Essential Oil Production Research Articles

Changes in composition, yield, antimicrobial and antioxidant activities of the Ocimum tenuiflorum L. essential oils as affected by fertilizers

The purpose of this study is to evaluate the impact of multifunctional microbial fertilizer and inorganic macronutrient fertilizers N, P, K on plant biomass, essential oil yield, chemical composition, antimicrobial and antioxidant activities of tulsi (Ocimum tenuiflorum L.) grown in Hanoi, Vietnam. Among the four formulas tested, F2 emerged as the most favourable, comprising a basal fertilization of 10 tons of decomposed manure, 15 kg of multifunctional microbial fertilizer, 150 kg of P fertilizer, and 75 kg of K fertilizer, together with top dressing of 200 kg of N fertilizer and 75 kg of K fertilizer per hectare. This formula yielded the highest tulsi dry biomass (4.73 ton/ha), essential oil yield (0.831%), and essential oil production (39.29 L/ha), which were significantly different (p < 0.001) from those of the remaining formulas. In addition, the concentration of the essential oil main compound - eugenol (63.1%) of tulsi in F2 was also the highest, which may be the cause of the strongest antibacterial activity against Bacillus subtilis, Escherichia coli (IC50 of 320, 273 µg/mL, respectively), and antifungal activity against Candida albicans (IC50 of 400 µg/mL), as well as antioxidant activity (IC50 of 0.165 µg/mL) compared to the other formulas tested. The results suggested the role of both multifunctional microbial fertilizer and inorganic macronutrient fertilizers N, P, K on growth and essential oil biosynthesis in tulsi. These findings are important in identifying the most efficient fertilization formula for cultivating tulsi, serving the needs of the cosmetic and medicinal industries.

Study of genotype × environment interaction on the morphological and chemical features of geranium (Pelargonium graveleons L'Her Ex Ait.)

Geranium is a multi-harvest perennial plant in the Geraniaceae family grown for its sweet-scented herbs and essential oils. It is well-known for its imposing rose-like aroma. Geranium essential oil is commonly used in the soap, fragrance, and cosmetic industries to isolate rhodinol, an aromatic compound found in most high-grade perfumes. The current study evaluated a total of 5 geranium genotypes across three years, at two locations, to identify the superior and stable geranium genotypes. "The pooled ANOVA results showed substantial genotype × environment interactions for all the traits under study. The CIM-Bio 171 genotype had the highest essential oil production per plant (g) (X9), followed by Kelkar (rank II, 10.24), Algerian CIM-Pawan (rank III, 10.03), CIM-Pawan (rank IV, 7.63), and Bourbon (rank V, 7.24) g/plant. For the trait citronellol content (X10), the Algerian genotype ranked top (37.83%), followed by CIM-Pawan (rank II, 30.81%), CIM-Bio 171 (rank III, 28.33%), Bourbon (rank IV, 26.89%), and Kelkar (rank V, 12.58%). The Kelkar genotype ranked the highest (6.20%) in the trait 10-epi-γ-Eudesmol content (X16), followed by CIM-Pawan (rank II, 5.89%), Algerian (rank III, 4.56%), Bourbon (rank IV, 4.29%), and CIM-Bio 171 (rank V, 4.25%). The genotype CIM Bio 171 exhibited the highest mean value for essential oil yield, and cis-Rose oxide content (%). The following genotypes, such as CIM Bio 171, Algerian, and CIM Pawan, emerged as high-mean performers and exhibited stability across diverse environments. The genotype CIM Bio 171 is closer to the ideal genotype, followed by CIM Bio 171, Algerian, and CIM Pawan as the most desirable genotypes. Similarly, the year Y3 was determined to be the most desirable based on GGE-biplot environment evaluations at both locations. Therefore, CIM Bio 171 has been released for commercial cultivation because of its exceptional performance in essential oil yield and quality attributes across locations and years. Kew wordscis-Rose oxide; essential oil; environment ranking; GGE-biplot; genotype × environment interaction.

Lavandula angustifolia Herb from Ukraine: Comparative Chemical Profile and in vitro Antioxidant Activity.

Lavandula L. genus plants have always been relevant as medicines for various purposes in food, medicine, pharmaceuticals, cosmetology and aromology. Ukraine is a new territory in the mass plant cultivation and lavender essential oil production. Therefore, the issue of integrated use of herbal raw materials and their intended use is still relevant. For the first time, ten samples of Lavendula angustifolia herb from 5 growing regions of Ukraine were studied for the composition and content of polyphenols and terpenoids using HPLC and HPTLC methods, respectively, to assess the prospects and quality of herbal raw materials. The results obtained showed that L. angustifolia herb has pronounced antioxidant activity due to the high content of phenolic compounds, namely hyperoside (5.665-11.629 mg/g), vanillic acid (5.986-11.196 mg/g), rosmarinic acid (0.211 to 1.488 mg/g), caffeic acid (0.369-3.835 mg/g), chlorogenic acid (0.239-4.619 mg/g), genistein-7-O-glucoside, as well as due to the presence of linalool and linalyl acetate, which was confirmed by qualitative analysis. The total antioxidant activity was the highest in samples from Lviv Botanical Garden (0.293 Trolox mg/mL), Kyiv OLawander (0.288 Trolox mg/mL), Kharkiv Bohodukhiv (0.270 Trolox mg/mL) which is due to the qualitative composition of phenolic compounds. At the same time, the most intense zones of terpenoids in lavender herb were noted for images from Kharkiv region Lebiazhe and Kitchenkivka villiges. Cluster analysis showed priority in the selection of marker compounds (vanillic acid, hyperoside, chlorogenic acid, rosmarinic acid) for lavender herb based on their quantitative content in the samples. In the future, lavender herb from Ukraine can be considered as a promising raw material with neuroprotective properties as part of its complex use, as research continues.

Synthesis of Methyl Esters from Banda Nutmeg and Papua Nutmeg Oil Production Wastes Using the Ultrasonication Method

Methysters from oil production waste from Banda nutmeg (Myristicafragrans Houtt) and Papuan nutmeg (Myristica Argentea Ware) go through several process stages, namely isolation of trimyristin and synthesis of methyl ester. The process of isolating trimyristin from nutmeg essential oil production waste by maceration using chloroform solvent. The transesterification process with methanol uses a CaO catalyst and ultrasonication method for 20 minutes; the results are analyzed using GCMS. The results of isolating trimyristin from nutmeg oil waste for Papuan nutmeg yielded 55.6 g of trimyristin (22.24%), which was greater than Banda nutmeg which was 49.7 g of trimyristin (19.88%). Transesterification results for Banda nutmeg oil waste obtained 28.57% soakage with a composition of 5 known major methyl ester compounds, namely methyl laurate (3.22%), myristicin (13.48%), metal myristate (53.39%), methyl Palmitate (5.24%), and Methyl Oleate (9.33%). In Papuan nutmeg oil waste, a 3.93% soakage was obtained with a composition of 5 known methyl ester compounds, namely metal myristate (19.80%), methyl arachidate (18.04%), methyl linoleate (1.42%), methyl oleate ( 48.37%), and methyl stearate (3.18%). The sonication method can synthesize methyl esters from nutmeg oil waste and gives different results for the two types of nutmeg. The results of the trimyristin transesterification of Banda nutmeg seeds and Papuan nutmeg seeds using a CaO catalyst using the sonication method resulted in a methyl ester soak of Banda nutmeg waste 28.57% and Papuan nutmeg 3.93%.

Controlled drought stress affects rosemary essential oil composition with minimal impact on biomass yield

Rosemary (Salvia rosmarinus Spenn.), an indigenous medicinal and aromatic plant within the Mediterranean region, yields essential oils renowned for their antimicrobial, antioxidant, anticancer, and anti-inflammatory properties. When subjected to various stress conditions, rosemary intensifies the production of essential oils as a defensive mechanism, as occurs when it is subjected to drought stress, making it a potentially interesting crop for marginal dryland areas of Sicily and other Mediterranean areas. Managing rosemary cultivation through controlled drought stress close to the balsamic period may increase the concentration and quality of essential oils and optimize the use of limited resources like water. We conducted two on-farm field experiments in Sicily, southern Italy, to assess the effect of controlled drought stress on rosemary biomass, essential oil yield, and composition. The hypothesis was that drought could improve the concentration of essential oils and modify their chemical composition by increasing valuable aromatic components without negatively impacting crop biomass production, increasing interest in cultivating this species. The experiments were co-designed with farmers selecting dedicated field experiments, cultivars, and crop management. Drought stress was applied during autumn and spring in correspondence with medium-high temperatures and rainwater scarcity. The irrigation input was reduced for three weeks during the balsamic period for each trail. Under stressed conditions, morphometric traits were measured. At harvest time, essential oils were extracted using microwave-assisted extraction. Under the same farm conditions, the canopy height was significantly higher in ‘Barbeque’ than ‘Tuscan Blue cv. (67.3 cm vs. 43.8 cm) This indicates a genotype influence on stress response. Essential oil yield increased by 30 % in plants of Tuscan blue cv. subjected to stress conditions in one of two farms. Additionally, drought stress altered the aromatic profile of the essential oil, resulting in differing percentages of key compounds between stressed and unstressed plants. Generally, there was a higher α-pinene percentage in unstressed plants and higher bornyl-acetate and β-caryophyllene concentrations in drought-stressed plants. In the Scicli farm, α-pinene decreased in response to water stress, while camphene and myrcene increased. Our results summarized that controlled drought stress had a minimal impact on rosemary growth, increasing the percentages of some terpenes in its essential oils. No severe decrease was observed in the synthesis of essential oils, suggesting that rosemary is suitable for marginal soils in many Mediterranean countries to protect soils and diversify crops in farms.

Operational parameters optimization of convection air-drying with ultrasound pretreatment of Cyperus rotundus L. tubers by RSM

Drying is an important step in the postharvest processing of agricultural products, as it allows the product to be preserved by reducing water activity to safe values, which stops microorganism growth and enzymatic reactions. In this context, the objective of this study was to assess how various drying temperatures, combined with ultrasonic pretreatment, affect drying rates and essential oil production. Assays were conducted according to a Central Composite Rotational Design, considering two factors with the following intervals: duration of the ultrasonic bath from 0 to 40 min, drying air temperature from 40 to 70 °C. The optimization was carried out using Response Surface Methodology (RSM). The essential oil was extracted by hydrodistillation and its constituents were identified by gas chromatography coupled to mass spectrometry. Histochemical analyses of fresh tubers were performed. The Midilli model was the one that best described the drying kinetics of Cyperus rotundus in all treatments. The drying time of C. rotundus tubers was dependent only on temperature (decreasing linear effect), it was possible to describe the variation in drying time as a function of temperature. It was not possible to adjust a model for ultrasonic bath time or drying temperature that would optimize both essential oil yield and the drying time of C. rotundus tubers. However, in this study, shorter drying times were observed compared to previous studies on C. rotundus tubers drying in the shade at room temperature. A total of 29 chemical constituents have been identified in the essential oil extracted from C. rotundus tubers, of which the majority are: 3,4-dimethyl-3-cyclohexen-1-carboxaldehyde (19.23%); caryophyllene oxide (17.63%); and α-cyperone (9.54%). Histochemical analyses of C. rotundus tubers showed the presence of starch, phenolic compounds, and lipids.

Silicon: A Powerful Aid for Medicinal and Aromatic Plants against Abiotic and Biotic Stresses for Sustainable Agriculture

Silicon plays a crucial role in enhancing plant tolerance to various abiotic and biotic stresses, including drought, salinity, heavy metals, and pathogen/pest attacks. Its application has shown promising results in improving stress tolerance and productivity in medicinal plants. This review synthesizes findings from numerous studies investigating the mechanisms by which silicon confers stress tolerance, including the regulation of antioxidant systems, water relations, nutrient homeostasis, phytohormone signaling, and stress-responsive gene expression. Additionally, it examines the effects of silicon supplementation on the production of valuable secondary metabolites and essential oils in medicinal plants. Silicon application can significantly mitigate stress-induced damage in plants, including medicinally important species such as borage, honeysuckle, licorice, Damask rose, savory, basil, and eucalyptus. The deposition of silicon in cell walls provides physical reinforcement and acts as a barrier against pathogen invasion and insect herbivory. Furthermore, silicon fertilization can enhance the production of valuable secondary metabolites in medicinal crops under stress conditions. The findings underscore the potential of silicon fertilization as a sustainable strategy for improving the productivity and quality of medicinal crops under changing environmental conditions, highlighting the need for further research to elucidate the molecular mechanisms underlying silicon-mediated stress tolerance and practical applications in medicinal plant cultivation.

Divergent Roles of the Auxin Response Factors in Lemongrass (Cymbopogon flexuosus (Nees ex Steud.) W. Watson) during Plant Growth.

Auxin Response Factors (ARFs) make up a plant-specific transcription factor family that mainly couples perception of the phytohormone, auxin, and gene expression programs and plays an important and multi-faceted role during plant growth and development. Lemongrass (Cymbopogon flexuosus) is a representative Cymbopogon species widely used in gardening, beverages, fragrances, traditional medicine, and heavy metal phytoremediation. Biomass yield is an important trait for several agro-economic purposes of lemongrass, such as landscaping, essential oil production, and phytoremediation. Therefore, we performed gene mining of CfARFs and identified 26 and 27 CfARF-encoding genes in each of the haplotype genomes of lemongrass, respectively. Phylogenetic and domain architecture analyses showed that CfARFs can be divided into four groups, among which groups 1, 2, and 3 correspond to activator, repressor, and ETTN-like ARFs, respectively. To identify the CfARFs that may play major roles during the growth of lemongrass plants, RNA-seq was performed on three tissues (leaf, stem, and root) and four developmental stages (3-leaf, 4-leaf, 5-leaf. and mature stages). The expression profiling of CfARFs identified several highly expressed activator and repressor CfARFs and three CfARFs (CfARF3, 18, and 35) with gradually increased levels during leaf growth. Haplotype-resolved transcriptome analysis revealed that biallelic expression dominance is frequent among CfARFs and contributes to their gene expression patterns. In addition, co-expression network analysis identified the modules enriched with CfARFs. By establishing orthologous relationships among CfARFs, sorghum ARFs, and maize ARFs, we showed that CfARFs were mainly expanded by whole-genome duplications, and that the duplicated CfARFs might have been divergent due to differential expression and variations in domains and motifs. Our work provides a detailed catalog of CfARFs in lemongrass, representing a first step toward characterizing CfARF functions, and may be useful in molecular breeding to enhance lemongrass plant growth.

Comparative analysis of the differences in volatile organic components of three lavender essential oils in Ili region using sensory evaluation, GC-IMS and GC-MS techniques

Lavender (Lavandula angustifolia Mill.) is a widely utilized aromatic plant, with the economic value of its essential oil (EO) largely dependent on its aroma. This study investigated the differences in volatile organic compounds (VOCs) within the EOs of three species of lavender (H70-1, French blue, Taikong blue) in Ili region from 2019 to 2023 with the combination of sensory evaluation, gas chromatography-ion mobility spectrometry (GC-IMS), and gas chromatography-mass spectrometry (GC-MS). The EO from Taikong blue lavender exhibited greater stability in VOC composition compared to the other two varieties. Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) effectively distinguished the aromas of the three EOs aroma. Combining odor activity value (OAV) and variable importance in projection (VIP) values identified five VOCs crucial for discriminating among the three lavender EO types. This study provides theoretical support for the cultivation and commercialization of lavender as an industrial crop, as well as for quality control of EO production in the Ili region.

Convolutional neural networks to assess bergamot essential oil content in the field from smartphone images

The essential oil (EO) extracted from bergamot peel (Citrus bergamia, Risso et Poiteau) is appreciated in perfumery and gastronomy. Notably, 90 % of the bergamot EO production is concentrated in the Province of Reggio Calabria (Southern Italy) under a protected designation of origin (PDO). The early estimation of EO content in fruits is fundamental to help farmers in their decision at harvesting period. The application of advanced modelling techniques based on artificial intelligence and digital device technology can contribute to this goal. This study proposes a method to estimate the EO content of fruits in the field using classification and regression models based on a deep learning approach in two cultivars: cv. “Fantastico” and cv. “Femminello”. The first step was to capture images of the fruit in the Red, Green, and Blue colours (RGB) using a mid-range smartphone camera and a portable inspection chamber designed and developed for this study. The acquisition of the images was carried out in the field. The fruits were collected and transported to the laboratory, where the EO was extracted using steam hydrodistillation. Custom-built convolutional neural networks (CNN) and three transfer learning models (VGG-16, VGG-19, and Xception architectures) were trained and applied for classification (among different discrete levels of oil content) and regression (to predict the EO content). The classification results showed an accuracy of 0.795 and 0.797 on the test samples of the two cultivars separately, while the best regression model achieved a minimum mean squared error of 0.12 and 0.04 for each cultivar, respectively. The results showed the effectiveness of the approach tested and how modelling each variety independently can lead to better performance for the CNNs tested.

History of studying essential oil crops

The article provides a historical overview of the formation and development of the essential oil industry. The main attention is paid to the history of scientific research of essential oil and medicinal plants. Our ancestors may have instinctively selected certain herbs for healing, just as sick animals today seek out plants they wouldn't normally eat. Based on an analysis of the current state, the need has been determined and the priority tasks have been formed for a full-scale revival of essential oil production in the Russian Federation.The problem tatement: in the republics of the former USSR, a number of essential oil plants were cultivated: coriander, lavender, essential oil rose, sage and others. In the 1970-80s the area of cultivation of essential oil plants exceeded 200 thousand hectares. At the same time, the demand for essential oils and other essential oil products was not fully satisfied. With the collapse of the USSR, the essential oil industry declined. The growing areas for most of the essential oil crops ended up on the territory of the newly formed independent states. The cultivation and processing of essential oils in Russia decreased significantly.The goal of the research is substantiation and acquisition of knowledge about the history of emergence and development of essential oil plants, herbal medicine, active substances as a tool for developing a common problem and combining the scientific, industrial and innovative potential of all interested parties.The research methods used are source study, historical-typological and biographical methods. The research results: the opportunity to gain new knowledge about the history of the origin and distribution of essential oil plants, and the creation of a huge food base for animals and people.

Foliar-applied melatonin and titanium nanoparticles modulate cadmium (Cd) toxicity through minimizing Cd accumulation and optimizing physiological and biochemical properties in sage (Salvia officinalis L.).

Notwithstanding the fact that melatonin (MT) and titanium nanoparticles (Ti NPs) alone have been widely used recently to modulate cadmium (Cd) stress in plants, there is a gap in the comparative impacts of these materials on lowering Cd toxicity in sage plants. The objective of this study was to determine how foliar application of MT and Ti NPs affected the growth, Cd accumulation, photosynthesis, water content, lipid peroxidation, and essential oil (EO) quality and quantity of sage plants in Cd-contaminated soils. A factorial experiment was conducted using MT at 100 and 200μM and Ti NPs at 50 and 100mg L-1 topically, together with Cd toxicity at 10 and 20mg Cd kg-1 soil. The results showed that Cd toxicity decreased plant growth and enhanced lipid peroxidation. The Cd stress at 20mgkg-1 soil resulted in increases in Cd root (693%), Cd shoot (429%), electrolyte leakage (EL, 29%), malondialdehyde (MDA, 72%), shoot weight (31%), root weight (27%), chlorophyll (Chl) a + b (26%), relative water content (RWC, 23%), and EO yield (30%). The application of MT and Ti NPs controlled drought stress by reducing MDA and EL, enhancing plant weight, Chl, RWC, and EO production, and minimizing Cd accumulation in plant tissues. The predominant compounds in the EO were α-thujone, 1,8-cineole, β-thujone, camphor, and α-humulene. MT and Ti NPs caused α-thujone to rise, whereas Cd stress caused it to fall. Based on heat map analysis, MDA was the trait that was most sensitive to treatments. In summary, the research emphasizes the possibility of MT and Ti NPs, particularly MT at 200μM, to mitigate Cd toxicity in sage plants and enhance their biochemical reactions.

Multi-platform sequencing explores the transcriptomics of terpenoid biosynthesis in Melaleuca alternifolia

Leaves of Melaleuca alternifolia are abundant in essential oils comprising terpenoids and volatile organic compounds, which play an important role in plant abiotic stress response. However, the molecular mechanisms underlying terpenoid biosynthesis in M. alternifolia remain poorly understood. To fill this knowledge gap, we profiled terpenoid content and composition across four distinct growth phases using gas chromatography-mass spectrometry (GC/MS). We also performed an integrated analysis of gene expression in leaf tissues through full-length transcriptome sequencing combined with high throughput RNA sequencing. We identified 46,313 transcripts, 99 % (45,848 transcripts) of which were annotated using existing databases. Our study also revealed 2,792 transcription factors (TFs) and 1,812 alternative splicing (AS) events. Through weighted gene co-expression network analysis (WGCNA), we clustered these identified genes into 11 co-expressed modules. Notably, two modules—designated as blue and brown—were significantly correlated with essential oil content. Homologous annotation with the Arabidopsis database revealed that genes within the blue module are largely involved in the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway, suggesting its pivotal role in essential oil synthesis in M. alternifolia. Furthermore, elevated expression levels of VAMP72 and DGK1 in the brown module indicate their potential function as negative regulators of essential oil synthesis. Our findings unveil key differentially expressed genes (DEGs) and pathways that can be targeted to enhance essential oil production in M. alternifolia. The identified TFs may serve as potential candidates for genetic modification through genome editing technologies. This research provides valuable insights into the processes involved in essential oil biosynthesis and highlights key genes for functional characterization in M. alternifolia.

Significance of Tissue Culture in Medicinal Plant Conservation and enhancement of Secondary metabolites by Homoeopathic intervention: A Narrative review

Aim: The objective of this study is to explore the potential of homoeopathic remedies in enhancing the biosynthesis of secondary metabolites in endangered medicinal plants. Background: Plants serve as a valuable source of medicine. Plant-based medicines are known for their simplicity, efficiency, and a broad range of activity with well-documented preventative or therapeutic effects. Secondary metabolites are active chemical components found in plants that are responsible for their medicinal properties. However, population growth, increased demand, illicit trafficking is driving the depletion of medicinal plants, and many are on the verge of extinction. The synthesis of phytochemicals in plants for medicinal purpose can be improved through various tissue culture techniques and homoeopathic remedies have been found to boost the generation of secondary metabolites. Methodology and Results: A comprehensive review of the scientific literature was carried out by searching through various databases, including Scopus, PubMed, Wiley, Google Scholar. Numerous investigations were conducted to assess the impact of homoeopathic remedies on the growth, phytochemical composition, and essential oil production of various medicinal plants. The most studied homoeopathic preparations were Phosphorus, Sulphur, and Silicea. Homoeopathic preparations were observed to improve photosynthetic rates by distributing greater amounts of photo-assimilated substances in the leaves, ultimately leading to enhanced growth. Homoeopathic medications work on the initial substances like pyruvic acid, ornithine and proline that contribute to the formation of shikimic acid and acetate, while providing the vital energy needed for plants to grow and flourish. These processes generate organic compounds that serve as precursors for various categories of secondary metabolites. Conclusion, Significance, and Impact of the study: Overall, the results suggest that homoeopathic preparations can positively impact the essential oil yield, growth, phytochemical profile of medicinal plants and expanded possibilities for the synthesis of pharmacologically and biologically active compounds. Research into applying homoeopathy to grow medicinal plants is highly relevant, as it's a long-standing practice aiming to optimize production and improve chemical constituent quality.

The Effect of Melatonin on Essential Oil Production in Mentha Spicata

The Effect of Melatonin on Essential Oil Production in Mentha Spicata

Variations in the biochemical characteristics of Lavandula sublepidota Rech.f. in response to the foliar enrichment of green-synthesized copper nano complexes from extract of neem and jujube

Copper (Cu) is an essential micronutrient in plant physiology and biochemistry. This article synthesized copper nano complexes (Cu–NCs) based on aqueous extracts of jujube and neem leaves. The effects of foliar application of Cu-jujube and Cu-neem Cu–NCs at concentrations of 0, 10, 25, and 50 mg L−1 on the bioactive compounds, antioxidant capacity, and essential oil of the Iranian native medicinal herb Lavandula sublepidota Rech. f. was investigated. The highest levels of flavonoids and polyphenols were observed in the plants treated with Cu–NCs at 25 mg L−1. However, no superiority was observed between the two types of Cu–NCs. Furthermore, 25 mg L−1 nCu-Z and nCu-N foliar application boosted essential oil yield (48 and 52%, respectively) over control. This suggests an ideal threshold beyond which toxicity was found. Similarly, the amount of commercially significant secondary metabolites increased at 25 mg L−1 CuNCs compared to 10 and 50 mg L−1 concentrations. The maximum antioxidant activity was found in extracts of lavender that had been treated with 25 mg L−1 CuNCs. When CuNCs were applied exogenously, the extracts' antibacterial activity (MIC μg mL−1) was substantially increased against the three pathogen strains. The results suggest that CuNCs demonstrate notably greater effectiveness, particularly at an ideal concentration of 25 mg L−1, in enhancing the production of essential oil and bioactive compounds in Lavandula sublepidota Rech. f. Therefore, these findings indicate the importance of the biosynthesis of NCs using plants and measuring the phytochemical changes of lavender plants.

The role of magnesium oxide foliar sprays in enhancing mint (Mentha crispa L.) tolerance to cadmium stress

This study investigates using magnesium foliar spray to enhance mint plants' growth and physiological performance under cadmium toxicity. It examines the effects of foliar application of magnesium oxide (40 mg L−1), in both nano and bulk forms, on mint plants exposed to cadmium stress (60 mg kg−1 soil). Cadmium stress reduced root growth and activity, plant biomass (32%), leaf hydration (19%), chlorophyll levels (27%), magnesium content (51%), and essential oil yield (35%), while increasing oxidative and osmotic stress in leaf tissues. Foliar application of magnesium increased root growth (32%), plant biomass, essential oil production (17%), leaf area (24%), chlorophyll content (10%), soluble sugar synthesis (33%), and antioxidant enzyme activity, and reduced lipid peroxidation and osmotic stress. Although the nano form of magnesium enhanced magnesium absorption, its impact on growth and physiological performance was not significantly different from the bulk form. Therefore, foliar application of both forms improves plants' ability to withstand cadmium toxicity. However, the study is limited by its focus on a single plant species and specific environmental conditions, which may affect the generalizability of the results. The long-term sustainability of such treatments could provide a more comprehensive understanding of magnesium's role in mitigating heavy metal stress in plants.

Innovative Techniques in Sandalwood Oil Extraction: Optimizing Phenolic and Flavonoid Yields with Subcritical Ethanol

Sandalwood essential oil, known for its rich content of phenolic and flavonoid compounds, holds great promise for applications in perfumery and medicine. However, traditional production methods have raised concerns regarding their environmental impact and sustainability. This study explored subcritical ethanol extraction as a green technique to address these concerns. Under optimized conditions (6.04 MPa, 109 °C, and 2.01 mL/min), maximum oil yield reached 4.04% with substantial total phenolic compounds (TPCs) of 4.11 mg GAE/100 g and total flavonoid compounds (TFCs) of 8.85 mg QE/100 g in the extracted sandalwood oil. Furthermore, the oil displayed notable antioxidant activity AA of 71.68%. The temperature was identified as a significant factor affecting oil yield, TPCs, TFCs, and AA. The fine-tuning of the extraction temperature enhanced the desired characteristics, improving bioactive compound yields and heightening antioxidant potential. This study uses a green extraction technique to contribute to sustainable sandalwood essential oil production.

ЛАВАНДА КОЛОСОВАЯ ПЕРСПЕКТИВНОЕ ЛЕКАРСТВЕННОЕ РАСТЕНИЕ

The plants containing essential oils are widely used in many industries and medicine. In this regard, it is necessary to conduct research on the introduction of essential oil crops with high productivity and yield to create a strong raw material base. The purpose of the study was to assess the morphological characteristics, seed productivity and quantitative content of essential oil in spike lavender under cultural conditions. The studies were carried out during the period of mass flowering of plants. It has been established that spiked lavender is winter-hardy and drought-resistant under cultural conditions, forms a bush 60 cm high, inflorescence yield is 1.22-3.1 kg/m2, actual seed productivity is 110-1500%, potential seed productivity is 216-2890. Seed productivity coefficient is 0.5-0.53%, laboratory seed germination reaches 90%, seed germination energy is 0.7%. The largest amount of essential oil in lavender was found in the mass flowering phase. During the budding period, the oil content increases, and towards the end of flowering and the beginning of seed ripening, the essential oil content decreases.

Sequential Separation of Essential Oil Components during Hydrodistillation of Fresh Foliage from Azorean Cryptomeria japonica (Cupressaceae): Effects on Antibacterial, Antifungal, and Free Radical Scavenging Activities.

Cryptomeria japonica wood industry generates large amounts of foliage biomass residues. Due to the increasing applications and markets for essential oils (EOs), fresh Azorean C. japonica foliage (Az-CJF) residues are used for local EO production. Hydrodistillation (HD), a common process for obtaining EOs, also provides the possibility to fractionate them. Thus, this study evaluated the in vitro antimicrobial and antioxidant activities of six Az-CJF EO fractions (Frs. 1-6), collected at sequential HD timeframes (HDTs: 0-2, 2-10, 10-30, 30-60, 60-120, and 120-240 min), in comparison to the crude EO, obtained from a non-fractionated HD (0-240 min HDT). Antimicrobial activities were assessed via disc diffusion method against seven bacteria (foodborne and/or human pathogens) and two Penicillium spp. (phytopathogenic fungi), and antioxidant activity was estimated using DPPH and ABTS assays. Concerning the antibacterial activity, all the EO samples were effective only toward Gram-positive bacteria. Fractions 1-3 (<30 min HDT) were the most active, with growth inhibition zones (GIZ) of 7.0-23.3 mm (1.4-2.2 times higher than those of the crude EO), being Bacillus spp. (B. licheniformis and B. subtilis) the most sensitive, followed by Staphylococcus aureus and Micrococcus luteus. Regarding the antifungal activity, Frs. 1-3 also displayed the best activities, but only against P. italicum (GIZ around 9.0 mm), while the crude EO showed no antifungal activity. Overall, the best antimicrobial properties of Frs. 1-3 could be attributed, at least in part, to their highest content in α-pinene and bornyl acetate. On the other hand, Frs. 4-6 (>30 min HDT) exhibited the strongest antioxidant activities (EC50 values: 1.5-2.3 and 1.0-1.7 mg mL-1 for DPPH and ABTS, respectively), being at least 1.3-fold higher than those of the crude EO. The presence of nezukol, elemol, and eudesmol isomers could strongly contribute to the best free radical scavenging properties of Frs. 4-6. In conclusion, HD was found to be an efficient process for obtaining new Az-CJF EO fractions with variable and enhanced bioactivities due to their differential composition, as assessed using GC-MS. Hence, these findings could contribute to increasing the commercial potential of the C. japonica EO industry, namely, the Fr2 and Fr6, which presented the most significant activities and can have potential applications in the food, medical, and agriculture sectors.