Search Results (46)

Paulownia tomentosa flowers are rich in flavonoids with promising biological activities. However, few studies have investigated their potential for α-glucosidase inhibition. This study compared ultrasound-assisted cellulase extraction and ultrasound-assisted aqueous two-phase extraction for the recovery of flavonoids from Paulownia tomentosa flowers. The aqueous two-phase extraction method demonstrated superior performance, with optimal conditions determined as 17.80% (NH₄)₂SO₄, 12 min ultrasonication, and 44 °C. Purification was efficiently achieved using NKA-9 macroporous resin. Scanning electron microscopy revealed that ultrasonic treatment disrupted the cell walls, facilitating flavonoid release. Ultra-performance liquid chromatography–tandem mass spectrometry identified apigenin-7-glucuronide and scutellarin as the predominant flavonoids. Notably, several compounds—including scutellarin, ombuin, robinetin, and astragalin—were reported for the first time in this plant. The extracted flavonoids exhibited significant α-glucosidase inhibitory activity, with an IC₅₀ value of 0.412 mg/mL, and showed mixed-competitive inhibition. Luteolin 7-O-glucuronide was identified as a major active constituent, exhibiting stronger inhibition than the total flavonoids while sharing the same mechanism. These findings establish a theoretical foundation for the efficient and sustainable extraction of P. tomentosa flavonoids and support their further development for pharmaceutical applications. Full article

Medicinal plants are used all over the world to prevent, cure, and manage many different diseases. The aim of this study was to provide knowledge on different medicinal plants that are native to Pike County, Eastern Kentucky, USA. The study involved two stages of activity. First, it involved a survey of some county locals to identify medicinal plants used for different medical purposes. The second part dealt with searching research databases like PubMed and Google Scholar to find out if any of those plants, identified in the survey, have any published scientific studies on them. The results of the survey identified 14 locally used medicinal plants (Asimina triloba, Callicarpa americana, Chimaphila umbellate, Cichorium intybus, Eupatorium perfoliatum, Monotropa uniflora, Paulownia tomentosa, Phytolacca americana, Portulaca oleracea, Sassafras albidum, Ampelopsis glandulosa, Ulmus rubra, Verbascum thapsus, and Xanthorhiza simplicissima) belonging to different families, plant types and used for a wide variety of purposes. Most plants belonged to the Ericaceae and Asteraceae families, were mostly herb type, while the most common plant part was berries, leaves and roots. The survey also showed that the local population use these plants for a variety of purposes, such as a food additive, insect repellant, antirheumatic, antiarthritic, coffee alternative, laxative, antitussive, analgesic, or anti-infective. Sometimes these plants and plant substances are used raw, made into tea, or even made into an edible jam product. For the second part of the study, all the plants were supported by multiple published studies. The most common pharmacological activity among the plants was antimicrobial, followed by anticancer, antioxidant and anti-inflammatory activities. Eastern Kentucky is well known for its scenic Appalachian Mountains, but the area holds potential for innovative herbal medicine as well. More interest and research are needed to further explore the treasure of medicinal plant use knowledge resting in this area. Additionally, more phytopharmacological and phytochemical studies are needed to investigate the scientific potential of traditionally used medicinal herbs from this region. Full article

Paulownia trees are grown globally for their robust timber, agroforestry, and effective carbon dioxide drawdown. China possesses rich Paulownia germplasm resources, offering favorable material for the genetic improvement. Understanding the taxonomy and phylogenetic relationships of Paulownia species is essential for the advancement of germplasm innovation. In this study, we re-sequenced 67 typical accessions of 11 species within the Paulownia genus. A total of 16,163,790 high-quality single nucleotide polymorphisms (SNPs) were identified. Based on these markers, these accessions were classified into three groups: P. fortunei and P. lampropylla (Group I); P. tomentosa, P. fargesii, and P. kawakamii (Group II); and P. taiwaniana, P. jianshiensis, P. catalpifolia, P. elongata, P. ichangensis, and P. albiphloea (Group III). Using maximum likelihood estimation, population genetic structure analysis revealed that the 11 species originated from four different ancestral populations. The two predominant breeding species—P. fortunei and P. tomentosa—exhibit divergent origins: P. fortunei arose from hybridization between two ancestral species followed by complex admixture, whereas P. tomentosa retains a predominantly singular ancestral lineage, with traces of P. kawakamii. The genetic diversity (π) of P. tomentosa was 0.002588, which was considerably lower than that of P. fortunei (0.004181) suggesting that P. tomentosa is subjected to a stronger breeding selection during the evolution than P. fortunei. A total of 59 selected regions and 65 genes were identified by selective sweep analysis. These genes may be involved in biological processes such as morphological development and response to abiotic stress and hormonal activity regulation. These findings provide valuable references for further research on the genetic differentiation and adaptive evolutionary mechanisms of Paulownia species, laying a foundation for future germplasm innovation and variety improvement. Full article

Objectives: This study presents a versatile, AI-guided workflow for the targeted isolation and characterization of prenylated flavonoids from Paulownia tomentosa (Thunb.) Steud. (Paulowniaceae). Methods: The approach integrates established extraction and chromatography-based fractionation protocols with LC-UV-HRMS/MS analysis and supervised machine-learning (ML) custom-trained classification models, which predict prenylated flavonoids from LC-HRMS/MS spectra based on the recently developed Python package AnnoMe (v1.0). Results: The workflow effectively reduced the chemical complexity of plant extracts and enabled efficient prioritization of fractions and compounds for targeted isolation. From the pre-fractionated plant extracts, 2687 features were detected, 42 were identified using reference standards, and 214 were annotated via spectra library matching (public and in-house). Furthermore, ML-trained classifiers predicted 1805 MS/MS spectra as derived from prenylated flavonoids. LC-UV-HRMS/MS data of the most abundant presumed prenyl-flavonoid candidates were manually inspected for coelution and annotated to provide dereplication. Based on this, one putative prenylated (C5) dihydroflavonol (1) and four geranylated (C10) flavanones (2–5) were selected and successfully isolated. Structural elucidation employed UV spectroscopy, HRMS, and 1D as well as 2D NMR spectroscopy. Compounds 1 and 5 were isolated from a natural source for the first time and were named 6-prenyl-4′-O-methyltaxifolin and 3′,4′-O-dimethylpaulodiplacone A, respectively. Conclusions: This study highlights the combination of machine learning with analytical techniques to streamline natural product discovery via MS/MS and AI-guided pre-selection, efficient prioritization, and characterization of prenylated flavonoids, paving the way for a broader application in metabolomics and further exploration of prenylated constituents across diverse plant species. Full article

As industries continue to prioritize sustainability and resource efficiency, Paulownia stands out as a sustainable candidate for replacing Balsa in engineered wood products, offering a lighter, cost-effective solution with the added benefit of reduced ecological impact. The aim of this research is to manufacture 7 mm- and 15 mm-thick plywood from Paulownia tomentosa x elongata veneers (as an alternative for balsa veneers) using polyurethane (PUR) and melamine–urea–formaldehyde (MUF) adhesives, and to analyze their physical and mechanical properties. Panels with five and seven layers and thicknesses from 0.8 to 3 mm were tested for bulk density (247–385 kg/m³), thickness swelling (2.47%–5.34%), and water absorption (35%–68%) according to European standards. Mechanical properties assessed included three-point bending strength (MOR) parallel (22–35.8 N/mm²) and perpendicular to the fiber/grain (13.4–21.8 N/mm²), three-point modulus of elasticity (MOE) in longitudinal (2824–3799 N/mm²) and transverse directions (1183–1825 N/mm²), tensile shear strength (1.76–2.52 N/mm²), and screw withdrawal resistance (41.9–60.6 N/mm). Results indicate that Paulownia plywood has significant potential for lightweight construction due to its low density and favorable properties, with MUF adhesive showing superior performance in terms of density and panel properties. This positions Paulownia plywood as a strong contender in the ongoing evolution of lightweight construction materials. Full article

Urban trees play a crucial role in regulating hydrological processes within urban ecosystems by intercepting rainfall to effectively reduce surface runoff and mitigate urban flooding. Current research lacks a systematic quantification of rainfall interception capacity and its community-level impacts at the urban scale. This study adopts a city-scale perspective, integrating field survey data with the i-Tree Eco model to systematically explore the contributions of 20 factors to the average annual rainfall interception of tree species and the average annual rainfall interception efficiency of communities. The study revealed that Deciduous broadleaf trees (1.28 m³ year⁻¹) and Pure coniferous forests (90.7 mm year⁻¹) exhibited substantial rainfall interception capacity. Relative Height, Average Tree Height, Average Crown Width, and Planting Density of trees significantly influence interception capacity. Urban planning can optimize the selection of tree species (e.g., Paulownia, Populus tomentosa, etc.) and community structure (e.g., mixed planting of conifers and deciduous broadleaf trees) to improve rainfall interception capacity, thereby effectively reducing stormwater runoff, mitigating the risk of urban flooding. These findings provide a scientific basis for designing urban vegetation to mitigate flooding, support water management, and advance sponge city development. Full article

Flowering street trees are important carriers of urban landscapes and ecological functions, as well as a significant boost to the construction of “Shanghai Flower City”. Most existing studies focus on the ornamental value or single ecological benefits, and there are insufficient systematic evaluations of the landscape–ecology synergistic effect, especially as there are few quantitative studies on the landscape value during the flowering period and long-term ecological benefits. Scientific assessment of multiple benefits is of great significance for optimizing tree species allocation and enhancing the sustainability of road landscapes. Taking flowering street trees in Shanghai’s central urban area as a case study, this paper verifies the feasibility of using digital technology to evaluate their landscape and ecological benefits and explores ways to enhance these aspects. Landscape, ecological, and comprehensive benefits were quantitatively assessed using digital images, the i-Tree model, and the entropy-weighted method. Influencing factors for each aspect were also analyzed. The results showed the following: (1) Eleven species or cultivars of flowering street trees from six families and ten genera were identified, with the majority flowering in spring, fewer in summer and autumn, and none in winter. (2) The landscape benefits model was: Scenic Beauty Estimation (SBE) = −0.99 + 0.133 × Flowering branches+ 0.183 × Degree of flower display + 0.064 × Plant growth + 0.032 × Artistic conception + 0.091 × Visual harmony with surrounding elements. Melia azedarach L., Prunus × yedoensis ‘Somei-yoshino’, and Paulownia tomentosa (Thunb.) Steud. ranked highest in landscape benefits. (3) Catalpa bungei C. A. Mey., Koelreuteria bipinnata Franch., and Koelreuteria bipinnata ‘integrifoliola’ (Merr.) T.Chen had the highest plant height, diameter at breast height (DBH), and crown width among the studied trees, and ranked top in ecological benefits. (4) Koelreuteria bipinnata, Catalpa bungei, and Melia azedarach showed the best overall performance. The comprehensive benefits model was: Comprehensive Benefits = 0.6889 × Ecological benefits + 0.3111 × Landscape benefits. This study constructs a digital evaluation framework for flowering street trees, quantifies their landscape and ecological benefits, and provides optimization strategies for the selection and application of flowering trees in urban streets. Full article

This investigation proposes an effective protocol (cutting) for Paulownia tomentosa production in Tunisia during the 2022–2024 period. The effects of the three interactive parameters: root cutting diameter (L1, 0.5; L2, 0.8; L3, 1.25; and L4, 2 cm), indole-3-butyric acid (IBA) hormone concentrations (C, 0; T1, 0.1%; and T2, 0.3%), and soil type (S1: 50% silt + 50% potting soil, and S2: 43% potting soil + 43% silt + 14% sand), were investigated. The data showed that cutting roots with 0.5 cm dimensions, a cutting treatment with hormone (0.3%), and the S2 soil type corresponded to a growth enhancement in height. These results revealed the broad changes in flowering of P. tomentosa. Also, data revealed that the root cutting diameter had the greatest influence on the biochemical contents of 4-month-old P. tomentosa sprouts. The studied pathway revealed that the auxin precursor IBA contributes toward active auxin [indole-3-acetic acid (IAA)] biosynthesis. Overall, this study found substantial changes in the morphological, biochemical, and floral features of new P. tomentosa sprouts under the interactive factors. To summarize, vegetative propagation of Paulownia, particularly through root cutting, allows for proliferation and plantation development. These findings can be applied to future breeding efforts with Paulownia to improve and protect it as a woody species, forage, and medicinal plant. Full article

The remediation of dredged sediments (DS) as a major waste generation field has become an urgent environmental issue. In response to the limited strategies to restore DS, the current study aimed to investigate the suitability of Paulownia tomentosa (Thunb.) Steud as a tool for decontamination of DS, both independently and in combination with a sewage sludge-based biochar. The experimental design included unamended and biochar-supplemented DS with the application rates of 2.5, 5.0, and 10.0%, in which vegetation of P. tomentosa was monitored. The results confirmed that the incorporation of biochar enriched DS with the essential plant nutrients (P, Ca, and S), stimulated biomass yield and improved the plant’s photosynthetic performance by up to 3.36 and 80.0 times, respectively; the observed effects were correlated with the application rates. In addition, biochar enhanced the phytostabilisation of organic contaminants and shifted the primary accumulation of potentially toxic elements from the aboveground biomass to the roots. In spite of the inspiring results, further research has to concentrate on the investigation of the mechanisms of improvement the plant’s development depending on biochar’s properties and application rate and studying the biochar’s mitigation effects in the explored DS research system. Full article

Paulownia species not only have significant economic benefits but also show great potential in ecological conservation. However, they are highly susceptible to phytoplasma infections, causing Paulownia witches’ broom (PaWB), which severely restricts the development of the Paulownia industry. Salicylic acid (SA) plays a crucial role in plant disease resistance. However, there have been no reports on the effect of SA on PaWB. Due to the properties of SA, it may have potential in controlling PaWB. Based on the above speculation, the prevention and therapeutic effect of SA on PaWB and its effect on the PaWB-infected Paulownia transcriptome and proteome were studied in this work. The results indicated that 0.1 mmol/L was the optimal SA concentration for inhibiting the germination of Paulownia axillary buds. In terms of resistance physiological indicators, SA treatment significantly affected both Paulownia tomentosa infected (PTI) seedlings and Paulownia fortunei infected (PFI) seedlings, where the activities of peroxidase (POD) and superoxide dismutase (SOD) were enhanced. Malondialdehyde (MDA), O₂⁻, and H₂O₂, however, were significantly reduced. Specifically, after SA treatment, SOD activity increased by 28% in PFI and 25% in PTI, and POD activity significantly increased by 61% in PFI and 58% in PTI. Moreover, the MDA content decreased by 30% in PFI and 23% in PTI, the H₂O₂ content decreased by 26% in PFI and 19% in PTI, and the O₂⁻ content decreased by 21% in PFI and 19% in PTI. Transcriptomic analysis showed that there were significant upregulations of MYB, NAC, and bHLH and other transcription factors after SA treatment. Moreover, genes involved in PaWB-related defense responses such as RAX2 also showed significant differences. Furthermore, proteomic analysis indicated that after SA treatment, proteins involved in signal transduction, protein synthesis modification, and disease defense were differentially expressed. This work provides a research foundation for the prevention and treatment of PaWB and offers references for exploring anti-PaWB methods. Full article

The volatile composition of Paulownia Shan tong (Fortunei × Tomentosa) essential oil isolated by steam distillation (yielding 0.013% v/w) from flowers (forestry wastes) was investigated by gas chromatography–mass spectrometry. Thirty-one components were identified, with 3-acetoxy-7, 8-epoxylanostan-11-ol (38.16%), β-monoolein (14.4%), lycopene, 1,2-dihydro-1-hydroxy- (10.21%), and 9,12-octadecadienoic acid, 2-phenyl-1,3-dioxan-5-yl ester (9.21%) as main compounds. In addition, molecular docking was employed to identify potential protein targets for the 31 quantified essential oil components. Inhibition of these targets is typically associated with antibacterial or antioxidant properties. Molecular docking revealed that six of these components, namely, 13-heptadecyn-1-ol, ascabiol, geranylgeraniol, anethole, and quinol dimethyl ether, outperformed the native ligand (hypoxanthine) of xanthine oxidase in terms of theoretical binding affinity, therefore implying a significant in silico inhibitory potential against xanthine oxidase. These findings suggest that the essential oil extracted from Paulownia Shan tong flowers could be valuable for developing protein-targeted antioxidant compounds with applications in the food, pharmaceutical, and cosmetic industries. Full article

The critical role of energy in contemporary life and the environmental challenges associated with its production imply the need for research and exploration of its novel resources. The present review paper emphasizes the continuous exploitation of non-renewable energy sources, suggesting the transition toward renewable energy sources, termed ‘green energy’, as a crucial step for sustainable development. The research methodology involves a comprehensive review of articles, statistical data analysis, and examination of databases. The main focus is biomass, a valuable resource for bioenergy and biopesticide production, highlighting not only its traditional diverse sources, such as agricultural waste and industrial residues, but also non-edible invasive alien plant species. This study explores the utilization of invasive alien species in circular economy practices, considering their role in bioenergy and biopesticide production. The potential conflict between bioproduct acquisition and food sector competition is discussed, along with the need for a shift in approaching non-edible biomass sources. The paper emphasizes the untapped potential of under-explored biomass resources and the necessity for policy alignment and public awareness. Species with a significant potential for these sustainable strategies include Acer negundo L., Ailanthus altisima (Mill.) Swingle., Amorpha fruticosa L., Elaengus angustifolia L., Falopia japonica (Houtt.) Ronse Decr., Hibiscus syriacus L., Koelreuteria paniculata Laxm., Paulownia tomentosa Siebold and Zucc., Partenocissus quenquefolia (L.) Planch., Rhus typhina L., Robinia pseudoacacia L. and Thuja orientalis L. In conclusion, the paper highlights the intertwined relationship between energy, environmental sustainability, and circular economy principles, providing insights into Serbia’s efforts and potential in adopting nature-based solutions for bioenergy and biopesticides acquisition. Full article

Flowers of Paulownia spp. wither and fall on a large scale after blooming in spring and have potential allelopathic effects on surrounding plants, including crops and weeds. In this study, the phytotoxic effects of water extracts of Paulownia tomentosa flower litter (EPF) on wheat (Triticum aestivum L.), lettuce (Lactuca sativa L.), green bristlegrass (Setaria viridis L.) and purslane (Portulaca oleracea L.) were evaluated in the laboratory. The mode of action of the phytotoxicity of EPF on lettuce seedlings was studied and the secondary metabolites in EPF were analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS). The results show that EPF significantly inhibited the seed germination and seedling growth of four target plants in a concentration-dependent manner. In addition, EPF could induce the excessive accumulation of reactive oxygen species (ROS) flowing with oxidative damage of the lipid bilayer of the biofilm, resulting in reduced cell viability and even apoptosis in lettuce. There were 66 secondary metabolites identified by LC-HRMS in P. tomentosa flowers. Among them, 10 compounds, including salicylic acid, caffeic acid, parthenolide, 7-hydroxycoumarin and abscisic acid (ABA), were all known allelochemicals. In summary, P. tomentosa flower litter displayed significant allelopathic effects, which were related to the accumulation of ROS in target plants. Phenolic acids, flavonoids as well as ABA are probably the main allelochemicals of P. tomentosa flowers. Full article

The research on Paulownia spp. has increased in the last twenty years thanks to the growing interest in the application modalities of this plant in various sectors such as wood, phytoremediation, environmental protection, paper, biofuel, chemistry and medicine. For the first time, this study analyzed the papers present in the Web of Science Core Collection on “Paulownia” to obtain a set of characteristics in the work carried out from 1971 to 2021. This analysis selected and took into account 820 articles and provided evidence of the scientific production of authors, institutions, and countries. This work showed that the most studied species was Paulownia tomentosa, followed by P. fortunei and P. elongate. The JCR category and research area with the most publications was plant science, with 20.4% of the total. The papers were published in 460 journals and in a book series. The journals with the most publications were Bioresources, Advanced Material Research, Agroforestry Systems, Journal of Wood Science and Industrial Crops and Products. The institutions with the most prolific affiliation with the field of Paulownia spp. research were Henan University, the US Department of Agriculture, Belgrade University, the Chinese Academy, and Georgia University. Finally, the 3842 keywords were divided into nine different clusters and the trends of interest in the last fifteen years were highlighted. Full article

Paulownia tomentosa is a representative deciduous tree in South Korea. After 10 years of growth, its wood can be used to make various products through chemical modifications, such as impregnation with a polymer, substitution with chemicals, and physical compression. However, research on the biological resistance of the sapwood and heartwood parts of P. tomentosa xylem is lacking. To ensure the complete utilisation of Paulownia wood, this study aimed to collect baseline data on the necessity of xylem extraction before chemical modification to enhance wood porosity. First, we assessed the decay and termite resistance of sapwood and heartwood blocks. Furthermore, we evaluated the anti-microbial effect of sapwood and heartwood extracts after solvent fractionation. Quantitative and qualitative analyses of the active substances of the fractions with anti-microbial activity were also conducted. The hexane and chloroform solvent fractions of sapwood and heartwood extracts showed fungal resistance against Trametes versicolor and Fomiptosis palustis. Paulownin and sesamin were the main compounds showing anti-microbial activity, and their content in the extracts varied, depending on the wood part. These results provide valuable data for advancing research on porous wood materials and the utilisation of xylem-derived active compounds from Paulownia wood. Full article