Search Results (6)

Heavy metal contamination of water sources has emerged as a major global environmental concern, affecting both aquatic ecosystems and human health. Therefore, this study aims to remove hexavalent chromium from an aqueous solution utilizing activated carbon developed from Spathodea campanulata. Chemical treatment with H₃PO₄ followed by thermal activation was employed to enhance the adsorption capability of the precursor material. On the other hand, a full factorial design of 2⁴ including pH (3 and 9), contact time (30 and 60 min), initial chromium concentration (40 and 100 mg/L), and adsorbent dosage of 0.2 and 0.6 g/100 mL was used to optimize the batch-wise adsorption of hexavalent chromium. The characterization results showed that the prepared activated carbon is composed of various functional groups (FTIR), a high specific surface area of 1054 m²/g (BET), morphological cracks (Scanning Electron Microscopy), and a pH point of zero charge of 5.8. The maximum removal efficiency of 96.5% was recorded at optimum working conditions of pH 3, contact time of 60 min, adsorbent dosage of 0.6 g/100 mL, and initial chromium concentration of 40 mg/L. Additionally, kinetics and isotherm studies revealed that the pseudo-second-order model with R² of 0.98 and the Sips model with R² of 0.99 were found to fit the adsorption data better, suggesting homogenous surface and chemisorption. Overall, this research suggests that Spathodea campanulata could be a promising natural source for the development of adsorbents with potential applications in remediating chromium-saturated wastewater at an industrial scale. Full article

Spathodea campanulata is an important medicinal plant with traditional uses in the tropical zone. In the current work, we aimed to determine the chemical profiles and biological effects of extracts (methanolic and infusion (water)) from the leaves and stem bark of S. campanulata. The chemical components of the tested extracts were identified using LC-ESI-QTOF-MS. Biological effects were tested in terms of antioxidant (radical scavenging, reducing power, and metal chelating), enzyme inhibitory (cholinesterase, amylase, glucosidase, and tyrosinase), antineoplastic, and antiviral activities. Fifty-seven components were identified in the tested extracts, including iridoids, flavonoids, and phenolic acids as the main constituents. In general, the leaves-MeOH extract was the most active in the antioxidant assays (DPPH, ABTS, CUPRAC, FRAP, metal chelating, and phosphomolybdenum). Antineoplastic effects were tested in normal (VERO cell line) and cancer cell lines (FaDu, HeLa, and RKO). The leaf infusion, as well as the extracts obtained from stem bark, showed antineoplastic activity (CC₅₀ 119.03–222.07 µg/mL). Antiviral effects were tested against HHV-1 and CVB3, and the leaf methanolic extract (500 µg/mL) exerted antiviral activity towards HHV-1, inhibiting the viral-induced cytopathic effect and reducing the viral infectious titre by 5.11 log and viral load by 1.45 log. In addition, molecular docking was performed to understand the interactions between selected chemical components and viral targets (HSV-1 DNA polymerase, HSV-1 protease, and HSV-1 thymidine kinase). The results presented suggest that S. campanulata may be a bright spot in moving from natural sources to industrial applications, including novel drugs, cosmeceuticals, and nutraceuticals. Full article

To exploit the ability of vegetation to capture particulate matter (dust) from the air and improve air quality, 546 clean air zones (CAZs) consisting of various types of urban green space have been established in Taiwan. This study systematically assessed the pollutant filtering efficiency of tree species planted in these green spaces. This research aims to provide quantitative data on individual trees’ dust retention functions for future green space planning in urban areas. Field surveys were conducted in 98 CAZs throughout Taiwan. The vegetation composition of approximately 14,000 woody trees, consisting of 210 species, was surveyed. The vegetation surveyed showed that the dominant species in many CAZs in southern Taiwan were introduced species. The dust capturing capacity of the tree species was found to be positively correlated with leaf size. However, the amount of dust retention was affected mainly by the surface structure and morphological characteristics of the leaves, such as a rough, hairy surface. Among the tree species, Spathodea campanulata, Pterocarpus indicus, and Delonix regia exhibited the best dust capture and retention capacity in southern Taiwan, and Ficus macrocarpa, Alstonia scholaris, and Melia azedarach were the most desirable dust retention species. The results suggest that native evergreen species are suitable for dust retention in urban green spaces. Full article

The medicinal plant Spathodea campanulata P. Beauv. (Bignoniaceae) has been traditionally applied for the prevention and treatment of diseases of the kidney and urinary system, the skin, the gastrointestinal tract, and inflammation in general. The present work shows for the first time how chemical components from this plant inhibit Helicobacter pylori growth by urease inhibition and modulation of virulence factors. The crude extract and the main fractions of S. campanulata bark were tested on H. pylori isolated strains and the active ones were further fractionated. Fractions and sub-fractions of the plant crude extract were characterized by ultra-high-performance liquid chromatographic tandem high resolution-mass spectrometry detection (UHPLC-HRMS). Several phenolics and triterpenoids were identified. Among the sub-fractions obtained, SB2 showed the capacity to inhibit H. pylori urease in a heterologous bacterial model. One additional sub-fraction (SE3) was able to simultaneously modulate the expression of two adhesins (HopZ and BabA) and one cytotoxin (CagA). The flavonol kaempferol was identified as the most interesting compound that deserves further investigation as a new hit for its capacity to modulate H. pylori virulence factors. Full article

Research Highlights: Established stands of Leucaena leucocephala (Lam.) de Wit, Spathodea campanulata P. Beauv., and Vitex parviflora Juss. modified soils in Guam’s limestone forests, reducing storage pools of carbon, nitrogen, and phosphorus. Background and Objectives: Invasive plants may engineer negative changes in ecosystem properties. This study was conducted to determine changes in soil chemistry following infestations of three problematic tree species on Guam. Materials and Methods: Minerals, metals, and mineralization dynamics were measured in invaded sites and paired sites with biodiverse native tree cover. Results: Most soil properties were significantly changed by long-term infestations of the invasive tree species. The soils within invaded sites exhibited total carbon, total nitrogen, and available phosphorus that were less than native sites. In contrast, the carbon/nitrogen ratio increased for every species-site combination. The other chemical properties were idiosyncratic among the sites and species. Conclusions: Mitigation and restoration activities that include the removal of these trees from project sites may require many years for the below-ground ecosystems to return to their native state. These three invasive trees decrease the ability of Guam soils to sequester recalcitrant forms of carbon, nitrogen, and phosphorus. Full article

Tropical cities can use urban greening designs featuring trees that provide shade and cooling in hot outdoor environments. The cooling effect involves numerous tree characteristics that are not easy to control during planting design, such as the canopy size and the optical properties of leaves. Planting the appropriate tree species dominates the cooling effects and the human thermal environment. Based on environmental and plant data, including the tree species, crown diameter of trees, physiologically equivalent temperature (PET), and sky view factor (SVF) in an outdoor space, a series of hierarchical cluster analysis (HCA) procedures was implemented to identify the tree species that are appropriate for improving thermal comfort. The results indicated strong correlations between SVF, average crown diameter, and PET. SVF decreased as the average crown diameter increased. For the average crown diameter of trees in an area wider than 1.5 m, the cooling effect was especially dominated by the tree species. Therefore, 15 species were screened by HCA procedures, based on a similar cooling effect. These species had various cooling effects, and were divided into four categories. Tree species, such as Spathodea campanulata and Cinnamomum camphora, had the appropriate crown diameter and cooling effect for the most comfortable thermal environment. Full article