Determination of aucubin by supramolecular solvent-based dispersive liquid-liquid microextraction and UPLC-MS/MS: Application to a pharmacokinetic study in rats with type 1 diabetes

Extraction and Purification of Aucubin from Eucommia ulmoides Seed Draff in Natural Deep Eutectic Solvents Using Macroporous Resins

Aucubin (AU) is an active ingredient that exerts strong antioxidant and anti-inflammatory effects in the treatment of several diseases. In order to improve the efficiency of resource utilization of traditional biomass waste, Eucommia ulmoides seed-draff (EUSD) waste biomass was used as the raw material, and a series of deep eutectic solvents were selected to evaluate the extraction efficiency of aucubin from EUSD. A response surface experiment was designed based on a single-factor experiment to optimize the extract conditions. The results showed that the best conditions for aucubin extraction were an HBD-HBA ratio of 2.18, a liquid-solid ratio of 46.92 mL/g, a water percentage of 37.95%, a temperature of 321.03 K, and an extraction time of 59.55 min. The maximum amount of aucubin was 156.4 mg/g, which was consistent with the theoretical value (156.8 mg/g). Then, the performance of 12 resins for adsorption and desorption was contrasted. The results revealed that HPD950 resin exhibited the best performance, with an adsorption capacity of 95.2% and a desorption capacity of 94.3%. Additionally, the pseudo-second-order model provided the best match to the kinetics data, the Langmuir model provided the best fit to the isotherm data, and adsorption was a beneficial, spontaneous, exothermic, and physical process. In the recyclability test, the HPD950 resin had great potential and excellent sustainability in aucubin recovery. In the antioxidant activity study, the aucubin extract exerted a strong antioxidant ability with scavenging capabilities for four free radicals. Furthermore, the antifungal activity study found that the aucubin extract exhibited a good antifungal effect against 5 tested pathogens. The research results can provide a theoretical basis for the extraction of high-value components from waste biomass by deep eutectic solvent and a certain application value for the development and utilization of natural aucubin products.

Recent Advances in Dispersive Liquid-Liquid Microextraction for Pharmaceutical Analysis

Sample clean-up and pre-concentration are critical components of pharmaceutical analysis. The dispersive liquid-liquid microextraction (DLLME) technique is widely recognized as the most effective approach for enhancing overall detection sensitivity. While various DLLME modes have been advanced in pharmaceutical analysis, there need to be more discussions on pre-concentration techniques specifically developed for this field. This review presents a comprehensive overview of the different DLLME modes used in pharmaceutical analysis from 2017 to May 2023. The review covers the principles of DLLME, the factors affecting microextraction, the selected applications of different DLLME modes, and their advantages and disadvantages. Additionally, it focuses on multi-extraction strategies employed for pharmaceutical analysis.

Aucubin administration suppresses STING signaling and mitigated high-fat diet-induced atherosclerosis and steatohepatosis in LDL receptor deficient mice

The rising obesity epidemic in developed countries is associated with many chronic inflammatory diseases including atherosclerosis and nonalcoholic steatohepatitis (NASH). Consuming aucubin may benefit health by suppressing inflammation. Herein, we studied the effects of aucubin consumption on atherosclerosis and NASH progression induced by high-fat diet (HFD) in LDL receptor deficient (LDLr^-/-) mice. Adult LDLr^-/- mice were fed with HFD for 12 weeks and received oral administration of aucubin for the last 6 weeks. Aucubin did not alter body weight or dyslipidemia, but lowered hyperglycemia and mitigated HFD-induced atherosclerosis and hepatic impairments in LDLr^-/- mice. Aucubin administration inhibited HFD-induced inflammation and downregulated mRNA and protein expression of stimulator of IFN genes (STING) in both aortas and livers of LDLr^-/- mice. In vitro, aucubin suppressed mitochondrial DNA (mtDNA)-induced activation of STING/NFκB pathway and downregulated gene expression of pro-inflammatory cytokines in cultured bone marrow-derived macrophages (BMDM). Furthermore, aucubin enhanced microRNA-181a-5p (miR-181a-5p) levels in both aortas and livers of LDLr^-/- mice. Importantly, miR-181a-5p mimicked the inhibitory effect of aucubin on STING/NFκB pathway and inflammation in BMDM. In conclusion, aucubin consumption attenuated HFD-induced atherosclerosis and NASH progression in LDLr^-/- mice, possibly through modulating miR-181a-5p/STING and inhibiting inflammation.

Miniaturized green sample preparation approaches for pharmaceutical analysis

The development of green sample preparation procedures is an extremely important research field in which more and more applications are constantly being proposed in different areas, including pharmaceutical analysis. This review article is aimed at providing a general overview of the development of miniaturized green analytical sample preparation procedures in the pharmaceutical analysis field, with special focus on the works published between January 2017 and July 2021. Particular attention has been paid to the application of environmentally friendly solvents and sorbents as well as nanomaterials or high extraction capacity sorbents in which the solvent volumes and reagents amounts are drastically reduced, with their subsequent advantages from the sustainability point of view.

Synergistic Combination of Facile Thiol-Maleimide Derivatization and Supramolecular Solvent-Based Microextraction for UHPLC-HRMS Analysis of Glutathione in Biofluids

Glutathione (GSH) is the most abundant non-protein thiol in biofluids, enabling diverse physiological functions. Among the proposed methods for GSH detection, ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry (HRMS) has the advantages of high sensitivity and efficiency. In this study, a novel analytical method was developed for the determination of GSH using supramolecular solvent (SUPRAS)-based dispersive liquid–liquid microextraction (DLLME) and UHPLC–HRMS. N-Laurylmaleimide was dissolved in tetrahydrofuran, which served three functions: 1) precipitate the proteins present in the biofluid sample, 2) provide a reaction environment for derivatization, and 3) enable the use of SUPRAS as the dispersing agent. Critical parameters were optimized based on single factor testing and response surface methodology. The established method was validated in terms of linearity, accuracy, precision, and successful quantitative analysis of GSH in saliva, urine, and plasma samples. Experimental results showed that SUPRAS as an extraction solvent was particularly suitable for the extraction of GSH from complex matrices. The current study provides a useful tool for accurate measurements of GSH concentrations, which could potentially be used for clinical diagnostics.

Sustainable green solvents for microextraction techniques: Recent developments and applications

The development and application of alternative green solvents in analytical techniques consist of trends in sample preparation, since this subject represents an important step toward sustainability in experimental procedures. This review is focused on the main theoretical aspects related to deep eutectic solvents (DES), switchable hydrophilicity solvents (SHS) and supramolecular solvents (SUPRAS). Recent applications are highlighted, particularly for the extraction of different analytes from environmental, biological and food matrices. Moreover, novel configurations are emphasized, aiming for efficient, automated and high-throughput procedures. This review also provides some critical points regarding the use of these solvents and their green aspects.