Chemistry & Biodiversity最新文献

In this study, a green and efficient method has been developed for the preparation of aryl semicarbazones using Kigelia pinnata flower-derived carbon quantum dots (KP-CQDs) as a sustainable catalyst. The reaction between various aldehydes/acetophenones and semicarbazide (SC) hydrochloride was carried out smoothly at room temperature in an ethanol–water (1:4) solvent system, and excellent yields (83%–95%) were achieved within a short reaction time of 5–20 min, demonstrating the high catalytic efficiency of KP-CQDs. A total of nine derivatives were synthesized, among which six compounds are reported for the first time. Furthermore, the biological potential of these compounds was investigated through in silico studies. The molecules were subjected to prediction of activity spectra for substances (PASS) online prediction to predict probable biological targets, and based on these predictions, molecular docking was performed against human mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase 2 (Protein Data Bank [PDB] ID: 2WYA), hepatitis A virus 3C protease (PDB ID: 1HAV), and foot-and-mouth disease virus (FMDV) 3C protease (PDB ID: 2WV4). On conducting molecular docking, molecules 3f (−15.57 kcal/mol), 3c (−5.61 kcal/mol), and 3e (−9.44 kcal/mol) showed remarkable activity with 2WYA, 1HAV, and 2WV4, respectively. This method offers several key advantages, including the use of a green and reusable CQD catalyst, mild reaction conditions, short reaction times, excellent yields, and the preparation of new semicarbazone derivatives with unexplored biological activities.

Piper longum Linn., or long pepper, is an important medicinal plant in Ayurveda known for its anti-inflammatory, antioxidant, and bio-enhancing properties. Its phytochemical composition, particularly piperine (PP) and piperlongumine (PLG), is affected by its cultivation in different geographical locations. Understanding these geographical variations is essential for optimizing its medicinal use and ensuring quality in herbal formulations. This study investigates the impact of geographical variation on the phytochemical and pharmacognostical properties of P. longum Linn, an essential Ayurvedic medicinal plant. Samples were collected from three distinct regions in India—Ranikhet, Western Ghats-Kerala, and Bangalore—to evaluate differences in the concentration of vital bioactive compounds, PP and PLG. Pharmacognostic, physicochemical, and phytochemical analyses were conducted using standard methods. Reverse phase high-performance liquid chromatography (RP-HPLC) was used to measure the amount of markers, and 1,1-diphenyl-2-picryl hydrazyl (DPPH) assays were used to calculate the antioxidant activity. The results reveal significant differences in bioactive marker concentrations across the regions, with the Ranikhet sample showing the highest levels of PP (12.57 ± 0.25 mg/g) and PLG (0.865 ± 0.012 mg/g), whereas the latter was absent in samples from the other regions. Additionally, the Ranikhet sample exhibited superior antioxidant activity and higher total phenolic and flavonoid content. Morphological differences were also observed in the plant fruits, varying in size and color across regions. According to these results, the location of P. longum affects its phytochemical makeup and antioxidant properties. This means that the Ranikhet region may be a better place to get it for making medicines that need PLG activity. This research highlights the importance of considering geographic origin in standardizing and sourcing medicinal plants for optimal therapeutic efficacy.

Benzylisoquinoline alkaloids (BIAs) are a diverse group of plant secondary metabolites with significant pharmacological activities, where methylation reactions catalyzed by methyltransferases play crucial roles in structural diversification and bioactivity modulation. In this study, we identified and functionally characterized two key methyltransferases, Sinomenium acutum 6-O-methyltransferase (Sa6OMT) and S. acutum coclaurine N-methyltransferase (SaCNMT), involved in BIA biosynthesis in S. acutum, a traditional Chinese medicinal plant with anti-rheumatoid arthritis properties. Candidate genes, including SaOMT3 and SaNMT4, were selected through transcriptome analysis of different tissues combined with phylogenetic analysis and expression pattern evaluation. Functional validation demonstrated that SaOMT3 encodes a 6OMT that catalyzes the conversion of (S)-norcoclaurine to (S)-coclaurine, while SaNMT4 encodes a CNMT that mediates the N-methylation of (S)-coclaurine to (S)-N-methylcoclaurine. Biochemical characterization revealed optimal activity at 40°C for both enzymes, with distinct optimal pH levels (8.5 for Sa6OMT and 8.0 for SaCNMT) and higher catalytic efficiency for SaCNMT. This study provides valuable insights into the molecular mechanisms underlying BIA biosynthesis in S. acutum and enhances our understanding of plant specialized metabolism.

The Red Sea, a biologically rich marine ecosystem, is a promising source of novel bioactive compounds with significant therapeutic potential. This review analyzes a decade of research on the isolation, characterization, and biological activities of compounds obtained from sponges, corals, microalgae, seaweeds, marine fish, and microorganisms. These bioactive molecules, including alkaloids, glycosides, terpenes, and peptides, exhibit antimicrobial, anticancer, anti-inflammatory, and neuroprotective properties. Various extraction techniques, ranging from traditional solvent extraction to advanced methods such as supercritical fluid and ultrasound-assisted extraction, aid in their isolation. Meanwhile, chromatographic purification and bioassay-guided fractionation enhance their identification. However, challenges such as limited availability, complex extraction processes, and regulatory constraints hinder the clinical translation of these technologies. Addressing these barriers requires innovative extraction strategies, advanced characterization techniques, and interdisciplinary approaches that integrate marine biology with emerging technologies, such as deep learning. Future research should focus on exploring molecular interactions within coral reef ecosystems, unraveling marine bacterial diversity, and implementing conservation strategies to protect the Red Sea's unique biodiversity while accelerating drug discovery.

One of the most crucial approaches to treating some aggressive diseases, like cancer, is to either discover new medications or to refine and adapt those that already exist. Among these approaches is the drug delivery system, which could help reduce drug doses and side effects. In the existing endeavor, cisplatin (CIS) was loaded on polyvinyl alcohol/polyethylene oxide nanofiber (PVA-PEO-CIS) by the electrospinning method. The fabricated nanofiber was characterized, and its anticancer impact against cervical cancer cells (HeLa) was measured. Also, its antibacterial effect was studied. The obtained findings indicated that (PVA-PEO-CIS) nanofiber inhibits HeLa growth with a half-maximal inhibitory concentration (IC₅₀) of 19.82 µg/mL compared to free CIS (IC₅₀ = 26.31 µg/mL). Importantly, the nanofiber was less toxic to normal WI-38 cells compared to free CIS. The improvement of the anticancer action of CIS was consistent with CIS release studies that indicated about 50% of CIS was released from nanofibers within 8 h. Further, PVA-PEO-CIS nanofiber showed potent bactericidal impact against different bacterial strains, including Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. For several biological applications, including tumor therapy and antibacterial research, PVA-PEO-CIS may be a potential medication candidate.

Platycladus orientalis (L.) Franco is an evergreen conifer widely used in folk medicine. However, few studies have explored the volatile composition of its fruits. The present study aimed to perform a comparative gas chromatography–mass spectrometry (GC–MS) profiling of the fruit essential oil and n-hexane extract, with assessment of the antioxidant and enzyme inhibitory potentials. In silico molecular docking and predictive absorption, distribution, metabolism, and excretion (ADME) profiling of the main identified components were adopted to support the obtained results. Results revealed that the hydrodistilled oil was dominated by monoterpene hydrocarbons (91.70%), with α-pinene (55.83%) as the main component. The n-hexane extract was dominated by diterpenoids (24.65%) and monoterpene hydrocarbons (25.46%), with 10-nonacosanol being the major component (18.95%). Both samples showed antioxidant properties. The hydrodistilled oil exhibited higher performance, indicated by ferric reducing antioxidant power (FRAP) and total antioxidant capacity assays. The n-hexane extract exhibited higher cupric reducing antioxidant capacity (CUPRAC) and metal chelating ability (MCA) activities. Both samples showed inhibition of acetylcholinesterase, butyrylcholinesterase, and tyrosinase enzymes. α-Amylase and α-glucosidase enzymes were only inhibited by the n-hexane extract, indicating its blood glucose management effect. The molecular docking and predictive ADME analyses supported the obtained results. These findings revealed that the extraction method markedly influenced the chemical composition and biological activity, highlighting the potential for treating dysregulated-enzyme conditions in addition to the health-promoting application of the essential oil in the food and pharmaceutical industries.

Tetrahydroserpentine (ThS), an indole alkaloid and α₁‑adrenergic receptor blocker, is used for treating hypertension, a condition often linked with diabetic pathophysiology. However, its toxicological profile and safety under hyperglycemic conditions remain unclear. This study aimed to assess the antioxidant activity, subacute toxicity, and effect of ThS under hyperglycemic conditions using in silico, in vitro, and in vivo approaches. In vitro toxicity analysis demonstrated that ThS exhibited dose-dependent cytotoxicity in both cancerous and noncancerous cells at ≥ 25 µM. It showed moderate antioxidant activity by reducing H₂O₂-induced ROS, although its antioxidant effect declined with time. In silico network pharmacology predicted 110 targets involved in metabolic, inflammatory, and proliferative pathways. In vivo subacute toxicity studies in mice showed that oral doses ≥ 5.0 mg/kg/day led to liver and kidney damage, as evidenced by altered hematological, biochemical, and histological parameters. A lower dose (2.5 mg/kg/day) was identified as non-toxic and used in streptozotocin-induced hyperglycemic mice. At this dose, ThS did not improve hyperglycemia-induced liver and kidney damage and, notably, worsened serum SGOT and urea levels. These findings highlight that while ThS possesses limited antioxidant capacity, it can be toxic at higher doses and harmful under hyperglycemic conditions. Further studies are required to ensure its safe therapeutic use in hyperglycemic conditions.

The preparation of metal or metal oxide nanoparticles (NPs) using the green method is rapid, low-cost, and eco-friendly. In this study, nickel oxide NPs (NiO NPs) were synthesized using Foeniculum vulgare seed extract. The green-synthesized NiO NPs were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. SEM and TEM images revealed spherical and sheet-like morphologies. The NiO NPs exhibited notable antioxidant, antimicrobial, and molecular interaction properties. Antioxidant activity was evaluated using DPPH⁺ and ABTS⁺ assays, showing IC₅₀ values of 12.68 ± 0.56 and 11.82 ± 0.84 µg/mL, respectively, compared to standard antioxidants ascorbic acid (8.94 ± 2.2 µg/mL) and gallic acid (1.2 ± 0.67 µg/mL). Antibacterial assays against Staphylococcus aureus, Bacillus sp., Pseudomonas aeruginosa, and Escherichia coli revealed concentration-dependent inhibition, with maximum zones of inhibition at 80 µg/mL, measuring 7.86 mm for E. coli and 7.21 mm for S. aureus. Antifungal activity showed dose-dependent inhibition of Aspergillus niger (6.00–7.96 mm) but minimal effect on Fusarium sp. (6.00–6.03 mm), compared to ketoconazole controls (9.36 and 9.21 mm, respectively). Molecular docking revealed strong binding affinities of NiO NPs with P. aeruginosa (−9.9 kcal/mol) and A. niger endoglucanase (−8.5 kcal/mol), comparable to streptomycin (−11.1 kcal/mol) and ketoconazole (−10.0 kcal/mol). These findings highlight the promising antioxidant and antimicrobial potential of NiO NPs for biomedical applications.