Chemistry & Biodiversity最新文献

Staphylococcus aureus is an important pathogen in humans, responsible for a wide range of community-acquired and nosocomial infections, and is especially known for its antibiotic resistance. Traditional therapies are increasingly failing, necessitating new approaches to antimicrobial therapy. One promising strategy involves the use of quorum-sensing inhibitors (QSIs) that target the communication systems of bacteria responsible for the regulation of virulence, toxin production, and biofilm formation. In this review, we provide an overview of QSIs by dividing the natural and synthetic QSIs and also their mechanism of action, the in vitro and in vivo assessments performed, and potential synergy with the conventional antibiotics. Literature was comprehensively reviewed from PubMed, Scopus, and Web of Science databases according to PRISMA guidance. QSIs showed great potential in interfering with the pathogenicity of S. aureus, especially with the accessory gene regulator (Agr) system. Nonetheless, bioavailability, selectivity, and translational issues persist. The review underlines the therapeutic potential and prospects of QS inhibition as an alternative antibacterial approach against S. aureus.

Artemisia vestita is a traditional Tibetan folk medicine. Bioactivity-guided fractionation revealed that the petroleum ether fraction of A. vestita possessed potent anti-complementary activity (CH₅₀: 0.016 ± 0.006 mg/mL), demonstrating therapeutic efficacy against H1N1-induced viral pneumonia in murine models. Subsequent phytochemical analysis of this bioactive extract using silica gel chromatography coupled with semi-preparative high-performance liquid chromatography yielded 14 compounds, including three new monoterpenes (1–3) and one coumarin (13) with relatively high abundance. Notably, studies on the activity of the isolated compounds revealed that the coumarin (scopoletin) exhibits dominant anti-complementary activity and provides significant protective effects against H1N1-induced viral pneumonia in mice. This study provides insights into the development and utilization of A. vestita and scopoletin.

Pharmacokinetic deficiencies account for nearly 40% of clinical drug candidate failures, emphasising the importance of early in vitro evaluation. Following the 3Rs principle, this study assessed the in vitro pharmacokinetic properties of thiourea derivatives of naproxen (1–14). Permeability assessment using the parallel artificial membrane permeability assay method revealed that derivatives 4 (-logPe = 4.13, p = 0.0859) and 7 (-logPe = 3.94, p = 0.2291) exhibited the highest passive gastrointestinal absorption potential, comparable to naproxen. Evaluation of binding affinity to human serum albumin (HSA) using the high-performance affinity chromatography method identified two groups of compounds: high-binding aromatic amine derivatives (except derivative 5) and low-binding aromatic amino acid ester derivatives. Microsomal stability assays indicated that compound 7 underwent the most extensive metabolic degradation (65.83% decrease). These findings suggest that further structural optimisation of compound 7, such as esterification with higher or branched alcohols, should lead to the improvement of HSA binding and reduction of metabolic susceptibility. Conversely, compound 4 combines favorable biological activity with a pharmacokinetic profile closely resembling that of naproxen. Although limited by the exclusive use of in vitro models and the absence of in vivo validation, this study provides valuable insights for the rational design of naproxen-based thiourea derivatives with enhanced anti-inflammatory and anticancer potential.

Ocimum basilicum L. is widely documented for its medicinal properties, primarily attributed to essential oils (EOs) produced by glandular trichomes on its leaves. The present study investigates how different leaf growth phases lag, log, and stationary affect EO yield and pharmacological activity. Microscopic analysis revealed that trichome density was highest during the lag phase, while trichome size peaked was greatest in the stationary phase. EO yield was greatest in the lag phase (1.26 mL/5 g fresh weight); however, GC–MS profiling indicated that the stationary phase EO contained the highest concentrations of key bioactive compounds, notably eriodictyol and 2,5-dioxoimidazolidin-4-yl urea. Bioactivity assays demonstrated that EO from the log phase exhibited the strongest DPPH radical scavenging activity (63.87 ± 2.95%), whereas the stationary phase EO showed highest total phenolic content (982.61 ± 62.45 mg GAE/g), antioxidant capacity (0.79 ± 0.01 mg EAA/g), anti-inflammatory activity (91.89 ± 10.28%), and antidiabetic potential (95.56 ± 0.00%). Antimicrobial testing confirmed the stationary phase EO as the most potent, with the lowest MIC and MBC values against Staphylococcus aureus (6.25 and 3.125 µL/mL), Ralstonia solanacearum (12.5 and 3.125 µL/mL), and Xanthomonas oryzae (50 and 3.125 µL/mL). These findings suggest that while EO yield is highest in the lag phase, the stationary phase offers the most comprehensive pharmacological potential, making it the optimal harvest stage for medicinal applications.

In the phytochemical study of the leaves of Ligustrum robustum, two new monoterpenoid glycosides named ligurobustosides V (1a), V₁ (1b), and a new secoiridoid glycoside named ligurobustoside W (2), together with three known glycosides (3–5), were isolated and identified by spectroscopic and chemical methods. The biological research discovered, compounds 3 and 4 showed powerful fatty acid synthase inhibitory activity (half inhibitory concentration [IC₅₀]: 4.21 ± 0.16–4.51 ± 0.12 µM); compounds 1, 4, and 5 displayed some α-glucosidase inhibitory activity; compounds 1-5 revealed some α-amylase inhibitory activity; compounds 1, 3, and 4 showed stronger 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging effect (IC₅₀: 3.98 ± 0.01–6.80 ± 0.07 µM) than L-(+)-ascorbic acid (IC₅₀: 10.06 ± 0.19 µM). Compounds 1, 3, and 4 were considered as some functional constituents of L. robustum to prevent diabetes mellitus and its complications.

To increase solubility, amines, including dimethylamine (DMA) and isopropylamine, are included in commercial formulations of phenoxyacetic acid herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA), but amine volatilization during production and use poses challenges for the social environment and living organisms. To mitigate the problem by replacing currently applied volatilized amines and developing high-efficacy and environment-friendly herbicides, three camphene-derived ammonium phenoxyacetates and one glyphosate were synthesized and characterized. The preliminary herbicidal activity tests showed that several compounds displayed higher herbicidal performance against Lolium multiflorum Lam. and Brassica campestris than their corresponding herbicide-amine salts. Compared to DMA salts of 2,4-D and MCPA, compounds 5b–5c containing one or two chlorine atoms presented similar or higher herbicidal activity against B. campestris even at a lower concentration (0.0006 mmol/L). Besides, compound 5b with the half maximal inhibitory concentration (IC₅₀) value of 0.000281 mmol/L against B. campestris shoot growth showed 611.7% higher herbicidal activity than that of DMA salt of 2,4-D, whereas compound 5c with an IC₅₀ value of 0.026 mmol/L against L. multiflorum Lam. shoot growth presented 38.5% higher herbicidal activity than DMA salt of MCPA. This study indicated that compounds 5b–5c could be promising herbicidal candidates.

This study explored the anti-inflammatory mechanisms of Gentiana szechenyii Kanitz. (GS), a Tibetan medicinal herb, by combining UPLC–MS/MS, network pharmacology, molecular docking, and molecular dynamics (MD) simulation. Using the lipopolysaccharide (LPS)-induced RAW264.7 cell inflammation model, the anti-inflammatory effect of GS was confirmed by detecting the release amount of nitric oxide (NO) and the levels of inflammatory factors tumor necrosis factor (TNF) and interleukin-6 (IL-6). UPLC–MS/MS identified 40 constituents, whereas network analysis predicted 5 core compounds (isovitexin 4′,7-diglucoside, loganin, isoorientin-2″-O-glucoside, gentiopicroside, sweroside), 5 key targets (TNF, IL-6, GAPDH, epidermal growth factor receptor [EGFR], HSP90AA1), and three critical pathways (PI3K-Akt, hypoxia inducible factor-1 [HIF-1], IL-17). Molecular docking showed strong binding between core compounds and targets; the binding energies were all lower than −5 kcal mol⁻¹, among which isovitexin 4′,7-diglucoside had the lowest binding energy to EGFR (−9.4 kcal mol⁻¹). MD simulation confirmed stable binding of TNF with the five core compounds. This study comprehensively clarifies the pharmacodynamic material basis and mechanism of action of GS in anti-inflammation, providing an experimental basis for further development and utilization. It is expected to be applied to the adjuvant treatment of inflammation-related diseases such as chronic bronchitis and pharyngitis in the future, thereby promoting the modernization of Tibetan medicine.