Sesquiterpenes constitute the principal components of the genus Ainsliaea, encompassing guaiane, germacrane, eudesmane, and polymer sesquiterpene lactones types. These secondary metabolites exhibit diverse pharmacological activities, including antitumor, antibacterial, anti-inflammatory, antiviral, antioxidant, hepatoprotective, and neuroprotective effects. Through a comprehensive literature search of the Web of Science, PubMed, SciFinder, and CNKI databases, it was discovered that there are as many as 145 main sesquiterpenoids in the genus Ainsliaea. However, the nuclear magnetic resonance (NMR) data for the sesquiterpenes in this genus have not been systematically compiled and summarized. Therefore, this review aims to highlight the chemical structures, NMR data, and pharmacological activities of sesquiterpenes in Ainsliaea. By meticulously analyzing published scholarly literature, our goal is to provide a solid foundation for further exploration of new sesquiterpenes and extensive utilization of this genus.

An optically active, amphiphilic meta-phenylene ethynylene (m-PE) bearing a chiral amide pendant was designed and synthesized. Living polymerization of m-PE using alkyne-Pd(II) as the initiator afforded well-defined poly(meta-phenylene ethynylene) (m-PPE). These m-PPEs were found to have a stable helical conformation in THF, 1,4-dioxane, and CH₃CN and showed split Cotton effects over the range of 245–400 nm. The positive first Cotton effect was observed at a wavelength of approximately 308 nm, and the negative second Cotton effect was observed at a wavelength of approximately 289 nm. The m-PPEs exhibited helical conformational changes in different mixed solvents and showed effective solvent-dependent helix inversion in CHCl₃/THF solutions. The sign of the Cotton effect of m-PPE was inverted at 25 °C by varying the mixing ratio of THF and CHCl₃. Finally, amphiphilic poly(meta-phenylene ethynylene)-block-polyisocyanide containing hydrophilic PPE and hydrophobic PPI segments were facilely prepared using Pd(II)-terminated m-PPE as the macroinitiator. This block copolymer can self-assemble into well-defined spherical nanostructures in a selective THF/CH₃OH solution. This efficient polymerization will open up enormous opportunities for the preparation of functional amphiphilic block copolymers in a wide variety of fields.

Mining structural novel and bioactive natural products from traditional Chinese drugs and folk medicines have attracted attention from pharmacologists and pharmaceutical chemists for a long time. In this study, the chemical constituents of Asplenium ruprechtii Sa. Kurata was systematically studied based on the evaluation of neuroprotective activity on hydrogen peroxide (H₂O₂)-induced damage of SH-SY5Y cell lines. Sixteen chemical monomers (1–16), including two new structures of 9,19-cycloartane-triterpenoid saponins (1,2), were discovered. Their chemical structures were established based on extensive spectroscopic data analysis, including the one- and two-dimensional (1D and 2D) nuclear magnetic resonance (NMR) data and high-resolution electrospray ionization mass spectrometry (HRESIMS). All monomer compounds were docked with an “active pocket” at the N-terminal of the GluN2B protein, where compounds 13–16 were found to possess high binding scores, which warrant further study on the molecular mechanism. Our findings provide insight and research techniques for discovering new drugs based on neuroprotective activity.