Preparation, characterization, and application of a porous poly (TAIC-co-MMA-co-EDMA) monolithic column for small molecules of aromatics and Chinese herbal medicine notoginseng by HPLC

Super-adsorbent microspheres based on a triallyl isocyanurate-maleic anhydride copolymer for the removal of organic pollutants from water

Owing to the frequent occurrence of diclofenac sodium (DS) in fresh aquatic environments and its potential toxicity towards living organisms, the effective removal of DS has attracted worldwide attention. Herein, a green and efficient strategy to fabricate crosslinked microspheres with interconnected mesoporous structures and abundant adsorption active sites was developed. With this strategy, triallyl isocyanurate (TAIC)-maleic anhydride (MAH) copolymer microspheres (TMs) with a diameter of 1.19-1.35 μm were first prepared by self-stabilized precipitation (2SP) polymerization, and the TMs possess a large amount reactive anhydride groups (62.5-71.8 mol%), a specific surface area of 51.6-182.4 m² g^-1 and a mesoporous structure (average pore size: 3.4-3.8 nm). Then the TMs were further functionalized with polyethylenimine (PEI) to give rise to cationic microspheres (Cat-TMs), which showed excellent adsorption performance to DS with a rapid adsorption rate (reached equilibrium within 30 min), a very high equilibrium adsorption capacity (1421 mg g^-1) and excellent recyclability. The pseudo-second-order model and Langmuir model were a good fit for the adsorption kinetic and isotherm process, respectively. Furthermore, due to the high cation density (4.291 mmol g^-1) and excellent pH buffer capacity of Cat-TMs, the adsorption capacity can be maintained at a high level within the pH range of 6-10. The regenerated Cat-TMs showed only a slight loss (<5%) in the adsorption capacity even after 5 adsorption-desorption cycles. In short, Cat-TMs can be considered as a highly promising adsorbent for the rapid and ultra-efficient removal of anionic organic contaminants and have significant potential to be applied in wastewater treatment.

Functionalized monolithic columns: Recent advancements and their applications for high-efficiency separation and enrichment in food and medicine

The chromatographic column is the core of a high-performance liquid chromatography (HPLC) system, and must have excellent separation efficiency and selectivity. Therefore, functional modification materials for monolithic columns have been rapidly developed. This study is a systematic review of the recently reported functionalized monolithic columns. In particular, the study reviews the types of functional monomers under different modification conditions, as well as the separation and detection techniques combined with chromatography, and their development prospects. In addition, the applications of functionalized monolithic columns in food analysis, biomedicine, and the analysis of active ingredient of Chinese herbal medicines in recent years are also discussed. Also reviewed are the functionalized monolithic columns for qualitative and quantitative analysis. It provided a reference for further development and application of organic polymer monolithic columns.

Preparative isolation of maltol glycoside from Dianthus superbus and its anti-inflammatory activity in vitro

Dianthus superbus is a traditional Chinese medicine that is commonly utilized as a treatment for inflammation, pain, and immunological conditions. In this study, an anti-inflammatory maltol glycoside derived from Dianthus superbus was isolated for the first time via medium and high-pressure liquid chromatography, and at the same time, the in vitro anti-inflammatory activity of this maltol glycoside was preliminarily explored. Initially, crude samples of Dianthus superbus were preprocessed via MCI GEL® CHP20P and Spherical C18 medium-pressure chromatography, under the guidance of evaluation of in vitro anti-inflammatory activity. Fr44 was found to be the target fraction, and it was further isolated via two-dimensional reversed-phase/hydrophilic interaction liquid chromatography, yielding > 95% pure and was identified as tunicoside B. MTT assay, nitric oxide and nitric oxide synthase were used to evaluate the effects of tunicoside B on murine macrophage Raw264.7 by nitric oxide synthase assay kit, molecular docking, and western blotting. The results showed that tunicoside B did not affect the viability of cells and exhibited significant anti-inflammatory activity. As far as we know, this is the first report of tunicoside B from Dianthus superbus and the first study on the anti-inflammatory activity of tunicoside B. More importantly, the approach established in this study is expected to provide a theoretical basis for the separation and pharmacological activity study of maltol glycosides from other natural products.

A novel chromatographic separation method for rapid enrichment and isolation of novel flavonoid glycosides from Sphaerophysa salsula

Flavonoid glycosides exist widely in medicine herbs and often used as nutraceuticals because of their excellent bioactivity and low toxicity. For accurate quality control and bioactivity assessment of Sphaerophysa salsula, a rapid and productive method to isolate flavonoid glycosides is needed. Therefore, this work reports the development of a novel comprehensive strategy based on an online middle-pressure chromatography and preparative high-performance liquid chromatography for rapid enrichment and separation of flavonoid glycosides from S. salsula. First, the flavonoid glycosides were enriched using an online middle-pressure chromatographic column containing stationary middle chromatogram isolated phase. During this process, the high-volume injection of the extracting solution was realized by an empty precolumn positioned before the main chromatographic tower. Then, the compounds were separated through preparative high-performance liquid chromatography with Megress C18. As a result, one new flavonol 3-O-glycoside (2) and two known flavonol 3-O-glycosides (1, 3) were targetedly isolated from S. salsula. The content of compounds 1-3 in S. salsula was 0.09, 0.11, and 0.18 wt%, respectively. Comparing to traditional enrichment and separation methods, our technique offers significantly shorter sample pretreatment time as well as high reproducibility. We believe that our separation method has a strong potential to be used for the processing of other medicinal plants.

Fabrication of a ferrocene-based monolithic column with a network structure and its application in separation of protein and small molecules

A novel ferrocene-based monolith with a network structure was fabricated via in situ free radical polymerization using vinyl ferrocene as the co-monomer within a stainless-steel column (50 × 4.6 mm i.d.) for the separation of proteins from complex bio-samples, taking merit of the specific absorption of ferrocene to protein, including human plasma, egg white, and standard proteins. The morphology and pore size distribution indicate that the optimized monolith has a relatively uniform structure with the network. The results showed that 26 fractions were separated from human plasma, and the column efficiency of the aromatic small molecule, naphthalene, was up to 30,560 plates m^-1. The homemade monolith showed excellent selectivity for intact proteins, mainly depending on the hydrophobic chromatography mechanism of ferrocene. In addition, the electrostatic interaction and hydrogen-bond interaction were the additional interactions in the chromatographic separation owing to the sandwich structure of ferrocene present in the monolithic column.