ABSTRACT Size‐exclusion chromatography (SEC) is one of the most widely used techniques for the isolation of extracellular vesicles (EVs) from biological samples due to its simplicity, high recovery, and effective removal of soluble contaminants. In this study, we quantitatively evaluated the efficiency of plasma protein removal during EV isolation from human plasma using commercially available SEC columns. SEC fractions were characterized according to the International Society for Extracellular Vesicles guidelines. In addition, a capillary electrophoresis method was developed for the targeted quantification of human serum albumin and human serum gamma‐globulins, enabling detailed assessment of their residual contamination.
ABSTRACT Tartary buckwheat ( Fagopyrum tataricum ) is a nutrient‐rich cereal abundant in flavonoids, including rutin, with excellent antioxidant, anti‐inflammatory, and other health‐promoting properties. Cultivated for its grain‐like seed, the vegetative tissues of buckwheat are considered feedstock or agricultural waste. In this study, we found that the rutin content in vegetative tissues such as leaves and stems is significantly higher than that in grains and seed hulls. A simple and efficient extraction approach was developed to extract rutin from Tartary buckwheat leaves via a mass spectrometry‐directed procedure. The purified rutin yield was 67.85 mg/g with a purity exceeding 98%. The subsequent one‐step hydrolysis produced quercetin with a purity above 99.5% and a yield of 49.25%. Compared with other plant materials and published extraction methods, this strategy features shorter operation time, mild conditions, higher purity, and maximizes the use of Tartary buckwheat leaf waste. This study provides a green, efficient, and feasible scheme for the large‐scale preparation of high‐purity phytochemicals from waste materials produced from agricultural operations.
ABSTRACT Occupational exposure to softwood dust has been linked to upper and lower respiratory symptoms, eye irritation, contact dermatitis, and an elevated risk of sino‐nasal cancer. Resin acids, naturally occurring extractives that vary by tree species, are suspected contributors to these health effects, yet existing analytical methods have struggled to resolve key isomeric acids. This study aimed to develop a rapid, robust, sensitive, and selective liquid chromatography‐mass spectrometry (LC‐MS) method for the determination of individual resin acids in personal wood dust samples from Norwegian sawmills. Six commercially available reversed‐phase columns and multiple mobile phase systems were evaluated for chromatographic performance. Optimal separation was achieved with a C18‐amide column (150 × 2.1 mm, 3 µm) using an isocratic mobile phase of acetonitrile and 30 mM ammonium acetate at pH 6.30, 0.3 mL min −1 with a 15‐min runtime. Optimal detection employed atmospheric pressure chemical ionization (APCI) in negative mode. This method was applied to six personal sawmill dust extracts, enabling determination of five resin acids (abietic acid, dehydroabietic acid, levopimaric acid, and the coeluting isopimaric and pimaric acids) and one oxidation product (7‐oxodehydroabietic acid). The LC‐APCI‐MS method improves separation of resin acids over prior LC approaches, with minimal sample preparation, and is suitable for routine monitoring of occupational exposure to resin acids in wood dust.
ABSTRACT Parabens are widely used as antimicrobial preservatives in food, cosmetics, and industrial products due to their stability and practicality. Long‐term exposure to parabens may pose risks to human health and ecosystems. Dispersive micro‐solid‐phase extraction (D‐µSPE) is a fast and effective sample preparation method used for cleaning complex matrices and enriching analytes, ensuring reliable analytical results. To enhance analytical selectivity and sensitivity, it is essential to design sorbents with high surface area and selective adsorption properties for target analytes. Zeolite imidazole framework‐derived porous carbon materials, ZnO@SiO 2 @C/Ni, were used as the adsorbent in this study, featuring a yolk‐shell porous structure with high surface area, chemical stability, and efficient adsorption performance for parabens extraction from food samples. To characterize the ZnO@SiO 2 @C/Ni composite, various characterization techniques were employed. In this study, D‐µSPE was integrated with high‐performance liquid chromatography coupled with ultraviolet detection. A series of experimental parameters were systematically evaluated to enhance the extraction performance of parabens, including sample pH (6), extraction duration (20 min), elution solvent type and volume (methanol, 600 µL), breakthrough volume (20 mL), sorbent mass (10 mg), desorption time (4 min), and salt amount (in the absence of salt). Following optimization, the analytical method demonstrated strong linearity for methylparaben (MP), ethylparaben (EP), and propylparaben (PP) across a concentration range of 0.1–800 µg L −1 . The method also achieved low limits of detection of 0.03 µg L −1 for each analyte, confirming its suitability for trace‐level analysis. Also, relative standard deviations ranged from 2.3% to 6.2%, indicating consistent precision across replicate measurements. Extraction recoveries varied between 46.8% and 82.6%, and coefficients of determination for MP ( R 2 = 0.9967), EP ( R 2 = 0.9907), and PP ( R 2 = 0.9970) confirmed excellent linearity and reliability of quantification. These findings support the method's suitability for trace‐level detection of parabens in fruit juice matrix.
ABSTRACT The pharmacodynamic material basis and mechanism of action of Bawei Chenxiang Powder (BWCP), a commonly prescribed Tibetan medicinal formulation for cardiovascular diseases, remain largely unclear. To address this issue, we established an angiotensin II type 1 receptor (AT 1 R) chromatographic method coupled with mass spectrometry for the systematic screening and identification of AT 1 R‐targeting bioactive compounds from BWCP for the first time. Five active components—myristicin, dehydrocostus lactone, naringenin, pinocembrin, and costunolide—were successfully identified as AT 1 R ligands from BWCP. Frontal analysis was employed to determine the binding constants of these compounds to AT 1 R, yielding values of (1.09 ± 0.15) × 10 4 M − 1 for myristicin, (1.59 ± 0.02) × 10 4 M − 1 for dehydrocostus lactone, (2.24 ± 0.50) × 10 4 M − 1 for naringenin, (6.09 ± 0.05) × 10 4 M − 1 for pinocembrin, and (2.59 ± 0.35) × 10 4 M − 1 for costunolide. Competitive displacement assays revealed that all five compounds share the same binding site with the clinically used AT 1 R antagonist valsartan, a finding further corroborated by molecular docking, which confirmed the affinity ranking and the overlapping binding pocket with valsartan. Collectively, this study demonstrates that AT 1 R receptor chromatography, based on specific molecular recognition, enables efficient screening and separation of target ligands from complex natural product matrices, thereby providing a novel and powerful technological platform for bioactive constituent research in ethnomedicines.
