Search Results (27)

Background/Objectives: As crucial natural predators, hornets contribute to ecosystem function by preying on agricultural and forest pests and facilitating plant pollination. However, the predatory preference of hornets for honeybees poses a significant threat to honeybee pollination and the development of the beekeeping industry. Foraging and pollination behaviors in hornets are largely governed by a sensitive olfactory system, but their olfactory molecular mechanisms remain poorly understood. Methods: VvelCSP1 and VvelCSP4 were successfully expressed in the prokaryotic expression system and purified by Ni-NTA affinity chromatography column. Fluorescence competitive binding assays were employed to evaluate their binding affinities to volatile compounds derived from the seed elaiosome of Stemona tuberosa and honeybees. Molecular docking was further performed to analyze key residues and interaction patterns within the binding pockets. Results: Fluorescence competitive binding assays showed that both proteins prefer long-chain alkanes yet exhibit significant substrate selectivity and high ligand specificity. VvelCSP1 specifically binds to hexacosane, while VvelCSP4 specifically recognizes docosane. Molecular docking results demonstrated that the binding process between VvelCSP1, VvelCSP4 and their respective ligands is dominated by hydrophobic interactions. Conclusions: This study provides functional evidence for investigating the olfactory molecular regulation mechanisms underlying hornet-mediated seed dispersal. These findings establish a foundation for potential applications of hornets in plant propagation, biological pest control, crop pollination and ecological balance maintenance in agroforestry systems. Full article

Background: Chemosensation in ticks opens a novel and unique field for scientific research. This study highlights ticks’ chemosensory system to comprehend its host-searching behavior and other integrated chemistry and biology involving Haller’s structure. Methodology: This study combines microanatomical, electrophysiological, and behavioral experiments to investigate the role of Haller’s organ in adult ticks in response to different classes of organic compounds. Results: We showed the microscopic anatomy of Haller’s organ in Haemaphysalis darjeeling, present at the terminal segment of the first pair of appendages. Haller’s structure serves a vital function in perceiving odor. The electrophysiological activity of adult ticks to different classes of organic compounds via electroscutumography was explored at five different concentrations: w/v 0.001, 0.01, 0.1, 1.0, and 2.0%. Among 55 organic compounds, moderate to high stimulation was recorded with pyruvate (13.28 mv at 2%), ammonia (12.26 mv at 2%), benzoic acid (1.99 mv at 0.001%), isobutyric acid (1.39 mv at 0.001%), 2,6-dichlorophenol (1.34 mv at 0.001%), p-Tolualdehyde (1.26 mv at 2%), tetradecane (1.23 mv at 2%), docosane (1.17 mv at 2%), citronellal (1.13 mv at 0.1%), isopropyl acetate (1.05 mv at 0.01%), cyclohexanol (1.03 mv at 2%), 1-octane-3-ol (1.02 mv at 2%), and 1-octanol (1.01 mv at 0.001%). Olfactometric bioassays at w/v 2.0% concentration further confirmed that ammonia, pyruvate, 1-octane-3-ol, hematin porcine, p-Tolualdehyde, methyl salicylate, uric acid, tetradecane, carbon dioxide, propanoic acid, 3-hexanol, hexanoic acid, adenine, 2,6-dichlorophenol, hexadecane, heptanoic acid, pentanoic acid, octadecane, guanine, and nonanoic acid acted as strong attractants, while citronellal, eugenol, butyric acid, geraniol, benzaldehyde, and tiglic aldehyde showed an active repellent effect against the tick species. Conclusions: This investigation provides knowledge of the olfactory sensilla of Haller’s structure as biosensors behind tick olfaction and the possibility for chemical detection of diverse attractants and repellents for future development of anti-tick compounds. Full article

The urban heat island effect raises road surface temperatures, increasing energy demands and accelerating pavement deterioration. This study evaluates a polymer-based pavement system using methyl methacrylate (MMA) resin with aluminum silicate (AS), glass bubbles (GBs), and microencapsulated n-docosane phase-change material (PCM) to identify the most effective solution. Indoor laboratory tests determined AS as the optimal choice, balancing thermal insulation, workability, and mechanical strength. AS-containing mixtures reduced surface temperatures by ~10 °C and exhibited superior compressive strength (28.2 MPa at 6 wt%) compared to GB (23.7 MPa at 4 wt%) and PCM (27.2 MPa at 6 wt%). AS also maintained stable viscosity at ≤10 wt%, unlike GB and PCM, which became unworkable above 5 wt%. The AS-based system achieved high skid resistance (90.2 BPN), abrasion resistance (0.1% wear after 500,000 cycles), and low VOC emissions (69.64 g/L). Adjusting the resin-to-BPO ratio to 1:0.42 enabled a 30 min curing time at 25 °C, ensuring practical application. These findings highlight AS as the most effective filler for large-scale deployment. Future work should assess long-term durability and optimize formulations for broader adoption in heat-mitigating infrastructure. Full article

Ptilostemon greuteri Raimondo & Domina is a rare Sicilian paleoendemic species. The aim of study was to investigate the micro-morphological features of leaves by light and scanning electron microscopy, to elucidate the phytochemical profile of essential oil (EO), n-hexane (HE) and hydroalcoholic extract (HAE) by gas and liquid chromatographic methods, and antioxidant and anti-inflammatory properties by in vitro assays. Leaves had a large lanceolate blade, dark green on the upper side and greyish on the lower one with a dense tomentum. Epidermis showed many protruding stomata. By lipid-specific dyes, lipophilic droplets within cells surrounding the secretory ducts and within palisade cells were detected, whereas the presence of polyphenols in the mesophyll was highlighted by toluide blue O. These observations have driven the subsequent phytochemical analyses. EO showed germacrene D (29.94%), carvacrol (14.3%) and eugenol (12.93%) as the most abundant compounds. In the HE, docosane, oleic and palmit acid, and lupeol were the predominant compounds, whereas caffeoylquinic acid and quercetin derivatives were the most common polyphenols in HAE. Considering the detected mean half-inhibitory concentrations (IC₅₀), HAE showed predominant antioxidant activity (IC₅₀ 30.54 µg/mL), while EO showed predominant anti-inflammatory activity (IC₅₀ 397.59 µg/mL). Finally, HE, rich in medium-to-long fatty acids, showed the best protease inhibitory activity Full article

Iris taxa are sources of valuable essential oils obtained from aged rhizomes used by various industries, including pharmacy, cosmetic, perfume, and food industry, in which irones are the most important aroma components. In this study, volatile organic compounds (VOCs) obtained from dried rhizomes of three endemics from Croatia, Iris pseudopallida, I. illyrica, and I. adriatica, were studied. The VOCs were isolated by three different methods: headspace solid-phase microextraction (HS–SPME) using divinylbenzene/carboxene/polydimethylsiloxane (DVB/CAR/PDMS) fiber or polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber, and hydrodistillation (HD). The samples were analyzed by gas chromatography–mass spectrometry (GC–MS). In five out of six samples, the main compounds detected by HS–SPME were perilla aldehyde, butan-2,3-diol, acetic acid, 2-phenylethanol, benzyl alcohol, hexanal, and nonanal, while 6-methylhept-5-en-2-one, trans-caryophyllene, and ethanol were common for all studied samples. The former VOCs were absent from the oldest, irone-rich I. pseudopallida sample, mainly characterized by cis-α-irone (43.74–45.76%). When using HD, its content was reduced (24.70%), while docosane prevailed (45.79%). HD yielded predominantly fatty acids, including myristic, common for all studied taxa (4.20–97.01%), and linoleic (40.69%) and palmitic (35.48%) as the major VOCs of I. adriatica EO. The performed GC–MS analyses of EOs, in combination with HS–SPME/GC–MS, proved to be useful for gaining a better insight into Iris VOCs. Full article

The use of depressant additives is the most effective and cost-effective way to improve the low-temperature properties of diesel fuels, like the cloud point, cold filter plugging point and pour point. However, the effectiveness of depressant additives depends on the composition of the diesel fuel and the content of certain groups of hydrocarbons in it. In this work, the effect of adding individual hydrocarbons of various groups and structures on the effectiveness of depressant additives is studied. This study is carried out on model aromatic (toluene, tetralin) and n-paraffin hydrocarbons (cetane, heptadecane, heneicosane, docosane) in various concentrations. It is shown that the most negative effect on the depressant additives’ effectiveness is due to the content of the most polar aromatic hydrocarbons and light n-paraffins in the composition of diesel fuel, and the most positive effect is exerted by the content of heavy n-paraffins in small quantities. It is proposed to involve small concentrations (1–3% vol.) of heavy n-paraffin hydrocarbons (heneicosane, docosane) to increase the effectiveness of the depressant additive. It has been established that for the more effective action of the depressant, it is necessary to take into account the content and structure of individual hydrocarbons in the diesel fuel’s composition. Full article

Predation risk posed by natural enemies can alter pest performance. In our previous study, we found Menochilus sexmaculatus provides risk cues to melon aphids, resulting in increased numbers of winged aphids. However, the effects of predation risk on multiple traits including behavior, physiology, growth rate, and reproductive capacity of pests are not clear. This study examined the effects of predation risk on host preference, the activities of two important defense enzymes (CAT and SOD), longevity, and offspring production. The Y-tube trial results showed that the risk of M. sexmaculatus significantly altered the host preference of the aphids, leading to avoidance behavior. When exposed to M. sexmaculatus for a long period (24 h), the reproductive period and offspring production were significantly decreased, and adult longevity was significantly shortened. The defense enzyme activities of SOD and CAT, as well as the MDA content (which is considered a marker of oxidative stress and cellular damage) in the aphids, significantly increased under M. sexmaculatus risk. The compounds of M. sexmaculatus extracted with n-hexane and volatile compounds collected with HS-SPME were analyzed by GC-MS, and when combined with the behavior response experiment, the results showed that the alkane compounds n-henicosane, n-docosane, n-tricosane, n-pentacosane, and n-hentriacontane may contribute to the impact of predation risk. The results will be helpful in the comprehensive evaluation of the ability of lady beetles to affect the aphid population, and provide new ideas for using these compounds in aphid control. Full article

Several methods have been used to determine the volatile organic compounds emitted by Ophrys orchids. The use of different methods results in incomparable data. Solid-phase microextraction (SPME) has not been used extensively on Ophrys orchids. The main components found in the SPME analysis of the scent in Ophrys orchids were as follows: O. apifera: benzyl benzoate and α-copaene; O. crabronifera subsp. biscutella: pentadecane, heptadecane, and nonadecane; O. bertolonii subsp. bertolonii: pentadecane and heptadecane; O. passionis subsp. garganica: i-propyl palmitate and heptadecane; O. holosericea subsp. apulica: α-copaene, pentadecane, and heptadecane; O. lacaitae: α-copaene, pentadecane, and heptadecane; O. bombyliflora: cyclosativene, pentadecane, and ethyl dodecanoate; O. insectifera: 8-heptadecene and pentadecane; O. lutea: heptadecane and docosane; O. tenthredinifera subsp. neglecta: α-copaene, caryophyllene, and i-propyl palmitate. Full article

Essential oils (EOs) are advised by traditional medical systems for the treatment of a variety of disorders worldwide. In many ancient medical systems around the world, Polygonum herbs have been employed as remedies including P. equisetiforme Sm. The EO profile of P. equisetiforme and its bioactivities have yet to be discussed in depth. As a result, the current study aims to investigate the chemical profile and free radical scavenging capacity of P. equisetiforme EO. Hydrodistillation was used to obtain the EO from P. equisetiforme, and gas chromatography–mass spectrometry (GC-MS) was used for analysis. A total of forty-three compounds, including terpenes and sesquiterpenes as the main components (76.13% and 69.06%, respectively), were identified in the oil using the GC-MS analysis. The main constituents of the oil were hexahydrofarnesyl acetone (29.45%), 7-epi-selinene (14.45%), isospathulenol (8.35%), and n-docosane (6.79%). The chemosystematic significance of the plant was established via multivariate assessing, comprising principal component analysis (PCA), hierarchical clustering, and constellation plot, of the EO principal components of the various Polygonum plants. The P. equisetiforme exhibited different associations with the studied Polygonum spp. Then, the scavenging of the free radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was used to evaluate the radical scavenging abilities of EO compared with those of vitamin C, a reference antioxidant. P. equisetiforme EO exhibited the scavenging capacity of the DPPH and the ABTS free radical with respective IC₅₀ values of 470.01 and 113.74 mg L⁻¹ compared with vitamin C, and with IC₅₀ values of 39.06 and 26.09 mg L⁻¹, respectively. The in silico studies revealed that the oxygenated sesquiterpenes, especially ar-turmerone, hexahydrofarnesyl acetone, and 5E,9E-farnesyl acetone, exhibited the best fitting with hematopoietic cell kinase (Hck) and human Peroxiredoxin 5 proteins with ΔG values of −6.14 and −4.93, −6.83 and −5.34, and −7.08 and −5.47 kcal/mol, respectively. The major components’ combined or individual effects may be responsible for the antioxidant properties. Therefore, additional extensive studies are advised to characterize the essential compounds as radical scavenger agents, either individually or in combination. Full article

Waste heat and organic contaminants are significant issues in water pollution, which has caused ecological problems and threatened human health. To provide an effective solution for wastewater recovery, we designed a novel type of multifunctional phase-change microcapsule. This type of microcapsule was synthesized using n-docosane as a core and a SiO₂/Fe₃O₄ composite as a base shell through in situ interfacial polycondensation with the assistance of a Fe₃O₄ nanoparticle as a Pickering emulsion stabilizer, followed by the deposition of BiOI nanosheets on the surface of the SiO₂/Fe₃O₄ composite shell. Benefiting from the n-docosane core, the resultant microcapsules obtained phase-change enthalpies of 46.8–115.7 J/g for absorbing waste heat from wastewater. The deposited BiOI nanosheets promoted photocatalysis for the microcapsules to degrade organic contaminants in wastewater. Owing to the magnetic response of the Fe₃O₄ nanoparticles, the separability and recyclability of the microcapsules were improved significantly by magnetic separation. Moreover, the microcapsules demonstrate outstanding phase-change reversibility, thermal cycling stability, and shape stability due to the tight SiO₂/Fe₃O₄ composite shell. This study provides a promising approach for designing and developing multifunctional phase-change microcapsules for waste heat recovery and wastewater treatment. Full article

In this paper, a new type of microencapsulated phase change materials (MPCMs) with docosane as the core and titanium dioxide (TiO₂) as the shell was prepared by in situ polymerization. Its phase transition temperature was approximately 40 °C, and it can be used as a phase change material (PCM) in a low-temperature solar heat collection system. The properties of the new material were examined including the microstructure, the chemical elements on the surface of the microcapsules, and thermal conductivity. In addition, to obtain the optimized formula of the microcapsules, single-factor analysis on the emulsifier type, its mass fraction, ultrasonic oscillation time, pH, and core–shell ratio were performed. The results showed that the MPCMs prepared in this paper had a particle size of 2–5 μm and were spherical. Its surface was uniform and smooth without cracks, and the TiO₂ was well dispersed around the docosane, completely coating the docosane without impurities. The MPCMs had good performance in terms of thermal properties and heat storage when using 0.40% SDS as an emulsifier, 10 min ultrasonic, a 3.5 pH value, and a 1:1 core–shell ratio. However, the stirring method, time, and experimental reaction temperature also affected the properties of the material, which was not studied in this experiment. We will continue to study these factors in the future. Full article

Previous research on specialized metabolites of olive leaves has focused on the phenolic components and their biological role. The research in this article focuses on the metabolites that form free volatile compounds (FVCs). The composition of FVCs is divided into compounds isolated in the oil phase (essential oils; EO) and in the aqueous phase (hydrosols; Hy) from leaves of Olea europaea L. cultivar Oblica. Plant material was collected from the same olive tree over a six-month period, from December to May, and analyzed by gas chromatography–mass spectrometry (GC–MS). The compounds β-caryophyllene, α-humulene, allo-aromadendrene, docosane, hexadecanoic acid and oleic acid were identified in all EO study periods. In the Hy in all studied periods, the major compounds are α-pinene, β-ionone, myristicin, docosane, 1-hexanol, oleic acid and (E)-β-damascenone. The differences in the qualitative composition of FVC are directly related to the phenological development of the leaves. Antioxidant capacity of the EOs and hydrosols was measured with two methods, ORAC and DPPH. Hydrosol extracts showed higher capacity than the EOs in all methods. Full article

Sargassum fusiforme, a plant used as a medicine and food, is regarded as a marine vegetable and health supplement to improve life expectancy. Here, we demonstrate that S. fusiforme extract (SFE) has antiviral effects against respiratory syncytial virus (RSV) in vitro and in vivo mouse model. Treatment of HEp2 cells with a non-cytotoxic concentration of SFE significantly reduced RSV replication, RSV-induced cell death, RSV gene transcription, RSV protein synthesis, and syncytium formation. Moreover, oral inoculation of SFE significantly improved RSV clearance from the lungs of BALB/c mice. Interestingly, the phenolic compounds eicosane, docosane, and tetracosane were identified as active components of SFE. Treatment with a non-cytotoxic concentration of these three components elicited similar antiviral effects against RSV infection as SFE in vitro. Together, these results suggest that SFE and its potential components are a promising natural antiviral agent candidate against RSV infection. Full article

n-Alkanes and n-alkenes are components of the unsaponifiable fraction of an olive oil. These were analysed by GC on-column analysis and are here proposed as an additional tool to certify the origin, authenticity, traceability and chemical quality of olive oil produced in the Reggio Calabria province (South Italy). Nine cultivars were studied: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the region of Calabria (South Italy). n-Alkanes in the range from 21 to 35 chain carbon atoms and alkenes in the range from 23:1 to 25:1 chain carbon atoms were found with the following elution order: heneicosane (C21), docosane (C22), tricosene (C23:1), tricosane (C23), tetracosene (C24:1), tetracosane (C24), pentacosene (C25:1), pentacosane (C25), hexacosane (C26), eptacosane (C27), octacosane (C28), nonacosane (C29), triacontane (C30), entriacontane (C31), dotriacontane (C32), tritriacontane (C33), tetratriacontane (C34), pentatriacontane (C35). The oil of all cultivars showed a decreasing trend in total n-alkane and n-alkene content, with the oil of Sinopolese showing the highest content, varying from 328.50 to 214.00 mg/kg. Odd-chain alkanes predominated over even-chain n-alkanes, and tricosane, tetracosane and pentacosane were the most represented alkanes. Cultivar and harvest date significantly influenced the n-alkane and n-alkene content. These findings can be useful to distinguish different olive cultivars and to decide the fruit harvest date for the oil of the Reggio Calabria province (South Italy). A daily quantity of 30 g of olive oil of the Sinoplese cv (the one with the highest n-alkane and n-alkene content) was found to be in accordance with the suggestions of the European Agency for the evaluation of medicinal products Committee for veterinary medicinal products and biogenic hydrocarbons intake for the human diet. Full article

Plants are considered green resources for thousands of bioactive compounds. Essential oils (EOs) are an important class of secondary compounds with various biological activities, including allelopathic and antimicrobial activities. Herein, the present study aimed to compare the chemical profiles of the EOs of the widely distributed medicinal plant Calotropis procera collected from Saudi Arabia and Egypt. In addition, this study also aimed to assess their allelopathic and antimicrobial activities. The EOs from Egyptian and Saudi ecospecies were extracted by hydrodistillation and analyzed via GC-MS. The correlation between the analyzed EOs and those published from Egypt, India, and Nigeria was assessed by principal component analysis (PCA) and agglomerative hierarchical clustering (AHC). The allelopathic activity of the extracted EOs was tested against two weeds (Bidens pilosa and Dactyloctenium aegyptium). Moreover, the EOs were tested for antimicrobial activity against seven bacterial and two fungal strains. Ninety compounds were identified from both ecospecies, where 76 compounds were recorded in Saudi ecospecies and 33 in the Egyptian one. Terpenes were recorded as the main components along with hydrocarbons, aromatics, and carotenoids. The sesquiterpenes (54.07%) were the most abundant component of EO of the Saudi sample, while the diterpenes (44.82%) represented the mains of the Egyptian one. Hinesol (13.50%), trans-chrysanthenyl acetate (12.33%), 1,4-trans-1,7-cis-acorenone (7.62%), phytol (8.73%), and myristicin (6.13%) were found as the major constituents of EO of the Saudi sample, while phytol (38.02%), n-docosane (6.86%), linoleic acid (6.36%), n-pentacosane (6.31%), and bicyclogermacrene (4.37%) represented the main compounds of the Egyptian one. It was evident that the EOs of both ecospecies had potent phytotoxic activity against the two tested weeds, while the EO of the Egyptian ecospecies was more effective, particularly on the weed D. aegyptium. Moreover, the EOs showed substantial antibacterial and antifungal activities. The present study revealed that the EOs of Egyptian and Saudi ecospecies were different in quality and quantity, which could be attributed to the variant environmental and climatic conditions. The EOs of both ecospecies showed significant allelopathic and antimicrobial activity; therefore, these EOs could be considered as potential green eco-friendly resources for weed and microbe control, considering that this plant is widely grown in arid habitats. Full article