Pyridinium ionic liquid-based liquid-solid extraction of inorganic and organic iodine from Laminaria

Iodine identification in major edible seaweed Kappaphycus alvarezii and establishment of an iodine reduction method for its protein extract for utilization as a protein source

Kappaphycus alvarezii is the most widely cultivated seaweed globally. The use of the protein contained in K. alvarezii as an alternative protein source seems to be an effective countermeasure against the protein crisis. Here, we identified the iodine chemical species in K. alvarezii and developed an iodine reduction method. We used various fractionation methods and showed that almost all the iodine in the K. alvarezii alkali extract is present as an iodinated protein, and reducing the amount of iodine per protein was difficult. Subsequently, an iodine reduction method was established to cleave the covalent bonds between the protein and iodine, and we could successfully reduce the amount of iodine per protein by approximately half.

High-sensitivity liquid chromatography-tandem mass spectrometry quantitative for alkyl imidazolium ionic liquids in human serum: Advancing biomonitoring of human exposure concerns

Alkyl imidazolium ionic liquids (Cn[MIM]), initially heralded as eco-friendly green solvents for diverse industrial applications, have increasingly been recognized fortheir biodegradability challenges and multiple biotoxicity. Despite potential health risks, research into the effects of Cn[MIM] on human health remains scarce, particularly regarding their detection in biological serum samples. This study validated a matrix-matched calibration quantitative method that utilizes solid-phase extraction (SPE) coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was used to analyze the presence of 10 ionic liquids (ILs) with varying alkyl carbon chain lengths (C2-C12) across 300 human serum samples. Efficient separation was achieved using optimized SPE conditions and a BEH C18 column with an appropriate mobile phase. Results demonstrated a strong linear relationship (0.05-100 ng/mL; R2 = 0.995-0.999), with detection and quantification limits with detection and quantification limits ranging from 0.001 to 0.107 ng/mL and 0.003-0.355 ng/mL, respectively. Intraday and inter-day precisions were 0.85-6.99 % and 1.50-7.46 %, with recoveries between 82 and 113 %. The validated method detected C6MIM in 19 % of samples and C8MIM in 8.3 % of samples, with concentrations ranging from 0.02 to 111.70 μg/L and 0.09-16.99 μg/L, respectively, suggesting a potential risk of human exposure. This underscores the importance of robust detection methods in monitoring environmental and human health impacts of alkyl imidazolium compounds.

Characterization of halogen species in seaweeds from the Antarctic using a multi-technique approach

BACKGROUND

Despite the recognized importance, the determination of halogens in Antarctic seaweeds remains understudied. Limited research exists due to challenges associated with sample preparation, and reliable analytical techniques for this type of analysis. Therefore, further investigations are necessary to bridge this knowledge gap and gain a comprehensive understanding of halogen metabolism in Antarctic seaweeds.

METHODS

In this study, seaweeds from the coast of the Antarctic continent were characterized concerning the total content of halogens and their species. For this purpose, different sample preparation methods, based on extraction and combustion, combining highly selective and sensitive chromatographic and spectrometric multi-technique approaches were used.

RESULTS

By using optimized methods, it was possible to determine total halogens content, the distribution of bromine and iodine in different classes of species (lipids, water-soluble, proteins, carbohydrates, and residue), as well as the identification of iodinated amino acids (MIT and DIT) in ten brown and red seaweeds. Bromate and iodate were not detected in the samples, which presented only bromide and iodide species in their composition. Additionally, unknown bromine and iodine species were observed in different extracts evaluated. Furthermore, 25 halogenated polyphenols were identified in seaweeds, of which only four were already reported in the literature.

CONCLUSION

The results obtained in this study comprise unprecedented data in the literature on species of halogens present in seaweeds from the Antarctic environment.

Preparation and application of an imidazolium-based poly (ionic liquid) functionalized silica sorbent for solid-phase extraction of parabens from food samples

In this work, an imidazolium-based poly (ionic liquid) (poly(1-octyl-3-vinyl- imidazolium naphthalene sulfonate)) functionalized silica (poly(C8VIm+NapSO3-) @SiO2) was successfully prepared for the determination of parabens in food samples. The prepared poly(C8VIm+NapSO3-)@SiO2 was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectrogram (XPS) and Scanning electron microscopy (SEM). The simulation calculation results indicated that the suitable binding energies were between the polymeric ionic liquids and parabens, and the main interactions for extraction were hydrogen bonding, electrostatic and π-π stacking interactions. In addition, compared with commercial extraction materials, the prepared poly(C8VIm+NapSO3-)@SiO2 sorbent showed comparable or even better extraction performance towards parabens. The effective parameters were optimized by a combination of the univariate method and Box-Behnken design (BBD). Under the optimum conditions, coupled with high performance liquid chromatography (HPLC), wide linear ranges (1.0-800 μg L-1), good linearity (R2 ≥ 0.9997) and low limits of detection (0.1 μg L-1) were obtained. In addition, the intra-day and inter-day relative standard deviations (RSDs) were all lower than 6.3%. Moreover, the proposed method was successfully used for the determination of parabens in food samples and satisfactory recoveries in the range of 76.9-97.4% were obtained. The results indicated that the proposed method had good sensitivity, accuracy and precision for the detection of parabens in food samples.

Use of ionic liquids for extraction separation and concentration of iodide ions in brine samples

Iodine in natural salt waters such as iodine-rich underground brine generally exists as iodide ions, and to extract iodide ions, it is necessary to oxidize them to nonpolar iodine molecules. In this study, we report that iodide ions in natural brine containing high concentrations of chloride ions can be quantitatively extracted without oxidation by extraction using ionic liquids. Extraction with the ionic liquids trihexyltetradecylphosphonium chloride and trioctyl ammonium chloride was found to be able to enrich trace amounts of iodide in brine samples up to 40- and 100-fold, respectively. The selectivity coefficients for I^- over Cl^- determined in this study clearly show that the ionic liquids have much higher I^-/Cl^- selectivity than typical strongly basic anion exchangers. Extraction with trihexyltetradecylphosphonium chloride was applicable as a preconcentration method for iodine determination by XRF analysis. Iodide ions extracted with trioctyl ammonium chloride were quantitatively stripped with an aqueous alkaline solution. These results indicate that ionic liquid extraction is useful for the separation and concentration of iodide from brines.

Identification of natural product 3, 5-diiodotyrosine as APOBEC3B inhibitor to prevent somatic mutation accumulation and cancer progression

BACKGROUND

The development of cancer is largely dependent on the accumulation of somatic mutations, indicating the potential to develop cancer chemoprevention agents targeting mutation drivers. However, ideal cancer chemoprevention agents that can effectively inhibit the mutation drivers have not been identified yet.

METHODS

The somatic mutation signatures and expression analyses of APOBEC3B were performed in patient with pan-cancer. The computer-aided screening and skeleton-based searching were performed to identify natural products that can inhibit the activity of APOBEC3B. 4-nitroquinoline-1-oxide (4-NQO)-induced spontaneous esophageal squamous cell carcinoma (ESCC) and azoxymethane/dextran sulfate sodium (AOM/DSS)-induced spontaneous colon cancer mouse models were conducted to investigate the influences of APOBEC3B inhibitor on the prevention of somatic mutation accumulation and cancer progression.

RESULTS

Here, we discovered that the cytidine deaminase APOBEC3B correlated somatic mutations were widely observed in a variety of cancers, and its overexpression indicated poor survival. SMC247 (3, 5-diiodotyrosine), as a source of kelp iodine without side effects, could strongly bind APOBEC3B (K_D=65 nM) and effectively inhibit its deaminase activity (IC₅₀=1.69 µM). Interestingly, 3, 5-diiodotyrosine could significantly reduce the clusters of mutations, prevent the precancerous lesion progression, and prolong the survival in 4-NQO-induced spontaneous ESCC and AOM/DSS-induced spontaneous colon cancer mouse models. Furthermore, 3, 5-diiodotyrosine could reduce colitis, increase the proportion and function of T lymphocytes via IL-15 in tumor microenvironment. The synergistic cancer prevention effects were observed when 3, 5-diiodotyrosine combined with PD-1/PD-L1 blockade.

CONCLUSIONS

This is the first prove-of-concept study to elucidate that the natural product 3, 5-diiodotyrosine could prevent somatic mutation accumulation and cancer progression through inhibiting the enzymatic activity of APOBEC3B. In addition, 3, 5-diiodotyrosine could reduce the colitis and increase the infiltration and function of T lymphocytes via IL-15 in tumor microenvironment. 3, 5-diiodotyrosine combined with PD-1/PD-L1 blockade could elicit synergistic cancer prevention effects, indicating a novel strategy for both prevent the somatic mutation accumulation and the immune-suppressive microenvironment exacerbation.

Micellization and thermodynamics study of ester functionalized picoline-based ionic liquid surfactants in water

A novel series of picoline-based ionic liquid surfactants, N-alkyoxycarbonyl-3-picoline bromides [C _n Empy][Br] (n = 10, 12, 14), have been synthesized. The thermal stability, aggregation behavior and surface activity of the synthetic ionic liquid surfactants were investigated systematically though a series of methods, such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensiometry and conductivity. The thermodynamics of micellization of the ionic liquid surfactants solution were studied by using the conductivity method in the temperature range 278.15-318.15 K. The surface activity parameters and thermodynamics parameters were derived, respectively. The enthalpy-entropy compensation effect was further discussed by using relative thermodynamics parameters. It was found that the [C _n Empy][Br] have moderate surface activity, and their critical micelle concentration (CMC) decreased with the ester-functionalized chain length and exhibited a U-shape with temperature. The calculation results of the thermodynamic parameters showed that the micellization processes of [C _n Empy][Br] were spontaneous, endothermic at low temperature and exothermic at higher temperature.

Rapid synthesis of polyimidazole functionalized MXene via microwave-irradiation assisted multi-component reaction and its iodine adsorption performance

The adsorption applications of MXene-based adsorbents have intensively investigated recently. However, the performance of MXene-based adsorbents has been largely limited owing to their lack of functional groups and adsorptive sites. Therefore, surface functionalization of MXene is an important route to achieve better performance for environmental adsorption. Herein, polyionic liquid functionalized MXene (named as MXene-PIL) was prepared through a multi-component reaction and adsorptive removal of iodine by MXene-PIL was also evaluated. The successful generation of PIL on MXene was confirmed by a series of characterization measurements. Furthermore, the effects of contact time, iodine concentration, environmental temperature and other factors on the adsorption performance of MXene-PIL were investigated. Adsorption kinetic analysis including pseudo-first-order dynamic model, pseudo-second-order dynamic model and Weber-Morris model, adsorption thermodynamic analysis such as Langmuir and Freundlich models and Van't Hoff equation were used for further analysis the adsorption behavior of iodine by MXene-PIL. We demonstrated that the adsorption capacity could be as high as about 170 mg/g, which is obviously larger than the unmodified MXene and most of other reported adsorbents. Taken together, a simple strategy has been developed for in-situ generation of PIL on MXene and the resultant composites show potential application for adsorptive removal of iodine.

Efficiency and selectivity of ionic liquids in microwave-assisted extraction of major lichen phenolic compounds: a scalable process with recycling of ionic liquids

INTRODUCTION

Pseudevernia furfuracea, a lichen used classically for cosmetic applications, contains interesting metabolites possessing antimicrobial and anti-inflammatory or antioxidant properties.

OBJECTIVES

Ionic liquid combined to microwave-assisted extraction (IL-MAE) was successfully applied for metabolites extraction from Pseudevernia furfuracea.

MATERIALS AND METHODS

Three imidazolium and pyridinium-based ionic liquids (ILs): 1,3-dimethylimidazolium methylsulphate [C₁ C₁ Im][MeSO₄ ], 1-ethyl-3-methylimidazolium ethylsulphate [C₂ C₁ Im][EtSO₄ ], and N-ethylpyridinium ethylsulphate [C₂ Py][EtSO₄ ] were assessed for this process. The efficiency of the extraction method was evaluated using thin-layer chromatography (TLC) coupled to a Camag® spectrophotodensitometer and using high-performance liquid chromatography (HPLC) analysis.

RESULTS

ILs under MAE showed extraction time efficiency (15 min vs. 24 h for conventional heating) and high selectivity in extracting the targeted metabolites: atranorin (AT), methyl-β-orcinol carboxylate (MOC), fumarprotocetraric acid (Fum. Ac.), and physodic acid (Phys. Ac.) despite the increased degradation of AT under MAE. We showed a tunable selectivity of ILs towards extracting metabolites by changing anion or cation due to the modification of the interaction between the IL and the metabolites. While [C₂ Py][EtSO₄ ] was the most efficient IL and could extract all the targeted metabolites, [C₂ C₁ Im][EtSO₄ ] was the most selective. It fully extracted AT and partially Fum. Ac. Moreover, the lichen prepared by mixing procedure provided AT and Fum. Ac. more than the milled one. A 100 times scale-up extraction was successfully performed on mixed samples with full IL recycling after back extraction.

CONCLUSION

IL-MAE is reliable for lichen metabolites extraction. The method is reproducible, scalable, with possible IL recycling, opening the door for potential industrial applications.

Multi-Interactions in Ionic Liquids for Natural Product Extraction

Natural products with a variety of pharmacological effects are important sources for commercial drugs, and it is very crucial to develop effective techniques to selectively extract and isolate bioactive natural components from the plants against the background of sustainable development. Ionic liquids (ILs) are a kind of designable material with unique physicochemical properties, including good thermal stability, negligible vapor pressure, good solvation ability, etc. ILs have already been used in pharmaceuticals for extraction, purification, drug delivery, etc. It has been reported that multi-interactions, like hydrogen bonding, hydrophobic interactions, play important roles in the extraction of bioactive components from the plants. In this review, recent progress in the understanding of scientific essence of hydrogen bonding, the special interaction, in ILs was summarized. The extraction of various natural products, one important area in pharmaceutical, by conventional and functional ILs as well as the specific roles of multi-interactions in this process were also reviewed. Moreover, problems existing in bioactive compound extraction by ILs and the future developing trends of this area are given, which might be helpful for scientists, especially beginners, in this field.

Development and validation of the quantitative determination procedure of iodine in the iodides form in the kelp thallus by the ionometry method

Introduction:

Iodine is an important compound in the kelp thallus; it should be determined to control the quality of crude herbal drugs of Laminaria sp. The ionometry method is perspective iodine (in the iodides form) determination method in the crude herbal drugs; it is characterized by the availability and relative cheapness of iodide-selective electrodes and equipment in general. This method provides an effective combination of the determination step with the fast, simple, and safe step of sample preparation.

Aim:

The current study aims to develop and validate a simple, effective procedure for the quantitative determination of iodine in the form of iodide by ionometry in the kelp thallus (Laminaria sp.).

Materials and methods:

The determination of iodides was carried out by using the “Ecotest-120” pH meter. “Ekom-I” was used as an ion-selective electrode. Silver chloride electrode “ESR 10101” was used as a reference electrode.

Results and Discussion:

The developed procedure has a suitable level of linearity (correlation coefficient = 0.9995%), correctness (variation coefficient = 1.58%), repeatability (variation coefficient = 6.67%), and analytical area (0.03–209.4 μg/mL analyte in the test solution). The procedure allows us to determine iodine in the form of iodides with an accuracy comparable to the accuracy of neutron activation analysis and can be recommended as an alternative to titrimetric methods existing in the world-leading pharmacopoeias.

Phycocosmetics and Other Marine Cosmetics, Specific Cosmetics Formulated Using Marine Resources

Marine resources exist in vast numbers and show enormous diversity. As a result, there are likely many possible applications for marine molecules of interest in the cosmetic industry, whether as excipients or additives, but especially as active substances. It is possible to obtain extracts from active substances; for example, quite a few algae species can be used in moisturizing or anti-ageing products. In the field of topical photoprotection, mycosporine-like amino acids and gadusol are important lines of enquiry that should not be overlooked. In the field of additives, the demonstration that certain seaweed (algae) extracts have antimicrobial properties suggests that they could provide alternatives to currently authorized preservatives. These promising leads must be explored, but it should be kept in mind that it is a long process to bring ingredients to market that are both effective and safe to use.

Micellization, surface activities and thermodynamics study of pyridinium-based ionic liquid surfactants in aqueous solution

The micellization and surface activity properties of long-chain pyridinium ionic liquids n-alkyl-3-methylpyridinium bromide ([C_nmpy][Br], n: the carbon numbers of hydrophobic tails, n = 12, 14, 16) in aqueous solution were systematically investigated through electronic conductivity measurement, surface tension, and ultraviolet-absorption spectra. The surface chemical parameters and thermodynamics parameters were obtained. The [C_nmpy][Br] ionic liquids exhibit higher surface activities than conventional surfactants with corresponding alkyl chain lengths. The effects of inorganic salts (LiBr, NaBr, MgBr₂), organic alcohols (C₂H₅OH, C₃H₇OH, C₄H₉OH, C₅H₁₁OH) and temperature on the critical micelle concentration (CMC) values of [C_nmpy][Br] aqueous solutions were also investigated. The CMC values remarkably decreased with the addition of inorganic salts. The CMC values increased slightly in the presence of ethanol, but decreased gradually as the chain length of the alcohol increased. The CMC values assumed a trend of decreasing and then increasing with the increase of temperature. The calculation results of thermodynamic parameters show that both adsorption and micellization processes of [C_nmpy][Br] are spontaneous; the enthalpy of [C₁₂mpy][Br] is negative at 293.15 K and becomes negative with temperature increasing. For [C₁₄mpy][Br] and [C₁₆mpy][Br] this transition occurs at 288.15 K and the micellization process is entropy-driven in the investigated temperature range.

This paper contains details on the micellization, surface activity properties, thermodynamics and effects of additives of [C_nmpy][Br].

Ionic Liquid⁻Ultrasound-Based Extraction of Biflavonoids from Selaginella helvetica and Investigation of Their Antioxidant Activity

As a new and green solvent, ionic liquids (ILs) have received more attention during the green extraction and separation process for natural medicines. In this paper, IL-ultrasound-assisted extraction (IL-UAE) of total biflavonoids (TBFs) from Selaginella helvetica was firstly developed, and different ILs were employed and compared. Based on single-factor experiment, solid⁻liquid ratio (1:10⁻1:14 g/mL), IL concentration (0.6⁻1.0 mmol/mL), and extract temperature (40⁻60 °C) were further explored, according to response surface methodology (RSM), with TBF yields as the index. Moreover, antioxidant activity of TBF extract was analyzed by four methods, i.e., 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzth-iazoline-6-sulphonate (ABTS) free radical scavenging assay, ferric ion reducing power assay, and chelation of ferrous ions assay. The results indicated that [C₆mim]PF₆ had a high selectivity and efficiency. Moreover, important parameters for the extraction process were investigated and optimized. Through parameter optimization (0.8 mmol/L, 250 W, 40 min, 1:12.7 g/mL, and 47 °C), a yield of 18.69 mg/g biflavonoids was obtained from the extract of S. helvetica. Compared with ethanol-UAE, heat-reflux extraction, Soxhlet extraction, and percolation extraction, IL-UAE could not only obtain higher yield in a shorter time, but also reduce the solvent consumption. In addition, TBF extract showed potential antioxidant activity based on the above four antioxidant methods. In short, IL-UAE was first employed to develop a novel and green extraction method for TBF content, and this experiment provides valuable references for further utilization of S. helvetica.