Search Results (5)

Plant polyphenols have significant importance due to their potential health benefits. Polygala major Jacq. is commonly found in Asia and has a long history of use in traditional medicine. This study investigated the extraction of polyphenols from the leaves and flowers of P. major Jacq. using various solvents (acetone, ethanol, and methanol) and employing two extraction methods: maceration and ultrasonication. Significant amounts of total phenolics were detected in all conditions, measuring between 26.69 and 48.51 mg GAE/g dry matter, with the highest concentration found in the ultrasonicated ethanol extract from the leaves. Compared to the other solvents, acetone was particularly effective in extracting flavonoids from the leaves. The antioxidant activities ranged from 0.65 to 0.86 mg TE/g dry matter, as determined by the DPPH radical scavenging activity method. The leaf extract displayed antibacterial activity against Bacillus cereus, Pseudomonas aeruginosa, and Staphylococcus aureus, while the flower extract had no antibacterial activity. UV-Vis spectroscopy and FTIR analysis confirmed the presence of polyphenols in the extracts. According to LCMS analyses, a total of 67 compounds were identified in the leaves and flowers, including several that are pharmaceutically significant, such as eupatorin, sinensetin, acacetin, ombuin, vanillic acid, sinapic acid, apigenin, naringenin, and luteolin. Full article

The leaves of Rhamnus erythroxylon Pall. are widely used as tea substitutes in northwest China for their fragrant aroma, anti-irritability, and digestion-enhancing properties. Ombuin, a main flavonoid compound found in the leaves, exhibited notable anti-inflammatory and antioxidant effects. However, its potential role in treating neuroinflammatory-related diseases remains unexplored. Thus, this study aims to evaluate the anti-neuroinflammatory effects of ombuin and to explore the underlying molecular mechanisms. According to our findings, ombuin dramatically reduced the release of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-1β, nitric oxide (NO), and reactive oxygen species (ROS) in lipopolysaccharide (LPS)-stimulated BV-2 microglia. Further analysis, including transcriptomics, network pharmacology, molecular docking, and cellular heat transfer assays, revealed that Src was a direct target of ombuin. Western blot analysis showed that ombuin effectively suppressed Src phosphorylation and inhibited the downstream expressions of p-PI3K p85, p-AKT1, p-IKKα/β, p-IκBα, and nuclear factor κB (NF-κB). Meanwhile, the repression of Src significantly reversed the anti-neuroinflammatory activity of ombuin. Our results identified Src as a direct target of ombuin and implied that ombuin exerted an anti-neuroinflammatory effect by inhibiting Src phosphorylation and suppressing the activation of the PI3K-AKT and NF-κB pathways, which might provide an alternative therapeutic strategy for neurodegenerative diseases. Full article

Microbial infections are leading causes of death and morbidity all over the world due to the development of the resistance to antibiotics by certain microorganisms. In this study, the chemical exploration of the ethanol (EtOH) extract of the aerial part of Dracaena stedneuri (Dracaenaceae) led to the isolation of one previously unreported chalcone derivative, i.e., 2′,4′-dihydroxy-2,3′-dimethoxychalcone (1), together with 12 known compounds: 8-(C)-methylquercetagetin-3,6,3′-trimethyl ether (2), methylgalangine (3), quercetin (4), kaempferol (5), 6,8-dimethylchrysin (6), ombuine-3-O-rutinoside (4ʹ,7-dimethylquercetin-3-O-α-L-rhamnopyranosyl-(1 → 6) -β-D-glucopyranoside) (7), alliospiroside A (8), β-sitosterol 3-O-glucopyranoside (9), ishigoside (10), betulinic acid (11), oleanolic acid (12), and lupeol (13). The structures were determined by spectroscopic and spectrometric analysis including 1- and 2-Dimensional Nuclear Magnetic Resonance (1D- and 2D-NMR), High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS), and comparison with literature data. The isolated secondary metabolites and crude extract displayed antibacterial activity against some multidrug-resistant strains with minimal inhibitory concentration (MIC) values ranging from 32 to 256 μg/mL. The antibacterial activity of compound 13 against Enterobacter aerogenes ATCC13048 (MIC value: 32 μg/mL) was higher than that of chloramphenicol used as the reference drug (MIC = 64 μg/mL). Full article

Polygala species are frequently used worldwide in the treatment of various diseases, such as inflammatory and autoimmune disorders as well as metabolic and neurodegenerative diseases, due to the large number of secondary metabolites they contain. The present study was performed on Polygala inexpectata, which is a narrow endemic species for the flora of Turkey, and resulted in the isolation of nine known compounds, 6,3′-disinapoyl-sucrose (1), 6-O-sinapoyl,3′-O-trimethoxy-cinnamoyl-sucrose (tenuifoliside C) (2), 3′-O-(O-methyl-feruloyl)-sucrose (3), 3′-O-(sinapoyl)-sucrose (4), 3′-O-trimethoxy-cinnamoyl-sucrose (glomeratose) (5), 3′-O-feruloyl-sucrose (sibiricose A5) (6), sinapyl alcohol 4-O-glucoside (syringin or eleutheroside B) (7), liriodendrin (8), and 7,4′-di-O-methylquercetin-3-O-β-rutinoside (ombuin 3-O-rutinoside or ombuoside) (9). The structures of the compounds were determined by the spectroscopic methods including 1D-NMR (¹H NMR, ¹³C NMR, DEPT-135), 2D-NMR (COSY, NOESY, HSQC, HMBC), and HRMS. The isolated compounds were shown in an in silico setting to be accommodated well within the inhibitor-binding pockets of myeloperoxidase and inducible nitric oxide synthase and anchored mainly through hydrogen-bonding interactions and π-effects. It is therefore plausible to suggest that the previously established anti-inflammatory properties of some Polygala-derived phytochemicals may be due, in part, to the modulation of pro-inflammatory enzyme activities. Full article

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4′-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3′,5′-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8–11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6–9, and 11–14 showed good alpha-glucosidase inhibition with IC₅₀ values in the range of 30.5–282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase. Full article