Natural Product Research最新文献

A previously undescribed cyclolignan, named Combretumlignan 1, was isolated from the methanolic extract of the twigs of Combretum zenkeri together with fifteen known compounds. Their structures were determined by a comprehensive analysis of their spectroscopic data in comparison with those published in the literature. The extract, fractions and compounds 1, 4 and 5 were evaluated against six Gram-negative and one Gram-positive bacteria strains. The methanol crude extract of twigs of this plant showed good antibacterial activities with MIC values of 31.2 and 62.5 μg/mL against Staphylococcus aureus and Salmonella enterica respectively. The ethyl acetate fraction showed strong antibacterial activity (MIC = 7.8 μg/mL) against Salmonella typhimurium 19430 while the crude extract and the n-hexane fraction exhibited significant activity (MIC = 31.2 μg/mL) against Staphylococcus aureus 12600 for crude extract, and against Salmonella typhimuriummurium 19430 and Pseudomonas aeruginosa HM801 for the n-hexane fraction. All the tested compounds inhibited the growth of the seven bacterial strains tested with MICs ranging from 3.9─125 µg/mL. Hexadecyl ferulate 5 displayed the best activity with a MIC value of 3.9 μg/mL against Salmonella typhimurium 19430. Compound 1 showed moderate activity against Salmonella typhimurium 19430 and Escherichia coli with MIC values of 62.5 μg/mL and 31.2 µg/mL, respectively.

One previously unreported acetylated dihydroflavonol derivative named (2 R,3R)-3-acetoxy-5-hydroxy-7,4'-dimethoxyflavonol (1), along with twelve known compounds (2-13), were isolated from the ethyl acetate soluble fraction of the methanol extract of the seeds of Aframomum letestuanum Gagnep. (Zingiberaceae). Their structures were established by means of spectroscopic techniques (1D and 2D NMR), High Resolution Electrospray Ionisation Mass Spectrometry (HR-ESIMS) as well as by comparison of their spectroscopic data with those reported in the literature. The absolute configuration of compound 1 was determined by Electronic Circular Dichroism analysis. Some of the isolated compounds were screened for their antibacterial activity and only rhamnocitrin (9) exhibited a moderate activity against Staphylococcus aureus with a MIC of 106 µM. Based on the traditional use of the seeds of this plant to manage heart palpitations and previous works demonstrating their pharmacological effects on some cardiovascular disorders, a correlation was established between their chemical constituents and the pharmacological activities.

Asperuloside (ASP) exhibits a broad range of biological and pharmaceutical activities. The purpose of this study was to investigate the hepatoprotective effects of ASP and its potential mechanisms in suppressing hepatic fibrosis. RNA sequencing revealed significant alterations in the SIRT6/Toll-like receptor pathway in TAA-induced mice. SIRT6 deficiency attenuated the effect of ASP on the expression of α-SMA, TLR2, TLR4, and IRAK4 in activated LX-2 cells. ASP reduced serum levels of ALT, AST, and TBil, ameliorated histopathological changes in the liver, and suppressed extracellular matrix (ECM) accumulation in TAA-induced hepatic fibrosis. Additionally, ASP downregulated inflammatory factors such as TLR2 and TLR4, while enhancing SIRT6 expression in TAA-induced mice. ASP alleviated hepatic inflammation and fibrogenesis in TAA-induced hepatic fibrosis and reversed the activation of HSCs. Collectively, these findings support the potential of ASP as a novel therapeutic option for hepatic fibrosis.

Using a combination of chromatographic techniques, two previously undescribed megastigmane glycosides, namely sapidisides A and B (1 and 2), along with 15 known metabolites (3-17), were identified from S. discolour leaves. Their structures were established by HRESIMS, NMR spectroscopic analyses, and experimental ECD spectra. Among them, metabolites 1, 2, 5, 9, and 10 exhibited suppression effects on NO production in LPS-induced RAW264.7 cells (IC₅₀: 24.4-48.7 μM), compared with the positive control dexamethasone (IC₅₀: 13.12 μM).

Phytochemical investigation on the aerial part of Fritillaria walujewii Regel resulted in the isolation of two new steroidal alkaloids, named as walujewine F (1) and G (2), and five previously reported compounds 3-7. Structural elucidation of compounds 1-7 was achieved by employing various spectroscopic techniques. The cholinesterase inhibitory potential of all the compounds was systematically evaluated. Compound 1 exhibited moderate AChE inhibition with the IC₅₀ value of 70.37 μM, while compound 2 demonstrated obvious dual AChE and BChE inhibitory effects, with the IC₅₀ values of 91.69 μM and 67.12 μM, respectively, but lower than the positive control galantamine (IC₅₀ values of 2.80 μM for AChE and 21.85 μM for BChE).

This manuscript revisits conventional uses of Artemisia roxburghiana Wall. ex Besser for treating hyperglycaemia, protozoal infections and cancer on scientific grounds. Secondary metabolites estimation revealed the presence of terpenoids, glycosides, tannins and saponins. Significant artemisinins were quantified in leaf n-hexane extract. Highest metal chelation, ABTS and OH scavenging were observed in leaf ethyl acetate extract (IC₅₀=30.21 ± 1.28, 54.21 ± 1.99 and 36.97 ± 2.67 µg/mL, respectively). Stem ethyl acetate extract delayed bleaching of β-carotene (IC₅₀=44.44 ± 1.03 µg/mL) and sequestered NO (IC₅₀=34.37 ± 1.15 µg/mL). Maximum antimicrobial (11 ± 0.09 mm zone of inhibition against A. niger), antimalarial (IC₅₀=18.76 ± 1.80 µg/mL), protein kinase inhibition (24 ± 1.09 mm) and potency (LD₅₀=29.02 ± 2.08 μg/mL) were recorded for leaf n-hexane extract. Leaf methanol and distilled water extracts inhibited α-amylase and α-glucosidase (82.35 ± 3.25 and 75.25 ± 2.5%, respectively). Highest tumour inhibition (84 ± 2.50%) and antiproliferative potential against DU-145 cell line (IC₅₀ 17.41 ± 2.31 µg/mL) were manifested by leaf ethyl acetate extract. The results reported herein provide in vitro evidence of the traditional use of Artemisia roxburghiana.

Ultraviolet B (UVB) radiation contributes to skin photoaging and inflammation. This study investigated the protective effects of two alkaloids from Aspergillus terreus C23-3 against UVB-irradiated human keratinocytes (HaCaT) and H₂O₂-stimulated fibroblasts (BJ cells). Alkaloids 1 and 2 effectively protected these cells without toxicity at concentrations ranging from 1 to 10 μM, significantly reducing ROS levels and oxidative stress. Molecular docking indicated that alkaloids 1 and 2 can form stable complexes with MMP-1, and inhibit its activity. This finding was verified by Western blot tests, which demonstrated that alkaloids 1 and 2 could effectively inhibit MMP-1 expression in H₂O₂-stimulated BJ cells. In addition, alkaloids 1 and 2 can inhibit UVB-induced activation of the MAPK pathway, reducing c-Jun and c-Fos phosphorylation and thereby reducing MMP-1 transcription. By blocking these signalling pathways and possibly inhibiting the nuclear translocation of p65, alkaloids 1 and 2 attenuate UVB-induced inflammatory responses, in particular by reducing the pro-inflammatory markers IL-6, IL-1β, COX-2 and iNOS. Consequently, these alkaloids may have therapeutic potential for alleviating skin photoaging and inflammation.

Baliospermum solanifolium (Burm.) Suresh, a plant extensively utilised in ayurvedic and traditional medicine for liver disorders and gastrointestinal ailments, has pharmacological properties that remain under explored. This study evaluated the protective effects of B. solanifolium leaf methanolic extract (BMLE) and its partially purified fraction (BMLE-AF) against peroxidative cellular injury. The extract was prepared using the percolation method and fractioned via silica gel column chromatography. Phytochemical and TLC analysis of a purified BMLE-AF ensured the presence of polyphenols, saponins, and terpenoids with LC/MS analysis revealed myricetin, kaempferol glycosides, cotinine and securinine. BMLE was toxic to HeLa cells but not the Vero or Raw 264.7 cells, while BMLE-AF showed no cytotoxicity. Both BMLE and BMLE-AF protected cells from H₂O₂/AAPH-induced death, but BMLE-AF exacerbated toxicity in Raw 264.7 macrophage likely due to the myeloperoxidase system. These findings highlight BMLE's potential as a new source of candidate drugs for chronic inflammatory diseases.

A phytochemical examination of the roots of Angelica acutiloba was undertaken, resulting in the identification of 21 distinct constituents. NMR spectroscopic characterisation revealed the presence of flavonoids, lignans, monoterpenes, aldehydes, amino acids, alkaloids, benzofurans, phenylpropanoids, glycosides, and sac-charides. Among these, two monoterpenes and one lignan were identified as previously undescribed compounds, designated as Angeliterpene A (1), Angeliterpene B (2) and Angelignan A (3), respectively. Furthermore, the results indicated that novel compounds 1, 2, 3, as well as compounds 6, 7, and 13, exhibited nitric oxide (NO) inhibitory activity, with compound 6 demonstrating the most potent effect.