Search Results (121)

Flavonoids, widely present in Artemisia argyi (AA), offer potential health benefits but are limited in food applications because of their bitter taste, inadequate absorption, and stability. Casein micelles encapsulation can enhance the flavonoid absorption, stability, and bioactivity. In this study, Artemisia argyi flavonoids (AAFs) were extracted using ultrasound-assisted extraction (UAE) to optimize the process. The glycosylation reaction between casein (CN) micelles and oat β-glucan (OBG) was employed to improve AAF’s emulsifying stability, sustained release during digestion, and cellular uptake. The maximum glycosylation degree of 32.33% was achieved at a CN-to-OBG ratio of 1:2, 120 min browning time, and 95 °C temperature. This glycosylated delivery system enhanced the emulsifying properties of the AAFs, digestive sustained release, and cellular uptake, showing potential as a cross-linking material for fat-soluble substances and medicines. Full article

To enhance the signal intensity of kynurenines, which are present at trace concentrations in biological fluids, a novel analytical approach was developed, combining pressure-assisted electrokinetic injection (PAEKI) with a mixed micelle system based on sodium dodecyl sulfate (SDS) and Brij-35. The method was applied to key compounds of the kynurenine pathway, including L-tryptophan, kynurenine, 3-hydroxykynurenine, and kynurenic acid, as well as to the aromatic amino acids (AAs) L-tyrosine and L-phenylalanine. PAEKI was performed by electrokinetic injection for 2 min at −6.5 kV (reversed polarity) and 0.5 psi (3.45 kPa) using a fused silica capillary (50 cm in length, 50 µm inner diameter). The background electrolyte (BGE) consisted of 20 mM Na₂B₄O₇ (pH 9.2), 2 mM Brij-35, 20 mM SDS, and 20% (v/v) methanol (MeOH). The limit of detection (LOD) using a diode array detector (DAD) was 1.2 ng/mL for kynurenine and ranged from 1.5 to 3.0 ng/mL for the other analytes. The application of PAEKI in conjunction with micellar electrokinetic capillary chromatography (MEKC) and solid-phase extraction (SPE) of artificial urine samples resulted in a 146-fold increase in signal intensity for kynurenines compared to that observed using the hydrodynamic injection (HDI) mode. The developed method demonstrates strong potential for determining kynurenine pathway metabolites in complex biological matrices. Full article

Objectives: Nanosized polymeric micelles (PMs) with an average size of about 80 nm and moderately positive ζ potential, based on an amphiphilic poly(4-methyl-piperazin-1-yl)-propenone)-b-polylactide (PMPP-PLA) block copolymer, were prepared. They were used as platforms for the delivery of bioactive sesquiterpene lactones from Inula helenium L. root extract. Methods: The PMs were characterized with good encapsulation efficiency as a maximum value of 72% was reached at a polymer-to-extract mass ratio of 10:1. The loaded micelles exhibited good colloidal stability. An in vitro release was performed showing a burst release profile. The biocompatibility of the resulting PMs was confirmed by assessing their cytotoxic effect on human keratinocytes in vitro by colorimetric assay and flow cytometry. Results: The systems demonstrated the capability to reduce the biomass of pre-formed Gram-positive and Gram-negative bacterial biofilms. Conclusions: The obtained data clearly determine a trend for a strong combined effect between the PMs and the root extract, distinguishing them with an excellent anti-biofilm potential and prospects for future applications in medical practice. Full article

A novel, environmentally friendly cloud point extraction (CPE) method based on 4-nitrocatechol (H₂L) was developed in this study to spectrophotometrically determine trace vanadium. This method utilizes a mixed micelle-mediated system comprising a cationic surfactant (cetylpyridinium chloride, CPC) and a nonionic surfactant (Triton X-114). In contrast to conventional CPE, the present approach does not employ centrifugation to separate the two phases. The distinguishing characteristic of the extracted species, (CP⁺)[V^VOL₂], is its ability to absorb light across the entire visible spectrum. The measurement at 670 nm, where the complex displays a local maximum, is advantageous for two primary reasons. Firstly, the blank exhibits virtually no absorption, a property that engenders stable and reproducible results. Secondly, selectivity is high because almost all other metal complexes have absorption bands at shorter wavelengths. The proposed method has the following characteristics: a linear range of 2–305 ng mL⁻¹, a limit of detection of 0.6 ng mL⁻¹, a molar absorptivity coefficient of 1.22 × 10⁵ M⁻¹ cm⁻¹, a Sandell sensitivity of 0.42 ng cm⁻², and a blue applicability grade index (BAGI) of 67.5. Its efficacy was demonstrated in the analysis of mineral water, a spent vanadium-containing catalyst, and a dietary supplement. Full article

Nanotechnology offers alternative approaches to the discovery of anticancer drugs. Hydrophobic bioactive components can be included in the cores of amphiphilic nanocarriers, which leads to the formation of a water-dispersible product with improved bioavailability, facilitated excretion, and reduced systemic toxicity in the treated organisms. This study was aimed at the formation of polymer nanocarriers, loaded with anticancer drug precursor podophylotoxin (PPT) or PPT-containing juniper leaf extracts, seeking to study their antineoplastic activity in A-431 epidermoid carcinoma cells and HaCaT normal keratinocytes. The amphiphilic, biodegradable, and biocompatible MPEG-b-PLA diblock copolymer was self-assembled in aqueous media into nanosized particles, whose physicochemical characteristics were studied by dynamic light scattering, transmission electron microscopy, and other methods. High encapsulation efficiency was determined for the PPT component-loaded micelles. DNA fragmentation, cell cycle arrest, nuclear condensation, membrane lipid order assessment, reactive oxygen species, and apoptosis induction by the loaded nanocarriers in A-431 or HaCaT cells were analyzed by the comet assay, FACS, Hoechst DNA staining, Laurdan generalized polarization, and other methods. As a result of various cellular processes induced by the PPT component-loaded nanoparticles, effector caspase-3 and caspase-7 activation showed selectivity towards tumor cells compared to the normal cells. The newly obtained PPT-containing nanoparticles have applications as potential drugs in the prospective nanomedicine. Full article

A novel method for the spectrophotometric determination of trace amounts of molybdenum has been developed. This method utilizes a centrifuge-less cloud point extraction (CL-CPE) in a mixed micellar (MM) system containing a nonionic surfactant (Triton X-114) and an ionic liquid (Aliquat^® 336, A336). The chromophore chelating reagent employed was 4-nitrocatechol (4NC, H₂L). This work marks its first application as a CPE reagent. Under the optimal conditions, Mo(VI) forms a yellow ternary complex with 4NC and A336, which can be represented by the formula (A336⁺)₂[MoO₂L₂]. The method possesses the following characteristics: limit of detection (LOD) of 3.2 ng mL⁻¹, linear range of 10.8–580 ng/mL, absorption maximum of 435 nm, molar absorptivity coefficient of 3.34 × 10⁵ L mol⁻¹ cm⁻¹, and Sandell’s sensitivity of 0.29 ng cm⁻². The method has been successfully employed for the determination of molybdenum in reference standard steel samples, bottled mineral water, and a molybdenum-containing dietary supplement. Full article

Microbial biosurfactants have become increasingly attractive as promising ingredients for environmentally friendly products. The reasons for this are their generally good performance and biodegradability, low toxicity, production from renewable raw materials, and benefits for the environment perceived by consumers. In this study, we investigated the chemical structure and properties of a novel glycolipid from a new biosurfactant-producing strain, Rouxiella badensis DSM 100043^T. Bioreactor cultivation was performed at 30 °C and pH 7.0 for 28 h using 15 g/L glycerol as a carbon source. The glycolipid was successfully purified from the ethyl acetate extract of the supernatant using medium pressure liquid chromatography (MPLC). The structure of the glycolipid was determined by one- and two-dimensional (¹H and ¹³C) nuclear magnetic resonance (NMR) and confirmed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI/MS). NMR analysis revealed the hydrophilic moiety as a glucose molecule and the hydrophobic moieties as 3-hydroxy-5-dodecenoic acid and 3-hydroxydecanoic acid, which are linked with the glucose by ester bonds at the C2 and C3 positions. Surface tension measurement with tensiometry indicated that the glucose–lipid could reduce the surface tension of water from 72.05 mN/m to 24.59 mN/m at 25 °C with a very low critical micelle concentration (CMC) of 5.69 mg/L. Moreover, the glucose–lipid demonstrated very good stability in maintaining emulsification activity at pH 2–8, a temperature of up to 100 °C, and a NaCl concentration of up to 15%. These results show that R. badensis DSM 100043^T produced a novel glycolipid biosurfactant with excellent surface-active properties, making it promising for further research or industrial applications. Full article

Several strategies, including UV detection with a diode array detector (DAD), laser-induced fluorescence (LIF), derivatization reactions, the use of micelles in the separation buffer, as well as online preconcentration techniques based on pressure-assisted electrokinetic injection (PAEKI), and offline preconcentration using solid-phase extraction (SPE) columns containing quaternary amine groups with a chloride counterion, were investigated for the simultaneous separation and signal amplification of free thyroid hormones (THs) in biological samples. Moreover, a sensitive method for the quantification of THs in selected biological samples using micellar electrokinetic capillary chromatography with LIF detection (MEKC-LIF) was developed. The THs present in biological samples (L-tyrosine, T2, T3, rT3, T4, and DIT) were successfully separated in less than 10 min. The analytes were separated following a derivatization procedure with fluorescein isothiocyanate isomer I (FITC). A background electrolyte (BGE) composed of 20 mM sodium tetraborate (Na₂B₄O₇) and 20 mM sodium dodecyl sulphate (SDS) was employed. Key validation parameters such as linearity, precision, limits of detection (LOD), and limits of quantification (LOQ) were determined. The use of PAEKI for the electrophoretic determination of free THs demonstrates significant potential for monitoring these hormones in real urine samples due to its high sensitivity and efficiency. Full article

Background: D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), an amphiphilic derivative of natural vitamin E, functions as both a drug efflux inhibitor and a protector against enzymatic degradation and has been widely incorporated into nano-formulations for drug design and delivery. Objective: This systematic review evaluates TPGS-based organic nanocarriers, emphasizing their potential to enhance bioavailability of active compounds which include drugs and phytochemicals, improve pharmacokinetic profiles, and optimize therapeutic outcomes, eventually overcoming the limitations of conventional oral active compounds delivery. Search strategy: Data collection was carried out by entering key terms (TPGS) AND (Micelle OR Liposome OR Nanoparticle OR Nanotube OR Dendrimer OR Niosome OR Nanosuspension OR Nanomicelle OR Nanocrystal OR Nanosphere OR Nanocapsule) AND (Oral Bioavailability) into the Scopus database. Inclusion criteria: Full-text articles published in English and relevant to TPGS, which featured organic materials, utilized an oral administration route, and included pharmacokinetic study, were included to the final review. Data extraction and analysis: Data selection was conducted by two review authors and subsequently approved by all other authors through a consensus process. The outcomes of the included studies were reviewed and categorized based on the types of nanocarriers. Results: An initial search of the database yielded 173 records. After screening by title and abstract, 52 full-text articles were analyzed. A total of 21 papers were excluded while 31 papers were used in this review. Conclusions: This review concludes that TPGS-based organic nanocarriers are able to enhance the bioavailability of various active compounds, including several phytochemicals, leveraging TPGS’s amphiphilic nature, inhibition of efflux transporters, protection against degradation, and stabilization properties. Despite using the same excipient, variability in particle size, zeta potential, and encapsulation efficiency among nanocarriers indicates the need for tailored formulations. A comprehensive approach involving the development and standardized comparison of diverse TPGS-incorporated active compound formulations is essential to identify the optimal TPGS-based nanocarrier for improving a particular active compound’s bioavailability. Full article

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization of the tea saponin extraction procedure was conducted by using the response surface method to increase the yield. Study results indicated that the maximum yield of tea saponin was 69.81 mg/g under the optimum conditions of an enzyme concentration of 0.67%, a solvent-to-material ratio of 16.82 mL/g, an extraction temperature of 58.14 °C and an extraction time of 1.89 h. The surface activity experimental study results indicated that the critical micelle concentration of tea saponin was 0.5 g/L at 30 °C, and the lowest surface tension was 39.61 mN/m. The surface tension and CMC of tea saponin remained basically unchanged between 30 °C to 60 °C. When the pH of the solution was slightly acidic, the surface tension of tea saponin decreased significantly, while the CMC remained almost unchanged. Tea saponin has good salt and hard water resistance, and its surface tension decreases to a certain extent in both saltwater and hard water. The foam volume of tea saponin can reach 490 mL, with a half-life of 2350 s, and the foam is relatively stable. The combination of tea saponin and other surfactants has a certain synergistic effect. The critical micelle concentration of its complex system with the natural surfactant rhamnolipids can increase by 69.23%, and the surface tension can be reduced to a minimum of 22.56 mN/m. Moreover, by using the proposed method, the foam performance and stability of the system have been improved to a certain extent. This has significant practical significance for fully utilizing and developing waste camellia dried cake resources. Full article

Quantification of free and bound carotenoids in pigmented fruit and vegetable matrices has previously been challenging due to carotenoid instability, degradation during extraction, and the prevalence of predominant carotenoid esters. The aim of the present study was to develop an optimized extraction procedure that minimises the loss of free and bound carotenoids by utilising a combination of extraction solutions, followed by an improved saponification process. A mixture of hexane, dichloromethane, ethanol and water achieved the highest extraction efficiency (>97%) from the chili/capsicum matrix. The study also addressed the previously unexplained loss of carotenoids during saponification by adding phosphate buffer to the sample–extract mixture, which prevented soap micelle formation. Additionally, the duration and temperature of the saponification procedure and pH of the final extraction solution were further optimised to achieve a higher total carotenoid recovery. A total of 48 free and bound carotenoids were identified in the capsicum fruit samples using UHPLC-DAD-MS/MS. The total carotenoid content within six bell pepper and chili fruits ranged between 1.63 (green bell capsicum) and 32.08 mg/100 g fresh weight (sweet red baby capsicum). The current methodology potentially could be used in a broad range of different carotenoid-containing matrices and commodities. Full article

Worldwide energy needs are growing, requiring new extraction techniques for crude oil from old reservoirs. However, conventional chemicals face difficulties when exposed to harsh reservoir environments such as solubility in high saline water and heat stability under harsh reservoir environments. This study investigates the potential of newly synthesized polymeric ionic liquids (PILs) as alternative options. A series of PILs was synthesized and characterized by using NMR and FTIR techniques. It was noticed that a PIL without ethoxy groups exhibits precipitation and therefore is not suitable for oilfield applications. However, the incorporation of ethoxy groups in the chemical structure of PILs leads to excellent solubility in low to high salinity brine. The solubility of the synthesized PILs in formation water, seawater, and deionized water, as well as their thermal stability using thermal gravimetric analysis (TGA), was assessed. In addition, the surface properties, including critical micelle concentration (cmc), surface tension (γ_cmc), surface excess concentration (Γ_max), minimal surface area per molecule (A_min), free adsorption energy (ΔG°_ads), and free micellization energy (ΔG°_mic), were also evaluated. The findings revealed that adding ethoxy groups in PILs led to a drop in Γ_max and an increase in A_min, suggesting reduced monolayer compactness at the air/water interface. The synthesized PILs demonstrated remarkable solubility, heat stability, and resistance to salt, rendering them well-suited for oilfield applications under challenging reservoir environments. Full article

Fluorescent labeling of membrane proteins is essential for exploring their functions, signaling pathways, interaction partners, and structural dynamics. Organic fluorophores are commonly used for this purpose due to their favorable photophysical properties and photostability. However, a persistent challenge is the inaccessibility of the surface-exposed cysteine residues required for site-specific labeling, as these residues often become sequestered within detergent micelles during protein extraction. To address this limitation, we developed an approach based on polymer-encapsulated nanodiscs that preserves the protein’s native-like lipid-bilayer environment while ensuring the accessibility of surface-exposed cysteine residues. In this method, His-tagged proteins embedded in native nanodiscs are retained on a nickel affinity column, allowing for simultaneous purification and labeling by adding fluorescent dyes. This versatile technique was demonstrated with two challenging-to-label membrane proteins, the potassium channel KvAP and the urea channel HpUreI, for which detergent-based labeling had failed. This opens new possibilities for studying a wide range of fluorescently labeled membrane proteins in near-native states, advancing applications in biophysics, structural biology, and drug discovery. Full article

Cloud point extraction is a sample preparation technique that involves using surfactants that are not harmful to the environment. It is based on micelle formation in which the extracted compound is encapsulated in the hydrophobic core of the micelles, which are the extracting agent. The most commonly used surfactants are nonionic. The others are anionic, cationic, or zwitterionic. The effectiveness of cloud point extraction might be enhanced by the addition of neutral salts, the application of proper pH, as well as acidic conditions and temperature. This sample preparation technique may be applied to extract analytes from the following matrices, such as biological and environmental samples. Cloud point extraction may be combined with various analytical techniques and detectors such as HPLC-UV, HPLC-MS, HPLC-FLD, inductively coupled plasma–optical emission spectrometry, gas chromatography, and flame atomic absorption spectrometry. When it is combined with electrothermal atomic absorption spectrometry, the limit of quantitation is low—even of the order of ng/L. The recovery of the analyte may reach the value of 100%. Full article

As a kind of bioactive component in the rhizome of natural plant Curcuma longa L. (turmeric), curcumin is almost insoluble in water at neutral and acidic pH, which limits its further utilization and development. At the same time, traditional extraction and separation processes typically require the use of a large number of organic solvents. Ionic liquids (ILs) are organic molten salts with melting points below 100 °C. When an ionic liquid exists in a liquid state at or near room temperature, it is referred to as a room-temperature ionic liquid (RTIL). They have a temperature range, good physical and chemical stability, and good structural designability. They have a strong solubilization enhancement effect for many organic compounds. This study first explored the molecular forms of curcumin in ionic liquid aqueous solutions and the intermolecular interactions between curcumin and ionic liquids using spectral analysis and computational chemistry methods; furthermore, using an ionic liquid aqueous solution as an extraction agent, curcumin-like substances (curcuminoids) were extracted from turmeric powders under ultrasound assisted conditions, revealing the relationship between the structure of the ionic liquid and the extraction efficiency. After that, a kinetic study was conducted for the extraction of curcuminoids from turmeric powders, using second-order kinetics fitting to obtain the rate constant and initial extraction rate during the extraction process. Finally, the comparison with a ComplexGAPI tool and antioxidant experiment was performed on the extraction by using ionic liquids and traditional solvent. The full results can provide reference for the design of IL extractants and their application for natural products. Full article