Search Results (113)

Bay laurel (Laurus nobilis L., Lauraceae) is an important Mediterranean aromatic species widely used as a culinary spice and a source of bioactive constituents. This study aimed to evaluate the essential oil (EO) composition, macronutrient content, polyphenolic profile and antioxidant activity of bay laurel along the Croatian Adriatic coast. A total of 49 volatile compounds were identified in dried leaves using GC–MS, representing 99.27–100.00% of the EO composition. The EOs were dominated by oxygenated monoterpenes (86.51–95.55%), with 1,8-cineole (42.40–56.83%), α-terpinyl acetate (6.89–12.76%), sabinene (6.10–8.65%), linalool (2.06–14.46%), and methyl eugenol (0.45–10.10%) as the major constituents. Polyphenolic profile obtained by spectrophotometric methods showed that total polyphenol content ranged from 6.03% to 9.65%, tannins from 1.81% to 4.76%, flavonoids from 0.23% to 0.71%, and total phenolic acids from 1.34% to 3.03% (rosmarinic acid equivalents) and 2.51% to 5.66% (chlorogenic acid equivalents). Furthermore, we highlighted the antioxidant activity of Croatian bay laurel using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Ethanolic extracts exhibited higher antioxidant activity than aqueous extracts, reaching 74.58–82.03% ABTS inhibition and 57.93–69.54% DPPH inhibition. This study provides the first integrated characterization of Croatian bay laurel leaves and highlights their antioxidant potential. Full article

The analytical characterization of essential oils (EOs) is often interpreted primarily in terms of biological variability, although analytical conditions may also affect compositional profiling and data comparability. In this study, the influence of chromatographic conditions on gas chromatography–mass spectrometry (GC–MS) profiling was investigated. Five EOs representing chemically diverse plant matrices, including Pistacia lentiscus (resin and stem) and leaf oils from Salvia rosmarinus, Laurus nobilis, and Thymus vulgaris, were analyzed using two capillary columns with different stationary phases: RTX-5MS (5% phenyl-substituted polysiloxane) and CP-Sil 5 CB (100% dimethylpolysiloxane). Comparative analysis revealed reproducible differences in chromatographic profiles and relative peak-area distribution, particularly within terpene-rich regions containing structurally related compounds. The most pronounced effects were observed for highly volatile monoterpenes, which were underrepresented under CP conditions. These findings demonstrate that chromatographic selectivity and column geometry may affect the semi-quantitative representation of EO profiles and contribute to variability in reported compositions. Overall, the results highlight the importance of carefully controlled analytical conditions in EO characterization. Full article

The valorization of medicinal and aromatic plant by-products represents a sustainable strategy to recover bioactive compounds and reduce agricultural waste. In this study, pruning residues of Laurus nobilis L. and Myrtus communis L. were investigated as sources of essential oils (EOs) for bio-based weed management. Leaves and young stems were subjected to anatomical, micromorphological, and histochemical analyses to ascertain that active secretory structures were maintained. EOs were then obtained by steam distillation and characterized by GC-FID and GC-MS. Phytotoxicity was evaluated on two crop species, Hordeum vulgare L. and Raphanus sativus L., and two weed species, Lolium multiflorum Lam. and Sinapis alba L.; ecotoxicity was assessed using Artemia salina and Daphnia magna. The EOs were mainly composed of oxygenated monoterpenes, with 1,8-cineole as the dominant constituent in both oils. Phytotoxicity was species- and concentration-dependent, with M. communis EO showing the strongest inhibition, particularly against S. alba. Ecotoxicological assays revealed limited toxicity toward A. salina, but concentration-dependent immobilization of D. magna. Overall, these findings support the circular valorization of laurel and myrtle pruning residues as sources of bioactive EOs while highlighting the need for further formulation, selectivity, and environmental safety studies before agricultural application. Full article

Bay laurel (Laurus nobilis L.) leaves and branches represent promising lignocellulosic residues for biorefinery and bioenergy applications. The present study evaluated the effect of autohydrolysis at different temperatures and residence times on the chemical composition, structural properties, and higher heating value (HHV) of both biomass fractions. The initial characterization revealed that leaves were richer in extractives and lignin, whereas branches contained higher amounts of α-cellulose and hemicelluloses. Autohydrolysis promoted the selective solubilization of biomass components, reaching maximum values of approximately 38% for leaves and 30% for branches. Increasing treatment severity enhanced hemicellulose removal and resulted in a relative enrichment of lignin and cellulose in the solid residues, while FTIR analysis showed that the main lignocellulosic structure was largely preserved. The solid residue after polyalcohol liquefaction presented a higher heating value, improving the heating value of the resulting solids, achieving maximum HHVs of 30.08 MJ kg⁻¹ for leaves and 29.46 MJ kg⁻¹ for branches at 180 °C for 30 min. Overall, the results indicate that autohydrolysis is a suitable strategy for the selective extraction of hemicellulose-rich fractions and the production of lignin-enriched solid residues. This process contributes to the sustainable valorization of bay laurel biomass within an integrated biorefinery framework. Full article

Laurel (Laurus nobilis L.) is a characteristic species of the Mediterranean flora, valued for its medicinal, aromatic, and culinary uses. Many of these properties are attributed to its volatile constituents. In this study, the effect of Atmospheric Room Temperature Plasma (ARTP) pretreatment on laurel powder was evaluated, with emphasis on volatile recovery and food application. Volatile extraction was optimized using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC-MS), investigating key parameters such as salt concentration, extraction temperature, equilibration time, extraction time, and fiber type. Subsequently, critical ARTP variables (nitrogen flow, treatment duration, treatment distance, substrate thickness, and plasma power) were optimized. Response Surface Methodology was applied in both optimization processes. The results demonstrated that fiber type was the most influential factor for volatile recovery, with extraction temperature also exerting a significant effect. A more nuanced pattern emerged during ARTP pretreatment, where moderate plasma intensities enhanced the recovery of several key volatiles. This trend was not uniform across compounds, indicating that plasma-induced microstructural changes interact with the physicochemical properties of individual analytes. To demonstrate food relevance, a ready-to-use broth model prepared with laurel powder confirmed improved headspace transfer of characteristic volatiles following ARTP treatment. Taken together, these findings suggest that ARTP can serve as a practical, non-thermal pretreatment for improving volatile release, supporting its potential use in the food, pharmaceutical, and cosmetic industries. Full article

Laural (Laurus nobilis) is a Mediterranean plant with reported antibacterial properties, yet the genetic basis of its antibacterial efficacy remains largely unexplored. This study evaluated the antibacterial activity of Laurus nobilis methanolic extracts against Escherichia coli, Staphylococcus aureus, and Bacillus cereus, combined with genome-wide association studies (GWAS) and machine learning (ML) approaches to identify genetic markers and predict antibacterial efficacy in 92 plant samples. Antibacterial tests revealed significant variability in inhibition zones, with E. coli showing the highest inhibition (Canakkale2: 24.5 mm), followed by S. aureus (Aydin2: 26.0 mm). Minimum inhibitory concentration (MIC) analysis demonstrated notable regional differences; extracts from Mersin3 showed the highest efficacy (MIC = 6.25 mg/mL), while Aydin1 exhibited the lowest activity (MIC = 100 mg/mL). Population structure and neighbor joining tree analysis split the germplasm into two groups. GWAS identified significant genetic markers associated with antibacterial traits, including marker 26557159 for EC-MEAN (Escherichia coli-Mean) (p = 1.10 × 10⁻⁴, MarkerR² = 0.1799, genetic variance = 9.41792) and marker 26584774 for BC-MEAN (Bacillus cereus-Mean) (p = 8.89 × 10⁻⁵, MarkerR² = 0.18512, genetic variance = 12.48948). Protein–protein interaction network of loci associated with marker trait association (MTA) marker (26557159) indicated involvement in high-affinity secondary active ammonium transmembrane transporter activity, providing insights into genetic regions influencing antibacterial properties. ML models predicted antibacterial activity with high accuracy. XGBoost achieved the best performance for MIC predictions (R² = 0.999, RMSE = 0.434), while random forest (R² = 0.984) demonstrated robust performance for both MIC and disc diffusion assays. LightGBM performed well for MIC prediction (R² = 0.988) but showed limited accuracy for disc diffusion outcomes (R² = 0.695). This study is the first to combine GWAS and ML for predicting antibacterial efficacy in L. nobilis, identifying specific genetic markers (e.g., 26557159, 26584774) and demonstrating that XGBoost achieves near-perfect MIC prediction (R² = 0.999). These findings provide a genomic and computational foundation for marker-assisted breeding of laurel with enhanced antibacterial properties and support the sustainable use of plant-derived anti-microbials. Full article

The quarantine pathogen Phytophthora ramorum has a high potential for dispersal due to its airborne inoculum, its wide range of hosts, and its ability to spread through the trade of nursery plants. For these reasons, it represents a serious threat to ornamental nursery production and, consequently, to urban, natural and semi-natural ecosystems. This oomycete pathogen (EU1 lineage, A1 mating type) has been detected on Viburnum tinus in a commercial nursery located in the Pistoia nursery district (PND) (Tuscany, central Italy), one of the main nursery areas for the production of ornamentals in Europe. Artificial inoculations were carried out in the laboratory under controlled conditions, following a standard detached-leaf assay protocol, on leaves of 16 ornamental shrub species commonly marketed by the PND. Disease severity was assessed, and susceptibility categories (high, moderate, low, and non-susceptible) were defined based on data collected at 7 and 14 days post-inoculation and validated through statistical analysis. Inoculated species exhibited variable levels of disease severity. The results confirmed the pathogen’s high virulence on Viburnum tinus and Rhododendron hybrid ‘Madame Masson’. The following species were also found to be highly susceptible: Ilex aquifolium, Loropetalum chinense, Magnolia stellata, Osmanthus fragrans, and Trachelospermum jasminoides. Camellia japonica, Nerium oleander, Osmanthus heterophyllus, Prunus laurocerasus, and Rhododendron obtusum showed moderate susceptibility. Arbutus unedo, Laurus nobilis, Photinia fraseri and Syringa vulgaris exhibited low susceptibility. At the end of the trial, no infected species fell into the non-susceptible categories. The oomycete proved particularly aggressive on Ilex aquifolium, the most susceptible host among those tested. This high susceptibility is a new finding that could have significant epidemiological implications. Our findings emphasize the need for rigorous phytosanitary surveillance in nursery systems, based on constant monitoring and the adoption of high-throughput diagnostic protocols, in order to implement effective and rapid control measures. Full article

Bay laurel (Laurus nobilis) pruning residues, including leaves and small branches, were chemically characterized and subjected to polyol-based liquefaction to evaluate their valorization potential. Leaves exhibited higher ash and extractive contents (3.37% and 10.8% against 2.53% and 4.9%, reflecting greater accumulation of minerals and lipophilic compounds, whereas branches were richer in structural polysaccharides such as α-cellulose and hemicelluloses. Acid-insoluble lignin was higher in leaves, likely due to phenolic compounds and recalcitrant structures like cutin. Liquefaction experiments using a glycerol–ethylene glycol solvent system revealed that both biomass fractions respond positively to increases in temperature, residence time and solvent-to-biomass ratio. Leaves showed higher liquefaction yields under milder conditions (57.8% at 15 min compared to 67.2% for branches), likely related to their extractive-rich and less organized structure, while branches tended to surpass leaves at higher temperatures and longer reaction times, possibly due to the greater susceptibility of their lignocellulosic matrix to breakdown under more severe conditions. FTIR-ATR analysis of the liquefied products suggested an increased presence of hydroxyl and carbonyl groups, indicating gradual breakdown of polysaccharides, lignin, and other structural polymers. These results highlight the distinct reactivity of leaves and branches, providing insights for tailored conversion strategies in polyol-based liquefaction processes. The results provide a basis for tailoring the process to specific biomass fractions, contributing to more efficient and selective biomass conversion into useful products. Full article

The aim of this research was to quantify the capacity of different shrub species to remove atmospheric CO₂, to adsorb particulate matter and to dissipate latent heat through transpiration. A total of 308 established plants comprising Deutzia scabra, Elaeagnus × ebbingei, Euonymus japonicus, Forsythia × intermedia, Laurus nobilis, Ligustrum vulgare, Pittosporum tobira, Prunus laurocerasus and Viburnum tinus were selected in Lugano (Switzerland) and Bolzano (Italy). Stem diameter, crown radius, Leaf Area Index, net CO₂ assimilation per unit leaf area (A_leaf), transpiration, and stomatal conductance (g_s) were measured during spring, summer, and fall. The net CO₂ assimilation per unit of crown projection area and per plant were calculated by upscaling A_leaf using a multilayer model. Latent heat dissipation was calculated using the Penman–Monteith equation. The amount of PM trapped on leaves was measured using a gravimetric method. Differences in leaf area and leaf gas exchange among species affected their capacity to deliver specific ecosystem services. Forsythia, Pittosporum, Elaeagnus and Deutzia removed about 40% more CO₂ per unit crown projection area than Laurus, Ligustrum, and Euonymus. Latent heat dissipation by shrubs was, on average, 130 W m⁻², which is comparable to that of tree species. PM removal per unit leaf area was higher in species with sparse canopies and rough leaf surfaces. Full article

Climate change poses significant threats to Mediterranean plant species, including Laurus nobilis L., an ecologically and economically important tree. This study evaluates potential shifts in its suitable distribution areas across Türkiye under future climate scenarios [Shared Socioeconomic Pathway 2-4.5 (SSP2-4.5) and 5-8.5 (SSP5-8.5)] using an ensemble species distribution model incorporating ten algorithms. Key environmental drivers—elevation, annual mean temperature (Bio1), and evaporation including sublimation and transpiration (evspsbl)—were identified as critical factors influencing habitat suitability. Results indicate substantial spatial redistributions, with habitat losses projected in inland transition zones toward continental climates, particularly in parts of the Aegean and Black Sea regions. The current suitable distribution area across the country, approximately 18.48%, could rise to 18.55% by 2040 under the SSP2-4.5 scenario and to 18.76% by 2060 under the SSP5-8.5 scenario. However, without human intervention, the species’ establishment in these new suitable distribution areas is not considered possible. Moreover, it has been determined that the suitable distribution area of the species could decrease to 17.48% by 2060 under the SSP2-4.5 scenario and to 17.31% by 2080 under the SSP5-85 scenario. This result indicates that there could be a loss of more than 8% of the suitable distribution area between 2060 and 2080, according to the SSP5-8.5 scenario. Conversely, limited expansions may occur in specific areas, including the northern Aegean and the Hatay-Antep region. By 2100, despite periodic fluctuations, a net decline in suitable habitats is expected under both scenarios. Notably, spatial analysis reveals that while some newly suitable areas may emerge, natural migration will likely be insufficient for population persistence, necessitating human-assisted adaptation strategies. These findings underscore the need for proactive conservation measures, such as identifying climate-resilient provenances, assisted migration, and targeted reforestation in future suitable zones. Given that most Turkish forests are state-managed, collaboration with the General Directorate of Forestry is essential to integrate climate adaptation into long-term management plans. This study provides a framework for mitigating climate-induced habitat loss in L. nobilis while offering insights applicable to other vulnerable Mediterranean species facing similar threats. Full article

Dietary phytogenic additives and microalgae are increasingly investigated as natural alternatives to antibiotic growth promoters in rabbit production due to their potential effects on gut health and nutrient utilisation. This study evaluated the nutraceutical potential of Chlorella vulgaris and Laurus nobilis as plant-based additives for growing New Zealand White rabbits. A 45-day feeding trial was conducted using control and experimental diets enriched with 0.1% Chlorella and 0.1% Laurus. Productive performance, nutrient digestibility, blood biochemistry and faecal composition were monitored, and polyphenolic compounds were analysed in feed, blood, faeces and caecal microbiota using HPLC-DAD. Final body weight (3097 vs. 2909 g) and feed intake (142.7 vs. 145.0 g day⁻¹) did not differ significantly between treatments. However, crude protein digestibility was significantly lower in the supplemented group than in the control group (54.39–47.79% vs. 63.73–62.33%; p < 0.05). Faecal chemical composition differed significantly between groups, particularly for dry matter, which was higher in the supplemented group across sampling times. Polyphenols detected across biological matrices confirmed the bioavailability of selected phytochemicals, with ferulic acid showing the highest stability. Correlation analysis indicated shared metabolic or absorptive pathways among several compounds. Overall, low-dose supplementation with C. vulgaris and L. nobilis appears safe and may support improved digestive physiology and nutrient utilisation without compromising rabbit health. Further research with larger sample sizes and detailed microbiome profiling is needed to clarify metabolic interactions and long-term effects of these nutraceutical strategies. Full article

Seasonal variation is recognized as a key factor affecting the essential oil (EO) yield, chemical composition, and antioxidant activity of Laurus nobilis L. from the Montenegro coast, which constituted the focus of this research. The bay essential oil (BEO) yield was higher in summer (2.12%) and autumn (2.03%) than in winter (1.26%) and spring (1.28%). The total number of BEO components, depending on seasonal variability, ranges from 31 (summer) to 34 (winter and spring). 1,8-cineole (eucalyptol) was the major aromatic compound in all seasons, with the highest content recorded in summer (52.4%). Linalool, as the second most abundant component, is present in the autumn harvest (14.1%), while α-terpinyl acetate, as the third most abundant component, is most prevalent in the winter–spring period (9.6–9.7%). Two groups of monoterpenes, namely the oxygen-containing monoterpene derivatives (80.1%), constitute the most abundant components in BEO leaves, as well as monoterpene hydrocarbons (14.3–15.5%). The phenylpropanoids were the least abundant (4.9–6.3%). Stronger antioxidant activity (DPPH) during an incubation time of 20 min was shown by the BEOs isolated from autumn (EC50 value of 1.15 mg/mL). Early autumn (September) represents the optimal harvest time for L. nobilis in Montenegro, as they ensure a high essential oil yield and better quality, reflected in a high 1,8-cineole content and stronger antioxidant activity of the oil. These results demonstrate that seasonal variations are key factors regulating the quantity and quality of BEO, providing important information for optimizing harvest strategies for medicinal and industrial purposes. Full article

Laurus nobilis hydrosol (HyLN), a water-soluble byproduct of essential oil extraction, containing beneficial antioxidants and antimicrobial compounds, was used as a sustainable ingredient in the development of a natural antioxidant-rich hydrogel formulation. Hydrogels were formulated using sodium hyaluronate and xanthan gum, natural ingredients with beneficial effects on the skin, while β-cyclodextrin (βCD) was added to enhance the stability of antioxidants in HyLN. Extensive rheological and textural analyses were employed to optimize the hydrogel formulation for dermal administration, while stability studies assessed the chemical and physical stability of developed formulations. A combination of sodium hyaluronate and xanthan gum provided several HyLN hydrogel formulations with tunable rheological and textural properties, presenting adequate physical and microbiological stability over 6 months of storage. The use of βCD failed to stabilize inherently unstable antioxidants in HyLN hydrogels, yet their residual antioxidant activity remained notable. An in vitro scratch test using a human keratinocyte cell line showed that the developed HyLN gel does not interfere with wound healing. HyLN hydrogels showed a pronounced occlusive effect in vitro, reaching up to 80% of that measured for Vaseline, which helps maintain skin hydration and appearance. Full article

The aim of this study was to investigate the effect of phyto-additive mixture supplementation on semen quality and on some reproductive parameters after artificial insemination in rabbits. The trial run 120 days on 20 adult New Zealand white rabbit bucks that were allocated into two different groups, first was control (CON; n = 10) fed with commercial pelleted-feed and second was considered experimental group (EXP; n = 10) which received in feed a natural feed additive mixture (0.1% of dried Chlorella vulgaris powder and 0.1% of dried Laurus nobilis leaves powder). Consequently, the quality assessment of semen by the Computer Assisted Semen Analyzer (CASA) system, samples were instrumentally inseminated on rabbit does for two consecutive reproductive cycles, and productive and reproductive indexes were evaluated. Results demonstrate that while spermatozoa concentration and ejaculate volume did not differ significantly among experimental groups or between reproduction cycles, spermatozoa motility parameters were significantly enhanced in rabbits receiving the phyto-additive mixture, as evidenced by increased total motility (87.83% vs. 70.63%) and progressive motility (75.68% vs. 50.10%) compared with the control group (p < 0.01). No differences were observed in prolificacy traits during the first reproductive cycle, whereas in the second cycle the phyto-additive treatment increased the number of kits born alive per litter (12.29 vs. 10.19; p < 0.05) and improved kit growth performance at birth (79.17 vs. 66.75 g), at weaning (1085.28 vs. 963.15 g), and in average daily gain (28.75 vs. 25.61 g/day). The study provides evidence of alternative practises based on feeding programme to enhance reproductive traits in rabbit production. The goal is to provide farmers with examples of good farming practise (such as precision farming), focused on sustainability and efficiency, and a certain transfer of knowledge. Full article

This study compares the chemical composition, antimicrobial effects, and antibiotic-potentiating capacity of three Lauraceae essential oils (EO): Cryptocarya agathophylla (CAEO), Litsea cubeba (LCEO), and Laurus nobilis (LNEO). Gas chromatography–mass spectrometry (GC–MS) analysis revealed distinct chemotypes: CAEO and LCEO were dominated by oxygenated monoterpenes, while LNEO contained the highest levels of monoterpene hydrocarbons. Antibacterial testing against nine bacterial strains showed strain-dependent growth suppression trends, while true minimum inhibitory concentrations (MICs) were reached only in selected cases. EO–ampicillin interactions were evaluated using MIC-based checkerboard criteria, whereas OD-derived inhibition parameters were used exclusively to describe sub-MIC potentiation trends. In combination assays, LNEO exhibited the most pronounced potentiating effects against Streptococcus pyogenes, Shigella flexneri, and Haemophilus influenzae, while CAEO and LCEO showed moderate or strain-dependent enhancement. Hierarchical clustering highlighted distinct oil- and strain-specific interaction profiles. Overall, although CAEO displayed stronger intrinsic antibacterial effects when tested alone, LNEO emerged as the most effective potentiator of ampicillin activity in a strain-dependent manner. The effects of the major compounds identified in the Lauraceae EO were assessed in silico against protein targets of some microorganisms using the AutoDock software version 4.2.6. The docking scores revealed binding affinities of the bioactive compounds towards Dpr protein (4.3–5.8 kcal/mol), DNA gyrase (4.7–7.1 kcal/mol), mono- diacylglycerol lipase (4.4–6.2 kcal/mol), CYP51 (5.8–8.0 kcal/mol), phage-encoded quorum sensing anti-activator (5.8–8.0 kcal/mol) and Chondroitin ABC lyase I (4.8–6.3 kcal/mol). Two (2) hit compounds (α-Citral, β-Citral) were finely defined by strong hydrophobic and hydrophilic interactions with the bacterial and fungal protein targets, respectively. Full article