Amounts Of Limonene Research Articles

Growth enhancement, metabolic profile improvement, and DXR and TPS2 gene expression changes in Thymus vulgaris L. by cyanobacterial inoculation.

In recent decades cyanobacterial species have attracted research attention as potential sources of new biostimulants. In this study, the biostimulant effects of five cyanobacterial suspensions on the growth and essential oil composition of Thymus vulgaris L. were evaluated. The expression of key genes involved in the biosynthesis of thymol and carvacrol, such as DXR and TPS2, were investigated. A pot culture experiment revealed that cyanobacterial application significantly improved T. vulgaris L. growth indices, including plant height, dry and fresh weight, leaf and flower number, leaf area, and photosynthetic pigment content. Total phenol and flavonoid content in inoculated plants also showed a significant increase compared with the control. Anabaena torulosa ISB213 inoculation significantly increased root and shoot biomass by about 65.38% and 92.98% compared with the control, respectively. Nostoc calcicola ISB215 inoculation resulted in the highest amount of essential oil accumulation (18.08 ± 0.62) in T. vulgaris leaves, by about 72.19% compared with the control (10.5 ± 0.50%). Interestingly, the amount of limonene in the Nostoc ellipsosporum ISB217 treatment (1.67%) increased significantly compared with the control and other treatments. The highest expression rates of DXR and TPS2 genes were observed in the treatment of N. ellipsosporum ISB217, with 5.92-fold and 5.22-fold increases over the control, respectively. This research revealed the potential of the cyanobacteria that were studied as promising biostimulants to increase the production of biomass and secondary metabolites of T. vulgaris L., which could be a suitable alternative to chemical fertilizers. © 2024 Society of Chemical Industry.

Effects of Fermented Citrus Peel on Ameliorating Obesity in Rats Fed with High-Fat Diet.

Although citrus peel is a waste material, it contains a variety of bioactive components. As our preliminary findings showed that citrus peels fermented with Saccharomyces cerevisiae T1 contained increased levels of anti-obesity flavonoids, the objective of this study was to prepare fermented citrus peel and to investigate its effect on ameliorating obesity in Sprague Dawley (SD) rats fed with a high-fat diet (HFD). After fermentation, the amounts of limonene, nobiletin and 3-methoxynobiletin in citrus peel were markedly increased. SD rats were fed with an HFD for 10 weeks, followed by fermented citrus peel-containing HFD (0.3% or 0.9% w/w) for 6 weeks. Compared with those fed with an HFD alone, lower levels of body weight, visceral fat, body fat percentage, blood triglyceride, total cholesterol, low-density lipoprotein, malondialdehyde and hepatic adipose accumulation were observed in rats fed with fermented citrus peel. In parallel, hepatic levels of acetyl-CoA carboxylase and fatty acid synthase were diminished, and the level of hormone sensitivity lipase in visceral fat was elevated. These results reveal fermented citrus peel is a promising natural product with beneficial effects of alleviating HFD-induced obesity.

Essential oil composition and antioxidant activity of citron fruit (Citrus medica var. macrocarpa Risso.) peel as relation to ripening stages

ABSTRACT Stages of maturity have decisive roles in determining the quality and quantity of essential oil (EO). In this regard, EO yield and composition and their antioxidant activity of citron fruit at four fruit maturity stages, i.e. the green mature (GM), intermediate (INT), yellow ripe (MAT) and overripe stage (OR) were studied. Obtained results showed significant effect of fruit maturity on most measured properties. The concentration of EO varied between 0.60 and 0.77% (v/w). The highest amount of limonene was 89.39% related to GM stage. The limonene decreased significantly during maturity. The highest antioxidant activity (76.08%) was measured at the OR stage, which is probably due to the presence of specific compounds in the EO and their synergistic effects. The phytochemical behaviors of this citron variety were different as relation to stages of fruit maturity. We can determine the ideal harvest period for maximum bioactive substances by recognizing these actions.

Demonstrating Basic Properties and Application of Polarimetry Using a Self-Constructed Polarimeter.

An easily constructed and inexpensive polarimeter with an optical rotation angle resolution of about 0.5° is presented. It is made from small pieces of polarizing film, 2 LEDs, a protractor, and a few wires, all held in place with plastic interlocking toy bricks, such as Lego bricks. The instrument was used to demonstrate the optical rotation of plane polarized light as a function of concentration, path length, temperature, and wavelength, and to determine enantiomeric excess in solutions of arabinose, the amount of limonene in citrus ski wax remover, and optical rotations of various types of honeys and essential oils. Results were comparable to values obtained on a commercial scientific instrument, and with literature values.

Changes in Essential Oil Content and Composition of Lemon Verbena (Lippia citriodora Kunth.) Under Various Drying Conditions

Background: Aromatic herbs and spices are sensitive to drying processes; thus, optimum drying is an essential requirement for attaining a high-quality herbal product. Objectives: The study evaluated the effects of drying conditions on essential oil content and composition of Lippia citriodora. Methods: In this study, leaves of Lippia citriodora were divided into two sets. The first set included immediate drying after harvest using the given drying methods and the second set included sun drying for 3 hours after harvest and then drying according to the given drying methods. The drying methods included oven-drying at 35, 45, and 55°C, microwave-drying at 100, 500, and 1000 W, and shade-drying in the laboratory. The essential oils were extracted by hydrodistillation using a Clevenger apparatus and analyzed by GC and GC-MS. Results: The drying methods significantly affected the essential oil content and composition. The maximum content of essential oil was achieved in microwave-drying at 100 W with the pre-drying operation. The highest contents of monoterpenes including monoterpene hydrocarbons and oxygenated monoterpenes were observed in microwave-dried and fresh plants, respectively. In addition, the maximum amounts of sesquiterpenes including sesquiterpene hydrocarbons and oxygenated sesquiterpenes were observed in oven-drying at 35°C with no pre-drying operation. In both pre-drying and no pre-drying conditions, the amount of limonene as a major monoterpene hydrocarbon was increased by microwave-drying. Although oxygenated monoterpenes including neral and geranial were decreased, the content of 1,8-cineol was increased after drying, especially without pre-drying. The maximum amount of curcumene as a sesquiterpene hydrocarbon was obtained in shade-drying without pre-drying operation. In pre-drying condition, the essential oil content and its components were more in the microwave and oven-drying procedures than in shade-drying. Conclusions: The microwave-drying at 100 W following pre-drying was the best drying method to achieve the highest quantity and quality of essential oil.

Variations in chemical compositions of essential oil from sour orange (Citrus aurantium L.) blossoms by different isolation methods

The main goal of this research was to study the impact of different extraction methods on the yield and chemical compositions of essential oil (EO) obtained from sour orange blossoms. Seven different methods were used for the purpose of extracting the EOs, namely, commercial hydrodistillation (CoM), hydrodistillation (HD), steam distillation (SD), Ohmic-assisted hydro distillation (OAHD), solvent-less microwave extraction (SLME), solvent-free microwave extraction (SFME), and microwave-assisted hydrodistillation (MAHD). The isolated EOs were analyzed by GC and GC-MS in three replications. The highest EO yield in relation to the extraction time was obtained by the HD method (0.34%) and the lowest one (0.04%) was detected by the SD method. The main compounds and their ranges of concentration in the EOs were as follows: linalool acetate (12.2 ± 0.08–28.9 ± 0.2) %, linalool (22.9 ± 0.07–54. ± 0.2) %, Farnesol (0.2 ± 0.04–10.4 ± 0.07) %, E-nerolidol (0.4 ± 0.1–21.4 ± 0.04) % and geranyl acetate (0.97 ± 0.05–9.3 ± 0.08)%. Moreover, SLME caused a selective extraction of E-nerolidol (21.42%) and farnesol (10.45%). The SFME resulted in a two-fold extraction of linalool (54.08%), compared to the COM which yielded an amount of 22.9%. Significant changes in the amounts of limonene (1−14) % and β-pinene (0–9.6)% were also observed by the extraction methods. Overall, the results suggest that MAHD and SFME can be termed as green technologies because of their less energy requirements and less carbon dioxide emissions. Their high-quality EO and cost effective performance for EO extraction can be of importance to pharmaceutical industries.

Use of Orange Oil Loaded Pectin Films as Antibacterial Material for Food Packaging.

This study aims to develop orange oil loaded in thin mango peel pectin films and evaluate their antibacterial activity against Staphylococcus aureus. The mango peel pectin was obtained from the extraction of ripe Nam Dokmai mango peel by the microwave-assisted method. The thin films were formulated using commercial low methoxy pectin (P) and mango pectin (M) at a ratio of 1:2 with and without glycerol as a plasticizer. Orange oil was loaded into the films at 3% w/w. The orange oil film containing P and M at ratio of 1:2 with 40% w/w of glycerol (P1M2GO) showed the highest percent elongation (12.93 ± 0.89%) and the lowest Young’s modulus values (35.24 ± 3.43 MPa). For limonene loading content, it was found that the amount of limonene after the film drying step was directly related to the final physical structure of the film. Among the various tested films, P1M2GO film had the lowest limonene loading content (59.25 ± 2.09%), which may be because of the presence of numerous micropores in the P1M2GO film’s matrix. The inhibitory effect against the growth of S. aureus was compared in normalized value of clear zone diameter using the normalization value of limonene content in each film. The P1M2GO film showed the highest inhibitory effect against S. aureus with the normalized clear zone of 11.75 mm but no statistically significant difference. This study indicated that the orange oil loaded in mango peel pectin film can be a valuable candidate as antibacterial material for food packaging.

Packaging methods and storage duration affect essential oil content and composition of lemon verbena (Lippia citriodora Kunth.).

Changes in essential oils (EOs) content and composition of lemon verbena leave at different packaging methods (packaged with air, nitrogen, or under vacuum) and during storage period (0, 2, 4, 6 and 8 months) were determined. All the samples were hydrodistilled every 2 months during storage for EO content evaluation. EO composition was determined by gas chromatography and gas chromatography–mass spectrometry. The results showed that by extending the storage period in all packaging methods, EO content was significantly decreased. Parallel to the increase in the storage duration in all packaging methods, citral content was decreased, whereas the amounts of limonene and 1,8‐cineole were increased. Packaging of lemon verbena leaves with nitrogen preserved the highest EO content during 8 months of storage and achieved the desired amounts of citral, limonene, and 1,8‐cineole. This investigation also showed camphene may be a useful marker for the indication of storage duration of lemon verbena.

Chemical constituents and antioxidant activity of essential oil and organic extract from the peel and kernel parts of Citrus japonica Thunb. (kumquat) from Iran

The constituents of essential oils and organic extracts from peel and kernels of Citrus japonica were analysed by GC and GC/MS. The content of essential oil in peel and kernel was 1.1 and 0.8% based on dry weight. The essential oil of C. japonica peel and kernel was characterised by a higher amount of limonene (51.0 and 47.1%) and germacrene D (12.1 and 6.3%), and the hexane extracts of its peel and kernel were characterised by a higher amount of dodecanol-1(12.9 and 20.8%) and linolenic acid (13.1 and 16.3%), respectively. The antioxidant activities of oils were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The results indicate that both oils from different parts of C. japonica possess considerable antioxidant activity. The fruit peel and kernel essential oil could thus be useful in the industries, chiefly in the food and pharmaceutical industries.

The Leaf Essential Oils of Melaleuca deanii F. Muell. and Melaleuca hypericifolia Sm. (Myrtaceae)

The essential oils from the leaves of Melaleuca deanii F. Muell.and Melaleuca hypericifolia Sm. have been obtained by hydrodistillation in yields 0.27 - 1.79 % and 0.30 - 2.28 % respectively. The almost entirely monoterpenoid oils have been analysed by GC-MS. The Melaleuca deanii oils contained major amounts of α-pinene (25.6 - 51.6 %) and 1,8-cineole (31.8 - 47.0 %) and lesser amounts of limonene (2.6 - 4.0 %) and α-terpineol (5.9 - 10.2 %). The Melaleuca hypericifolia oils contained mainly 1,8-cineole (74.0 - 80.9 %) and lesser amountsof α-pinene (3.8 - 10.2 %), limonene (3.5 - 8.9 %) and α-terpineol (1.4 - 3.1 %). The production of leaf oil in a single tree of Melaleuca deanii, monitored over a period of 46 years, diminished from 1.79 % to 0.10 %.

Volatile analysis and antimicrobial screening of the parasitic plant Cuscuta reflexa Roxb. from Nepal

The essential oil from the parasitic vine Cuscuta reflexa Roxb., collected from Kirtipur, Kathmandu, Nepal, was obtained by hydrodistillation and analysed by gas chromatography–mass spectrometry. From a total of 62 peaks, 61 compounds were identified in the oil, accounting for 99.6% of the oil. The majority of the essential oil was dominated by the relatively rare component cis-3-butyl-4-vinylcyclopentane (26.4%). The oil also contained substantial amounts of limonene (5.1%) and (E)-nerolidol (9.5%). Biological screening for antimicrobial activities did not show appreciable activity against either Gram-positive (Bacillus cereus and Staphylococcus aureus) or Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. However, marginal activity against Aspergillus niger was observed (minimum inhibitory concentration = 313 μg/mL).

Differences in the effects of essential oil from Citrus junos and (+)-limonene on emotional behavior in mice

Citrus junos (Yuzu, CJ) is a traditional fruit in Japan and its essential oil (EO) has been used in food, cosmetics, and traditional medicine. The present study examined the influence of essential oil from Citrus junos (EOCJ) on emotional behavior in mice, and how its action differed in comparison to (+)-limonene (LI), its major component. The influence of inhaled administration (i.h.) of EOCJ for 90 minutes on mouse emotional behavior was examined using the light/dark box (LDB) test, open field (OF) test, and elevated plus-maze (EPM) test. In addition, gas chromatography (GC) was used in clarifying the amount of LI absorbed in the internal organs. Inhalation of EOCJ at 3.4 and 6.7 mg/L air indicated the tendency for an anxiolytic-like effect in LDB and EPM tests. In addition, an increase in locomotor activity was observed at 6.7 mg/L air EOCJ (i.h.) in the OF test. Inhalation of (+)-LI at 3.4 and 6.7 mg/L air indicated the same anxiolytic-like effect in EPM test as with EOCJ. In contrast, the anxiolytic-like effect of (+)-LI was smaller than that of EOCJ in the LDB test. Furthermore, an increase in locomotor activity was not observed at 6.7 mg/L air (+)-LI (i.h.).

Essential oil content and composition of Achillea biebersteinii Afan. in different plant parts and phenological stages

In this study, the essential oil content and composition of Achillea biebersteinii Afan. at different phenological stages including vegetative, floral budding, full flowering (leaves, stems and flowers) and fruit set were studied by means of gas chromatography (GC) and gas chromatography–mass spectometry (GC–MS). All oil samples from different plant parts and phenological stages were mostly made up of monoterpenoid compounds (88.6 – 99.6%), especially oxygenated ones (52.4 – 82.4%). The oil of the vegetative stage contained high amounts of limonene, 4aα-7β-7aα-nepetalactone, p-cymene and 1,8-cineole. The major constituents in the flower budding stage oil were found to be limonene, 1,8-cineole and 4aα-7β-7aα-nepetalactone. In the oil of the fruit set stage, γ-terpinene, p-cymene and cis-chrysanthenyl acetate were the predominant constituents. On the other hand, the most important compounds from the stem oil were 4aα-7α-7aα-nepetalactone, 1,8-cineole, 4aα-7β-7aα-nepetalactone and camphor. 4aα-7α-7aα-nepetalactone, limonene, 1,8-cineole and cis-p-menth-2-en-1-ol were found in high concentration in the oil of leaves, whereas 4aα-7α-7aα-nepetalactone, 4aα-7β-7aα-nepetalactone, limonene and p-cymene were present in large amounts in the oil of flowers.

The monoterpene limonene in orange peels attracts pests and microorganisms

Plant volatiles include terpenoids, which are generally involved in plant defense, repelling pests and pathogens and attracting insects for herbivore control, pollination and seed dispersal. Orange fruits accumulate the monoterpene limonene at high levels in the oil glands of their fruit peels. When limonene production was downregulated in orange fruits by the transgenic expression of a limonene synthase (CitMTSE1) in the antisense configuration, these fruits were resistant to the fungus Penicillium digitatum (Pers.) Sacc. and the bacterium Xanthomonas citri subsp. citri and were less attractive to the medfly pest Ceratitis capitata. These responses were reversed when the antisense transgenic orange fruits were treated with limonene. To gain more insight into the role of the limonene concentration in fruit responses to pests and pathogens, we attempted to overexpress CitMTSE1 in the sense configuration in transgenic orange fruits. Only slight increases in the amount of limonene were found in sense transgenic fruits, maybe due to the detrimental effect that excessive limonene accumulation would have on plant development. Collectively, these results suggest that when limonene reaches peak levels as the fruit develops, it becomes a signal for pest and pathogen attraction, which facilitate access to the fruit for pulp consumers and seed dispersers.

Chemical Compositions of the Leaf and Fruit Essential Oils ofEugenia monteverdensis from Monteverde, Costa Rica

The leaf and fruit essential oils of Eugenia monteverdensis Barrie (Myrtaceae), from Monteverde, Costa Rica, were isolated by hydrodistillation and analyzed by GC-MS. A total of 18 compounds were identified in the leaf oil and 19 compounds were identified in the fruit oil, accounting for 100 % of the total compositions. The leaf oil of E. monteverdensis was dominated by α-pinene (92.0 %) with a small amount of linalool (2.1 %) and (E)-caryophyllene (1.1 %). The major components in the fruit essential oil were α-pinene (55.1 %) and linalool (22.7 %) with lesser amounts of limonene (7.7 %), (E)-caryophyllene (4.7 %), β-pinene (2.3 %), and α-terpineol (2.0 %). The essential oils were screened for cytotoxic and antibacterial activity, but were found to be inactive.

A Comparison of Volatile Components from the Peel of Ohshima No. 1 with Its Parent Cultivars

A total of 20 volatile organic compounds from the peel of citrus fruit Ohshima no. 1 were identified by gas chromatography-mass spectrometry (GC-MS). The amount of limonene in Ohshima no. 1 was lower than those in the parent cultivars, Miyauchi iyokan and Yoshiura ponkan, whereas those of gamma-terpinene, linalool, sabinene, p-cymene, and terpinolene in Ohshima no. 1 were somewhat higher. However, comparing the results, it was found that volatile components from both parent cultivars were present in the peel of Ohshima no. 1. Principal component analysis (PCA) of data obtained with an electronic nose indicated that the odor of Ohshima no. 1 showed a clear upward displacement as compared with those of parent cultivars in PC1. The oils of Miyauchi iyokan and Yoshiura ponkan showed displacement in a negative direction, and a positive one in PC2. By PCA analysis, it was found that the odor quality of Ohshima no. 1 was very different from those of the parent cultivars.

Evaporation from a Limonene Emulsion

A publication to honor the legacy of Per Ekwall, the Finnish colloid chemist, whose research was on the forefront for several decades in the area of colloidal association structures. In the article an algebraic method was applied to obtain information about the conditions during evaporation of the volatile compounds in a system of limonene, water and Laureth 4 (a commercial tetraoxyethylene dodecyl ether). The evaporation path was calculated using published information about the phase diagram of the system and about the vapor pressures of the components at selected compositions. In the calculations intervals between steps were made proportional to the difference between the excess vapor pressure of water at the selected level of relative humidity and its full vapor pressure at zero relative humidity. This calculation method inherently gave linear time dependence of the remaining water in the emulsion because of its constant vapor pressure. The calculations also revealed the amount of limonene to be close to linearly dependent on time. The reason for this latter result was found in the features of the phase diagram; in turn caused by the limonene oil phase being a W/O microemulsion with moderate vapor pressure variation with composition.

Retention of selected aroma compounds by polysaccharide solutions: A thermodynamic and kinetic approach

Partitioning and release of limonene and trans−2-hexenal from polysaccharide solutions was studied by applying static headspace gas chromatography. Experiments were carried out on xanthan/propylene glycol alginate and xanthan/gum arabic solutions at various concentrations. Changes in the polysaccharide matrix exhibited a considerable effect on the thermodynamic component as expressed by the air/liquid partition coefficient ( K a/l) values at equilibrium (37 °C). Viscosity increase was shown to affect the initial release rate, as this is defined by the amount of limonene and trans-2-hexenal released over the first few minutes of the experiments. The physicochemical properties of both aroma compounds, especially their hydrophobicity, were also of importance in air/liquid partition, with limonene to be mostly affected by polysaccharide addition.

Essential Oil Composition of Piper Anonofolium (Kunth) C. DC

Seven samples of aerial parts of Piper anonifolium were collected in the municipalities of Santa Isabel, Ananindeua and Bujaru, Pará state, brazilian Amazon. The samples were hydrodistilled and analysed by GC and GC-MS. The oils of samples 5, 6 and 7 showed very similar chromatographic profiles presenting α-pinene (45.5%, 45.7% and 41.1%), β-pinene (17.7%, 17.2% and 17.8%) and limonene (7.1%, 8.4% and 6.1%) as their main constituents. The oil of sample 1 was dominated by α-pinene (53.1%) and β-pinene (22.9%), followed by minute amount of limonene (1.7%), resembling the oils of samples 5, 6 and 7 . The main constituents found in the oils of samples 2 and 4 were α-pinene (40.9% and 41.8%), β-pinene (18.8% and 18.6%), limonene (7.4% and 8.5%) and δ-2-carene (7.7% and 8.0%), presenting a small difference in comparison with the oils of samples 1, 5, 6 and 7. The oil of sample 3 was quite different concerning with the other oils, where the principal components were α-eudesmol (33.5%), ishwarane (19.1%), germacrene D (9.6%), α-pinene (7.3%) and limonene (5.9%). We imputed the different collection sites for the reason of the distinguished oil composition of Piper anonifolium.

Composition and in vitro toxicity of the essential oil of Tagetes terniflora HBK. (Asteraceae)

AbstractThe essential oil from aerial parts of Tagetes terniflora HBK. (Asteraceae) was obtained by hydrodistillation. The oil content was 0.15% (v/w), on a fresh weight basis. The oil composition was analysed by GC and GC/MS. Sixty‐five compounds were identified accounting for 96.1% of the oil. Tagetones (22.4%), ocimenes (20.6%) and ocimenones (15.9%) predominated in the oil, with (E)‐β‐ocimene (12.8%) and trans‐tagetone (10.7%) as the main compounds. The oil contained considerable amounts of limonene (3.9%), isomenthone (3.1%), and of spathulenol (2.7%) in sesquiterpenoidic fraction. cis‐(4.1%) and trans‐Anethole (2.1%) are the main constituent of the phenylpropanoid group. A preliminary in vitro toxicity test, carried out with Artemia salina, showed an ED50 value of the essential oil of 3.16 µg/ml. Copyright © 2004 John Wiley & Sons, Ltd.