Molecularly imprinted polymers for the selective extraction of tiliroside from the flowers of Edgeworthia gardneri (wall.) Meisn

Recent advances in methods of extraction, pre-concentration, purification, identification, and quantification of kaempferol

As a naturally widely-occurring dietary, cosmetic, and therapeutic flavonoid, kaempferol has gained much consideration for its nutritional and pharmaceutical properties in recent years. Although there have been performed a high number of studies associated with different aspects of kaempferol's analytical investigations, the lack of a comprehensive summary of the various methods and other plant sources that have been reported for this compound is being felt, especially for many biological applications. This study, aimed to provide a detailed compilation consisting of sources (plant species) and analytical information that was precisely related to the natural flavonoid (kaempferol). There is a trend in analytical research that supports the application of modern eco-friendly instruments and methods. In conclusion, ultrasound-assisted extraction (UAE) is the most general advanced method used widely today for the extraction of kaempferol. During recent years, there is an increasing tendency towards the identification of kaempferol by different methods.

Ultrasound-assisted solid phase microextraction-HPLC method based on Fe3O4@SiO2-NH2-molecularly imprinted polymer magnetic nano-sorbent for rapid and efficient extraction of harmaline from Peganum harmala extract

In the present study, a magnetic molecularly imprinted polymer (MMIP) was synthesized for the extraction of harmaline from Peganum harmala by dispersive solid-phase microextraction (DSPME). The MMIP for selective and intelligent extraction of harmaline with excellent functionality and high selectivity was synthesized using the sol-gel method with functionalized superparamagnetic core-shell nanoparticles, ethylene glycol dimethacrylate (EDMA) as a cross-linker, methacrylic acid (MAA) as a functional monomer, and 2,2-azobisisobutyronitrile (AIBN) as a porogen. To study the properties and morphology of the coated polymer, FT-IR spectroscopy, FESEM, TEM images, and VSM were used. The DSPME-HPLC-UV equipment was used to quantify and analyze the data obtained from harmaline extraction. In this research, the efficiency of the synthesized polymer in harmaline extraction was modeled and optimized using the response surface methodology based on central composite design (RSM-CCD). In addition, for modeling the isotherm of harmaline sorption by the MMIP, Langmuir and Freundlich isotherm equations were used. The obtained results showed that the extraction of harmaline with the MMIP was well described with Freundlich isotherm. The results of the validation of the method showed that the measurement of harmaline in the concentration range of 1.0-4000 ng mL^-1 followed a linear relationship (R² = 9986.0). Moreover, the accuracy or repeatability index (% RSD) was determined to be < 10, and the LOQ and LOD values were 0.526 and 0.158 ng mL^-1, respectively. The results of this study showed that the DSPME technique by using the synthesized MMIP as an effective sorbent with high efficiency and capacity could be utilized for pre-concentration and extraction of harmaline from real and complex samples.

Selective separation and purification of polydatin by molecularly imprinted polymers from the extract of Polygoni Cuspidati Rhizoma et Radix, rats' plasma and urine

Molecularly imprinted polymers (MIPs) based on polydatin were prepared by precipitation polymerization method. Synthesis process of MIPs was optimized by discussion of functional monomers, porogens and the molar ratio of template- functional monomer-cross linker. Then, MIPs were prepared with polydatin as the template, 4-vinyl pyridine as the functional monomer, ethylene glycol dimethyl acrylate as the cross linker, acetonitrile as the porogen and the molar ratio of template-monomer-cross linker at 1:10:20. Scanning electron microscopy and Fourier transform infrared spectrometer were used to inspect macroscale and chemical bond of MIPs. Adsorption capability and selectivity of MIPs to polydatin were investigated by carrying out the static, dynamic and selective experiments. The results showed MIPs performed high adsorption ability and selectivity to polydatin, indicating MIPs could be used to separate and enrich polydatin from the complex systems. Finally, MIPs were applied as the adsorbent for isolation and purification of polydatin from the extract of Polygoni Cuspidati Rhizoma et Radix, rats' plasma and urine samples. MIPs were successfully used to separate polydatin from the Polygoni Cuspidati Rhizoma et Radix and recovery ranged from 89.2% to 91.6%. The maximum concentration of polydatin in rats' plasma and urine samples was 2.84 ± 0.0748 µg mL^-1 and 2.64 ± 0.485 µg mL^-1, respectively. Moreover, to compare with the MIPs method, organic solvent methods were used to analyze the polydatin in rats' plasma and urine samples. The results illustrated MIPs method was effective and selective for enrichment of polydatin from the medicinal plants and biological samples.

Computer simulation aided preparation of molecularly imprinted polymers for separation of bilobalide

In this study, the preparation of molecularly imprinted polymers for bilobalide (BBMIPs) was successfully achieved by bulk polymerization with methacrylamide (MAM), trimethylolpropane triacrylate (TMPTA), and acetonitrile (ACN) as functional monomer, cross-linker, and solvent, respectively. After Gaussian software simulation and single factor experiments, the prepared MIPs with a molar ratio of 1:4:15 for BB-MAM-TMPTA were systematically characterized. The hydrogen bonding interaction between BB and MAM was confirmed by a combination of FTIR and NMR analysis. Thermal gravimetric analysis results displayed that MIPs have excellent thermal stability under high temperature. Additionally, the average pore size and surface area of MIPs were found to be higher than those of NIPs through nitrogen adsorption results. The results of static adsorption and kinetic adsorption suggested that the adsorption equilibrium concentration was 0.6 mg/mL and the equilibrium time was 5 h, and the Langmuir and pseudo-second-order kinetic models were proven to fit with static and kinetic adsorption behaviors, respectively. Meanwhile, the selective adsorption study revealed that MIPs show high adsorption and great selectivity towards BB in comparison with other substances having similarly structure. MIPs also possessed a good performance on reusability, maintaining a high recovery rate after being reused 5 times. The application experiment further indicated that MIPs can effectively separate BB from low purity samples. Therefore, the prepared MIPs had a great potential for BB separation.

Tiliroside is a new potential therapeutic drug for osteoporosis in mice

Osteoporosis is a class of metabolic bone disease caused by complexed ramifications. Overactivation of osteoclasts due to a sudden decreased estrogen level plays a pivotal role for postmenopausal women suffering from osteoporosis. Therefore, inhibiting osteoclast formation and function has become a major direction for the treatment of osteoporosis. Tiliroside (Tle) is a salutary dietary glycosidic flavonoid extracted from Oriental Paperbush flower, which has been reported to have an anti-inflammation effect. However, whether Tle affects the osteoclastogenesis and bone resorption remains unknown. Herein, we demonstrate that Tle prevents bone loss in ovariectomy in mice and inhibits osteoclast differentiation and bone resorption stimulated by receptor activator of nuclear factor-κB ligand (RANKL) in vitro. Molecular mechanism studies reveal that Tle reduces RANKL-induced activation of mitogen-activated protein kinase and T-cell nuclear factor 1 pathways, and osteoclastogenesis-related marker gene expression, including cathepsin K (Ctsk), matrix metalloproteinase 9, tartrate-resistant acid phosphatase (Acp5), and Atp6v0d2. Our research indicates that Tle suppresses osteoclastogenesis and bone loss by downregulating the RANKL-mediated signaling protein activation and expression. In addition, Tle inhibits intracellular reactive oxygen species generation which is related to the formation of osteoclasts. Therefore, Tle might serve as a potential drug for osteolytic disease such as osteoporosis.

A Review on the Dietary Flavonoid Tiliroside

Among flavonoid derivatives, tiliroside is a flavonoid contained in several edible plants or specific plant parts (fruits, leaves, or roots). These parts are often widely used as both food and medicines, in the treatment of various ailments and, in some cases, as food supplements. Considering the easy access to many publications concerning tiliroside and the lack of a review that summarizes the current progress in studies on its safety, efficacy, and presence in the plant kingdom, we present here a review paper on tiliroside and its principal derivatives. The paper also highlights the basic knowledge regarding this molecule, its derivatives, and the analytical approaches used for extraction and quantification, as well as reports on the biological activities against different key enzymes linked to various human diseases. The reported information is also devoted to highlighting the concept "learn from nature to discover new products," particularly in the development of new drugs, food supplements, and nutraceuticals, starting from a natural lead compound such as tiliroside and improving its biological activities (and selectivities) against a specific target for therapeutic purposes.

Molecularly imprinted covalent organic polymers for the selective extraction of benzoxazole fluorescent whitening agents from food samples

Molecularly imprinted covalent organic polymers were constructed by an imine-linking reaction between 1,3,5-triformylphloroglucinol and 2,6-diaminopyridine and used for the selective solid-phase extraction of benzoxazole fluorescent whitening agents from food samples. Binding experiments showed that imprinting sites on molecularly imprinted polymers had higher selectivity for targets compared with those of the corresponding non-imprinted polymers. Parameters affecting the solid-phase extraction procedure were examined. Under optimal conditions, actual samples were treated and the eluent was analyzed with high-performance liquid chromatography with diode-array detection. The results showed that the established method has a wide linearity, satisfactory detection limits and quantification limits, and acceptable recoveries. Thus, this developed method possesses the practical potential for the selective determination of benzoxazole fluorescent whitening agents in complex food samples.