Yuangui Yang

In this study, an integrated analytical method coupling ultra-high-performance liquid chromatography–photodiode array detection–quadrupole time-of-flight mass spectrometry with total antioxidant capacity determination (UHPLC-PDA-Q-TOF/MS-TACD) was developed for the rapid screening and identification of antioxidants in complex natural extracts. The system enables simultaneous chromatographic separation, mass spectrometric characterization, and on-line activity assessment by combining 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and ferric ion reducing antioxidant power (FRAP) assays. When applied to Rosa rugosa samples from five different origins, the approach efficiently separated the extract and successfully localized antioxidants directly from the chromatographic profile. A total of 86 compounds were identified, including flavonoids, tannins, and phenolic acids. Among them, 60 exhibited free radical scavenging capacity and 59 showed reducing activity. Activity verification experiments showed that all seven compounds exhibited good antioxidant activity. The IC₅₀ values of gallic acid, ellagic acid, quercetin 3-O-rhamnoside, and rutin were 0.019, 0.025, 0.043, and 0.046 mM, respectively, which were significantly better than the positive control (vitamin C). This method provides methodological and technical support for the rapid discovery of antioxidant components in complex natural products.

Background/Objectives: As a non-medicinal part resource of Ziziphus jujuba, this study focuses on the total flavonoids from Ziziphus jujuba mesocarp (TFZJM), aiming to optimize the extraction process and explore its sedative and hypnotic effects. Methods: The extraction process of TFZJM was optimized by using single-factor experiments and the Box-Behnken response surface design method. The material basis of TFZJM was analyzed using Ultra-Performance Liquid Chromatography-Quadrupole-Time of Flight-Mass Spectrometry (UPLC-Q-TOF-MS). The mouse insomnia model was induced by intraperitoneal injection of PCPA, and the effects of TFZJM on this model and its potential mechanism were evaluated using multiple methods, such as sleep enhancement induced by pentobarbital sodium, HE staining of tissue sections, ELISA, RT-PCR, WB, and serum metabolomics. Results: The results showed that by optimizing the extraction conditions, a solid-liquid ratio (SLR) of 1:25 g·mL⁻¹, ethanol concentration of 60%, extraction time of 60 min, and extraction rate of 1.98% were achieved. The common chemical basis of the 10 flavonoid components was identified using UPLC-Q-TOF-MS analysis. Compared with the model group, the high-dose TFZJM (TFZJM-H) group had the most significant effect, followed by the medium-dose (TFZJM-M) and low-dose (TFZJM-L) groups. Conclusions: Metabolomic analysis revealed that TFZJM regulates pathways related to the metabolism of phenylalanine, tyrosine, cytochrome P450, and alanine. This lays the foundation for further exploration of the active substances and mechanisms of action of TFZJM in sedation and hypnosis.

Zizyphus spinosus Hu (ZS), as a “medicinal and food-homologous” plant, has been used for a long history. The study was to assess the sedative and hypnotic effects among various parts of ZS. The model, diazepam (DZP), ZS kernel (ZSS), ZS flesh (ZSF), and ZS husk (ZSKS) group occurred subsequent to the successful establishment of the para-chlorophenylalanine induced insomnia model via intraperitoneal injection. The latency and duration of sleep in mice in each group were recorded. The substance basis of various parts of ZS was analyzed by the UPLC-QTOF-MS technique. The results showed that relative to the model group, DZP, ZSS, ZSF, and ZSKS groups demonstrated shortened sleep latency (p < 0.05) and extended sleep duration (p < 0.01). The GABA, 5-HT, and BDNF levels were significantly upregulated in the brain tissues of the mice in the DZP, ZSF, and ZSS groups (p < 0.01). However, the improvement in ZSKS was non-significant. Additionally, the mRNA and protein expression levels of 5-HT1AR, GABAARα1, and BDNF in mice in the DZP, ZSS, and ZSF groups were significantly enhanced (p < 0.01). However, the improvement in the ZSKS group was insignificant (p < 0.05). The examination of the substance composition across different parts revealed that the shared chemical basis contributing to the sedative and hypnotic potency of different parts of ZS may involve the presence of compounds such as (1) magnoflorine, (8) betulinic acid, (9) ceanothic acid, and (10) alphitolic acid. It provides a basis for further elucidation of the substance basis responsible for the functional and medicinal effects of ZS.