Search Results (29,464)

Barbituric acid is a heterocyclic compound with various pharmacological and biological applications. This review paper provides a comprehensive overview of barbituric acid’s synthesis, reactions, and bio-applications, highlighting its multifaceted role in various fields. Many heterocyclic derivatives were formed based on barbituric acid, for instance, pyrano-fused pyrimidine derivatives, spiro-oxindole derivatives, chrome-based barbituric acid derivatives, and many more via the atom economic method, Michael addition reaction, Knoevenagel condensation reaction, etc. In the context of bio-applications, this review examines the production of a wide range of bioactive drugs like anti-histamine, anti-leprotic, sedative–hypnotic, anti-inflammatory, anti-urease, antiviral, anti-AIDS, antimicrobial, antioxidant, anticonvulsant, anesthetic agent, antitumor, and anticancer drugs using efficient multicomponent reactions. By showcasing the versatility and potential of this compound, it aims to inspire further research and innovation in the field, leading to the development of novel barbituric acid derivatives with enhanced properties and diverse applications, with coverage of the literature relevant up to 2024. Full article

With the increase in human activities and the acceleration of urbanization, over-exploitation of natural resources has led to a decline in ecosystem services (ESs), subsequently affecting the achievement of sustainable development goals (SDGs). As the key ecological zone of Qinghai-Tibet Plateau, the stability and enhancement of ESs in the Hehuang Valley are crucial for achieving SDGs and biodiversity conservation. This study quantifies nine SDGs for the Hehuang Valley in the last twenty years. Four ecological models were utilized to compute key ESs: net primary productivity (NPP), water yield, soil retention, and sand fixation. Panel data were analyzed using a coupling coordination model to quantify the relationship between ESs and sustainable development level (SDL) in each county. Additionally, the Geographically and Temporally Weighted Regression (GTWR) model was employed to examine the correlation between ESs and SDL. The results indicate the following: (1) During the period, NPP and water yield first increased and then decreased. The capacity for soil retention and sand fixation showed an overall increase, highlighting substantial variability among counties in their ability to deliver these ESs. (2) The SDL of counties in the Hehuang Valley increased, with Xining City showing slightly higher SDL than other counties. (3) The overall coupling coordination degree among NPP, water yield, soil retention, sand fixation, and SDL in the Hehuang Valley exhibited an upward trend in the last twenty years. SDL demonstrated the highest coordination degree with NPP, followed by soil retention, water yield, and sand fixation. (4) Most counties in the Hehuang Valley exhibited a lag in SDL relative to NPP, water yield, and soil retention in the last twenty years. In the early stage, sand fixation and SDL were primarily lagging in SDL, while in the late stages, sand fixation lagged behind SDL. (5) During the period, there was an increasing negative correlation observed between the four ESs and SDL. The positive contribution of NPP and sand fixation in some counties gradually shifted to a negative effect, and the negative effect of water yield and soil retention on SDL intensified. The impact of human activities on ecosystem function hindered local SDL. This study offers scientific theoretical backing and practical recommendations for promoting SDL and biodiversity conservation in the Hehuang Valley. Full article

In three consecutive experiments, natural yogurt (NY) and fruit yogurt (FY) fortified with 5 and 10% skimmed milk powder (SMP) and 10% jam from black currant (BC), elderberry (EB), and their mixture of 1:1 (BCEB) were analyzed, and consumer acceptance was assessed. In Experiment 1, the effect of SMP (0, 5, and 10%) on selected physicochemical parameters of the NY was evaluated. With the increasing addition of SMP, a decrease in fat content (up to −19%) and, conversely, an increase in protein content (up to +82%) and viscosity were noted. Analyses of fruits and jams intended for yogurt fortification revealed a significantly higher vitamin C content in BC than in EB and higher anthocyanins in EB than in BC. In Experiment 2, NY with 5 and 10% SMP was fortified with 10% jams (BC or EB). A joint effect of SMP and the type of fruit jam was evaluated. The same trends in fat and protein contents as in Experiment 1 were detected. The sensory evaluation showed better acceptance of FY with 10% SMP and no differences between BC and EB perception. Thus, for Experiment 3, FY was prepared with only 10% SMP and 10% jam (BC, EB, BCEB). Significant differences were detected in active acidity and color measured in the CIELab system. These results were also confirmed in sensory evaluation. The overall acceptability showed that FY with different types of jam did not significantly differ. The launching of innovative fortified yogurt onto the market represents a promising way to increase the diversity of fermented dairy products with nutritionally desirable properties. Full article

Marine-derived fungi are assuming an increasingly central role in the search for natural leading compounds with unique chemical structures and diverse pharmacological properties. However, some gene clusters are not expressed under laboratory conditions. In this study, we have found that a marine-derived fungus Aspergillus sp. SYPUF29 would survive well by adding an exogenous nitric oxide donor (sodium nitroprusside, SNP) and nitric oxide synthetase inhibitor (L-NG-nitroarginine methyl ester, L-NAME) in culture conditions. Moreover, using the LC-MS/MS, we initially assessed and characterized the difference in metabolites of Aspergillus sp. SYPUF29 with or without an additional source of nitrogen. We have found that the metabolic pathway of Arginine and proline metabolism pathways was highly enriched, which was conducive to the accumulation of alkaloids and nitrogen-containing compounds after adding an additional source of nitrogen in the cultivated condition. Additionally, the in vitro anti-neuroinflammatory study showed that the extracts after SNP and L-NAME were administrated can potently inhibit LPS-induced NO-releasing of BV2 cells with lower IC₅₀ value than without nitric oxide. Further Western blotting assays have demonstrated that the mechanism of these extracts was associated with the TLR4 signaling pathway. Additionally, the chemical investigation was conducted and led to nine compounds (SF1–SF9) from AS1; and six of them belonged to alkaloids and nitrogen-containing compounds (SF1–SF6), of which SF1, SF2, and SF8 exhibited stronger activities than the positive control, and showed potential to develop the inhibitors of neuroinflammation. Full article

Sphaerococcenol A is a cytotoxic bromoditerpene biosynthesized by the red alga Sphaerococcus coronopifolius. A series of its analogues (1–6) was designed and semi-synthesized using thiol-Michael additions and enone reduction, and the structures of these analogues were characterized by spectroscopic methods. Cytotoxic analyses (1–100 µM; 24 h) were accomplished on A549, DU-145, and MCF-7 cells. The six novel sphaerococcenol A analogues displayed an IC₅₀ range between 14.31 and 70.11 µM on A549, DU-145, and MCF-7 malignant cells. Compound 1, resulting from the chemical addition of 4-methoxybenzenethiol, exhibited the smallest IC₅₀ values on the A549 (18.70 µM) and DU-145 (15.82 µM) cell lines, and compound 3, resulting from the chemical addition of propanethiol, exhibited the smallest IC₅₀ value (14.31 µM) on MCF-7 cells. The highest IC₅₀ values were exhibited by compound 4, suggesting that the chemical addition of benzylthiol led to a loss of cytotoxic activity. The remaining chemical modifications were not able to potentiate the cytotoxicity of the original compounds. Regarding A549 cell viability, analogue 1 exhibited a marked effect on mitochondrial function, which was accompanied by an increase in ROS levels, Caspase-3 activation, and DNA fragmentation and condensation. This study opens new avenues for research by exploring sphaerococcenol A as a scaffold for the synthesis of novel bioactive molecules. Full article

Although there are numerous available immunomodulators, those of natural origin would be preferable based on their safety profile and effectiveness. The research and clinical interest in immunomodulators have increased in the last decades, especially in the immunomodulatory properties of plant-based therapies. Innovative technologies and extensive study on immunomodulatory natural products, botanicals, extracts, and active moieties with immunomodulatory potential could provide us with valuable entities to develop as novel immunomodulatory medicines to enhance current chemotherapies. This review focuses on plant-based immunomodulatory drugs that are currently in clinical studies. However, further studies in this area are of utmost importance to obtain complete information about the positive effects of medicinal plants and their chemical components and molecules as an alternative to combatting various diseases and/or prevention. Full article

With the booming of renewable clean energies towards reducing carbon emission, demands for lithium-ion batteries (LIBs) in applications to transportation vehicles and power stations are increasing exponentially. As a consequence, great pressures have been posed on the technological development and production of valuable elements key to LIBs, in addition to concerns about depletion of natural resources, environmental impacts, and management of waste batteries. In this paper, we compile recent information on lithium, nickel, and cobalt, the three most crucial elements utilized in LIBs, in terms of demands, current identified terrestrial resources, extraction technologies from primary natural resources and waste. Most nickel and cobalt are currently produced from high-grade sulfide ores via a pyrometallurgical approach. Increased demands have stimulated production of Ni and Co from low-grade laterites, which is commonly performed through the hydrometallurgical process. Most lithium exists in brines and is extracted via evaporation–precipitation in common industrial practice. It is noteworthy that at present, the pyrometallurgical process is energy-intensive and polluting in terms of gas emissions. Hydrometallurgical processes utilize large amounts of alkaline or acidic media in combination with reducing agents, generating hazardous waste streams. Traditional evaporation–precipitation consumes time, water, and land. Extraction of these elements from deep seas and recycling from waste are emerging as technologies. Advanced energy-saving and environmentally friendly processes are under extensive research and development and are crucial in the process of renewable clean energy implementation. Full article

Biostimulants are a new category of materials that improve crop productivity by maximizing their natural abilities. Out of these biostimulants, those that increase seed production are considered to be particularly important as they contribute directly to the increase in the yield of cereals and legumes. Ergothioneine (EGT) is a natural, non-protein amino acid with antioxidant effects that is used in pharmaceuticals, cosmetics, and foods. However, EGT has not been used in agriculture. This study investigated the effect of EGT on seed productivity in Arabidopsis thaliana. Compared with an untreated control, the application of EGT increased the seed yield by 66%. However, EGT had no effect on seed yield when applied during or after bolting and did not promote the growth of vegetative organs. On the other hand, both the number of flowers and the transcript levels of FLOWERING LOCUS T (FT), a key gene involved in flowering, were increased significantly by the application of EGT. The results suggest that EGT improves seed productivity by increasing flower number through the physiological effects of the FT protein. Furthermore, the beneficial effect of EGT on flower number is expected to make it a potentially useful biostimulant not only in crops where seeds are harvested, but also in horticultural crops such as ornamental flowering plants, fruits, vegetables. Full article

Considerable efforts have been made to replace formaldehyde-containing adhesives in the manufacturing of wood products, particularly particleboard, with natural alternatives. One promising solution is the liquefaction of lignocellulosic materials such as wood using glycerol (C₃H₈O₃) under sulfuric acid catalysis (H₂SO₄). The aim of this study was to investigate the chemical composition and properties of spruce and oak biomass after liquefaction and to evaluate its potential as a formaldehyde-free adhesive substitute. All samples were liquefied at 150 °C for 120 min in five different wood–glycerol ratios (1:1 to 1:5). The liquefaction percentage, the insoluble residue, the dry matter and the hydroxyl (OH) number were determined as characteristic values for the polymer properties of the liquefied samples. The results showed the liquefaction percentage was up to 90% for spruce and oak. The insoluble residue ranged from 10 to 29% for spruce and from 10 to 22% for oak, the dry matter ranged from 54 to 70% for spruce and from 51 to 62% for oak, while the highest xydroxyl number was 570 mg KOH/g for spruce and 839 mg KOH/g for oak. Based on these results, liquefied wood was shown to be an effective natural alternative to synthetic resins in particleboard adhesives and a way to reduce formaldehyde emissions. This research not only supports environmentally sustainable practices but also paves the way for various bioproducts derived from liquefied biomass and points to future avenues for innovation and development in this area. Full article

This article presents a detailed analysis of the energy availability of a 15 kW hybrid wind–solar photovoltaic microplant, designed to supply the electricity demand of the power-to-gas (PtG) pilot plant located at the University of La Guajira, Colombia. The study addresses the lack of specific data on the energy availability curve, which is essential for quantifying the production percentages of green hydrogen from wind and solar photovoltaic sources. To this end, continuous data were collected over a seven-month period, recording the daily power output from both sources. Additionally, the energy requirements of the PtG pilot plant, which relies on the microplant for its electrical supply, were determined. The results indicated that during certain periods, such as specific days in November 2022 and February and March 2023, it was necessary to rely on the conventional electrical grid for backup. Moreover, it was observed that solar photovoltaic energy contributed the most electricity to the system for green hydrogen production. In the study area, although green hydrogen production is predominantly supported by the solar photovoltaic source, it is crucial to have the backup of an additional source, such as wind, due to the intermittent nature of the climatic conditions affecting these technologies. Full article

Facing persistent natural catastrophes, the necessity for disaster prevention products in afflicted cities becomes paramount. Modular design has proven to be a viable method for streamlining transportation and manufacturing processes for disaster prevention products. However, existing post-disaster prevention products often fail to incorporate the green modular concept, with limited research on spatial allocation strategies. In response to the current challenges, a new breed of green post-disaster prevention products is urgently warranted to mitigate the impact of major natural disasters and safeguard lives and property. To achieve the goal, this study employs a combined analytic hierarchy process (AHP) and geographic information systems (GIS) analysis to propose an inflatable cabin for emergency disaster prevention, specifically designed for flood scenarios. Using the inflatable cabin as an empirical case, this study introduces a layered design approach progressing from macro to meso and then to micro levels to construct an objective decision-making model to prioritize key design elements, develop spatial post-disaster prevention strategies, and analyze the mechanical performance. Results indicate that at a distance of 30 m from the base of the slope (SPIC), the impact force is most significant, reaching up to 1.8 × 10⁷ kN. As the distance increases from 30 m to 150 m, the maximum impact force decreases by an order of magnitude, and the average impact force decreases by approximately two orders of magnitude. Furthermore, this comprehensive approach, which starts from a holistic design perspective and culminates in optimizing individual disaster structures, offers practical significance for engineering design research. Full article

The dissolution of Ca and Mg in soil and their translocation in plants from different families when using different doses of liming materials of industrial waste origin have not yet been sufficiently studied. In this study, the influence of increasing doses of ameliorants of carbonate (dolomite flour—DF) and silicate (blast furnace slag—BFS) natures on the change in acid–base properties of soddy-podzolic light loamy soil, yield, and chemical composition of plants of the families Gramíneae (spring wheat), Brassicáceae (spring rapeseed), and Leguminósae (vetch and beans) was studied in five-year pot experiments. In the five-year experiments, the ameliorant of a carbonate nature showed greater effect on soil acid–base properties than that of a silicate nature. A return to the initial state of soil pH was not established in any of the treatments. Both ameliorants showed similar effects on wheat straw biomass, but DF had a greater positive effect on wheat grain yield than BFS. Regardless of the dose of DF applied, the accumulation of Ca and Mg by the plants throughout the study period was higher than when BFS was applied. Among the studied plants, those of the family Brassicáceae were the most responsive to liming and, at the same time, showed high ecological adaptability. Differences in the effects of the two ameliorants on the soil chemical properties were more significant than differences in their effects on plant productivity. Full article

Traditional approaches employing natural plant products to treat a wide array of ailments have been documented and described for thousands of years. However, there remains limited scientific study of the therapeutic potential or effectiveness of ethnobotanical applications. Increases in the incidence of cancer and emerging infectious diseases demonstrate a growing need for advances in the development of therapeutic options. In this study, we evaluate the therapeutic potential of aqueous extracts prepared from four plants, purple aster (Symphyotrichum novae-angliae (L.) Nemsom), common sage (Salvia lyrata (L.)), northern spicebush (Lindera benzoin (L.) Blume), and lamb’s ear (Stachys byzantina (K.) Koch)) traditionally used in Native American medicine in Indiana, USA. Using a combination of cytotoxicity assays, immunofluorescence microscopy, and antiviral assays, we found that sage and spicebush extracts exhibit cytotoxic and antiproliferative effects on HeLa cell proliferation and that sage, spicebush, and aster extracts were capable of significantly inhibiting human respiratory syncytial virus (hRSV), a major respiratory pathogen of infants and the elderly. Chemical analysis of the four extracts identified four major compounds which were subsequently evaluated to identify the responsible constituents in the extracts. While none of the identified compounds were shown to induce significant impacts on HeLa cell proliferation, two of the compounds, (1S)-(-)-Borneol and 5-(hydroxymethyl)-furfural, identified in sage and spicebush, respectively, were shown to have antiviral activities. Our data suggest that several of the extracts tested exhibited either anti-proliferative or antiviral activity supporting future further analysis. Full article

Blooms of the dinoflagellate Karenia selliformis in Chile, often associated with massive fish kills, have been noted alongside other species from the Kareniaceae family, such as Karenia spp. and Karlodinium spp. However, the potential allelopathy impact of Chilean K. selliformis on other phytoplankton species remains unexplored. Here, we assessed the allelopathic effects of cell-free exudates from a Chilean K. selliformis strain on six phytoplankton strains representing diverse microalgal groups. The findings of these experiments offer valuable insights into the varied responses of both non-toxic and toxic microalgae to allelochemicals produced by a toxic microalga, showcasing the intricate and multifaceted nature of allelopathic interactions in microalgal communities. The study revealed species-dependent effects, with variable response in cell growth, photosynthetic efficiency (i.e., F_v/F_m), and intracellular reactive oxygen species (ROS) production. While certain strains exhibited significant growth inhibition in response to the allelochemicals, others demonstrated no apparent effect on cell proliferation, indicating varying sensitivity to specific allelochemicals or potentially distinct detoxification mechanisms. Similarly, the diverse effects on F_v/F_m highlight the complexity of allelopathic interactions, with some species showing reduced efficiency without alterations in intracellular ROS production, while others displayed increased ROS production alongside impaired photosynthesis. Full article

Flavonoids are secondary metabolites that exhibit remarkable biological activities, including antimicrobial properties against Klebsiella pneumoniae, a pathogen responsible for several serious nosocomial infections. However, oral administration of these compounds faces considerable challenges, such as low bioavailability and chemical instability. Thus, the encapsulation of flavonoids in nanosystems emerges as a promising strategy to mitigate these limitations, offering protection against degradation; greater solubility; and, in some cases, controlled and targeted release. Different types of nanocarriers, such as polymeric nanoparticles, liposomes, and polymeric micelles, among others, have shown potential to increase the antimicrobial efficacy of flavonoids by reducing the therapeutic dose required and minimizing side effects. In addition, advances in nanotechnology enable co-encapsulation with other therapeutic agents and the development of systems responsive to more specific stimuli, optimizing treatment. In this context, the present article provides an updated review of the literature on flavonoids and the main nanocarriers used for delivering flavonoids with antibacterial properties against Klebsiella pneumoniae. Full article