Lignin-based hydrophobic DESs extracts Sudan dyes from aqueous solution

As a synthetic pigment, Sudan red is commonly used as a food additive and is harmful to the human kidney and can even cause cancer. In this work, we developed a one-step strategy to synthesize lignin-based hydrophobic deep eutectic solvents (LHDES), which were fabricated via methyltrioctylammonium chloride (TAC) as hydrogen bond acceptor and alkali lignin as hydrogen bond donor. LHDES with different mass ratios were synthesized and the mechanism of formation was determined by different characterization techniques. The synthetic LHDES was used as the extraction solvent to establish a vortex-assisted dispersion-liquid microextraction method for the determination of Sudan red dyes. The practicality of LHDES was evaluated by applying it to the detection of Sudan Red I in real water samples (seawater, river water) and duck blood in foodstuffs, and the obtained extraction rate reached up to 98.62 %. The method is simple and effective for the determination of Sudan Red in food.

Quinoline Hydrazide/Hydrazone Derivatives: Recent Insights on Antibacterial Activity and Mechanism of Action

Antibiotics are becoming gradually ineffective due to drug resistance, leading to greater difficulty in the treatment of infectious diseases. Therefore, the development of new chemical entities with different mechanisms of action is essential in the fight against resistant microorganisms. Various studies have shown that quinoline hydrazide/hydrazone derivatives possess several biological activities, such as antimalarial, antitubercular, anticancer, anti-inflammatory, and antimicrobial. Among these activities, the antibacterial activity of quinoline hydrazide/hydrazone derivatives is noteworthy. The synthetic flexibility of the quinoline ring has led to the development of a wide range of structurally diverse quinoline hydrazide/hydrazone derivatives, which can act at various bacterial targets such as DNA gyrase, glucosamine-6-phosphate synthase, enoyl ACP reductase, and 3-ketoacyl ACP reductase. This review emphasizes the antibacterial potential of various reported quinoline hydrazide/hydrazone derivatives based on substitution in the quinoline ring. The antibacterial activity of various metal-quinoline hydrazide/hydrazone complexes is also discussed. The aim of this review is to assemble and scrutinize the latest reports in this promising area of drug development.

A Chemosensor of 1,8-Dihydroxyanthraquinone PMOs Prepared in a Ternary Deep Eutectic Solvent for the Sensitive Detection of Cu2

A novel type of organic-inorganic hybrid periodic mesoporous materials based on 1,8-dihydroxyanthraquinone (DHAQ-PMOs) was synthesized in a ternary deep eutectic solvent (DES). In the process of the material synthesis, an organosiloxane precursor (DHAQ-Si) and tetraethylorthosilicate (TEOS) were used as the mixed Si source, and cetyltrimethylammonium bromide (CTAB) was used as the structure directing agent. The DES formed by choline chloride (ChCl), urea (U), and ethylene glycol (EG) was used as a green solvent. The water needed for the hydrolysis of DHAQ-Si and TEOS was provided from free water in the sodium hydroxide solution. As characterized by small-angle X-ray scattering, nitrogen adsorption/desorption isotherms, and high-resolution transmission electron microscopy, the obtained mesoporous materials exhibit a two-dimensional hexagonal (P6mm) structure. DHAQ possesses double fluorescence emission peaks at ca. 520 and 580 nm due to the effect of the excited-state intramolecular proton transfer (ESIPT). For DHAQ-PMOs, the silica framework can provide a rigid environment that makes the fluorescence properties more stable and the fluorescence emission peak appears to red-shift obviously. The DHAQ-PMOs have high selectivity and sensitivity in a wide pH range that can be used to detect Cu²⁺, and the limit of detection (LOD) is as low as 2.39 × 10^-9 M. Fluorescence polarization experiments, high-resolution mass spectrometry, and Fourier transform infrared spectroscopy were used to study the coordination interaction between DHAQ and Cu²⁺. The density functional theory (DFT) was used to further prove the coordination ability and interaction between DHAQ and Cu²⁺. XPS spectra were also done to prove the coordination of DHAQ and DHAQ-PMO-10 with Cu²⁺. In addition, confocal fluorescence microscope images exhibit that DHAQ-PMOs can detect Cu²⁺ in living cells. The results show that DHAQ-PMOs have great application potential as a sensor for the detection of Cu²⁺.

From liquid hot water pretreatment solution to lignin-based hydrophobic deep eutectic solvent for highly efficient extraction of Cr (VI)

Liquid hot water (LHW) pretreatment has been widely investigated attributed to its advantages, such as environmental friendliness, the potential application of dissolved hemicellulose, and no chemical addition. Expanding the portfolio of products that can be made from LHW pretreatment solutions will be critical to enabling a viable LHW-based economy. We provide a one-step method to separate and functionalize lignin from the LHW pretreatment solution. A hydrophobic deep eutectic solvent (hDES) was prepared by using methyltrioctylammonium chloride (MTAC) and the LHW pretreatment solution and directly applied to the extraction of Cr (VI) in an aqueous solution. In the process of forming hDES, the removal rate of liquid hot water lignin (LHWL) was reached 99%. The new LHW-hDES exhibited excellent extraction performance for Cr (VI), the extraction capacity was as high as 198.402 mg g^-1, optimum extraction conditions at the mass of hDES 0.10 g, vortex time 90 s, room temperature, and natural pH. Notably, we have shown that the method of combining the separation and functionalization of lignin in the LHW pretreatment solution, which can provide a way of thinking for the application of the LHW pretreatment solution.

Some applications of deep eutectic solvents in alkylation of heterocyclic compounds: A review of the past 10 years

This mini-review encapsulates the latest findings (past 10 years) in the field of the deep eutectic solvents (DESs) application in the alkylation/arylation of different heterocyclic compounds. These solvents have been developed to fulfill the green chemistry concept demands and have been proven excellent for the application in various fields. This review describes their application in different types of alkylation, C-, N-, O- and S-alkylation. P-alkylation has not yet been published within this scope. Not only have the authors in this study proven that DESs could be successfully applied for this specific type of reaction, but they have also offered an excellent insight into the mechanisms of their action.