Wei Li

In this study, a green and efficient extraction methodology was developed by leveraging the unique properties of chitosan—namely its non-toxicity, biocompatibility, and adhesive nature—to enhance the recovery of bioactive ingredients from Forsythia suspensa leaves. The core mechanism involves the formation of complexes between chitosan and the target bioactive ingredients, which significantly boosts their extraction efficiency. To substantiate this mechanism, comprehensive characterization was performed using Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), and molecular docking analyses. The results provided robust evidence of a strong interaction between chitosan and the bioactive ingredients, leading to a marked enhancement in both the stability and aqueous solubility of the target compounds. For process optimization, a multi-objective approach was implemented using the Non-dominated Sorting Genetic Algorithm II (NSGA-II) to simultaneously maximize the extraction yields of phillyrin and forsythoside A. The algorithm identified the optimal parameters as a leaf-to-chitosan mass ratio of 10:11.75, a solid-to-liquid ratio of 1:52 g/mL, a temperature of 80 °C, and a duration of 120 min. Under these optimized conditions, the corresponding extraction yields for phillyrin and forsythoside A were 1.68 ± 0.16% and 3.23 ± 0.27%, respectively. These findings collectively indicate that chitosan-assisted extraction represents a highly promising and advanced technology for the sustainable and effective extraction of bioactive ingredients from botanical sources.

Context Ionic liquids (ILs) have garnered significant attention as eco-friendly media for living/controlled cationic polymerization due to their tunable solvation properties and enhanced reaction control. However, the fundamental principles governing cationic polymerization and the specific role of ionic liquids in these reactions remain poorly understood, leading to the continued reliance on a trial-and-error approach for ILs selection. To address this fundamental challenge, we conducted computational investigations of the CumOH/BF₃OEt₂-initiated living cationic polymerization of p-methylstyrene within the prototypical hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([BMIM][NTf₂]). Additionally, a comparative analysis of solvent effects was conducted, contrasting the performance of [BMIM][NTf₂] with the conventional organic solvent dichloromethane (CH₂Cl₂). Quantum chemical calculations revealed that both the BMIM⁺ cation and CH₂Cl₂ significantly lower the activation barrier of the initiation step. More importantly, the NTf₂⁻ anion was found to play a dual catalytic role by stabilizing key cationic intermediates and modulating the transition state geometry during chain initiation and dimerization. These mechanistic insights quantitatively account for the the observed differences in reaction rates and yields of p-MeSt polymerization in [BMIM][NTf₂] compared to CH₂Cl₂. Methods Employing density functional theory (DFT) at the B3LYP/6–311 + + G(d,p) level of theory using Gaussian-03, we conducted a comprehensive mechanistic investigation of three pivotal elementary steps governing the early-stage polymerization: (i) initiator activation, (ii) monomer chain initiation, and (iii) dimer formation.

The structures, electron affinities and bond dissociation energies of BrO₄F/BrO₄F⁻ species have been investigated with five density functional theory (DFT) methods with DZP++ basis sets. The planar F-Br…O₂…O₂ complexes possess ³A' electronic state for neutral molecule and ⁴A' state for the corresponding anion. Three types of the neutral-anion energy separations are the adiabatic electron affinity (EA_ad), the vertical electron affinity (EA_vert), and the vertical detachment energy (VDE). The EA_ad value predicted by B3LYP method is 4.52 eV. The bond dissociation energies D_e (BrO₄F → BrO_4-mF + O_m) (m = 1-4) and D_e^- (BrO₄F^- → BrO_4-mF^- + O_m and BrO₄F^- → BrO_4-mF + O_m^-) are predicted. The adiabatic electron affinities (EA_ad) were predicted to be 4.52 eV for F-Br…O₂…O₂ (³A'← ⁴A') (B3LYP method).