Phytochemical Analysis最新文献

Introduction: Traditionally, Callicarpa species have been utilized their anti-inflammatory and hemostatic properties. Prominently featured species in the 2020 Edition of the Chinese Pharmacopoeia were Callicarpa nudiflora (CN), Callicarpa macrophylla (CM), Callicarpa formosana (CF), and Callicarpa kwangtungensis (CK), which were formulated into several medicinal preparations. Extensive applications led to the significant depletion of CN's wild resources. The management of germplasm resources was significantly disordered. Adulteration issues were also prevalent.

Objective: It is imperative that the study aims to identify alternative sources for CN and other pharmacopeial varieties and develop methods to distinguish different Callicarpa species.

Results: Data were acquired using three mass spectrometry modes: Data Dependent Analysis (DDA), Data-Independent Analysis (DIA), and full mass spectrometry (MS). The DDA mode identified or inferred information on 54 compounds. The Full MS mode identified or inferred 74 compounds, including 20 that were previously unreported in Callicarpa. These compounds were confirmed using standards. The DIA mode did not facilitate identification due to missing precursor ion data. With metabolomics, 19 differential compounds were identified or inferred. Luteolin, chrysoeriol, and quercetin were selected as potential markers, integrating the 10 active compounds from network pharmacology.

Conclusion: Based on the relative abundance of these markers, it was proposed that Callicarpa giraldii Hesse ex Rehd. var. (CGHRV) and CM could serve as alternative resource species to CN, while CGHRV and Callicarpa giraldii Hesse ex Rehd. (CGHR) could substitute the pharmacopeial CM. Callicarpa longissimi (CLG) was suggested as an alternative to CK, while Callicarpa cathayana (CC) and Callicarpa rubella (CRL) could replace CF. Furthermore, the absence of certain compounds in CK presented a novel opportunity for the differentiation of various Callicarpa species.

Introduction: Yangxinshi tablet (YXST) is a effective traditional Chinese medicine in treating cardiovascular diseases such as heart failure and myocardial infarction.

Objectives: This study aims to develop a method for screening thrombin inhibitors from YXST using an online immobilized enzyme microreactor (IMER) based on capillary electrophoresis (CE).

Materials and methods: Thrombin (THR) was immobilized on the capillary's inner wall using polydopamine (PDA). The chromogenic substrate S-2238 was employed to assess thrombin (THR) activity and kinetic parameters. The stability and repeatability of the constructed thrombin-immobilized enzyme microreactor (THR-IMER) were evaluated over 40 runs, maintaining 85% of initial activity. The Michaelis-Menten constant (K_m) for THR was determined to be 11.98 mM. The half-maximal inhibitory concentration (IC₅₀) and inhibition constant (K_i) for argatroban on THR were calculated. Ten compounds in YXST were screened for THR inhibitory potency using the THR-IMER.

Results: Salvianolic acid B and caffeic acid were identified as potential THR inhibitors in YXST, with inhibition rates at 200 μg/mL of 55.06 ± 6.70% and 31.88 ± 4.79%, respectively, aligning with microplate reader assay results. Molecular docking analysis confirmed their interactions with key THR residues, verifying their inhibitory activity.

Conclusion: The CE-based THR-IMER method was successfully developed for screening thrombin inhibitors from YXST, offering a reliable approach for identifying potential therapeutic compounds.

Introduction: Annonaceous acetogenins are a group of natural polyketide compounds possessing notable cytotoxic and antitumor properties. Mass spectrometry (MS) techniques can be used for the structural determination of these compounds, including the location of functional groups along the long alkyl chain.

Objective: This study aims to develop a convenient liquid chromatography (LC)-MS-based method for the dereplication of acetogenins in plant extracts using a molecular networking approach.

Methodology: The LC-electrospray ionization (ESI)-MS/MS spectra of pure adjacent bis-tetrahydrofuran (THF) acetogenins isolated from Uvaria rufa (Annonaceae) were acquired, along with those of the crude ethyl acetate and hexanes fractions of the plant extract, followed by dereplication and molecular networking analysis using the Global Natural Products Social Molecular Networking (GNPS) platform.

Results: A high level of fragmentation of the protonated molecules [M + H]⁺ was observed at collision energies of 37.5 and 25.0 eV. The application of feature-based molecular networking (FBMN) allowed for distinguishing diastereoisomers based on different retention times in the reversed-phase high-performance liquid chromatography method. The acetogenin possessing one or more additional OH groups on the methyl-terminal chain side of the OH-flanked bis-THF ring unit were grouped separately from those lacking such substructure. Furthermore, the MS2LDA analysis revealed shared Mass2Motifs among acetogenins, confirming the structural relations within the molecular network.

Conclusions: The ESI-MS/MS-based molecular networking method provided an effective strategy for the dereplication of acetogenins in plant extracts. It is anticipated that this molecular networking approach could be extended to other types of acetogenins to facilitate rapid identification of this class of compounds.

Introduction: A rapid procedure was developed for the targeted isolation and assessment of antibacterial compounds from plant-based materials. The effectiveness of this method was demonstrated using Feijoa sellowiana fruit peels.

Objective: The objectives of this study are as follows: develop an efficient procedure utilizing direct thin-layer chromatography (TLC)-bioautography to facilitate the targeting, identification, and purification of antibacterial compounds from plant extracts and delineate a method based on TLC-bioautography to determine the minimum effective dose (MED), alongside a colorimetric broth microdilution aided by high-performance liquid chromatography (HPLC) for evaluating the isolated active compounds.

Methodology: Active compounds were targeted using TLC-bioautography against Staphylococcus aureus, and the identification was achieved through liquid chromatography-mass spectrometry (LC-MS) combined with Compound Discoverer. Purification was carried out using a customized separation method. The structure was confirmed using nuclear magnetic resonance (NMR) spectroscopy. The MED, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were determined by two enhanced antibacterial assays.

Results: The main antibacterial compound identified was flavone. A TLC-bioautography-based antibacterial assay and a colorimetric broth microdilution assisted by HPLC were described as the enhanced antibacterial assay protocols. The MED, MIC, and MBC of flavone against S. aureus were found to be 4.2-5.2 μg/cm², 225-275 μg/mL, and 550-650 μg/mL, respectively. Similarly, the MED, MIC, and MBC against Escherichia coli were determined to be 5.2-6.1 μg/cm², 325-375 μg/mL, and 375-425 μg/mL, respectively.

Conclusion: This study proposed an enhanced bioassay-guided separation technique for the isolation of antibacterial compounds from plants, along with two improved methods for assessing the antibacterial efficacy of insoluble or colored compounds.

Introduction: Insight into comparing key active ingredients of Radix Bupleuri (RB) based on different processing technologies is a key step to reveal the material basis of drug efficacy and a challenging task for developing traditional Chinese medicine (TCM).

Objective: This work aims to establish a comprehensive comparative analysis method of TCM and its processed products, which can be used to analyze the changing trend of active components of RB before and after processing.

Methods: First, RB was processed with rice vinegar, rice wine, and honey. Then, ultra-high-performance liquid chromatography (UHPLC) and gas chromatography (GC) coupled with mass spectrometry (MS) technology as well as multiple statistical analyses were used to comprehensively evaluate the compositional variation of polar and volatile compounds in RB under different processing processes. Meanwhile, in UHPLC-MS, a sequential window acquisition of all theoretical fragment ion spectral and information-dependent acquisition mutual authentication (SIMA) was developed.

Results: A total of 30 polar components and 33 volatile components were identified as chemical markers (mainly type II saikosaponins, terpenes, and fatty acid esters). These may be the material basis for giving unique pharmacological activities to RB and its processed products.

Conclusions: These findings provided a solid foundation for the differentiated clinical application of RB, and the SIMA method held great potential for achieving accurate analysis of TCM processing ingredients.

Introduction: European aspen (Populus tremula L.) knotwood contains large amounts of polyphenolic metabolites, mainly flavonoids, and can be considered as a promising industrial-scale source of valuable bioactive compounds. Valorization of knotwood extractives requires detailed information on their chemical composition and a relevant analytical methodology.

Objective: This study proposes combined analytical strategy for non-targeted screening and identification of polyphenolic plant metabolites and is aimed at comprehensive characterization of knotwood extractives.

Materials and methods: Aspen knotwood acetone extract with determined antioxidant activity was an object of the study. Two-dimensional NMR spectroscopy with Structure Elucidator expert system was used for preliminary search of major components and specific structures. Liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) with data-dependent MS/MS spectra acquisition was used as a complementary technique providing molecular-level characterization and identification of the detected metabolites.

Results: Twenty-eight phenolic metabolites were found and identified. Among them, flavonoids, aromadendrin and naringenin, as well as their glycosylated derivatives (mainly O-glucosides) and methyl ethers, dominated. Taxifolin and its 7-O-glucoside were detected as minor components. Other detected compounds are represented by p-coumaric acid and its rutinoside and small amounts of glycosylated ferulic acid. Nineteen of the detected compounds were discovered in aspen knotwood for the first time. The results were confirmed by preparative isolation of individual compounds and NMR studies.

Conclusion: The proposed analytical strategy based on 2D NMR and HPLC-HRMS can be considered a powerful tool in the analysis of plant extractives and allowed for the identification and semi-quantification of a large number of polyphenols in aspen knotwood.