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The increasing prevalence of drug resistance, adverse side effects of existing antibiotics, and the resurgence of previously known infections have necessitated the search for new, safe, and effective antimicrobial agents. The peels of Citrus sinensis L. (300 g) were extracted using maceration and ultrasonic-assisted extraction methods with ethanol, resulting in yields of 20.99 g and 11.5 g (7%, 7.5%), respectively. Silica gel column chromatographic separation of the ethanol extract yielded N-(1,3,4,5-tetrahydroxydecan-2-y1) octanamide (1), decanoic acid (2), β-sitosterol-3-O-β-D-glucopyranoside derivative (3), and (z)-ethyl tetradec-7-enoate (4). GC-MS analysis of the essential oil detected 7 chemical components accounting for 99.84% of the total composition of which limonene was found to be the predominant constituent (87.5%). In vitro antibacterial tests revealed promising zones of inhibition by ethanol extract (12.67±0.58 mm, at 150 mg/mL), compound 4 (15.67±2.88 mm, at 6 mg/mL), and compound 1 (12.00±0.00 mm, at 6 mg/mL) against E. faecalis, S. typhimurium, and P. aeruginosa, respectively, compared to gentamicin (13.00±1.73 mm, 18.00±1.00 mm, and 16.67±1.15 mm, respectively at 10 µg/mL). DPPH radical scavenging activity indicated that compound 1 exhibited an IC50 value of 0.05 mg/mL, compared to ascorbic acid's 0.016 mg/mL. In silico molecular docking studies revealed that compounds 1 and 3 had the lowest scoring poses against E. coli DNA gyrase B enzyme, human peroxiredoxin 5, and S. aureus pyruvate kinase, respectively. These findings support traditional applications of Citrus peels in treating infectious diseases, particularly against Gram-positive strains, and highlight their potential use as antibacterial ingredients in cosmetics. [ABSTRACT FROM AUTHOR]

Glyptostrobus pensilis (Staunton ex D. Don) K. Koch is a critically endangered species, native to southeastern China and also very locally found in Dak Lak Province, Vietnam. Essential oil isolated from leaves is a monoterpene-rich oil containing mainly limonene (33.3%), α-pinene (23.4%) and bornyl acetate (9.2%). The composition of G. pensilis wood oil is rather complex and the identification of individual components needed fractionation over column chromatography. The main components, identified by GC(RI), GC-MS and 13C NMR, were cedrol (29.3%), occidentalol (6.6%) and occidentalol isomer (5.9%). [ABSTRACT FROM AUTHOR]

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

IntroductionEfforts have always been made to protect valuable compounds of medicine, food and aromatics materials that are highly sensitive to environmental conditions by the encapsulation method. encapsulation of flavors, in addition to its protection, allows the aromatic substance to be released in a long time, and the time and place of its release can be controlled. To design these protection systems requires detailed information on encapsulation and release methods, the nature of walls and aromatic materials (Gunning et al.,1999). For encapsulation of sensitive compounds such as lipophilic materials, it is necessary to produce an emulsion of the desired substance in wall materials such as proteins, polysaccharides or a mixture of them. The important factors in encapsulation are the molecular weight, chemical properties and polarity of the core materials, the properties of the materials of the walls, and finally, the methods used to produce microcapsules. (Jafari et al., 2008).The aim of this study was to produce and evaluate the properties of two and six layer multilayer microcapsules containing limonene using soy protein isolate and starch modified by spray drying. The release of encapsulated limonene was investigated under artificial oral conditions under different stress conditions. The results of this study can be used to predict the release rate of the encapsulated flavors and their release conditions.Materials and MethodsSolution preparation: The solution of SPI (0-3%) was prepared by methods of Huang et al. (2012). The OSA starch stock solution (0-2%) was prepared by methods of Nilsson and Bergens (2007).Emulsion’s preparation: the primary emulsion of the optimum SPI and secondary emulsion of optimum OSA starch concentration prepared by the method of Noshad et al (2015).Microcapsule production: To prepare the Microcapsules, a laboratory spray dryer was used. 180±5 ᵒC, inlet air temperature, 25 (ml/min) feed rate, and 90±10 ᵒC outlet air temperature were used. Six layer microcapsules was also prepared in the same conditions (Ansarifar et al., 2017)The micro structure, morphology and release of limonene were evaluated and finally by Zero order, First order, Higuchi, and Korsemeyer- peppas models were used to the fitting of experimental data.Limonene release: To investigate the release of the encapsulated limonene, the release of these microcapsules (two and six layer) at 37 ° C and pH = 6.8, as well as frequent chewing (0, 50 and 100 rpm) were examined. For the apply of shear stress, an oral simulator was designed and developed by the Department of Food Science and Technology of Ferdowsi University of Mashhad was used. Results and DiscusionThe results of particle size changes of the initial emulsion formed with different levels of soy protein isolate showed that the particle size decreased with increasing the concentration of this protein to 1.5% and then it was increased. The results of zeta potential showed that with increasing the concentration of soy protein isolate to 1.5%, the zeta potential of the samples increased and with more than 1.5%, it did not have much effect on the zeta potential of the samples, which indicates that concentrate of 1.5% soy protein isolate has a good ability to cover surface of limonene particles. Similarly, 1.2% of OSA starch was determined for the secondary layer.SEM images of the microcapsules showed that in the two-layer wall microcapsules have cavities, cracks and shrinkage. In the starting of drying, the rate of moisture lost is high and on the other hand, the wall is not strong enough to withstand the stresses caused by the exit of moisture from the walls, so the microcapsule has cavities. In six-layer microcapsules, a smooth, non-cracked surface was observed, which can be attributed to the wall strength due to the increase in the number of layers. Fourier transform infrared spectroscopic (FTIR) test showed that the outer surface of the microcapsules was covered by OSA starch in two and six layer microcapsules.The release profile of encapsulated limonene showed that the release rate in two layer samples was faster than six layer samples. Also, with increasing shear rate, the amount of release increased. The results of experimental models fitting showed that the first-order model had the best description for releasing limonene from two- and six-layer samples in different conditions. Calculation of diffusion coefficient showed that six-layer microcapsules have a lower diffusion coefficient than two-layer microcapsules, which leads to a decrease in the release rate of limonene.Conclusion The results of this study showed that the layer-by-layer method could be used to produce limonene microcapsules. Soy protein isolate and modified starch can cover limonene droplets well. SEM images showed that the structure of six-layer microcapsules is free of cracks and cavities and has a more uniform surface than two-layer microcapsules. To investigate the mechanism of limonene release from two- and six-layer microcapsules, different kinetic models were used to fit the experimental release data. The results showed that the release of these microcapsules occurred based on the diffusion mechanism and Fick's law, which is the main mechanism of mass transfer in the release process. Also, the results showed that the six-layer microcapsules had a lower diffusion coefficient than the two-layer microcapsules and the release rate was lower in the two-layer microcapsule; This is due to the repetitive coating of soy protein isolate and modified starch around the microcapsules and the increase in wall thickness.

Essential oils (EOs) from Citrus sinensis (Rutaceae) possess diverse biological activities. However, a comprehensive comparison of their chemical composition and bioactivity across different plant parts has not been studied yet. The current research comparatively assesses the yield, chemical composition, chiral distribution, antioxidant properties, and larvicidal activity of EOs extracted from the peels, leaves, and flowers of C. sinensis. EOs extracted via hydro-distillation (HD) and steam distillation (SD) were analyzed by gas chromatography–mass spectrometry (GC-MS) and chiral GC-MS to explore their chemical composition and enantiomeric distribution. In addition, their larvicidal and antioxidant potentials were evaluated following standard protocols. Peels of C. sinensis exhibited significantly higher oil content (1.75–2.25%) compared to its leaves (0.75–0.78%) and flowers (0.20–0.25%). The GC-MS analysis identified around 60 compounds, including terpenoids, sesquiterpenoids, and oxygenated terpenoids in the HD and SD extractions. Higher concentrations of sabinene were found in flower extract (38.05–39.89%) and leaf extract (32.30–36.91%), while peel extract contained more than 90% limonene. The larvicidal activity of peel oil was primarily attributed to limonene, with an LC50 value of 0.0031 µL/mL. The current study reports the first chiral (GC-MS) analysis in the essential oil of the leaves and flowers of C. sinensis, paving the way for authenticity and purity. Furthermore, the chemical profiling of citrus EOs, particularly from the peel, demonstrates a safe and promising candidate for diverse biological applications.

Nowadays, the effective processing of natural monoterpenes that constitute renewable biomass found in post-production waste into products that are starting materials for the synthesis of valuable compounds is a way to ensure independence from non-renewable fossil fuels and can contribute to reducing global carbon dioxide emissions. The presented research aims to determine, based on DFT calculations, the activity and reactivity of limonene, an organic substrate used in previous preparative analyses, in comparison to selected monoterpenes such as cymene, pinene, thymol, and menthol. The influence of the solvent model was also checked, and the bonds most susceptible to reaction were determined in the examined compounds. With regard to EHOMO, it was found that limonene reacts more easily than cymene or menthol but with more difficultly than thymol and pienene. The analysis of the global chemical reactivity descriptors “locates” the reactivity of limonene in the middle of the studied monoterpenes. It was observed that, among the tested compounds, the most reactive compound is thymol, while the least reactive is menthol. The demonstrated results can be a reference point for experimental work carried out using the discussed compounds, to focus research on those with the highest reactivity.

Essential oils have been identified as effective natural compounds to prevent bacterial infections and thus are widely proposed as bioactive agents for biomedical applications. Across the literature, various essential oils have been incorporated into electrospun fibres to produce materials with, among others, antibacterial, anti-inflammatory and antioxidant activity. However, limited research has been conducted so far on the effect of these chemical products on the physical characteristics of the resulting composite fibres for extended periods of time. Within this work, electrospun fibres of poly(lactic acid) (PLA) were loaded with the essential oil limonene, and the impact of storage conditions and duration (up to 12 weeks) on the thermal degradation, glass transition temperature and mechanical response of the fibrous mats were investigated. It was found that the concentration of the encapsulated limonene changed over time and thus the properties of the PLA–limonene fibres evolved, particularly in the first two weeks of storage (independently from storage conditions). The amount of limonene retained within the fibres, even 4 weeks after fibre generation, was effective to successfully inhibit the growth of model microorganisms Escherichia coli, Staphylococcus aureus and Bacillus subtilis. The results of this work demonstrate the importance of evaluating physical properties during the ageing of electrospun fibres encapsulating essential oils, in order to predict performance modification when the composite fibres are used as constituents of medical devices.

Terpenes are high-value chemicals which can be produced by engineered cyanobacteria from sustainable resources, solar energy, water and CO2. We previously reported that the euryhaline unicellular cyanobacteria Synechocystis sp. PCC 6803 (S.6803) and Synechococcus sp. PCC 7002 (S.7002) produce farnesene and limonene, respectively, more efficiently than other terpenes. In the present study, we attempted to enhance farnesene production in S.6803 and limonene production in S.7002. Practically, we tested the influence of key cyanobacterial enzymes acting in carbon fixation (RubisCO, PRK, CcmK3 and CcmK4), utilization (CrtE, CrtR and CruF) and storage (PhaA and PhaB) on terpene production in S.6803, and we compared some of the findings with the data obtained in S.7002. We report that the overproduction of RubisCO from S.7002 and PRK from Cyanothece sp. PCC 7425 increased farnesene production in S.6803, but not limonene production in S.7002. The overexpression of the crtE genes (synthesis of terpene precursors) from S.6803 or S.7002 did not increase farnesene production in S.6803. In contrast, the overexpression of the crtE gene from S.6803, but not S.7002, increased farnesene production in S.7002, emphasizing the physiological difference between these two model cyanobacteria. Furthermore, the deletion of the crtR and cruF genes (carotenoid synthesis) and phaAB genes (carbon storage) did not increase the production of farnesene in S.6803. Finally, as a containment strategy of genetically modified strains of S.6803, we report that the deletion of the ccmK3K4 genes (carboxysome for CO2 fixation) did not affect the production of limonene, but decreased the production of farnesene in S.6803.

First reported in 2004, and subsequently advanced by Chemat's team and other research teams in the following two decades, the use of D -limonene as a natural product extraction solvent offers multiple benefits that go beyond its environmentally benign nature. Following a review of the main research achievements concerning the use of this biosolvent in the extraction of widely different natural products, we offer a comprehensive perspective including usually neglected economic and safety aspects. The study concludes by identifying three main research outcomes and providing two guidelines to bioeconomy practitioners willing to use this terpene in new natural production extraction and production processes. [ABSTRACT FROM AUTHOR]

Erucamide is used as an important slip agent for polymers. However, erucamide can degrade during processing and long-term storage, forming various oxidation products. These degradation products can affect the recovery rates of erucamide. In this study, investigated different solid–liquid extraction methods (Soxhlet, microwave, and ultrasound) and used gas chromatography with mass spectrometry (GC-MS) to quantify erucamide and its degradation byproducts in polypropylene (PP). A multivariable experiment was designed, and a mixed-effect approach was used to analyze the results. Various extraction variables were examined, such as temperature, time, solvents, and PP pretreatments. Using a mixed-effect model with a Kenward–Roger approximation, an R2 of the model of 97% and p values of 0.168, 0.000, and 0.000 were obtained for the technical, solvent, and type of PP pretreatment variables, respectively. The highest average recoveries of erucamide were found with the microwave technique and were 96.4% using dichloromethane, 94.57% using cyclohexane, and 93.05% using limonene. With ultrasound, recoveries ranged between 85 and 92% for dichloromethane and limonene. In addition, it was observed that the extraction method had better recovery results in ground PP than in films and in pellets. Nine oxidative degradation byproducts of erucamide were identified and semi-quantified by GC-MS. The reaction mechanisms for forming each byproduct were proposed. The byproducts that experienced a higher rate of degradation of erucamide were erucamide with a hydroxyl group at position one and 12-amino-6-12-oxo-dodecanoic acid, showing more prominent peaks using the Soxhlet method with cyclohexane and dichloromethane as solvents and polypropylene (PP) films as the type of material used. [ABSTRACT FROM AUTHOR]

Kumquat essential oil (KEO) extracted from ripe kumquats has considerable potential value in the cosmetic, phytopharmaceutical, and food industries due to its desirable fragrance and diverse biological activities. However, compared to other plant essential oils, there are relatively few studies on the biological activity of KEO and limited data have been reported on its health benefits. This paper summarizes the composition of KEO and discusses the aromatic properties and pharmacological activities of some key components in KEO. We also discuss the impacts of a variety of processing conditions on these parameters. In particular, we focused on the application of KEO for therapeutic purposes, such as oxidative stress mitigation and organ protection benefits. Furthermore, relevant technologies for enhancing the performance of KEO, the related biomedical research, and future perspectives are discussed. Terpenoids, such as limonene and myrcene, are rich in double-bonded structures and are the most abundant components of KEO. In addition to terpenoids, there are also small amounts of oxygen-containing derivatives. These bioactive substances contribute to the unique flavor of KEO and exert various pharmacological effects, including antimicrobial, anti-inflammatory, antioxidant, anti-proliferative, anti-hypertensive, and protective effects on the heart, kidneys, lungs, and other organs. Overall, KEO and its bioactive substances are safe, and effective, and KEO is relatively easy to obtain. These substances represent alternative functional substances that can be used in a variety of applications in the food, nutraceutical, pharmaceutical, and cosmetic industries. • Kumquat essential oil (KEO) contains several active ingredients. • (KEO) can be used in various applications in the food, nutraceutical, pharmaceutical and cosmetic industries. • The technology and processing methods for extraction, preservation, production, and application of (KEO) need to be optimized. [ABSTRACT FROM AUTHOR]

The drug resistance of pathogenic bacteria is often due efflux pumps—specific proteins that remove foreign compounds from bacterial cells. To overcome drug resistance, adjuvants are often used that can inhibit efflux pumps or other systems that ensure the resistance of bacteria to the action of antibiotics. We assumed that a new level of effectiveness with the use of an antibiotic + an adjuvant pair could be achieved by their joint delivery into the pathogen. To test this hypothesis, we constructed a series of molecular carriers based on poly-(olygo-, dendry)mers based on cyclodextrin-grafted PEI or mannan, as well as glycol chitosan, covalently bound to antibiotic, adjuvant, and the oligosaccharide ligand to the macrophage mannose receptor (CD206), which we studied earlier and showed high efficiency and selectivity of delivery of a therapeutic "cargo" to macrophages. Moxifloxacin was used as an antibiotic, and terpenoid and allylbenzene compounds were used as adjuvants, for which we previously discovered the ability to inhibit bacterial efflux pumps. We show that: (a) the resulting structures were stable in vitro for a long time (up to 10 days); (b) they were adsorbed on bacterial cells, providing a local increase in the concentration of the antibiotic and adjuvant in pathogen cells; (c) they were internalized by bacterial cells, ensuring the accumulation of both antibiotic and adjuvant inside bacterial cells; (d) the adjuvant, after entering the bacterial cell, provided inhibition of the efflux pumps; (e) due to this action of the adjuvant, combined with the targeted delivery by the carrier, the antibiotic's half-life in rats increased by more than 2 times, the effective concentration of the drug in the blood plasma (AUC) increased up to 8–10 times; (f) a significant increase in the effectiveness of the antibacterial action against Gram+ and Gram- cells was achieved (up to 3 times). Potentially, such an approach would significantly increase the effectiveness of therapies for a number of infectious and other diseases, reduce the dosage of antibiotics, shorten the duration of treatment, and reduce the risk of developing bacterial resistance. Moreover, the use of a polymer carrier with covalently bound organic molecules of different structures will avoid problems linked to different (suboptimal) solubility and bio-distribution of the administered molecules, which would be almost inevitable when using the same compounds separately. It would be very difficult to find antibiotic/adjuvant pairs that simultaneously achieve optimal concentrations in the same target cells. In our case, terpenoids and alkylbenzenes used as adjuvants are practically insoluble as individual compounds, and their unacceptable pharmacological properties would not allow them to be used as efflux pump inhibitors. [ABSTRACT FROM AUTHOR]

Background: Hydroperoxides of limonene (Lim‐OOHs) and linalool (Lin‐OOHs) are potent contact sensitizers. Objectives: To investigate the prevalence of positive patch test (PT) reactions to Lim‐OOHs and Lin‐OOHs in consecutive patients, their demographic factors and concomitant reactions. Methods: Between 7/2018 and 12/2020, Lim‐OOHs 0.3% pet. and Lin‐OOHs 1% pet. were patch tested in 5511 consecutive patients. We assessed PT reactivity and analysed data from patients with either positive or negative PTs to Lim‐OOHs and Lin‐OOHs. Results: Positive PT results to Lim‐OOHs (n = 170, 3.1%) and Lin‐OOHs (n = 483, 8.8%) were frequent. Most of the positive reactions were weak (LimOOHs n = 134/LinOOHs n = 429), and even more frequently, doubtful (n = 252/n = 578) or irritant reactions (n = 81/n = 178) were documented. PT reactivity to Lim‐OOHs and Lin‐OOHs was increased in patients with irritant reactions to sodium lauryl sulphate (SLS). The proportion of leg dermatitis and concomitant positive reactions to fragrances and essential oils was increased in patients with reactivity to these hydroperoxides. Conclusion: The observed reaction pattern suggests that both test preparations display an irritant potential with an increased risk of false positive reactions. Preparations should be chemically monitored in order to reduce irritancy. Mindful interpretation of PT results and aimed patch testing of lower concentrations is recommended. [ABSTRACT FROM AUTHOR]

The chemical composition and antioxidant activity of the essential oil from the leaves and flowers of Baccharis odorata Kunth grown in Cuzco, Peru were studied. One hundred forty-one compounds were identified in the essential oil. Oxygenated sesquiterpene and sesquiterpene hydrocarbons were the most represented classes of volatiles with 36.1% and 33.6%, respectively. The main constituents of the essential oil were δ-cadinene (9.1%), β-pinene (8.8%), α-cadinol (8.1%) and limonene (6.2%). Antioxidant properties were examined using the DPPH ferric-reducinging antioxidant power assays. For DPPH radical scavenging assay, the IC50 value was 10.2 ± 1.6 μg/mL, while the FRAP was between 301.3 ± 23.4 to 480.2 ± 21.2 μM of ascorbic acid equivalents. [ABSTRACT FROM AUTHOR]

Transglutaminase (TG) cross-linked whey proteins are used to prepare a D -limonene emulsion, which can solve the problems of easy oxidation and poor water solubility of D -limonene. TG cross-linking can improve the emulsion stability of whey protein isolate (WPI). SDS PAGE results showed that TG cross-linked WPI and limonene were emulsified under high-pressure homogenization to form the emulsion (WPI-TG-Oil), which had more molecular polymers. The adsorption rate of interfacial protein of the WPI-TG-Oil emulsion was significantly increased by 5.15 % compared to the WPI limonene emulsion cross-linked with TG (WPI-Oil-TG). After a 10-day storage interval, the CDs and POV showed that the WPI-TG-Oil emulsion had the strongest oxidation stability and a thickened interfacial layer. It was also noted that WPI-TG-Oil was difficult to hydrolyze during the digestion process due to the large degree of cross-linking and many high molecular weight polymers. The WPI-TG-Oil emulsion was more stable with a high molecular weight and improved the overall properties. Moreover, these findings provide basic theoretical and technical support for improving the stability of D -limonene emulsions. The most suitable processing method was TG-crosslinked WPI to form a stable emulsion, which improved the physiochemical and emulsifying properties of its emulsion for potential uses in food, cosmetics, and other industries. [Display omitted] • TG cross-linking and emulsification were crucial for D -limonene emulsion. • WPI-TG-Oil had more molecular polymers than WPI-Oil-TG. • WPI-TG-Oil emulsion had the strongest oxidation stability. [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to develop a cost-effective and eco-friendly mosquito-repellent textile finish based on microcapsules incorporated with limonene, camphor, linalool, menthol, and 1-octanol individually. Essential oil-based microcapsules were prepared by the emulsion extrusion microencapsulation method. The concentration of active components was determined by the gas chromatography-mass spectrometry (GC-MS) technique at different time intervals. The prepared microcapsules were incorporated into the textile finish to prepare an insect-repellent finish and applied to polyester: cotton (40:60) fabric using a conventional pad-dry cure method. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) analyses were performed to ensure the presence and stability of essential oil components on the fabric. FT-IR spectra showed that peaks observed in the range of (3400–3200 cm−1) and (1720–1600 cm−1) correspond to –OH stretching and bending vibrations in both untreated and microencapsulated essential oil-treated fabric. Mosquito-repellent activity was assessed by exposing treated and untreated fabric to mosquitoes. To study the long-lasting impact of microencapsulation of essential oil components on fabric, mosquito repellency was repeated every 10 to 50 days. Fabrics treated with microencapsulated essential oil components presented higher and longer-lasting protection from mosquitoes than untreated fabrics. Menthol (97%), linalool (93%), and limonene (93%) encapsulated finishes showed significantly higher repellency (>90%) as compared with octanol finishes. The studied mosquito repellent finishes could be ideal candidates for textile finishing industries. [ABSTRACT FROM AUTHOR]

Xanthomonas campestris pv. vesicatoria (Xcv) causes brown spots on the leaves, stems, and fruits of plants, called bacterial leaf scorch (BLS). For the control of pathogens, antibiotics have been used frequently, and they can develop the resistance. In this study, the bactericidal and synergistic effects of caraway oil and its main components against the pathogen (Xcv) were investigated. The tested caraway oil consisted of 58.4% of carvone and 31.1% of limonene. The minimum inhibitory concentration (MIC) of caraway oil and carvone was the same as 125 μg mL−1, and the minimum bactericidal concentration (MBC) was 1000 μg mL−1 for caraway oil and 500 μg mL−1 for carvone, while limonene showed no inhibition below 1000 μg ml−1. In the growth of Xcv, carvone treatment over 31.3 μg mL−1 inhibited dose-dependently, and the bactericidal effect showed after 18 h more than 250 μg mL−1; It was agreed with the release of intracellular components over 250 μg mL−1, especially. Furthermore, carvone damaged the plasmid DNA of Xcv, and it would be the reason for the bactericidal activity. The synergistic effect of carvone was found with β-lactams selectively; the fractional inhibitory concentration (FIC) indexes of carvone with ampicillin or amoxicillin were below 0.5, and the mixture of carvone (125 μg mL−1) and ampicillin (500 μg mL−1) showed the bactericidal activity as well. [ABSTRACT FROM AUTHOR]

R-(+)-limonene, one of the major constituents of citrus oils, is a monoterpene that is widely used as a fragrance additive in cosmetics, foods, and industrial solvents. Nowadays, its detection mainly relies on bulky and expensive analytical methods and only a few research works proved its revelation through affordable and portable sensors, such as electrochemical and quartz crystal microbalance sensors. In response to the demand for effective miniaturized sensing devices to be integrated into Internet of Things systems, this study represents a pioneering investigation of chemoresistive gas sensor capabilities addressed to R-(+)-limonene detection. An array of seven metal-oxide sensors was exploited to perform a complete electrical characterization of the target analyte. The experimental evidence allowed us to identify the WO3-based sensor as the most promising candidate for R-(+)-limonene detection. The material was highly sensitive already at sub-ppm concentrations (response of 2.5 at 100 ppb), consistent with applicative parameters, and it resulted in selective vs. different gases at a lower operating temperature (200 °C) than the other sensors tested. Furthermore, it exhibited a humidity-independent behavior under real-life conditions (relative humidity > 20%). Finally, the WO3 sensor also demonstrated a remarkable cross-selectivity, thus enabling its exploitation in cutting-edge applications. [ABSTRACT FROM AUTHOR]

Biological contamination is one of the main bottlenecks in microalgae production, reducing quality and productivity and sometimes leading to the complete loss of the cultures. Selecting terpenes can be a pathway toward eco-friendly contamination control in microalgae cultures. This work evaluated the presence of bacterial contaminants in N. oleoabundans cultures through HTS and 16 S analysis and their susceptibility to six natural terpenes (α-pinene, β-pinene, limonene, trans-cinnamaldehyde, linalool, and eugenol). The principal phyla identified were Proteobacteria, Bacteroidetes, and Actinobacteria, and based on these data, 89 bacterial isolates of seven genera were obtained (36 Aureimonas sp., 27 Microbacterium sp., 5 Pseudomonas sp., 9 Bacillus sp., 14 Shinella sp., 1 Brevundimonas sp., and 1 Exiguobacterium sp.) at 25ºC in the presence of light. It was possible to observe that Beta-pinene 50 mg L− 1 only inhibited Bacillus sp. In contrast, Alpha-pinene, Linalool, and Trans-cinnamaldehyde, at a concentration of 6.25 mg L− 1 efficiently inhibited most isolates. The inhibition percentages found were 79-99%. [ABSTRACT FROM AUTHOR]

Highly oxygenated organic molecules (HOMs) play a pivotal role in the formation of secondary organic aerosol (SOA). Therefore, the distribution and yields of HOMs are fundamental to understand their fate and chemical evolution in the atmosphere, and it is conducive to ultimately assess the impact of SOA on air quality and climate change. In this study, gas-phase HOMs formed from the reaction of limonene with OH radicals in photooxidation were investigated with SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction chamber), using a time-of-flight chemical ionization mass spectrometer with nitrate reagent ion (NO 3- -CIMS). A large number of HOMs, including monomers (C 9–10) and dimers (C 17–20), were detected and classified into various families. Both closed-shell products and open-shell peroxy radicals (RO 2) were identified under low NO (0.06–0.1 ppb) and high NO conditions (17 ppb). C 10 monomers are the most abundant HOM products and account for over 80 % total HOMs. Closed-shell C 10 monomers were formed from a two peroxy radical family, C 10 H 15 O x⚫ (x=6 –15) and C 10 H 17 O x⚫ (x=6 –15), and their respective termination reactions with NO, RO 2 , and HO 2. While C 10 H 17 O x⚫ is likely formed by OH addition to C 10 H 16 , the dominant initial step of limonene plus OH, C 10 H 15 O x⚫ , is likely formed via H abstraction by OH. C 10 H 15 O x⚫ and related products contributed 41 % and 42 % of C 10 HOMs at low and high NO, demonstrating that the H-abstraction pathways play a significant role in HOM formation in the reaction of limonene plus OH. Combining theoretical kinetic calculations, structure–activity relationships (SARs), data from the literature, and the observed RO 2 intensities, we proposed tentative mechanisms of HOM formation from both pathways. We further estimated the molar yields of HOMs to be 1.97-1.06+2.52 % and 0.29-0.16+0.38 % at low and high NO, respectively. Our study highlights the importance of H abstraction by OH and provides the yield and tentative pathways in the OH oxidation of limonene to simulate the HOM formation and assess the role of HOMs in SOA formation. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Trichomoniasis, caused by Trichomonas vaginalis protozoan, is the most common nonviral sexually transmitted infection (STI) worldwide. Although metronidazole and tinidazole are the only approved drugs for treatment, drug-resistant cases of infection are on the rise. The aim of this study was the evaluation of antitrichomonal potential of Piper nigrum and limonene. The phytochemical profile of P. nigrum oil was also investigated. Methods: The parasites were treated in vitro with essential oil and different extracts of P. nigrum seed and limonene using microtiter plate method. The oil of P. nigrum was also analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. Furthermore, the cytotoxicity assay of P. nigrum oil and limonene were screened on Vero cell line by MTT method. Results: The tested P. nigrum fractions were able to kill 100% of Trichomonas trophozoites at minimum lethal concentration (MLC) and reduce the trophozoite viability at sub-MLC and lower concentrations. After 48 hours exposure, the most potent fraction was the n-hexane extract with MLC of 78 µg/mL followed by the essential oil and methanol extract with MLC of 156 µg/ mL, limonene (MLC=1250 µg/mL), and then, aqueous extract with MLC value of 25 mg/mL. Moreover, according to cytotoxicity assay, P. nigrum oil was less toxic to Vero cell than limonene, with a selectivity index (SI) of 13.2 and 2.04, respectively. Conclusion: This study clearly demonstrated the trichomonacidal potential of P. nigrum. Thus, P. nigrum fractions can be considered promising antiprotozoal agents and the basis for further development to discover new phytochemicals compounds. [ABSTRACT FROM AUTHOR]

Limonene, obtained from citrus oils such as orange, grapefruit, and lemon, is widely used in cosmetics as a scenting agent. It is regarded as safe because it is not mutagenic, carcinogenic, or nephrotoxic to people and has low human toxicity. This study aims to show the beneficial effects of limonene against hydrogen peroxide (H2O2) induced ageing in human keratinocytes (HaCat) cell line. For this purpose, the concentration value at which H2O2 can cause ageing in HaCaT cells was determined as 200 µM by the MTT method. Then, cytotoxic effects of limonene (1, 10, 25, 50, 100, 250 and 500 µg/mL) alone and in aging-induced cells were determined by the MTT method; possible antigenotoxic effects were determined by alkaline single-cell gel electrophoresis (Comet) method. According to the results obtained, limonene, an ingredient in cosmetics, has protective effects against skin aging in HaCaT cells. [ABSTRACT FROM AUTHOR]

Enzymatic terpene functionalization is an essential part of plant secondary metabolite diversity. Within this, multiple terpene-modifying enzymes are required to enable the chemical diversity of volatile compounds essential in plant communication and defense. This work sheds light on the differentially transcribed genes within Caryopteris × clandonensis that are capable of functionalizing cyclic terpene scaffolds, which are the product of terpene cyclase action. The available genomic reference was subjected to further improvements to provide a comprehensive basis, where the number of contigs was minimized. RNA-Seq data of six cultivars, Dark Knight, Grand Bleu, Good as Gold, Hint of Gold, Pink Perfection, and Sunny Blue, were mapped on the reference, and their distinct transcription profile investigated. Within this data resource, we detected interesting variations and additionally genes with high and low transcript abundancies in leaves of Caryopteris × clandonensis related to terpene functionalization. As previously described, different cultivars vary in their modification of monoterpenes, especially limonene, resulting in different limonene-derived molecules. This study focuses on predicting the cytochrome p450 enzymes underlying this varied transcription pattern between investigated samples. Thus, making them a reasonable explanation for terpenoid differences between these plants. Furthermore, these data provide the basis for functional assays and the verification of putative enzyme activities. [ABSTRACT FROM AUTHOR]

Aromatic white wines contain monoterpenes that can alter aroma qualities based on their concentration and enantiomeric ratios. Limonene has been identified as a monoterpene that is used to differentiate monovarietal white wines. The aim of this study was to evaluate the influence of limonene on aroma perception at different enantiomeric ratios. Its interaction with linalool and α-terpineol compounds was also investigated. Eighteen model wines were created with different ratios and/or concentrations of limonene and diverse concentrations of linalool and α-terpineol. Triangle tests, check-all-that-apply (CATA) and descriptive analysis were used to evaluate the aroma of the wines. Results show that different limonene ratios had no influence on wine aroma. Descriptive analysis showed that the addition of only limonene influenced citrus characteristics depending on the concentration. Linalool addition did not alter aroma quality when the limonene was at low concentrations, but it did change aroma perception at high limonene levels. α-Terpineol only altered the aroma of the wine at medium and high concentrations. At high concentrations, linalool and α-terpineol presented tropical aromas with some floral notes, irrespective of limonene levels. Depending on the desired aroma qualities of the wine, altering the monoterpene content resulted in very different aromatic wines. [ABSTRACT FROM AUTHOR]

NaOH, dolomite and NiCl2 were used as catalysts to examine their effects on co–pyrolysis with waste bicycle tires (WT) and waste engine oil (WEO). The pyrolysis behaviors with catalysts were investigated by thermogravimetric analysis. The activation energy of the catalytic main reaction stage was derived by the Kissinger–Akahira–Sunose (KAS) method under four different heating rates conditions. The calculations show that all three catalysts can reduce the activation energy of the reaction. Co–pyrolysis of WT and WEO with different catalysts was performed in a self–made lab bench at 600 °C to explore the impact on the distribution of three–phase products. The properties of gas and oil products were characterized by FTIR and Py–GC/MS (Agilent 7890B, Santa Clara, CA, USA). With the mixing of catalysts, activation energy (Eα) decreased by 15–30% in the main reaction process. NaOH and dolomite increased the yield of gas by 7% and 10%. NaOH can significantly improve the yield of CH4. The proportion of limonene in pyrolysis oil increased to 19.65% with 10% NaOH. This article provides a new method for efficiently producing limonene by mixing WT and WEO with NaOH. [ABSTRACT FROM AUTHOR]

Although both fabricated insoles and customized insoles were designed with varied function components, current knowledge approved that customized insoles worked much better. However, how the customized insoles achieved a better performance in term of load re-distribution was still lacking quantitative assessment. The aim was to determine whether the customized insole structure based on a novel customization procedure proposed in this study performs better than the prefabricated insoles in terms of plantar pressure re-distribution efficiency. This study included ten healthy subjects, each wearing four types of insoles accordingly (control insoles; arch support insoles; orthotic insoles; customized insoles), and plantar pressure was collected in a walking state. The custom insoles are made by determining the subject’s plantar surface and key plantar points, then following the customization procedure to finish them. The plantar area was divided into eight zones and then a pressure transfer algorithm was used to gain insight into the plantar pressure. Compared to the control group insoles, the arch support of the customized insoles reduced pressure in the hallux region and transferred pressure from the M4-5 to the MH and LH regions, while the metatarsal pad enhanced the pressure transfer in the mid-foot, and the anterior-posterior height difference of the insole plays a role in pressure transfer. Furthermore, the customized insoles performed close to the professional orthotic insoles. Design strategy with accurate insole’s component location and reasonably plantar surface matching, our customized insole demonstrated advantages such as a better loading redistribution and significant pressure relieving on the forefoot. [ABSTRACT FROM AUTHOR]

Two antimicrobial gels, formulated with natural biopolymers (collagen and chitosan), limonene, and an imidazole derivative, were subjected to cytotoxicity tests. In these two compositions, the limonene content was 0.4% and 0.67%. The cytotoxicity tests were performed in vitro, using MTT methodology, and a standardized human normal cells line, HUVEC type. These cells were exposed to different levels of gel concentrations in the culture media. The final concentration of each gel type in culture media was situated between (0-0.125) μL/mL. The cell viability was determined after 24, 48 and 72h of exposure. The analyses showed that after 24h of exposure, the viability of the cells is greater than 91%, after 48h the viability is greater than 80%; after 72 h of exposure, the viability of the cells is greater than 74%. These values reveal that both selected gels exhibit no cytotoxicity for the normal cell line. [ABSTRACT FROM AUTHOR]

Starting from the consideration that the pharmacological and therapeutic properties of an essential oil are given by their chemical components, components that differ depending on the origin, soil, temperature, humidity, etc., we set out to determine the content of volatile compounds in the oil essential thuja purchased from the trade and to test its antimicrobial effect. The objectives of the research were to identify volatile compounds from thuja essential oil by the GS-MS method and to test the antimicrobial effect on gram positive and gram negative species. The obtained results showed that Thuja essential oil has significant inhibitory effects against gram-positive and gram-negative bacteria, which are associated with clinical diseases; it is more effective against gram positives than gram negatives; ineffective against Salmonella typhimurium and the major components identified were: α-pinene, 3-carene, terpinolene, limonene, β-myrcene and camphene. The presence of these compounds shows that thuja essential oil has a great potential for use in many medical applications. [ABSTRACT FROM AUTHOR]

African savanna elephants use pre-ingestive olfactory cues when making dietary choices, and previous research has observed that elephant diet choice is negatively correlated with vegetation species that contain high concentrations of monoterpenes. However, the frequency and concentration of monoterpenes can vary dramatically across plant species. Thus, we aimed to explore the effects that the odours of individual monoterpenes have on elephant diet choice and how these effects vary with concentration. To do this, we conducted three odour-based choice experiments focusing on eight common monoterpenes found in the woody plants in Southern African savannas. In the first experiment, we tested whether elephant diet choice for a frequently consumed plant (Euclea crispa) was influenced by the addition of the odour of an individual monoterpene at a set concentration. In the second experiment, we explored the relative deterrence of each monoterpene. Lastly, we tested how elephant diet choice varied as a function of the addition of individual monoterpene odours at 5%, 10%, and 20% concentrations. We found that the elephants avoided most individual monoterpenes at high concentrations, with the exception being α-pinene. Furthermore, we found that the odours of some individual monoterpenes were, in fact, more deterrent than others. In the third experiment, we found that the elephants avoided β-pinene, limonene, ocimene, γ-terpinene, and terpinolene across all concentrations, but only avoided sabinene and linalool at high concentrations. Ultimately, our results show that the odour of individual monoterpenes may deter elephant consumption, but that this deterrent effect depends on both the monoterpene and its concentration. [ABSTRACT FROM AUTHOR]

Aromatic plants have broad-spectrum applications in many life aspects and possess rich volatile essential oil components. Pure essential oils have been divided into two groups as hydrocarbons and oxygenated on the basis of their chemical constitutions. These essential oils are being applied against many insects and pests as an alternative approach. In this review, the most effective essential oil components that possess pesticidal activity via fumigant, contact, or ingestion on storage pests are discussed. Moreover, the effective components possessing repellent and feeding deterrent activities, and cause development, reproductive, and physiological inhibition, especially on stored-product pest insects are highlighted. Although there are many effective ingredients, some components such as eucalyptol, camphor, linalool, eugenol, limonene, terpinen-4-ol, menthone, and anethole have the most effective and competitive activities when compared with some synthetic chemicals in terms of insecticidal activity in fumigant and contact toxicity tests. Similarly, components such as eugenol, eucalyptol, anethole, camphor, and linalool have displayed significant repellent activity against storage pests. Moreover, components such as limonene, linalool, eugenol, isoeugenol, methyleugenol, and sparteine have caused significant feeding deterrence on stored-product insect pests. Besides, some components such as eucalyptol, eugenol, camphor, isoeugenol, methyleugenol, α-pinene, β-caryophyllene, limonene, α-bisabolol, linalool, terpinen-4-ol, and geraniol have prevented the development stages and decreased the life span of stored-product pests. Components such as eucalyptol, eugenol, camphor, anethole, α-pinene, β-caryophyllene, limonene, and linalool displayed a significant reduction in the productivity of stored-product pests. Some components of essential oils have also been evaluated for their modes of action. Keeping in view the importance of these pure components of essential oils against stored-product pests, we have summarized the most significant studies as a review paper on this aspect. [ABSTRACT FROM AUTHOR]

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Simple Summary: The inclusion of plant-derived products, such as herbs or essential oils, in the feed can improve the production of animals. Moreover, these photogenic products can fight against parasites in an animal's digestive system. The scope of the present study was to observe the impact of a feed supplement containing carvacrol and limonene on the performance and parasitological status of sheep. The feed supplement exerted an advantageous effect on the metabolic processes of lactating ewes after 42 days of supplementation, while the average live weight and average daily weight gain of their twin suckling lambs increased by the termination of the study. In another experiment, fattening lambs fed the same supplement showed a decreased faecal egg count of gastrointestinal nematodes. Additionally, no differences in live weight, average daily gain, or mean number of Haemonchus contortus nematodes in the abomasum were observed. The results highlighted that carvacrol and limonene in the feed of lactating ewes effectively increased the weight gain of their twin suckling lambs, presumably due to the ewes' energy status improvement. At the same time, further studies are needed to elucidate the effects of carvacrol and limonene against gastrointestinal parasites. There is currently worldwide interest in phytogenic feed supplements (PFSs) because they can lead to improved animal production. The scope of the present study was to observe the impact of a feed supplement containing carvacrol (CAR) and limonene (LIM) on the performance and parasitological status of sheep. The feed supplement decreased the plasma levels of β-hydroxybutyrate (p < 0.001), triglycerides (p = 0.014), nonesterified fatty acids (p = 0.021), and fructosamine (p = 0.002) in lactating ewes after 42 days of supplementation, while the average live weight (p = 0.002) and average daily weight gain (p = 0.001) of their twin suckling lambs increased significantly by the end of the study. In another experiment, fattening lambs fed the same supplement showed a decrease in fecal egg number of gastrointestinal nematodes (p = 0.02) but no differences in live weight, average daily gain, or mean number of Haemonchus contortus nematodes in the abomasum. The results highlighted that the inclusion of carvacrol and limonene in the feed of lactating ewes effectively increased the weight gain of the suckling lambs, presumably due to the ewes' improved energy, but further studies are needed to elucidate the effects of carvacrol and limonene against gastrointestinal parasites. [ABSTRACT FROM AUTHOR]

Propranolol is the first-line drug for managing migraine attacks. D-limonene is a citrus oil known for its neuroprotective mechanism. Thus, the current work aims to design a thermo-responsive intranasal limonene-based microemulsion mucoadhesive nanogel to improve propranolol efficacy. Microemulsion was fabricated using limonene and Gelucire® as the oily phase, Labrasol®, Labrafil®, and deionized water as the aqueous phase, and was characterized regarding its physicochemical features. The microemulsion was loaded in thermo-responsive nanogel and evaluated regarding its physical and chemical properties, in vitro release, and ex vivo permeability through sheep nasal tissues. Its safety profile was assessed via histopathological examination, and its capability to deliver propranolol effectively to rats' brains was examined using brain biodistribution analysis. Limonene-based microemulsion was of 133.7 ± 0.513 nm diametric size with unimodal size distribution and spheroidal shape. The nanogel showed ideal characteristics with good mucoadhesive properties and in vitro controlled release with 1.43-fold enhancement in ex vivo nasal permeability compared with the control gel. Furthermore, it displayed a safe profile as elucidated by the nasal histopathological features. The nanogel was able to improve propranolol brain availability with Cmax 970.3 ± 43.94 ng/g significantly higher than the control group (277.7 ± 29.71 ng/g) and with 382.4 % relative central availability, which confirms its potential for migraine management. [ABSTRACT FROM AUTHOR]

The peel of Citrus sinensis (L.) Osbeck is a source of essential oils, particularly limonene, which is this plant’s characteristic molecule. The main goal of this study was to test the potential analgesic and anti-inflammatory properties of limonene-rich essential oils derived from the peel of C. sinensis L. (orange) in vivo, as well as their antioxidant activity in vitro. Carrageenan-induced paw edema in Wistar rats and the formalin test in Swiss albino mice were used to examine anti-inflammatory activity. The analgesic activity was assessed using hot plate and acetic acid writhing tests, while the antioxidant activity was assessed using the 1,1-diphenyl-2-picrylhydrazyl and ferric reducing antioxidant power methods. The essential oil (EO) safety was determined using an acute toxicity experiment on mice. The phytochemical analysis confirmed the existence of limonene as the primary molecule (88.94%), and in vivo experiments revealed that the EO had a significant pain and inflammation-relieving effect, especially at the dose of 50 mg/kg, when compared to the used control drugs. The acute toxicity evaluation reported this EO’s safety. This study contributes to the pharmacological valorization of the peel of C. sinensis L., confirming that, in addition to its numerous cosmetic and industrial uses, it may be effective in the treatment of inflammatory and pain-related illnesses.

Abstract The strategy of synergistic application of biological and chemical catalysis is an important approach for efficiently converting renewable biomass into chemicals and fuels. In particular, the method of determining the appropriate intermediate between the two catalytic methods is critical. In this work, we demonstrate p-cymene production through the integration of biosynthesis and heterogenous catalysis and show how a preferred biologically derived precursor could be determined. On the biological side, we performed the limonene and 1,8-cineole production through the mevalonate pathway. Titers of 0.605 g/L and a 1.052 g/L were achieved, respectively. This difference is in agreement with the toxicity of these compounds toward the producing microorganisms, which has implications for subsequent development of the microbial platform. On the heterogeneous catalysis side, we performed the reaction with both biological precursors to allow for direct comparison. Using hydrogenation/dehydrogenation metals on supports with acid sites, both limonene and 1,8-cineole were converted to p-cymene with similar yields under equivalent reaction conditions. Thus, we could determine that the most promising strategy would be to target 1,8-cineole, the higher titer and lower toxicity bio-derived precursor with subsequent catalytic conversion to p-cymene. We further optimized the biological production of 1,8-cineole via fed-batch fermentation and reached the titer of 4.37 g/L which is the highest known 1,8-cineole titer from microbial production. This work provides a valuable paradigm for early stage considerations to determine the best route for the high-efficiency production of a target biobased molecule using an integration of biology and chemistry.

ABSTRACT: Concentration is a key determinant in the overall positive impact of terpenes on milk and cheese aroma; additionally, route of intake may affect the achievable concentrations of dietary terpenes in milk and cheese. In this study, we explored the possibility that the amount of the monoterpene limonene transferred to sheep milk and its corresponding cheese could differ depending on the route of intake and that the aroma profile of these products could also differ. To this aim, 12 lactating dairy ewes were repeatedly exposed to limonene by the oral or respiratory route during a 48-h test period, according to a 3 × 3 Latin square experimental design. Limonene content was measured in individual and bulk milk samples, in 1-d-old and 15-d-old Caciotta cheese obtained from that milk, in the related whey and curd, and in the air inhaled by the ewes in the respiratory treatment group (to obtain an estimate of the dose actually supplied by this route). Bulk milk and fresh (1-d-old) cheese underwent sensory analysis by ortho-olfactory evaluation. Both intake routes demonstrated transfer of limonene to milk, but the respiratory route transferred limonene with greater efficiency than the oral route. Moreover, according to the protocol used in this study, a short period of respiratory exposure induced a slightly higher limonene content in milk compared with oral exposure. As to the fate of limonene during cheesemaking, an important part of it was lost into the whey, perhaps through volatilization. The differences between milk and cheese tended to dissipate in curd and fresh cheese and disappeared completely after 15 d of ripening. Finally, it was possible to distinguish between the 2 routes of limonene intake using sensory analysis, even though no direct relationship was identified between the different aroma profiles of milks and cheeses from the oral and respiratory groups and their respective limonene contents. Overall, our results expand current knowledge on the biological pathways of terpene transfer from feed to sheep milk and cheese, as well as on the role played by terpenes in the formation of aroma in these products. Our observations may contribute to future development of strategies for external control and better standardization of the presence of odor compounds in milk and cheese from dairy ruminants.

Introduction: There are several factors that affect the quality and quantity of active ingredients and essential oil (EO) content, including pre and postharvest practices such as drying conditions. One of the most important factors in drying is temperature and then selective drying temperature (DT). In general, DT has a direct effect on the aromatic properties of Anethum graveolens. Methods: On this basis, the present study was conducted to evaluate the effects of different DTs on the aroma profile of A. graveolens ecotypes. Results and discussion: The results showed that different DTs, ecotypes, and their interaction significantly affect EO content and composition. The highest EO yield was obtained from the Parsabad ecotype (1.86%) followed by the Ardabil ecotype (1.4%), both at 40° C. More than 60 EO compounds were identified, mainly monoterpenes and sesquiterpenes, highlighting α-Phellandrene, Germacrene D, and Dill apiole as major components in all treatments. Besides α-Phellandrene, the major EO compounds at shad drying (ShD) were β-Phellandrene and p-Cymene, while plant parts dried at 40° C showed l-Limonene and Limonene as the main constituents, and Dill apiole was detected in greater amounts in the samples dried at 60°C. To determine the appropriate DT, simple and factorial based-ANOVA together multivariate analysis demonstrated significant differences in the compounds produced under different DTs. The results indicated that more EO compounds, mainly monoterpenes, were extracted at ShD than other DTs. On the other hand, the content and composition of sesquiterpenes increased significantly when DT was increased to 60°C. From the genetic backgrounds point of view, the Parsabad ecotype (with 12 similar compounds) and Esfahan ecotype (with 10 similar compounds) were the most suitable ecotypes under all DTs in terms of EO compounds. Accordingly, the present study would help various industries to optimize specific DT(s) to obtain special EO compound(s) from different A. graveolens ecotypes based on commercial requirements. [ABSTRACT FROM AUTHOR]

The oxidation of monoterpenes under atmospheric conditions has been the subject of numerous studies. They were motivated by the formation of oxidized organic molecules (OOMs), which, due to their low vapor pressure, contribute to the formation of secondary organic aerosols (SOA). Among the different reaction mechanisms proposed for the formation of these oxidized chemical compounds, it appears that the autoxidation mechanism, involving successive events of O 2 addition and H migration, common to both low-temperature-combustion and atmospheric conditions, leads to the formation of highly oxidized products (HOPs). However, cool-flame oxidation (∼500 –800 K) of terpenes has not received much attention even if it can contribute to atmospheric pollution through biomass burning and wildfires. Under such conditions, terpenes can be oxidized via autoxidation. In the present work, we performed oxidation experiments with limonene–oxygen–nitrogen and α -pinene–oxygen–nitrogen mixtures in a jet-stirred reactor (JSR) at 590 K, a residence time of 2 s, and atmospheric pressure. Oxidation products were analyzed by liquid chromatography, flow injection, and soft-ionization–high resolution mass spectrometry. H–D exchange and 2,4-dinitrophenyl hydrazine derivatization were used to assess the presence of OOH and C = O groups in oxidation products, respectively. We probed the effects of the type of ionization used in mass spectrometry analyses on the detection of oxidation products. Heated electrospray ionization (HESI) and atmospheric-pressure chemical ionization (APCI) in positive and negative modes were used. We built an experimental database consisting of literature data for atmospheric oxidation and presently obtained combustion data for the oxidation of the two selected terpenes. This work showed a surprisingly similar set of oxidation products' chemical formulas, including oligomers, formed under the two rather different conditions, i.e., cool-flame and simulated atmospheric oxidation. Data analysis (in HESI mode) indicated that a subset of chemical formulas is common to all experiments, independently of experimental conditions. Finally, this study indicates that more than 45 % of the detected chemical formulas in this full dataset can be ascribed to an autoxidation reaction. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Volatile compounds are present in fruits in two forms, free and glycosidically bound. The latest has been studied in several fruits and are considered important aroma precursors because their release by acid or enzymatic hydrolysis has been reported higher than the free fraction. Recently, volatiles released by acid hydrolysis in jackfruit were reported, however, enzymatic hydrolysis of glycosidically bound fraction has not been studied yet. Thus, in this study, the free and glycosidically bound volatile compounds from jackfruit were isolated by absorption onto a column of Amberlite XAD‐2. Enzymatic hydrolysis with β‐glucosidase was carried out to release the glycosidically bound compounds and identified by GC–MS. Fifty‐four volatiles encompassed both fractions with 14 compounds in common. 2,4‐dimethylbenzaldehyde, 4‐methylpentan‐2‐ol, 2,6‐dimethylheptan‐4‐one, neral, butan‐1‐ol, and hexadecanoic acid were prominent in the free fraction. Meanwhile, 3‐hydroxy‐β‐ionol, 2‐phenylethanol, benzyl alcohol, lavandulol, 3‐oxo‐α‐ionol, and hexadecanoic acid were predominant in the bound form. Odor activity values (OAV) and relative odor contribution (ROC) of free and glycosidically bound compounds were calculated. Thus, ethyl 3‐methylbutanoate, methyl 2‐methylbutanoate, methyl butanoate, 3‐methyl‐3‐buten‐1‐ol, octan‐1‐ol, 3‐methylbutanal, hexanal, 2‐nonanone, 2‐phenylethanol, and limonene showed OAV >1 after hydrolysis, contributing to the overall aroma. Results revealed that the bound fraction of jackfruit volatiles is eight times fold that their free counterpart. Information about the first research of glycosidically bound compounds in jackfruit released by enzymatic hydrolysis is provided. The results reinforce the importance of aroma precursors to suggest the raw material according to the applied pretreatment and thus take advantage of the aromatic potential that they can develop. [ABSTRACT FROM AUTHOR]

Cannabis sativa is a multipurpose plant that has been used in medicine for centuries. Recently, considerable research has focused on the bioactive compounds of this plant, particularly cannabinoids and terpenes. Among other properties, these compounds exhibit antitumor effects in several cancer types, including colorectal cancer (CRC). Cannabinoids show positive effects in the treatment of CRC by inducing apoptosis, proliferation, metastasis, inflammation, angiogenesis, oxidative stress, and autophagy. Terpenes, such as β-caryophyllene, limonene, and myrcene, have also been reported to have potential antitumor effects on CRC through the induction of apoptosis, the inhibition of cell proliferation, and angiogenesis. In addition, synergy effects between cannabinoids and terpenes are believed to be important factors in the treatment of CRC. This review focuses on the current knowledge about the potential of cannabinoids and terpenoids from C. sativa to serve as bioactive agents for the treatment of CRC while evidencing the need for further research to fully elucidate the mechanisms of action and the safety of these compounds. [ABSTRACT FROM AUTHOR]

The end-to-end fusion of enzymes that catalyse successive steps in a reaction pathway is a metabolic engineering strategy that has been successfully applied in a variety of pathways and is particularly common in terpene bioproduction. Despite its popularity, limited work has been done to interrogate the mechanism of metabolic enhancement from enzyme fusion. We observed a remarkable >110-fold improvement in nerolidol production upon translational fusion of nerolidol synthase (a sesquiterpene synthase) to farnesyl diphosphate synthase. This delivered a titre increase from 29.6 mg/L up to 4.2 g/L nerolidol in a single engineering step. Whole-cell proteomic analysis revealed that nerolidol synthase levels in the fusion strains were greatly elevated compared to the non-fusion control. Similarly, the fusion of nerolidol synthase to non-catalytic domains also produced comparable increases in titre, which coincided with improved enzyme expression. When farnesyl diphosphate synthase was fused to other terpene synthases, we observed more modest improvements in terpene titre (1.9- and 3.8-fold), corresponding with increases of a similar magnitude in terpene synthase levels. Our data demonstrate that increased in vivo enzyme levels – resulting from improved expression and/or improved protein stability – is a major driver of catalytic enhancement from enzyme fusion. • Fusion of farnesyl diphosphate synthase (FPPS) to nerolidol synthase increased nerolidol production by >110-fold. • Fusion of nerolidol synthase to metabolically inactive proteins also increased titres. • Fusion of FPPS to other terpene synthases produced smaller increases in titre. • Increases in titre coincided with elevated levels of terpene synthase. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Atherosclerosis, a leading cause of mortality worldwide, is driven by multiple risk factors such as diabetes. Oxidative stress and inflammation assist interrelated roles in diabetes-accelerated atherosclerosis. Thereby, treatment of diabetic atherosclerosis from an oxidative stress/inflammatory perspective seems to be a more effective modality to prevent and delay plaque formation and progression. This study aimed to evaluate the effects of l-limonene (LMN) on oxidative stress/inflammatory responses in the aortic artery of diabetic atherosclerosis-modeled rats. Male Wistar rats (n = 30, 250-280 g, 12 weeks old) were used to establish a diabetic atherosclerosis model (8 weeks) using high-fat diet/low-dose streptozotocin. LMN (200 mg/kg/day) was administered orally, starting on day 30th before tissue sampling. Plasma lipid profiles, aortic histopathological changes, atherogenic index, aortic artery levels of oxidative stress markers (manganese superoxide dismutase, glutathione, and 8-isoprostane), inflammatory markers (tumor necrosis factor-alpha, interleukin (IL)-6, and IL-10), and expression of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK)/AMPK, Sirtuin 1 (SIRT1), and p-p65/p65 proteins were evaluated. The administration of LMN to diabetic rats improved lipid profiles, aortic histopathological morphology, and atherogenic index (P < 0.05 to P < 0.001). It also increased enzymatic antioxidant activities, decreased 8-isoprostane level, suppressed inflammatory response, upregulated p-AMPK and SIRT1 proteins, and downregulated p-p65 protein (P < 0.05 to P < 0.01). Inhibiting the AMPK through the administration of compound C significantly abolished or reversed the positive effects of LMN in diabetic rats (P < 0.05 to P < 0.01). LMN treatment had dual anti-oxidative and anti-inflammatory actions against atherosclerosis in the aortic artery of diabetic rats. Atheroprotection by LMN was mediated partly through modulation of AMPK/SIRT1/p65 nuclear factor kappa B signaling pathway. LMN appears to be a promising anti-atherosclerotic modality to improve the quality of life in diabetic patients. [ABSTRACT FROM AUTHOR]