Caiyun Peng

Flavonols are an important class of flavonoids widely distributed across various plant species. They have garnered significant attention from synthetic chemists due to their extensive biological activities and medicinal value. This review provides a systematic overview of five classical synthetic methods, including the Auwers reaction, the Allan–Robinson reaction, the Baker–Venkataraman rearrangement, the Algar–Flynn–Oyamada (AFO) reaction, and DMDO-mediated oxidation. Each methodology is comprehensively discussed in terms of its advantages, limitations, and potential optimization strategies. Additionally, the biological activities, including antioxidant, anticancer, anti-inflammatory, and antiviral properties, are summarized and discussed in the context of structure–activity relationships (SARs).

Objectives: Kadsura coccinea fruit is a traditional medicinal plant rich in dibenzocyclooctadiene lignans, with established hepatoprotective effects. Binankadsurin A (BKA), a dibenzocyclooctadiene lignan isolated from the K. coccinea fruits. This study aims to evaluate its hepatoprotective efficacy in an acetaminophen (APAP)-induced mouse liver injury model. Methods: The structure of BKA was elucidated by HR-ESI-MS, NMR, single-crystal X-ray diffraction and comparison of their data with those of the literature. Mice were randomly divided into five groups: Control, APAP (400 mg/kg, single intraperitoneal injection), APAP + bicyclol (50 mg/kg), APAP + low-dose BKA (50 mg/kg), and APAP + high-dose BKA (100 mg/kg). Untargeted metabolomics, immunohistochemistry, Western blot analysis, and molecular docking were performed. Results: BKA was determined as a dibenzocyclooctadiene lignan, and the single-crystal structure is reported for the first time. The untargeted metabolomics revealed that metabolites and pathways are closely associated with oxidative stress. In vivo studies showed that pretreatment with BKA can mitigate liver injury. BKA reduced serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and stored hepatic glutathione (GSH) levels. Immunohistochemical analysis results also showed that CYP2E1 expression in the mouse liver could be improved through BKA pretreatment. Furthermore, Western blot analysis presented that BKA could increase the protein expression of Nrf2, HO-1, and NQO-1. Additionally, molecular docking indicated that BKA directly blocks the binding site of Nrf2 with Keap1. Conclusions: BKA reduces APAP-induced acute liver damage by inhibiting oxidative stress by activating the Keap1/Nrf2/HO-1 signaling pathway, providing a theoretical basis for BKA as a potential therapeutic agent for APAP-induced liver injury.

Clematis henryi (C. henryi) is a valuable medicinal plant in the Tujia ethnic family, which is widely used for the treatment of rheumatism arthritis and limb numbness. There are few studies on the chemical composition and biological activity of C. henryi at present. In this study, we isolated and purified thirty-one compounds in total, including four new compounds (1, 29–31) and twenty-seven known compounds (2–28). These isolated compounds were identified by a variety of spectroscopic data including NMR spectrometry and mass spectroscopy. These thirty-one compounds were tested for their proliferation inhibition activity on RAFLs and HepG2 cells. The results indicated that compound 29 and 30 exhibited weak inhibition of proliferation activity against RAFLs cells. Meanwhile, compounds 8, 10, 29, and 30 exhibited moderate inhibition of proliferation activity on HepG2 cells with an IC₅₀ value between 16.07 and 19.83 µM. The results of this study could serve as a reference for the further comprehensive utilization of C. henryi.

The proposed 3D bipedal DNA walker demonstrates a highly sensitive detection capability for APE1 and holds promise for future screening of other potential APE1 inhibitors.

Extracellular vesicles (EVs) are microparticles released from cells in both physiological and pathological conditions and could be used to monitor the progression of various pathological states, including neoplastic diseases. In various EVs, tumor-derived extracellular vesicles (TEVs) are secreted by different tumor cells and are abundant in many molecular components, such as proteins, nucleic acids, lipids, and carbohydrates. TEVs play a crucial role in forming and advancing various cancer processes. Therefore, TEVs are regarded as promising biomarkers for the early detection of cancer in liquid biopsy. However, the currently developed TEV detection methods still face several key scientific problems that need to be solved, such as low sensitivity, poor specificity, and poor accuracy. To overcome these limitations, DNA walkers have emerged as one of the most popular nanodevices that exhibit better signal amplification capability and enable highly sensitive and specific detection of the analytes. Due to their unique properties of high directionality, flexibility, and efficiency, DNA walkers hold great potential for detecting TEVs. This paper provides an introduction to EVs and DNA walker, additionally, it summarizes recent advances in DNA walker-based detection of TEVs (2018– 2024). The review highlights the close relationship between TEVs and DNA walkers, aims to offer valuable insights into TEV detection and to inspire the development of reliable, efficient, simple, and innovative methods for detecting TEVs based on DNA walker in the future.

Chrysanthemum tea, a typical health tea with the same origin as medicine and food, is famous for its unique health benefits and flavor. The taste and sensory quality of chrysanthemum (Juhua) tea are mainly determined by secondary metabolites. Therefore, the present research adopted untargeted metabolomics combined with an electronic tongue system to analyze the correlation between the metabolite profiles and taste characteristics of different varieties of chrysanthemum tea. The results of sensory evaluation showed that there were significant differences in the sensory qualities of five different varieties of chrysanthemum tea, especially bitterness and astringency. The results of principal component analysis (PCA) indicated that there were significant metabolic differences among the five chrysanthemum teas. A total of 1775 metabolites were identified by using untargeted metabolomics based on UPLC-Q-TOF/MS analysis. According to the variable importance in projection (VIP) values of the orthogonal projections to latent structures discriminant analysis (OPLS-DA), 143 VIP metabolites were found to be responsible for metabolic changes between Huangju and Jinsi Huangju tea; among them, 13 metabolites were identified as the key metabolites of the differences in sensory quality between them. Kaempferol, luteolin, genistein, and some quinic acid derivatives were correlated with the “astringency” attributes. In contrast, l-(-)-3 phenyllactic acid and L-malic acid were found to be responsible for the “bitterness” and “umami” attributes in chrysanthemum tea. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the flavonoid and flavonol biosynthesis pathways had important effects on the sensory quality of chrysanthemum tea. These findings provide the theoretical basis for understanding the characteristic metabolites that contribute to the distinctive sensory qualities of chrysanthemum tea.