Natural Product Research最新文献

Viburnum cylindricum Buch. -Ham. ex D. Don is abundant in bioactive secondary metabolites with promising functions such as anti-inflammation and anti-diabetes. In this work, the polyphenolic extract of V. cylindricum leaves (VCLP) exhibited significant inhibition on α-glucosidase and urease activity. Two previously undescribed phenolic glycosides (1, 2) and fourteen known analogues (3-16) were isolated from VCLP, which were determined by spectroscopic analyses and chemical methods. The bioactivity assessment revealed that compounds 3, 4, 8, 14, and 16 could potently inhibit α-glucosidase activity with IC₅₀ values ranging from 20.83 to 28.52 μM compared to acarbose (IC₅₀ = 29.71 μM) (p < 0.05). In addition, compounds 3 and 4 showed significant urease inhibition with IC₅₀ values of 10.73 and 7.61 μM, respectively, comparable to thiourea (IC₅₀ = 28.57 μM) (p < 0.05). Moreover, the molecular docking analysis elucidated the binding mechanisms between these bioactive compounds and the enzymes α-glucosidase and urease.

This study investigates the chemical composition and cytotoxicity potential of Calophyllum fraseri M.R.Hend. & Wyatt-Sm essential oil, complemented by molecular docking analysis. Gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) identified 15 components, representing 93.1% of the total oil content. The major components were β-caryophyllene (19.4%), α-cubebene (18.3%), δ-cadinene (14.0%), α-humulene (10.3%), and γ-muurolene (9.5%). The essential oil exhibited weak cytotoxic activity against HepG2, MCF-7, and A549 cancer cell lines, with IC₅₀ values of 93.4 ± 0.15 μg/mL (HepG2), 89.2 ± 0.11 μg/mL (MCF-7), and 96.3 ± 0.12 μg/mL (A549). Molecular docking results revealed favourable interactions between γ-muurolene and Akt1, α-humulene and oestrogen receptor α (ERα), and α-cubebene and the epidermal growth factor receptor tyrosine kinase (EGFR-TK) domain. These docking results provide supportive molecular insights into potential target interactions of individual constituents rather than direct predictors of the biological activity of the crude essential oil.

A phytochemical investigation of the ethanol extract of Salvia cavaleriei var. simplicifolia E.Peter yielded two new abietane-type diterpenoids, salcasins C and D (1 and 2), along with six known diterpenoids (3-8). The chemical structures and absolute configurations of these isolates were unambiguously determined using comprehensive spectroscopic methods, coupled with DP4+ analysis and electronic circular dichroism (ECD) calculations. Additionally, the in vivo anti-Alzheimer's disease (AD) activity of all isolates (1-8) was assessed using a transgenic Caenorhabditis elegans AD pathological model. However, at a concentration of 100 μM, none of the tested compounds demonstrated anti-AD activity.

Arboviruses such as dengue and Zika are clinically significant human pathogens lacking effective antiviral treatments. Studies seeking DENV inhibitors, consider lipophilicity as a crucial parameter for optimising drug entry into infected host cells. In this study, Aloesaponarin I (1), Aloe-Emodin (2), obtained from Aloe vera roots, together with Methylnaphthazarin (3) were derivatized to increase lipophilicity, by acylation and alkylation reactions. The derivatives obtained were evaluated for antiviral activity against all four DENV serotypes and ZIKV in vitro using the Focus Reduction Neutralisation Test and Celgosivir and human sera as positive controls. Additionally, cytotoxic studies were performed showed that derivatives from (1) and (2) were non-toxic at 250-1.9 µM, while (3) derivatives from 156-7.8 µM. Derivatives as 10, 19 and 24 had the maximum inhibition percentages ranged from 82 to 99% with IC₅₀ values between 18 to 1 µM, mainly against DENV4 and Zika viruses.

Biflavonoids, a unique group within the plant flavonoid family, consist of flavonoid dimers connected by either C-C or C-O-C bonds. Two new biflavonoids (2 R, 3 R) bis-3-O-galloyl-7,3'-dimethoxy dihydroquercetin (1) and (2S, 3S) [7-O-7]-bis 3-O-galloyl, 5-methoxy dihydroquercetin (2) were identified from the Ficus racemosa L. leaf extract. The structure was determined through techniques such as ultraviolet (UV) spectroscopic, nuclear magnetic resonance (¹H NMR,¹³C NMR) spectroscopic, heteronuclear multiple bond correlation (HMBC) and mass spectrometry. Bioactivity and drug scores were evaluated through Osiris Property Explorer. The drug scores for compound 1 and compound 2 were found to be 0.38 and 0.39, respectively. Furthermore, both compounds and their derivatives were evaluated for ADME (absorption, distribution, metabolism, and excretion) and toxicity risk. Predicted scores suggested that the isolated novel dihydroquercetin possesses promising potential for biological activity and are relatively safe further explored for potential COX‑1/COX‑2 inhibitors and other important biological applications.

A chemical investigation of the ethyl acetate extract of the endophytic fungus Penicillium sp. HZ-5 derived from the leaf of Hypericum wilsonii N. Robson, led to the discovery of four alkaloids, including two undescribed compounds, penibutanoic A (1), a suspected extracting artefact, and penibutanoic B (2), along with two known compounds (3 and 4). Their structures were characterised by extensive spectroscopic and ECD calculations. Remarkably, the anti-inflammatory activities evaluation results revealed that compounds 1 and 2 possessed a moderate NO production inhibitory effects with the IC₅₀ values of 14.6 ± 0.2 and 13.9 ± 0.8 µM, respectively.