Chemistry & Biodiversity最新文献

Twelve published enzyme kinetic datasets were fitted with the Michaelis–Menten equation via non-linear regression and with linear transformations (Lineweaver–Burk, Eadie–Hofstee, and Hanes–Woolf) via linear regression to compare parameter estimates (V_max and K_M). Model performances were compared based on the sum of squared error values calculated on the untransformed scale. The best method to obtain V_max and K_M was to fit the Michaelis–Menten equation via nonlinear regression. Among linear transformations, the Hanes–Woolf yielding the closest estimates to the non-linear fit in seven out of 12 datasets, and the Eadie–Hofstee in five out of 12. Lineweaver–Burk, despite its widespread use, consistently performed the poorest, providing no closest estimates in any dataset. We concluded that the Lineweaver–Burk transformation may be utilized for data visualization; however, it is not recommended for estimating kinetic parameters, at least without weighted linear regression. If simple linear regression is to be employed for the determination of V_max and K_M, Hanes–Woolf transformation presents a preferable alternative, albeit with certain inherent limitations that must be considered. It can also be used for educational purposes (Excel solutions of this study are available at https://drive.google.com/drive/u/0/folders/1KfyvXTGG-3Hgc9MVlXiKQH1YHbpAYwNm for further reference). Researchers should apply non-linear regression to obtain V_max and K_M.

This study compared Sphagnum papillosum, Rhytidiadelphus triquetrus, and Ditrichum gracile in terms of total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS, ferric reducing antioxidant power [FRAP]), phenolic profiles, fatty acid compositions, and mineral contents. S. papillosum had the highest TPC (986.11 mg GAE/kg) and ABTS activity (9732.14 mg Trolox/kg). R. triquetrus showed the highest TFC (874.01 mg QE/kg) and was rich in protocatechuic (18 803 mg/g) and 4-hydroxybenzoic acids (23.219 mg/g). Although D. gracile had lower antioxidant activity, it contained high lipid (6.71%) and ash (27.66%) levels, along with substantial potassium (73 573.86 mg/kg) and calcium (26 135.94 mg/kg) accumulation. Palmitic acid (C16:0) was the dominant fatty acid in all species. These results demonstrate significant biochemical variation among the studied mosses, underlining their potential as sources of natural antioxidants, bioindicators of environmental stress, and candidates for bioremediation.

Plant essential oils, rich in natural bioactive constituents, demonstrate significant antioxidant potential and have emerged as a prominent research focus in this domain. Ledum palustre L. essential oil (LPEO), abundant in terpenoids, exhibits considerable value for its antioxidant mechanisms. However, traditional extraction methods result in low LPEO extraction yield. Consequently, this work employs ionic liquid (IL)-assisted hydrodistillation, with 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF₄) selected as the optimal IL through systematic screening. The Box–Behnken design (BBD) was used to determine the optimal extraction conditions for LPEO. The optimal extraction yield was 0.839% ± 0.018%. The extraction yield of essential oil extracted from L. palustre was increased by 103.64% compared to traditional hydrodistillation method. Subsequent antioxidant activity assays were conducted on the extracted LPEO, and the experimental data demonstrated that LPEO exhibits excellent scavenging activity against both free radicals and superoxide anions. These findings hold significant reference value for the high-value utilization of medicinal plant resources.

Cancer remains a global health challenge, with colorectal cancer ranking third in prevalence and second in cancer-related deaths worldwide. Conventional treatments have limitations, leading to increased interest in phytotherapy as a potential alternative. Asparagus racemosus Willd., known for its pharmacological properties, remains scientifically underexplored. Our previous study demonstrated that the ethanolic extract of A. racemosus Willd. exhibited potent cytotoxic effects on HCT-116 colorectal cancer cells, prompting further investigation of its therapeutic potential. In this study, A. racemosus Willd. ethanolic extract (ARE)’s apoptotic effects on HCT-116 cells were explored through various molecular techniques. DAPI (4′–6′-diamidino-2-phenylindole) staining showed clear signs of apoptosis, and DCFH-DA (2′,7′-dichlorodihydrofluorescein diacetate) staining indicated an ROS-dependent apoptotic pathway. Rhodamine staining revealed mitochondrial membrane potential disruption, suggesting the involvement of the intrinsic pathway. Annexin V assays showed a significant increase in apoptotic cells, and DNA fragmentation confirmed apoptosis. Cell cycle analysis indicated cell cycle arrest, whereas Caspase-3/7 activity assays and Western blotting confirmed apoptosis induction via a Caspase-3-dependent pathway. These findings suggest that ARE is a potent natural anticancer agent targeting colorectal cancer through interconnected apoptotic pathways. This research highlights the potential of ARE for developing a nontoxic, cost-effective anticancer treatment, offering hope for colorectal cancer patients.

Seven terpenoids were isolated from Artemisia argyi leaves, including one new triterpenoid featuring a unique terminal diagonal methoxy-substituted side chain and six known analogues. Their structures were confirmed by NMR and HR-ESI-MS spectral analyses, and the absolute stereochemistry of Compound 1 was elucidated via x-ray diffraction analysis. Bioassays revealed that 2 exhibited cytotoxicity against U251 glioma cells (IC₅₀ = 5.6 µM) and potently abrogated cell migration and invasion in a dose-proportional manner by suppressing PI3K/AKT/mTOR phosphorylation, as confirmed by Transwell and Western blot analyses. Bioinformatics analysis further suggested EGFR as a potential upstream target mediating these effects. These findings indicated A. argyi as a possible source of bioactive terpenoids with anti-glioma potential, providing a theoretical basis for further pharmacological studies.

Prunella vulgaris, a medicinal and edible plant, is traditionally recognized for its ability to clear heat and relieve liver fire. This study investigated the metabolic composition, antioxidant, and anti-inflammatory activities of P. vulgaris. Multivariate analysis revealed a significant difference in the metabolic profile among different samples from four distinct regions. Notably, the sample Xingren displayed the preferred antioxidant and anti-inflammatory activities. Network pharmacology analysis and molecular docking further confirmed the high binding affinity of the main active ingredients (isothankunic acid) and targets. Furthermore, naringenin 7-O-(2'',6''-di-O-α-rhamnopyranosyl)-β-glucopyranoside, okanin 4'-gentiobioside, 2''-(6-acetylglucosyl)astragalin, and dihydroscoparin may be active markers of antioxidant activity. These results validate the traditional anti-inflammatory use of P. vulgaris and underscore its potential as a source of natural food antioxidants, supporting its further development as a functional ingredient.

Cancer continues to be a leading cause of morbidity and mortality worldwide, with significant variability in incidence and treatment outcomes. This study investigates novel benzimidazole-hydrazone derivatives aimed at inhibiting receptor tyrosine kinases essential for cancer progression. We synthesized a series of compounds, verifying their structures using IR, NMR, and mass spectral analyses. Biological evaluations assessed cytotoxicity against cancer cell lines (HCT-116, MCF-7, HepG2) alongside a normal cell line (WI-38). Several compounds, particularly 6f and 6h–j, demonstrated potent cytotoxicity, with IC₅₀ values as low as 4.82–10.23 µM against MCF-7 cells, surpassing reference drugs like sorafenib and doxorubicin. Compound 6i exhibited the highest activity against kinases such as EGFR, Her2, and VEGFR2, while cell cycle analysis showed G₀–G₁ phase arrest in HepG2 cells. Apoptotic mechanisms were activated, with significant increases in caspase-3 and BAX levels and decrease in Bcl2. In silico studies indicated strong binding interactions of the compounds with kinases, and pharmacokinetic assessments revealed favorable properties. These findings underscore the potential of benzimidazole-hydrazone derivatives as effective cancer therapeutics, meriting further investigation into their mechanisms and clinical implications.

Breast cancer persists as the most prevalent malignancy and principal contributor to cancer-associated mortality among women worldwide, exhibiting marked disease heterogeneity and therapeutic resistance. Consequently, the development of novel therapeutic agents remains imperative. Ribociclib, a cyclin-dependent kinase 4/6 inhibitor, has emerged as a focus in adjuvant breast cancer research due to its mechanism of cell cycle arrest induction. Building upon this rationale, we designed and synthesized a novel Ribociclib derivative, RB-BC, systematically investigating its anti-neoplastic efficacy and molecular mechanisms in breast cancer through an integrated in vitro and in vivo experimental system. The compound's anti-proliferative effects were quantitatively assessed via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, 5-ethynyl-2’-deoxyuridine incorporation assays, and colony formation assays. Functional characterization through cell adhesion assays, scratch wound healing assays, and Transwell invasion assays demonstrated RB-BC's dose-dependent suppression of tumor migration and invasion. Mechanistic analyses, conducted via RNA sequencing and Western blotting, revealed that its anti-tumor activity primarily stems from the activation of the p53 pathway, which induces caspase-3-mediated apoptosis in breast cancer cells. Machine learning algorithms identified p53-associated genetic signatures, and subsequent bioinformatics analyses elucidated their significant correlation with immune cell infiltration dynamics in the tumor microenvironment. Moreover, RB-BC effectively suppressed tumor growth in vivo and significantly disrupted angiogenesis in the chick chorioallantoic membrane assay. In summary, the Ribociclib-derived compound, RB-BC, demonstrates compelling potential as a candidate therapeutic agent for breast cancer.

This study evaluated the branch, leaf, and fruit extracts of Laurus nobilis collected from Artvin in terms of phenolic composition, antioxidant, antimicrobial, and antidiabetic activities and additionally investigated the binding of selected phenolics to α-amylase/α-glucosidase targets through molecular docking. Using LC–ESI–MS/MS analysis, 31 phenolic compounds were quantitatively identified, with epicatechin, luteolin-7-O-glucoside, and rutin predominating particularly in the branches and leaves. Antioxidant capacity was higher in branches and leaves (total phenolic content [TPC]/FRAP/DPPH IC₅₀: branches and leaves, respectively, 95.27–60.84 mg gallic acid equivalent [GAE]/g, 206.16–162.05 mg Trolox equivalent [TE]/g, and 46.95–113.49 µg/mL). Antimicrobial activity was observed within a minimum inhibitory concentration (MIC) range of 1.25–10 mg/mL; leaves exhibited the strongest effect against Bacillus cereus (1.25 mg/mL), whereas fruits were most effective against Candida albicans (1.25 mg/mL). In antidiabetic evaluation, fruits yielded the lowest IC₅₀ values against α-amylase and α-glucosidase (4.31 and 8.97 mg/mL, respectively), suggesting a “composition-over-quantity” effect despite low total phenolic content. Docking results supported high binding affinities of rutin (α-glucosidase −9.3 kcal/mol; α-amylase −8.1 kcal/mol) and luteolin (−8.6 kcal/mol for both enzymes). Overall, although branches and leaves exhibited strong antioxidant profiles, fruits showed more pronounced inhibitory effects on digestive enzymes; therefore, fractionation studies and in vivo/kinetic validations are recommended.