of magnetic molecularly imprinted polymers for selective extraction of Benzoxazolinone-type alkaloids from acanthus plants

Benzoxazolinone-type alkaloids found in Acanthus ebracteatus and Acanthus ilicifolius Linnaeus possess various beneficial properties, such as antileishmanial, antipyretic, analgesic, antibacterial, and antioxidant effects. In this study, we employed a surface imprinting technique on nanomaterials. We utilized functionalized Fe3O4@SiO2NH2 as a scaffold, with 2-benzoxazolinone and 2H-1,4-benzoxazin-3(4H)-one serving as dual templates, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, and 2,2-azodiisobutyric nitrile (AIBN) as the initiator. Prior to polymerization, we screened functional monomers using ultraviolet (UV) spectroscopy. The resulting magnetic surface molecular imprinting polymer (Fe3O4@SiO2@MIP) was thoroughly characterized using Fourier transform infrared spectrometry (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). We also conducted assessments of its adsorption isotherms, dynamics, and selective binding capabilities. Our findings indicate that the MIPs exhibited exceptional selective recognition performance. Through meticulous screening and optimization of extraction and separation conditions, we established an LC‒MS/MS method based on magnetic solid-phase extraction technology. The method exhibited a recovery range of 78.80-106.99 % (RSD, 0.46-3.31 %) for 2-benzoxazolinone, with a limit of detection (LOD) and limit of quantification (LOQ) of 2.85 and 9.00 μg L-1, respectively. For 2H-1,4-benzoxazin-3(4H)-one, the method yielded a recovery range of 84.75-103.53 % (RSD, 0.07-5.96 %), with an LOD and LOQ of 3.60 and 12.60 μg L-1, respectively, in real samples. The resulting Fe3O4@SiO2@MIP demonstrated a high capacity for class-specific adsorption.

Identification and Quantification of Selected Benzoxazinoids and Phenolics in Germinated Spelt (Triticum spelta)

In this study, we investigated the effects of germination on the secondary metabolite composition in spelt grains. Germination significantly increased the content of various metabolites in free and bound forms. Benzoxazinoids were the most important compounds in the free fraction of the 96 h germinated grains (MBOA content as the predominant compound was 277.61 ± 15.29 µg/g DW). The majority of phenolic acids were present in the bound fraction, with trans-ferulic acid as the main component, reaching 753.27 ± 95.87 µg/g DW. The often neglected cis-isomers of phenolic acids accounted for about 20% of the total phenolic acids. High levels of apigenin di-C-glycosides were found in spelt grains, and the schaftoside content was most affected by germination, increasing threefold. The accumulation of secondary metabolites significantly increased the antioxidant activity of germinated spelt. According to the results of this study, the content of most bioactive compounds was highest in spelt grains after 96 h of germination. These data suggest that germinated spelt could potentially be valuable for the production of functional foods.

An Integrated Strategy for Investigating Antioxidants from Ribes himalense Royle ex Decne and Their Potential Target Proteins

Natural products have been used extensively around the world for many years as therapeutic, prophylactic, and health-promotive agents. Ribes himalense Royle ex Decne, a plant used in traditional Tibetan medicine, has been demonstrated to have significant antioxidant and anti-inflammatory properties. However, the material basis of its medicinal effects has not been sufficiently explored. In this study, we established an integrated strategy by online HPLC-1,1-diphenyl-2-picrylhydrazyl, medium-pressure liquid chromatography, and HPLC to achieve online detection and separation of antioxidants in Ribes himalense extracts. Finally, four antioxidants with quercetin as the parent nucleus were obtained, namely, Quercetin-3-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside, Quercetin-3-O-β-D-xylopyranosyl(1-2)-β-D-glucopyranoside, Quercetin-3-O-β-D-glucopyranoside, and Quercetin-3-O-β-D-galactoside. Until now, the four antioxidants in Ribes himalense have not been reported in other literatures. Meanwhile, the free-radical-scavenging ability of them was evaluated by DPPH assay, and potential antioxidant target proteins were explored using molecular docking. In conclusion, this research provides insights into the active compounds in Ribes himalense which will facilitate the advancement of deeper studies on it. Moreover, such an integrated chromatographic strategy could be a strong driver for more efficient and scientific use of other natural products in the food and pharmaceutical industries.