Highest Essential Oil Content Research Articles

Phytochemical compositions and antioxidant activity of green and purple basils altered by light intensity and harvesting time

Ocimum basilicum L. is one of the most important medicinal and vegetable crops due to its essential oil, pleasant aroma and taste. In this study, we evaluated the impact of different light intensities, including 100 %, 50 %, and 30 % of natural sunlight, on the growth, phytochemical compositions, and antioxidant activity of green and purple basil cultivars at two different harvest times: early morning and noon. The height of the plant, number of leaves per plant, length of the petiole, diameter of the stem, and fresh and dry weight of the shoot were all reduced by decreasing light intensity in both basil cultivars. When the plants of both cultivars were grown under full light intensity and were sampled at noon, they showed the highest phenolic and flavonoid contents. The highest antioxidant activity was detected in purple basil cultivars grown under 30 and 50 % of sunlight in both harvests. The green basil cultivar showed the highest antioxidant activity when exposed to 30 % sunlight and harvested in the early morning. The highest essential oil content and yield in both basil cultivars were obtained under full sunlight in the early morning harvests. In summary, light intensity and harvest time influence the phytochemical yield, composition, and growth of two studied basil cultivars. Optimal results, particularly for medicinal purposes, were achieved by morning harvesting to maximize the essential oil yield of basils.

Phytochemical Composition, Antioxidant and Antimicrobial Activity ofThree Monarda Species: M.bradburianaL.C.Beck,M.×mediaWilld.,and M. punctata L.

Plants of the genus Monarda receive growing interest as the sources of herbal raw materials with wide range of potential applications in food, cosmetics, and phytopharmaceutical industry. This study aimed to evaluate the differences in chemical characteristics and biological activity among different organs of plants representing three underinvestigated species of this genus: Monarda bradburiana L. C. Beck, Monarda × media Willd., and Monarda punctata L. The content of phenolic compounds and the antioxidant activity of leaves, stems, and inflorescences were determined. Essential oil (EO) content, composition, and antimicrobial activity were also examined. M. punctata leaves and inflorescences had the highest EO content (4.43% and 5.59%, respectively), with carvacrol as a dominant constituent. Leaf EO was also rich in thymoquinone (17.48%). In EOs of M. bradburiana and M. × media, thymol dominated. EOs inhibited the growth of all tested strains of microorganisms at a concentration of 0.625 µL × mL-1. The studied plant organs were rich in phenolic compounds, especially rosmarinic acid. M. bradburiana inflorescences were distinguished by high linarin content. Differences in flavonoid distribution seem to have special chemotaxonomic importance. Further research is needed to facilitate standardisation of the investigated plant organs as potential new herbal raw materials.

Study of peculiarities of essential oil accumulation by common yarrow herb of synanthropic flora of Rostov region

Abstract.
 Aim - study the peculiarities of essential oil accumulation in common yarrow herb harvested in urban areas of Rostov region.
 Materials and Methods. Raw materials were collected along a country road with non-vibrant traffic, the North Caucasus railroad and along the M-21 highway with heavy vehicular traffic belonging to IA category. A step of 100 meters (from 1 to 300 meters) was chosen away from the studied highways. In addition, the raw materials were harvested in the area devoid of anthropogenic impact (control) and near the agricultural enterprise JSC "Aston".
 Results. For samples of control areas and agrobiocenoses we can note a higher content of essential oil than in samples of urban biocenoses. The maximum indicator of the essential oil content is noted for the sample harvested in the control area, devoid of anthropogenic impact, the minimum content - for the sample collected along the highway M-21.
 Conclusions. According to the studies we can conclude about the negative impact of anthropogenic impact, as well as the peculiarities of the growing area on the accumulation of essential oil in the grass of common yarrow.

ОЦЕНКА СОРТИМЕНТА КАЛЕНДУЛЫ ЛЕКАРСТВЕННОЙ КАК КУЛЬТУРЫ ДЛЯ ОЗЕЛЕНЕНИЯ

Calendula officinalis L. is one of the most common pharmaceutical crops cultivated not only in the Krasnodar region, but also in the south of the Russian Federation as a whole. In addition to its medicinal qualities, a high content of essential oils, as well as phenols and flavonoids, the crop is an excellent alternative to annual floral and ornamental plants in landscaping. In this regard, the purpose of the research was to evaluate seven varieties of Calendula officinalis L. in terms of duration,intensity and timing of the beginning of flowering, the activity of growth processes, size, color, inflorescence structure and the identification of the most adapted to growing conditions varieties that have high decorative qualities. Proposals were made on the directions of using the studied varieties in ornamental gardening and landscaping of the territory. The studies were carried out in 2022-2023 at the experimental site of private household plots in the central zone of the Krasnodar region. As a result of the research, it was found that the studied varieties of calendula had significant differences in a number of morpho-biometric indicators, but turned out to be highly adapted to the growing conditions in the south of the Russian Federation. According to the combination of ornamental qualities, three varieties of calendula officinalis were identified for cultivation in the central zone of the Krasnodar region. The Tutti-Frutti yellow variety is recommended for planting in flower beds due to the bright flowers of the inflorescence and the low growth of the plants. It is advisable to use the Geisha variety for the design of plots in landscape design and for cutting flowers. In garden and park landscaping, attention should be paid to the King's Cup variety, which stands out for a complex of decorative qualities and a long flowering period. Key words: CALENDULA, LANDSCAPING, ASSORTMENT, PHENOLOGY, GROWTH, FLOWERING, ORNAMENTAL TRAITS

RELATIONSHIP BETWEEN BIOCHEMICAL INDICATORS AND PHENOTYPICAL CHARACTERISTICS OF THYME (THYMUS VULGARIS L.)

Introduction. Thyme (Thymus vulgaris L.) is a sought-after medicinal crop, the raw materials of which are included in the Pharmacopoeias of several countries and are widely used in scientific medicine. Due to the presence of strong intraspecific diversity in thyme, it seems interesting to identify phenotypic characteristics that most likely indicate the presence of certain pharmacologically significant compounds. The presence of such information will allow targeted selection both in natural populations and during the hybridization of cultivars and the development of new varieties. The purpose of the work was to identify phenotypic traits indicating a high content of essential oil and thymol in thyme, the amount of phenolic compounds, flavonoids and tannins. Material and methods. Samples and varieties of thyme from different geographical origins were selected as objects. Biometric, anatomical indicators and yield were determined in the flowering phase. The essential oil content was determined by Clevenger hydrodistillation method. Component composition was determined by gas chromatography. The amount of phenolic compounds and tannins according to the Folin-Ciocalteu method in aqueous-alcoholic extract calculated as gallic acid. The determination of flavonoids in the aqueous-alcoholic extract was carried out using the spectrophotometryс method calculated as rutin. Results. As a result of the research, no signs were found indicating a high content of essential oil. Flavonoid content calculated as rutin had a negative correlation (−0.72) with stomatal density. A negative relationship was noted between the intensity of coloring of the pistil and anthers and the content of the total phenolic compounds calculated as gallic acid (0.71 and 0.72, respectively). Large stomata on both the underside and upper side of the leaf may indicate a high tannin content (0.8 and 0.88). All studied components of common thyme belonged to the thymol type, and the content of this component ranged from 37.6 to 80.8%. An increased content of thymol in essential oil is observed such signs as an elongated leaf shape (leaf index R = 0.78), lack of downward curling of the edges of the leaf blade (R = –0.78) and pronounced veins on the underside of the leaf (R = 0.92). Large stomata on the lower epidermis also indicate an increased proportion of thymol in the essential oil (R = 0.78). When analyzing the interdependence between the content of the main components of essential oil, it was noted that there is a close negative correlation between the content of p-cymene and thymol (R = –0.91) and carvacrol (R = –0.88). Conclusion. As a result of the research, phenotypic and anatomical characteristics were identified that make it possible to diagnose promising samples of common thyme, which will help speed up the selection process.

Essential oil variation in Melissa officinalis L. cultivated under industrial field conditions: effects of different harvesting times and plant materials

Melissa officinalis L. is a cosmopolitan aromatic and medicinal plant from the Lamiaceae family, which is necessary for pharmaceutical and cosmetic production. To evaluate the impact of different harvesting times and plant materials on the essential oil content and composition of M. officinalis 4-year-old plants, the present study was conducted in Fars province, Iran, under industrial field conditions. A randomized factorial experiment with three replications was used. Each replication contained six treatments [3 harvesting of M. officinalis × 2 treatments (shade drying + fresh state)]. Hydrodistillation was used to obtain the essential oils from each treatment, which were subsequently analyzed using GC-FID and GC-MS. The results demonstrated a significant influence of harvesting times and plant materials on the essential oil content and composition of M. officinalis. The average essential oil content was 0.028% to 0.095% (w/w). At different harvest times, the fresh plant yielded a higher content of essential oil compared to the dry plant. The number of chemical constituents in the essential oils was influenced by different harvesting times and plant materials. The predominant and common constituents in all harvested plant materials were the oxygenated monoterpenes geranial (28.7-43.2%) and neral (12.9-30.9%). Based on the major compounds, the essential oils from different harvesting times and plant materials were categorized into two chemotypes: chemotype I (geranial/thymol) and chemotype II (geranial/neral). It is recommended that drying operations not be used as a post-harvest processing method to achieve the highest essential oil yield from M. officinalis.

Новый сорт горчицы сарептской яровой Дюна

The new mustard cultivar Dyuna was developed by a method of multiple individual selection of elite plants from an interspecific hybrid combination of a brown mustard cultivar Rosinka and a spring rapeseed BN-2254 using self-pollination. The main features of the cultivar are brown color of seed coat and high content of essential oil – about 0.76%. The new cultivar is characterized with high potential yield, which exceeds the standard variety by 0.22 t/ha. Cultivation of the cultivar Dyuna allows obtaining raw material with increased contents of antioxidants and phytoncides to produce wide diversity of condiments, most particularly popular and spiciest Dijon mustard that requires for dark mustard seeds with high content of essential oil.

Chemical Diversity of Wild-Growing and Cultivated Common Valerian (Valeriana officinalis L. s.l.) Originating from Poland.

Common valerian is a medicinal plant. The underground organs of this species are used as a mild sedative and sleeping aid. Poland is one of the largest producers of this raw material in Europe, with local cultivar 'Lubelski' as a primary cultivated form. Although valerian is the subject of more or less deliberate selection carried out by farmers, it is still genetically unstable. The aim of this study was to determine the diversity of the 'Lubelski' cultivar originating from four regions of Poland (forms: L1-L4) in relation to wild-growing populations of the species. The plants were assessed in terms of the mass of underground organs and the content of valerenic acids and essential oils (EOs). The content of valerenic acids was determined using HPLC, whereas the content of EOs was determined using hydrodistillation. The composition of EOs was assessed using GC-MS GC-FID. The ploidy level of the analyzed objects was determined as well. Wild-growing populations (diploids) were characterized by lower masses of underground organs and lower contents of valerenic acid than cultivated forms (tetraploids). However, they produced higher contents of EOs. All the cultivated forms were strongly diversified with respect to the analyzed traits, including the mass of the roots (CV 49-75%), the content of valerenic acids (CV 18-55%), and the content of EOs (CV 28-57%). A total of 44 compounds were identified in the EOs. The dominant compound of both wild-growing populations and the 'Lubelski' forms were: α-fenchene, bornyl acetate, and valerenal. Among 'Lubelski' forms, the most interesting seems to be the L2 form, which was characterized by a relatively high yield and high content of valerenic acids and EOs. Thus, it appears to be a promising source of objects for further valerian cultivar improvement.

Intraspecific variability of Salvia officinalis (Lamiaceae) according to DNA repeats chromosome patterns

Salvia officinalis L. (Lamiaceae) is a widespread economically valuable species. Due to the high content of essential oil, it is actively used in pharmaceutical, food and perfume industries. However, the chromosome structure and organization of its genome is still not well understood. For the first time, an analysis of intraspecific variability of S. officinalis was carried out based on the patterns of FISH localization of various DNA repeats in karyotypes of four species samples and two varieties from different habitats. Patterns of chromosome localization on of classical markers, 45S rDNA and 5S rDNA, confirmed the stability of genomes of the studied species samples and varieties. However, the intraspecific variability in localization of SO202 in karyotypes of the studied samples was found. In addition to the main set of chromosomes, B chromosomes were found in some karyotypes, including those containing 45S rDNA and SO202 clusters. The results of this study allowed us to identify all chromosome pairs in karyotypes and construct karyograms of the studied samples of S. officinalis. Our findings confirmed the stability of karyotypes of these samples according to the classical chromosomal markers but also demonstrated the presence of intraspecific variability in localization of the SO202 repeat, which can be used in breeding new varieties of S. officinalis.

Essential oil profiles, improvement of enzymatic and non-enzymatic antioxidant systems in different populations of Salvia subg. Perovskia by irrigation management

Salvia subg. Perovskia is an aromatic medicinal plant from the Lamiaceae family. Essential oil (EO) content and composition, along with enzymatic and non-enzymatic antioxidants, were evaluated in 18 plant populations under three levels of irrigation for two consecutive years. Based on the GC-MS analysis, the main components of EO were borneol (1.18–36.53%), followed by camphor (0.54–32.17%), 1,8-cineole (12.44–29.26%), δ-3-carene (0.39–21.20%), myrcene (0.59–16.28%), and α- pinene (0.79–12.87%) in the studied treatment. Except for malondialdehyde and hydrogen peroxide in leaves and roots, all the examined parameters showed lower values in the first harvest year compared to those of the second year. The activities of antioxidant enzymes, total phenolics, and flavonoids of the extracts were substantially enhanced as stress intensified to reach maximum values in leaves under severe stress and in roots under moderate stress conditions. The maximum root tanshinones content was observed under moderate water deficit conditions, while the highest EO content was obtained in plants exposed to severe stress conditions. Taking into account the evidence provided by this study, it can be inferred that the use of water deficit stress can serve as an effective method to stimulate and improve antioxidant properties, as well as the quantity and quality of secondary metabolites in Salvia subg. Perovskia.

Co-inoculation of mycorrhizal fungi and plant growth-promoting rhizobacteria improve growth, biochemical and physiological attributes in Dracocephalum kotschyi Boiss. under water deficit stress.

Because of swift climate change, drought is a primary environmental factor that substantially diminishes plant productivity. Furthermore, the increased use of chemical fertilizers has given rise to numerous environmental problems and health risks. Presently, there is a transition towards biofertilizers to enhance crops' yield, encompassing medicinal and aromatic varieties. This study aimed to explore the impacts of plant growth-promoting rhizobacteria (PGPR), both independently and in conjunction with arbuscular mycorrhizal fungi (AMF), on various morphological, physiological, and phytochemical characteristics of Dracocephalum kotschyi Boiss. This experimentation took place under different irrigation conditions. The irrigation schemes encompassed well watering (WW), mild water stress (MWS), and severe water stress (SWS). The study evaluated the effects of various biofertilizers, including AMF, PGPR, and the combined application of both AMF and PGPR (AMF + PGPR), compared to a control group where no biofertilizers were applied. The findings of the study revealed that under water-stress conditions, the dry yield and relative water content of D. kotschyi Boiss. experienced a decline. However, the application of AMF, PGPR, and AMF + PGPR led to an enhancement in dry yield and relative water content compared to the control group. Among the treatments, the co-application of AMF and PGPR in plants subjected to well watering (WW) exhibited the tallest growth (65 cm), the highest leaf count (187), and the most elevated chlorophyll a (0.59 mg g-1 fw) and b (0.24 mg g-1 fw) content. Regarding essential oil production, the maximum content (1.29%) and yield (0.13 g plant -1) were obtained from mild water stress (MWS) treatment. The co-application of AMF and PGPR resulted in the highest essential oil content and yield (1.31% and 0.15 g plant-1, respectively). The analysis of D. kotschyi Boiss. essential oil identified twenty-six compounds, with major constituents including geranyl acetate (11.4-18.88%), alpha-pinene (9.33-15.08%), Bis (2-Ethylhexyl) phthalate (8.43-12.8%), neral (6.80-9.32%), geranial (9.23-11.91%), and limonene (5.56-9.12%). Notably, the highest content of geranyl acetate, geranial, limonene, and alpha-pinene was observed in plants subjected to MWS treatment following AMF + PGPR application. Furthermore, the co-application of AMF, PGPR, and severe water stress (SWS) notably increased the total soluble sugar (TSS) and proline content. In conclusion, the results indicate that the combined application of AMF and PGPR can effectively enhance the quantity and quality of essential oil in D. kotschyi Boiss., particularly when the plants are exposed to water deficit stress conditions.

Phenotypic Diversity of Litsea cubeba in Jiangxi China and the Identification of Germplasms with Desirable Characteristics

Litsea cubeba (Lour.) Pers. is an important economic tree. We aimed to explore the phenotypic diversity of wild L. cubeba provenances from Jiangxi province and identify the germplasms with desirable characteristics. Nest variance analysis, multiple comparisons, correlation analysis, path analysis, redundancy analysis, and cluster analysis were conducted to compare the phenotypes of 526 wild L. cubeba trees from 27 provenances. We detected significant differences in the growth traits, fruit traits, and essential oil (EO) content of L. cubeba provenances, as well as significant differences in tree height, thousand seed dry weight, and the proportion of five essential oil components (citral, neral, geranial, D-limonene, and citronellal) within the provenances. The fresh fruit yield (FFY) was mainly determined by the ground diameter and the annual average minimum temperature. The EO content was mainly affected by the water content, annual average temperature, longitude, and latitude. The proportion of citral (CitrP) was negatively affected by extreme low temperatures. Four individual L. cubeba trees had a high FFY of over 10.00 kg·tree−1. Two trees had a high EO content exceeding 5%, with their CitrP over 80%. The provenances with high FFY were Guixi and Yushan (2.65 kg·tree−1; 2.89 kg·tree−1). The provenances with a high EO content of about 4.00% were Dayu, Yudu, Ji’an, Xinfeng, and Yushan. The provenance with the highest CitrP level (80.61%) was Ningdu.

Изучение коллекции розы эфиромасличной по комплексу хозяйственно ценных показателей

Abstract. The article presents the results of the study of essential oil-bearing rose samples according to the most valuable indicators. The purpose of the current research was twofold: characterize essential-oil-bearing rose collection in terms of the morphobiological parameters and economically valuable traits; identify samples promising for selection. Research methods. Analysis of essential-oil-bearing rose samples was carried out according to the methodological guidelines for essential oil crops in 2017–2020. Under field and laboratory conditions, we analyzed such indicators as flowering time, winter hardiness, budding ability, flower weight, essential oil content in inflorescences. Statistical processing of the data obtained was carried out. Results. The essential-oil-bearing rose collection nursery was laid in 2012 at the experimental site of the Department of Aromatic and Medicinal Plants located in the foothill zone of Crimea (Krymskaya Roza vill., Belogorskiy district). Significant variability of the flower weight and mass fraction of essential oil (Cv = 24.6…36.3 %) was noted. The dependence of the main indicators on meteorological conditions during the period of active vegetation of plants was analyzed. It was found that extremely high temperature regime and insufficient rainfall in April–May reduced the duration of flowering in the essential-oil-bearing rose collection, on average, by 3–5 days. It was noted that, despite the differences in the response of samples to weather conditions, the leading factor determining the level of essential oil accumulation in inflorescences is genotype. According to the complex or individual valuable indicators, we identified 14 best specimens, seven of which were with the highest content of essential oil in inflorescences (0.030–0.049 %). Scientific novelty. For the first time, a one-time detailed study of the collection was conducted according to a set of valuable traits. The collection comprises 50 specimens including five varieties of Crimean breeding (originator – Research Institute of Agriculture of Crimea) and five – from Bulgaria. The information obtained will allow selecting samples that are promising as source material for breeding, as well as predicting the expected productivity of essential-oil-bearing rose varieties under specific weather conditions of the region.

Main Habitat Factors Driving the Phenotypic Diversity of Litsea cubeba in China.

Litsea cubeba (Lour.) Pers. is an important woody spice tree in southern China, and its fruit is a rich source of valuable essential oil. We surveyed and sampled L. cubeba germplasm resources from 36 provenances in nine Chinese provinces, and detected rich phenotypic diversity. The survey results showed that plants of SC-KJ, SC-HJ, and SC-LS provenance presented higher leaf area (LA); YN-SM and YN-XC plants had larger thousand-grain fresh weight (TFW); and HN-DX plants had the highest essential oil content (EOC). To explain the large differences in the phenotypes of L. cubeba among different habitats, we used Pearson's correlation analysis, multiple stepwise regression path analysis, and redundancy analysis to evaluate the phenotypic diversity of L. cubeba. It was found that compared to other traits, leaf and fruit traits had more significant geographical distributions, and that leaf phenotypes were correlated to fruit phenotypes. The results showed that elevation, latitude, longitude, total soil porosity (SP), soil bulk density (SBD), and average annual rainfall (AAR, mm) contributed significantly to the phenotypic diversity of L. cubeba. Geographical factors explained a higher percentage of variation in phenotypic diversity than did soil factors and climate factors. Plants of SC-KJ and HN-DX provenances could be important resources for domestication and breeding to develop new high-yielding varieties of this woody aromatic plant. This study describes significant phenotypic differences in L. cubeba related to adaptation to different environments, and provides a theoretical basis for the development of a breeding strategy and for optimizing L. cubeba cultivation.

Extraction and in vitro active evaluation of essential oil of Acorus tatarinowii Schott rhizome rich in β-asarone using enzymatic pretreatment and solvent-free microwave-assisted method

The essential oil from fresh rhizomes of Acorus tatarinowii Schott was obtained using the EP-SFM method (an enzymatic pretreatment and solvent-free microwave-assisted method) and characterized. The optimal conditions for essential oil extraction have been obtained experimentally through experiments on single-factor and response surface-based optimization. The highest essential oil content (1.48%, w/w) was obtained under the optimal conditions by SEM, TGA, FTIR, GC-MS and acetylcholinesterase inhibition activity analysis in vitro assay. The EP-SFM method was found to be effective in improving the extraction rate of essential oils and reducing extraction time, as indicated by the results. More importantly, this method greatly increased the active component content of β-asarone (65.87%), and the content of β-asarone was increased by 18.06% compared with the conventional steam distillation method (SD). The acetylcholinesterase inhibiting activity of EP-SFM essential oil was evaluated as well, which had the best acetylcholinesterase inhibitory activity and was closest to the positive control group.

Anti-nutrient contents and methane reduction potential of medicinal plants from maize stover based diet

Greenhouse gas emissions from Ethiopian agriculture are significantly increasing, with the largest share is from enteric fermentation and manure left on pasture. An investigation was conducted to evaluate the anti-nutrient composition and effect of commonly used medicinal plant extracts on enteric methane emission from fibrous feeds using maize stover as substrate feed. Total phenols, flavonoid, tannin and essential oil contents were analyzed using established standards. Effects of leaf extracts of Acacia nilotica, Azadirachta indica, three varieties of Cymbopogon citratus (Cymbopogon citratus-I, Cymbopogon citratus java and Cymbopogon citratus upper awash), Leucaena leucocephala, Moringa stenopetala, three varieties of Rosmarinus officinalis (Rosmarinus officinalis I, Rosmarinus officinalis II and Rosmarinus officinalis III) and Thyme schimperi, seed of three Coriandrum sativum varieties (Coriandrum sativum Batu, Coriandrum sativum Tulu and Coriandrum sativum Waltai) and root of Echinops kebericho on total gas production, digestibility and methane production of maize stover were investigated at different doses using the standard procedures. The results indicated that leaf extracts of Acacia nilotica had the highest (P < 0.001) total phenolic and total tannin contents. Compared to other evaluated plant species, all varieties of Cymbopogon citratus had the highest (P < 0.001) flavonoid content. Significantly high (P < 0.001) essential oil content was observed in Rosmarinus officinalis II than other varieties of Rosmarinus officinalis and other plant species. Significant reduction (P < 0.001) of methane production was observed with extracts of Cymbopoon citratus java (22.5 % less methane than the control) and thyme schimperi (16.7 % less methane than the control) at dose of 50 mg/kg DM. There was also significant (P < 0.001) interaction effect between plant species and dose rates at 50 mg/kg DM for both plant species. It can be concluded that the use of 50 mg/kg DM of Cymbopoon citratus java and Thyme schimperi extract to maize stover reduced methane production without negatively affecting feed digestibility. Further studies are necessary to examine the storability of the extracts in different time durations and evaluate their effects in vivo with animals.

Novel approaches for lemon grass essential oil extraction: Ultrasound sonication and sparger‐based microwave assisted extraction as a combined technique

AbstractThe utilization of essential oils spans across various industries, encompassing food, pharmaceuticals, and cosmetics. Lemongrass, an herb renowned for its high essential oil content, was the focal point of this research. The objective was to explore a novel approach to extract essential oil from lemongrass by employing ultrasonic sparger‐based microwave‐assisted extraction (U Sp‐MAE) coupled with ultrasound sonicator pretreatment. The findings revealed that the application of the U Sp‐MAE technique, combined with ultrasound sonicator pretreatment, resulted in a significant increase in lemongrass essential oil yield. At a mixing ratio of 80 g of chopped lemongrass per 500 mL of deionized water, a remarkable yield of 1.87% was achieved. This study demonstrates the potential of the U Sp‐MAE technique, with ultrasound sonicator pretreatment, as a promising and efficient method for extracting essential oil from lemongrass. Furthermore, its potential applications extend to industrial settings, offering new avenues for utilization.

Chemical characterization of mint (Mentha spp.) germplasm from Central Java, Indonesia

Abstract. Lianah L, Kusumarini N, Hafshah M, Krisantini K, Kurniawati A, Ahmad MA. 2023. Chemical characterization of mint (Mentha spp.) germplasm from Central Java, Indonesia. Biodiversitas 24: 4307-4313. The main objective of this work was to evaluate and compare the leaf production and oil content of the four mint genotypes (Mentha spp.) from Central Java, Indonesia. Four genotypes were collected from Rejosari Village, Kudus District, Central Java, Indonesia, namely spearmint (Mentha spicata), peppermint (Mentha x piperita), orange mint (Mentha x piperita ‘Orange’) and chocolate mint (Mentha x piperita ‘Chocolate’). Essential oil extraction was carried out by steam distillation. Identification of the chemical compounds of the oil and their relative percentage were analyzed using GC-MS. Leaves productivity ranged between 500-1000 kg/ha, and essential oil content from 0.4 to 1.36%. The major essential oil constituents detected were 1,8-cineole, carvone, limonene, linalool, linalyl acetate, menthol, menthone, menthyl acetate, and piperitenone oxide. Chocolate mint had the highest leaf production and the highest content of essential oil (4.17%) and menthone yield (28%) compared to the other genotypes.

A new approach on essential oil production of Origanum onites L.: Microbial fertilization and microwave extraction

In many studies plant and microbe interaction has been observed due to its stimulating effect on plant oil content. Bacillus spp. isolates used as microbial fertilizer/biostimulant have shown a higher potential for enhancing plant production and quality. However, there is still a need for investigating the essential oil content of plants, particularly for the pharmaceutical industry, to increase the targeted essential oil quantity and quality. Thyme is a crucial plant in medicinal aromatic herbal production and export, and its economic value is steadily increasing due to its high essential oil content. This study explores a novel approach to increase essential oil content through microbial fertilization (biostimulation) and microwave extraction methods. The microwave extraction method offers comparable yields to other methods, requiring less time, energy, and only a small amount of water to hydrate the dried plants. Microbial fertilizer formulations were applied to İzmir thyme (Origanum onites L.) to assess their effects on yield and quality. Three distinct microbial fertilizer formulations (N, P, NP) containing bacterial isolates of Bacillus subtilis and Bacillus megaterium, as well as a consortium of these two bacteria, were employed in this study. Among the applications on İzmir thyme, the NP formulation (a combination of two bacteria at a dosage of 6 L/ha−1) exhibited the highest efficacy in terms of yield and quality criteria. Moreover, the essential oil ratios (1–2%) obtained from the same fertilizer application, using microwave extraction to enhance quality and accelerate the extraction process, yielded higher than other methods.This study provides preliminary data and a new approach to regulate and enhance the targeted yield and essential oil content of thyme plants by utilizing microbial fertilizer applications and the microwave extraction method.

Larvicidal activity, enzyme inhibitory effect, and molecular docking by essential oil, hydrolate, aqueous extract, and major compounds from the leaves of Eugenia uniflora against Aedes aegypti

Eugenia uniflora is a plant native to Brazil that has a wide geographical distribution and produces a high content of essential oils. The aim of the present study was to investigate the larvicidal activity of the hydrolate (Eu-HYD), aqueous extract (Eu-AE), essential oil (Eu-EO), and major compounds obtained from E. uniflora leaves against Aedes aegypti as well as assess the effects on the digestive enzymes of the larvae. Eu-HYD and Eu-AE were obtained from the leaves as byproducts of the EO isolation by hydrodistillation. Selina-1,3,7(11)-trien-8-one (1, 57.55 %) and oxidoselina-1,3,7(11)-trien-8-one (2, 21.18 %) were the major chemical compounds in the EO, as determined by gas chromatography with flame ionization detection and gas chromatography coupled to mass spectrometry. Eu-EO exhibited the most promising larvicidal activity (LC50 = 35.9 ± 1.02 mg/L), followed by Eu-AE (LC50 = 12.205 ± 1.04 mg/L) and Eu-HYD (LC50 = 42.4 ± 1.02 mg/L), whereas compounds 1 and 2 had an LC50 of 77.8 ± 1.06 and 41.2 ± 1.06 mg/L, respectively. Moreover, Eu-EO, Eu-AE, and Eu-HYD inhibited α-amylase activity in the Ae. aegypti larvae. Docking studies on the altered enzymes indicated that the affinity of compound 2 for Ae. aegypti α-amylase is slightly higher than that of compound 1. These results suggest notable larvicidal activity for all products of Eugenia uniflora leaves, making such products bioactive candidates for interrupting the reproduction cycle of Ae. aegypti, which is the main vector of arboviruses.