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The unimolecular reactions of protonated myrcene and linalool were investigated by collision‐induced dissociation and density functional theory calculations. Experiments on a triple quadrupole mass spectrometer showed that protonated myrcene undergoes two major unimolecular reactions losing propene and isobutene, and two minor reactions of ethene and propane loss. In each case, the product ion consists of a substituted five‐member ring. Protonation of myrcene was found to form four distinct protomers, three of which can be significantly populated in the ion source. The observed fragmentation reactions were calculated and found to depend on the starting protomer. Each pathway consisted of several hydrogen‐migration and ring‐forming/opening steps on the way to the observed products. Likewise, protonation of linalool also produces three distinct protomers, with the global minimum being formed by protonation of a central double bond. The major reaction is water loss to form protonated myrcene, but two minor channels were also observed resulting in loss of acetone and isobutene. The calculated minimum energy reaction pathways were found to be consistent with the relative abundances of the ions in the experimental breakdown diagrams. [ABSTRACT FROM AUTHOR]

Humulus lupulus, or hops, is a vital ingredient in brewing, contributing bitterness, flavor, and aroma. The female plants produce strobiles rich in essential oils and acids, along with bioactive compounds like polyphenols, humulene, and myrcene, which offer health benefits. This study examined the aromatic profiles of five hop varieties grown in Brazil versus their countries of origin. Fifty grams of pelletized hops from each strain were collected and analyzed using HS-SPME/GC-MS to identify volatile compounds, followed by statistical analysis with PLS-DA and ANOVA. The study identified 330 volatile compounds and found significant aromatic differences among hops from different regions. For instance, H. Mittelfrüher grown in Brazil has a fruity and herbaceous profile, while the German-grown variety is more herbal and spicy. Similar variations were noted in the Magnum, Nugget, Saaz, and Sorachi Ace varieties. The findings underscore the impact of terroir on hop aromatic profiles, with Brazilian-grown hops displaying distinct profiles compared to their counterparts from their countries of origin, including variations in aromatic notes and α-acid content. [ABSTRACT FROM AUTHOR]

The inhibitory effect of Rosemary oil on the corrosion of aluminum alloy EN AW-2011 in 1M H2SO4 solution was studied by weight loss and electrochemical methods such as open circuit potential (OCP), linear sweep voltammetry (LSV) and linear polarization resistance (LPR). The inhibition efficiency increases with increasing the concentration and shows maximum inhibition efficiency (70.7 %) at optimum concentration (0.05 g.L-1). The linear polarization resistance measurements show that the presence of Rosemary oil in 1M H2SO4 solution influences polarization resistance increasing and corrosion current decreasing. The voltammetric curve shows that Rosemary oil reduces the anodic process. Open circuit potential results confirmed that organic compounds present in Rosemary oil can form a protective layer on aluminum surfaces. The inhibitive effect was probably caused by the adsorption of organic compounds such as 1,8-cineole, α-pinene, borneol, limonene, and myrcene on aluminum surfaces which are non-toxic and environmentally friendly. This study showed that the essential oil of Rosemary could be used as an environmentally friendly inhibitor of the corrosion of alloy EN AW-2011 in an acidic medium. [ABSTRACT FROM AUTHOR]

This study aims at investigating the chemical composition of root, stem and leaf essential oils from Ivorian Synedrella nodiflora, with the root oil being described for the first time. Sixty, fifty-one and forty-nine constituents were, respectively identified in the root, stem and leaf oils using a combination of GC(RI), GC-MS and 13C-NMR analyses. They accounted for 95.6–97.3%, 92.6–97.6% and 93.3–98.8% of the total composition, respectively. The main components of the root oil samples were γ-curcumene, (E)-β-caryophyllene, α-curcumene and curcuphenyl acetate. Three stem oil samples (S1, S2a, S3) were dominated by myrcene and limonene, while the most abundant components of sample S2b were thymol, germacrene D and β-elemene. (E)-β-caryophyllene and germacrene D were the major compounds of the leaf oil. Hierarchical cluster and principal component statistical analyses were performed and confirmed that the location does not influence the chemical composition. Group I consisted of the seven leaf oil samples, group II consisted of four stem oil samples and group III consisted of three root oil samples. The root oil composition differed considerably from the stem and leaf oil composition due to the presence of curcumene derivatives as major constituents. The leaf oil showed significant amounts of (E)-β-caryophyllene and germacrene D, while the stem oil stood out for its high myrcene, limonene and thymol contents. [ABSTRACT FROM AUTHOR]

Aedes mosquito-borne diseases remain a significant global health threat, necessitating effective control strategies. This study introduces monoterpenes-based nanohydrogels for potential use as repellents against Aedes aegypti, the primary dengue vector worldwide. We formulated hydrogels using cymene- and myrcene-based nanoemulsions with different polymers: chitosan, carboxymethylcellulose (CMC), and carbopol®. Our evaluations of rheological, texture, and bioadhesive properties identified CMC hydrogel as the most promising gelling agent for topical application, exhibiting sustained monoterpene release over 12 h with low skin permeation and high retention in the stratum corneum. Myrcene-loaded CMC hydrogel achieved a 57% feeding deterrence compared to 47% with cymene hydrogel in the mosquito membrane-feeding model. Molecular docking studies revealed interactions between myrcene and an essential amino acid (Ile116) in the Ae. aegypti odorant-binding protein 22 (AeOBP22), corroborating its higher repellent efficacy. These findings suggest that myrcene-loaded CMC hydrogels offer a promising, minimally invasive strategy for personal protection against Ae. aegypti and warrant further investigation to optimize monoterpene concentrations for vector control. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the impact of two chain transfer controllers, ethyl 2-(phenylcarbonothiolthio)-2-phenylacetate (EPPA) and 2-(4-methoxyphenylcarbonothiolthio) ethanoic acid (MPEA), from the dithioester family (dithiobenzoates), on the RAFT polymerization of β-myrcene. The initiators employed were azobisisobutyronitrile (AIBN) or dicumylperoxide (DCP), at 65 °C and 90 °C, respectively. The study analyzed the impact of the type of controller, temperature, and initiator/controller ratio on the living nature of β-myrcene polymerization. The results showed that with an increase in the initiator/controller ratio, the rate of polymerization increased, but the obtained molar masses decreased. The MPEA controller showed better performance in controlling the termination and chain transfer reactions, especially when AIBN was used as the initiator. A rise in polymerization temperature led to a loss in the control of polymerization, causing an increase in the degree of polydispersity due to the presence of transfer reactions. The most effective control in the RAFT polymerization of β-myrcene was achieved using MPEA as the controller and AIBN as the initiator, resulting in a poly(β-myrcene) with 87% 1,4-addition according to proton NMR analyses and a polydispersity of 1.27 by gel permeation chromatography (GPC). Finally, the study synthesized a poly(β-myrcene)-b-poly(styrene) block copolymer with low polydispersity (Ð1.1) by sequentially adding styrene to the previously synthesized MPEA-poly(β-myrcene)-based RAFT macrocontroller. [ABSTRACT FROM AUTHOR]

As part of our continuing interest in the essential oil compositions of gymnosperms, particularly the distribution of chiral terpenoids, we have obtained the foliar essential oils of Chamaecyparis lawsoniana (two samples), Thuja plicata (three samples), and Tsuga heterophylla (six samples) from locations in the state of Oregon, USA. The essential oils were obtained via hydrodistillation and analyzed by gas chromatographic techniques, including chiral gas chromatography—mass spectrometry. The major components in C. lawsoniana foliar essential oil were limonene (27.4% and 22.0%; >99% (+)-limonene), oplopanonyl acetate (13.8% and 11.3%), beyerene (14.3% and 9.0%), sabinene (7.0% and 6.5%; >99% (+)-sabinene), terpinen-4-ol (5.0% and 5.3%; predominantly (+)-terpinen-4-ol), and methyl myrtenate (2.0% and 5.4%). The major components in T. plicata essential oil were (−)-α-thujone (67.1–74.6%), (+)-β-thujone (7.8–9.3%), terpinen-4-ol (2.7–4.4%; predominantly (+)-terpinen-4-ol), and (+)-sabinene (1.1–3.5%). The major components in T. heterophylla essential oil were myrcene (7.0–27.6%), α-pinene (14.4–27.2%), β-phellandrene (6.6–19.3%), β-pinene (6.4–14.9%; >90% (−)-β-pinene), and (Z)-β-ocimene (0.7–11.3%). There are significant differences between the C. lawsoniana essential oils from wild trees in Oregon and those of trees cultivated in other geographical locations. The essential oil compositions of T. plicata are very similar, regardless of the collection site. There are no significant differences between T. heterophylla essential oils from the Oregon Coastal Range or those from the Oregon Cascade Range. Comparing essential oils of the Cupressaceae with the Pinaceae, there are some developing trends. The (+)-enantiomers seem to dominate for α-pinene, camphene, sabinene, β-pinene, limonene, terpinen-4-ol, and α-terpineol in the Cuppressaceae. On the other hand, the (−)-enantiomers seem to predominate for α-pinene, camphene, β-pinene, limonene, β-phellandrene, terpinen-4-ol, and α-terpineol in the Pinaceae. [ABSTRACT FROM AUTHOR]

Background Myrcene and cymene, aromatic monoterpenes found in plants and essential oils, possess distinctive aromatic qualities. However, their volatility and limited solubility pose challenges in precise handling and formulation. Meanwhile, nanoemulsions emerge as promising drug delivery systems, improving the bioavailability and stability of these active ingredients. Objective This article aimed to develop an HPLC method for the quantification of two monoterpenoids, p-cymene and myrcene, in nanoemulsions. Method The method used a Phenomenex® Synergi™ Fusion-RP column (150 mm × 4.6 mm id, 4 μm particle size) on an HPLC system with isocratic elution. The mobile phase was composed of acetonitrile and water (60:40, v/v) and was validated in terms of specificity, linearity, accuracy, precision, robustness, and selectivity. Results The method provided accurate and precise results with a correlation coefficient of 0.999 and RSD values of less than 2%. The method can be used for quality control of nanoemulsions containing these monoterpenoids and as a reference for future studies on their efficacy and stability. Conclusions The study demonstrates the feasibility of using HPLC for the quantification of monoterpenoids in nanoemulsions and its potential as a quality control tool for nanoemulsion-based drug delivery systems. Highlights The method's accuracy, precision, and reliability, as evidenced by high correlation coefficients and low RSD values, underscore its suitability for ensuring the consistent formulation of these monoterpenoid-containing nanoemulsions, while also serving as a reference point for future research endeavors in this field. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the effect of drying on the aroma profile and bioactivity of Cinnamomum camphora L. leaf. Clevenger was used to extract essential oils and were analyzed by GC and GC-MS. Principal component analysis (PCA) was used to visualize the variance in the aroma profile. These oils were tested for their antioxidant and anti-inflammatory potential. Fresh oil was found to be rich in camphor, limonene, α-pinene and myrcene. Camphor, limonene and α-pinene were the major constituents of all the oils under different drying conditions. The content of camphor increased significantly upon drying. Shade drying could be used as the most prominent drying method for C. camphora L. as it was found to have the highest camphor content (67.30 %), essential oil yield (0.34 %) and in-vitro anti-inflammatory activity potential (IC50: 7.46 μg mL−1). Monoterpene hydrocarbons might be responsible for the antioxidant activity. [ABSTRACT FROM AUTHOR]

Background/Objective: Wyethia amplexicaulis (shiny mule's ears) and Wyethia helianthoides (white-head mule's ears) are conspicuous forbs growing in open hillsides and prairies at mid to upper elevations in the Intermountain West region of the United States. There have been no previous reports on the essential oil compositions of any Wyethia species, so the objective of this study is to examine the chemical compositions, including enantiomeric distribution of chiral terpenoids, of W. amplexicaulis and W. helianthoides from southern Idaho. Methods: Three individual samples of W. amplexicaulis and W. helianthoides were collected, and the essential oils were obtained by hydrodistillation using a Likens-Nickerson apparatus and analyzed by gas chromatography coupled with mass spectrometry (GC-MS), gas chromatography with flame ionization detection, and enantioselective GC-MS. Results: The essential oils were obtained in yields of 0.090% to 0.136% and 1.489% to 1.771% for W. amplexicaulis and W. helianthoides, respectively. The three W. helianthoides samples showed high similarity with (−)-germacrene D (16.5%-21.5%), (E)-β-ocimene (10.0%-14.3%), myrcene (8.6%-12.4%), α-pinene (6.3%-7.3%, ≥ 95% (+)-α-pinene), 15-copaenol (4.3%-6.0%), and carotol (3.5%-5.9%) as the major components. The W. amplexicaulis essential oils, on the other hand, showed variation. Two samples were rich in monoterpene hydrocarbons, mostly myrcene (22.4% and 32.2%), while the third sample was dominated by oxygenated sesquiterpenoids, 15-copaenol (11.4%), carotol (10.0%), silphiperolan-7β-ol (8.2%), and caryophyllene oxide (5.8%). This is the first investigation of Wyethia essential oils. Conclusions: There are 11 recognized Wyethia species, so additional research is needed to understand the volatile phytochemicals present in this genus. [ABSTRACT FROM AUTHOR]

In order to face the environmental concern about the use of traditional fossil‐based monomers for the production of thermosetting resins, herein this study reports the synthesis of bio‐based materials from waste cooking oil (WCO). In this context, this study explores the epoxidation‐acrylation strategy for the synthesis of the starting functionalized oil for the production of thermosetting resins composed of only WCO‐derived monomers or in combination with terpenic comonomers such as limonene and myrcene. Furthermore, employing myrcene as comonomer produces thermosetting resins that reveal the best properties in terms of mechanical strength if compared to the homopolymer ones. [ABSTRACT FROM AUTHOR]

The two‐electron reduction of 2,3‐dimethylbuta‐1,3‐diene (DMB) with β‐diketiminate and guanidinate substituted dimagnesium(I) compounds has given complexes in which two bidentate amido‐magnesium fragments are bridged through the π‐system of the DMB dianion, viz. [(LMg)2(μ‐DMB)] (L=XylNacnac, [HC(MeCNXyl)2]−, Xyl=2,6‐xylyl; or Priso=[(DipN)2CNPri2]−, Dip=2,6‐diisopropylphenyl). Similar double reductions of [4]dendralene (4dend) have afforded the complexes, [(LMg)2(μ‐4dend)] (L=ArNacnac, Ar=Xyl or mesityl (Mes); or Priso) in which the 4dend dianion is π‐coordinated to the bidentate amido‐magnesium fragments. Treatment of several such complexes with THF leads to Z‐ to E‐isomerization of the dendralene fragment, and formation of purely σ‐bonded Mg−C interactions in the THF coordinated products [{(ArNacnac)(THF)Mg}2(μ‐4dend)] (Ar=Xyl, Mes or Dip). Reaction of myrcene (Myr) with [{(XylNacnac)Mg}2] proceeds via reductive coupling of Myr to give a previously unknown acyclic, branched C20 tetra‐olefin dianion complex [{(XylNacnac)(THF)Mg}2(μ‐Myr)2]. Preliminary reactions of [(LMg)2(μ‐DMB)] with H2 and/or CO yielded a series of products, including novel magnesium hydride compounds, products derived from couplings of CO with the reduced DMB fragment (viz. magnesium dimethylcyclohexadienediolates), and one magnesium cyclopropanetriolate complex from the magnesium(I) induced coupling of DMB with H2 and CO. [ABSTRACT FROM AUTHOR]

Background: Sedative agents are utilized to mitigate stress and improve fish welfare during and after transportation. Objectives: We aimed to assess the effects of myrcene addition to the transportation water on the plasma biochemical profile of common carp, Cyprinus carpio. Methods: For this purpose, common carp (mean weight of 45.3±1.65 g) were transported in plastic bags containing myrcene at concentrations of 0 (CTL), 10 (10 M), 20 (20 M), 30 (30 M), and 50 (50 M) μL/L for 6 h. Then, their plasma parameters were compared to those values before transportation (BT). Results: Transportation significantly (P<0.05) decreased plasma total protein, albumin, alternative complement, lysozyme, sodium, and chloride, while increasing potassium, calcium, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase in the CTL treatment, as compared to BT. Adding 50 μL/L myrcene to water prevented total plasma protein and albumin loss. Supplementing 20 μL/L myrcene to water prevented or reduced the changes in plasma ions, alanine aminotransferase, and alkaline phosphatase. Addition of 10-50 μL/L myrcene to water decreased the changes in plasma aspartate aminotransferase. Adding 20 and 30 μL/L myrcene to water mitigated the changes in plasma alternative complement, as 30 μL/L myrcene increased plasma lysozyme activity. Transportation and myrcene addition had no significant effects on plasma immunoglobulin (P>0.05). However, a significant increase was observed in plasma globulin in the 20 M treatment (P<0.05). Conclusion: In summary, adding 20 μL/L myrcene to the transport water of common carp reduced hepatic enzyme levels and improved immune parameters, and therefore, the use of myrcene improves fish welfare during transportation. [ABSTRACT FROM AUTHOR]

Monoterpenes are among the important natural plant terpenes. Monoterpenes usually have the characteristics of volatility and strong aroma. β-Myrcene and its isomer (E)-β-ocimene are typical acyclic monoterpenes. They are high-value monoterpenes that have been widely applied in foods, cosmetics, and medicines. However, large-scale commercial production of β-myrcene and (E)-β-ocimene is restricted by their production method that mainly involves extraction from plant essential oils. Currently, an alternative synthetic route utilizing an engineered microbial platform was proposed for effective production. This study used a Saccharomyces cerevisiae strain previously constructed for squalene production as the starting strain. Farnesyl diphosphate synthase (Erg20) expression was weakened by promoter replacement and screened for optimal myrcene synthase (MS) and ocimene synthase (OS) activities. In the resulting S. cerevisiae engineered for β-myrcene and (E)-β-ocimene synthesis, titers of β-myrcene and (E)-β-ocimene were enhanced by a fusion expressing a mutant Erg20* with the obtained monoterpene synthase and optimizing the added solvent in a two-phase fermentation system. Finally, by scaling up in a 5-L fermenter, 8.12 mg/L of β-myrcene was obtained, which was first reported in yeast, and 34.56 mg/L of (E)-β-ocimene was obtained, which is the highest reported to date. This study provides a new synthesis route for β-myrcene and (E)-β-ocimene. [ABSTRACT FROM AUTHOR]

In this study, electronic nose (E-nose), electronic tongue (E-tongue) and Headspace solid phase microextrac-tion-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with relative odor activity value (ROAV) were used to evaluate the volatile components and key aroma components of Xinjiang pilaf. The results show that the electronic nose can effectively distinguish the volatile components in different Xinjiang pilaf; the electronic tongue cannot effectively distinguish the taste of different Xinjiang pilaf. A total of 132 volatile compounds were detected by HS-SPME-GC-MS, including 25 alkanes, 16 olefins, 27 aldehydes, 26 alcohols, 11 ketones, 9 esters, 15 phenols and 3 other compounds. A total of 39 common volatile flavor compounds were detected. Combined with ROAV analysis, Myrcene, Caryophyllene, (E,Z)-2,4-decadienal, 4-(1-methylethyl)-Benzaldehyde, 4-Isopropylcyclohexa-1,3-dienecarbaldehyde, (E,E)-2, 4-decadienal, (E)-2-Decenal, Nonanal, (E)-2-nonenal, beta-Ionone were the key aroma substance of Xinjiang pilaf. [ABSTRACT FROM AUTHOR]

Aedes mosquito-borne diseases remain a significant global health threat, necessitating effective control strategies. This study introduces monoterpenes-based nanohydrogels for potential use as repellents against Aedes aegypti, the primary dengue vector worldwide. We formulated hydrogels using cymene- and myrcene-based nanoemulsions with different polymers: chitosan, carboxymethylcellulose (CMC), and carbopol®. Our evaluations of rheological, texture, and bioadhesive properties identified CMC hydrogel as the most promising gelling agent for topical application, exhibiting sustained monoterpene release over 12 h with low skin permeation and high retention in the stratum corneum. Myrcene-loaded CMC hydrogel achieved a 57% feeding deterrence compared to 47% with cymene hydrogel in the mosquito membrane-feeding model. Molecular docking studies revealed interactions between myrcene and an essential amino acid (Ile116) in the Ae. aegypti odorant-binding protein 22 (AeOBP22), corroborating its higher repellent efficacy. These findings suggest that myrcene-loaded CMC hydrogels offer a promising, minimally invasive strategy for personal protection against Ae. aegypti and warrant further investigation to optimize monoterpene concentrations for vector control.

Myrcene, as a kind of conjugated diene from plants, its unique side chain and double bond structure on side chain provided a new way for the synthesis of new materials. This article introduced the research progress of homopolymerization and co-polymerization of myrcene with other monomers, as well as the application of myrcene in preparation of new materials, and prospected its development trend with 25 references.

Introduction: The genus Myrcianthes ranges from southern Florida to Chile, including the Caribbean, and the species Myrcianthes storkii is a shrub or tree found in Costa Rica and western Panama, in wet to very rainy, cloud, and oak forests (altitude 1300-3150m). Objective: To identify the chemical composition of essential oils from leaves, floral buds, and twigs of M. storkii of Costa Rica. Methods: We obtained the essential oils through hydrodistillation in a Clevenger-type apparatus. The chemical composition of the oils was done by GC/FID and GC/MS, using the retention indices on DB-5 and Carbowax types of capillary columns in addition to mass spectra. Results: The oils consisted mainly of terpenoids (55,45-87,75%). A total of 281 compounds accounted for 91,27-74,56% of the total amount of oils. The major constituents from the leaf oil were myrcene (17,44%), cis-calamenene (12,60%), α-pinene (5,48%), (E)-caryophyllene (5,16%), limonene (3,91%), p-cymene (3,71%), 1,8-cineole (2,80%), and α-humulene (2,80%). The floral bud essential oil consisted mainly of α-pinene (15,23%), cis-calamenene (12,70%), myrcene (8,59%), 1,8-cineole (4,26%), germacrene B (3,65%), α-humulene (3,55%), and (E)-caryophyllene oxide (2,93%). The major components of twig oil were cis-calamenene (11,31%), palmitic acid (7,99%), (E)-caryophyllene (4,68%), -cadinene (3,28%), cubenol (3,24%), and (Z)-caryophyllene oxide (2,94%). Conclusion: The presence of a significant quantity of myrcene and cis-calamenene seems to be characteristic of this species.

Cobalt complexes carrying 2‐acetyl‐6‐iminopyridine ligand are synthesized and characterized. Single‐crystal X‐ray diffraction reveals the cobalt ion is chelated with two nitrogen atoms and an acetyl oxygen atom additionally. A significant prolonged Co–O distance (2.3960(57) Å) is found, indicative of a labile character. Activated by diethylchloroaluminum, all complexes show high conversion rates for isoprene and myrcene polymerizations, affording cis‐1,4/3,4 regulated 1,3‐diene polymers. The polymerization of butadiene, interestingly, gives predominant cis‐1,4 selectivity (>99.2%) with moderate activity. The substituent at ortho‐position of arylimine plays a minor role in controlling activity and selectivity as well as the molecular weight of the resultant polymers. The properties of resultant poly(1,3‐diene)s are stable even in a wide range of operational conditions, such as [Al]/[Co] varied from 20 to 600, temperature spanning from 0°C to 60°C, and monomer–catalyst ratio from 1000 to 4000. These additional benefits of minimum fluctuation in catalytic performances may be suitable for industrial polymerization process. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the variation in essential oil content and composition within nine distinct Ukrainian hop varieties, with a particular focus on their genetic stability and suitability for brewing applications over 11 years of their cultivation. The hydrodistillation method (Analytica-EBC 7.10) was used to evaluate hop essential oil content and gas-liquid capillary chromatography (Analytica-EBC 7.12) to discern its qualitative composition. Variability was evaluated using statistical parameters. The essential oil content across the studied varieties spanned from 0.51 to 2.58 ml/100 g of dry hop cones. The highest content was measured in the bitter-aroma variety with a special aroma - Ruslan. The predominant essential oil components, including myrcene, caryophyllene, humulene, and farnesene, collectively constituted 70.0-84.2% of the total amount. The aroma varieties displayed myrcene content typical for European varieties (with the level up to 56.2% in the Ruslan variety). Farnesene content exhibited significant variation ranging from 0.3 to 17.6% with the highest content in Saaz-type varieties (Klon 18, Zlato Polissya, and National) and the bitter type Promin variety. Humulene content ranged from 13.2 to 32.6%. Among all studied varieties, Alta displayed the least variability for all parameters evaluated (Cv = 15.2%). This study underscores the genetic basis of essential oil composition in hops, emphasizing its potential as a biochemical criterion for identifying hop breeding varieties. The study revealed, that despite annual fluctuations, the essential oil content and composition remained within passport data declared for the variety. The findings provide valuable insight into a sustainable cultivation and optimal utilization of hops in the brewing industry. [ABSTRACT FROM AUTHOR]

Bio-fuel produced from inexpensive organic waste is a renewable alternative eco-friendly energy source compared to hazardous fossil fuel. Organic wastes contain significant amount of carbohydrates when subjected to acid hydrolysis, yield fermentable sugar wort. Organic waste collected from various source was converted into fermentable sugar by acid hydrolysis carried out using different concentration (2%, 6% and 10%) of sulphuric acid. Sugar wort thus obtained was converted to ethanol by fermentation process using Saccharomyces cerevisiae. The maximum yield of 36.2 ml bio-ethanol was obtained from sample hydrolyzed with 10% sulphuric acid. The minimum yield of 17.3 ml bio-ethanol was obtained from sample hydrolyzed with 2% sulphuric acid. Considering the quantity of ethanol yield from the biomass, it is concluded that food waste is a potential source for the production of ethanol under optimum preprocess. [ABSTRACT FROM AUTHOR]

Phytochemicals derived from plants can act as larvicides, insect growth regulators and repellents. They can play an important role in the interruption of the transmission of mosquito borne diseases. Essential oils are rich source of bioactive monoterpenoids against insects. Curcuma longa L. (Zingiberaceae) is well known for its medicinal values and contain pungent and odoriferous oils. Among the various genotypes of C. longa maintained at this institute, 25 genotypes were screened for insecticidal activities against two mosquito species and genotype CH-66 was found to be active. Therefore, leaf essential oil of this genotype was studied for toxic effects against eggs and larvae of two mosquito species, Anopheles stephensi and Aedes aegypti. The leaf essential oil was obtained by hydrodistillation and analyzed by gas chromatography. The leaf oil rich in compound myrcene (40.19%) gave 100% larvicidal activity at 0.25 and 0.30 mg/ml against A. stephensi and A. aegypti with LC50 of 0.12 and 0.14 mg/ml, respectively. However, chlorpyrifos taken as positive control gave LC50 of 0.0013 and 0.0014 mg/ml against A. stephensi and A. aegypti, respectively The effective concentration (EC50) to inhibit 50% egg viability was observed to be 0.27 and 0.29 mg/ml for A. stephensi and A. aegypti, respectively. Since only rhizome part of C. longa is currently used, bioactivities of the leaf may find use as leads in controlling vectors spreading dreadful diseases like malaria and dengue fever. [ABSTRACT FROM AUTHOR]

γ-terpinene, α-terpinene, p-cymene, and myrcene are monoterpenes found in many essential oils extracted from a variety of plants and spices. Myrcene also occurs naturally in plants such as hops, cannabis, lemongrass, and verbena and is used as a flavoring agent in food and beverage manufacturing. In this research, the biological efficacy of γ-terpinene, α-terpinene, p-cymene, and myrcene was studied in human cell lines (HeLa, SH-SY5Y, and HDFa). Cytotoxicity, cell proliferation, cell migration, and morphology assays were performed to obtain detailed information on the anticancer properties. Our results show that myrcene has potential biological activity, especially in HeLa cells. In this cell line, it leads to an arrest of proliferation, a decrease in motility and morphological changes with loss of sphericity and thickness, and DNA damage. In addition, the interaction of γ-terpinene, α-terpinene, p-terpinene, and myrcene with calf thymus DNA (ct-DNA) was studied by UV-visible spectrophotometry. DNA binding experiments show that only myrcene can interact with DNA with an apparent dissociation constant (Kd) of 29 × 10−6 M. [ABSTRACT FROM AUTHOR]

Myrcene can be used as a versatile starting material for a myriad product for various applications. The drawbacks of the available myrcene separation techniques promote the investigation of application of environmentally clean, faster, more powerful, and cheaper methods. The combination of microwave heating system and application of urea in hydrotropic-based distillation of myrcene-rich essential oil of Cymbopogon Citratus was investigated in this work. A mathematical model of microwave assisted hydrotropic distillation (MAHtD) of essential oil based on the diffusion-control assumption is also proposed and validated. The MAHtD of C. citratus were performed by varying urea concentrations (20-30%) and temperature (105-110°C). The essential oil composition as well as its concentration were analyzed and determined by applying GC-MS. Research result shows that urea is proved as a good hydrotrop for MAHtD of myrcene–rich essential oil of C. citratus. MAHtD performed with 25% urea at a temperature of 105°C for 10 minutes gives a high myrcene content of up to 53.53%. The obtained myrcene–rich essential oil of C. citratus can be investigated for its utilization in various types of applications. Moreover, the proposed model was validated with the experimental data of MAHtD performed at a solid-liquid ratio of 1:10, 25% urea solution, and a temperature of 105°C. The experimental data show a good agreement with the proposed model with SSE of 0.033. The obtained effective diffusivity of the essential oil and the Henry constant in which essential for industrial scale-up process are 2.245 and 0.42,, respectively. The effective diffusivity value was higher than those obtained from hydro distillation and microwave-assisted hydro distillation of other essential oil, which shows that urea, is a good solubilizing agent for C. citratus essential oil.

Being widely used, medicinal products based on vegetable oils require strict regulation and evaluation of quality attributes, determination of shelf-life periods, and monitoring of storage conditions. The most common testing method for unsaturated compounds in vegetable oils is the iodine value determination, which has a range of limitations. An alternative method for determining the degree of unsaturation is based on epoxidation.The aim of the study was to evaluate the possibility of determining the degree of unsaturation of terpenoids and essential oils using peroxycarboxylic acids.Materials and methods. The authors performed epoxidation of linalool, myrcene, and lemon oil with peroxydecanoic and peroxyoctanoic acids, followed by iodometric titration of the excess acid.Results. The study demonstrated the possibility of measuring the degree of unsaturation of the selected essential oil and terpenoids using peracid epoxidation. The authors developed a procedure for determining the iodine value of essential oils and calculated the iodine values of linalool, myrcene, and lemon oil. Epoxidation proceeded as a second-order reaction. The authors obtained the following reaction rate constants: 3.9 L×mol–1×min–1 for linalool (298 К), 1.76 L×mol–1×min–1 for myrcene converting to monoxide (298 К), 0.044 L×mol–1×min–1 for myrcene epoxide converting to diepoxide (298 К), and 3.9 L×mol–1×min–1 for lemon oil (297 К).Conclusions. The suggested procedure involving peracid titration for rapid and efficient determination of the degree of unsaturation (iodine value) provides a potential basis for developing a quantification method for total unsaturated bioactive compounds in essential oils.

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 interest in the production of hops in Brazil, motivated by the third position in the world ranking of beer producers and the growth of the craft brewery business, justifies the intensification of studies into its adaptation to local growing conditions. Due to the high internal demand, the aim of this study was to evaluate the phytochemical profiles of hop varieties grown in subtropical conditions under different cropping systems. Studies that promote the expansion of cultivation areas in distinct climate conditions and ensure quality are very important. A randomized block design was adopted with a 2 × 5 subdivided plot. The main factor was the cropping system (organic and conventional), and the secondary factor was the hop variety (Columbus, Chinook, Nugget, Cascade and Hallertau Mittelfrüeh), with four blocks and four plants per plot. The quality parameters monitored in this work were the contents of alpha and beta acids, and xanthohumol in the inflorescences of hops, as well as the relative composition of their essential oils. The variations in the chemical profiles of essential oils showed differences between some varieties, and the different compositions and levels resulting from the two cropping systems show that management and cultural practices can influence the aromatic characteristics of hops; in total, 23 compounds were found. The terpene fraction represented 79.67% of the oil in Hallertau and 93.63% in Cascade, with myrcene being the main compound. The levels of bitter acids and xanthohumol did not differ statistically as a function of the treatments. This study contributes the first records of the chemical profiles of hops grown in subtropical conditions in Brazil, in general, the Nugget variety had the highest qualitative potential [ABSTRACT FROM AUTHOR]

Microbial synthesis of plant-based myrcene is of great interest because of its high demand, however, achieving high biosynthetic titers remains a great challenge. Previous strategies adopted for microbial myrcene production have relied on the recruitment of a multi-step biosynthetic pathway which requires complex metabolic regulation or high activity of myrcene synthase, hindering its application. Here, we present an effective one-step biotransformation system for myrcene biosynthesis from geraniol, using a linalool dehydratase isomerase (LDI) to overcome these limitations. The truncated LDI possesses nominal activity that catalyzes the isomerization of geraniol to linalool and the subsequent dehydration to myrcene in anaerobic environment. In order to improve the robustness of engineered strains for the efficient conversion of geraniol to myrcene, rational enzyme modification and a series of biochemical process engineering were employed to maintain and improve the anaerobic catalytic activity of LDI. Finally, by introducing the optimized myrcene biosynthetic capability in the existing geraniol-production strain, we achieve de novo biosynthesis of myrcene at 1.25 g/L from glycerol during 84 h aerobic-anaerobic two-stage fermentation, which is much higher than previously reported myrcene levels. This work highlights the value of dehydratase isomerase-based biocatalytic in establishing novel biosynthetic pathways and lays a reliable foundation for the microbial synthesis of myrcene. [Display omitted] • LDI catalyzes the isomerization of the geraniol to linalool and also its dehydration to myrcene in anaerobic environment. • Induction temperature and biocatalytic conditions of LDI are critical for its functionality. • G132A and S123H mutations result in increased activity of LDI against geraniol. • De novo biosynthesis of myrcene at 1.25 g/L from glycerol through an aerobic-anaerobic two-stage fermentation. [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]

Hybrid non‐isocyanate poly(urethanes) (HNIPUs) are designed from a precursor whose carbonate functionality is derived from epoxy‐functional statistical copolymers. Specifically, a bio‐based diene (β‐myrcene) is copolymerized via conventional free radical polymerization with glycidyl methacrylate (GMA) at different molar ratios, producing flexible copolymers with epoxy pendant groups, which are then reacted with carbon dioxide to yield the precursors with cyclic carbonate functionality. Subsequent addition of an amine‐terminated telechelic poly(propylene glycol) (PPG) forms urethane linkages in the side chains, whose concentration is tuned by varying the GMA initial molar fraction. The NIPUs are end‐capped with silanes to enable moisture curing, resulting in HNIPUs with elongations at break up to 150%, and relatively low elastic moduli varying from 32 kPa to 50 kPa as the number of urethane side linkages increases from 6 to 22. The swelling ratio of the NIPUs is also measured in tetrahydrofuran (THF). As the number of urethane side chains increases, the swelling ratio of the NIPUs decreases (710% to 620%), indicating a higher crosslinking density. All samples have gel contents higher than 50% in THF, indicating non‐crosslinked species in the hybrid samples which confirms the relatively low reported tensile moduli. [ABSTRACT FROM AUTHOR]

Myrcene can be used as a versatile starting material for a myriad product for various applications. The drawbacks of the available myrcene separation techniques promote the investigation of application of environmentally clean, faster, more powerful, and cheaper methods. The combination of microwave heating system and application of urea in hydrotropic-based distillation of myrcene-rich essential oil of Cymbopogon Citratus was investigated in this work. A mathematical model of microwave assisted hydrotropic distillation (MAHtD) of essential oil based on the diffusion-control assumption is also proposed and validated. The MAHtD of C. citratus were performed by varying urea concentrations (20-30%) and temperature (105-110°C). The essential oil composition as well as its concentration were analyzed and determined by applying GC-MS. Research result shows that urea is proved as a good hydrotrop for MAHtD of myrcene–rich essential oil of C. citratus. MAHtD performed with 25% urea at a temperature of 105°C for 10 minutes gives a high myrcene content of up to 53.53%. The obtained myrcene–rich essential oil of C. citratus can be investigated for its utilization in various types of applications. Moreover, the proposed model was validated with the experimental data of MAHtD performed at a solid-liquid ratio of 1:10, 25% urea solution, and a temperature of 105°C. The experimental data show a good agreement with the proposed model with SSE of 0.033. The obtained effective diffusivity of the essential oil and the Henry constant in which essential for industrial scale-up process are 2.245x10-7cm²/s and 0.42,, respectively. The effective diffusivity value was higher than those obtained from hydro distillation and microwave-assisted hydro distillation of other essential oil, which shows that urea, is a good solubilizing agent for C. citratus essential oil. [ABSTRACT FROM AUTHOR]

Antifungal effects of myrcene, the plant-based naturel compound, were investigated on Fusarium graminearum PH-1 and Fusarium culmorum FcUK99 references, for the first time. Minimum inhibitory concentration (MIC) and half of MIC (MIC50) of both Fusarium strains against myrcene were found as 25 µg/µl and 12.5 µg/µl, respectively. MIC50 application decreased the cell viabilities in the ratios of 34.90% and 33.91% in PH-1 and FcUK99, respectively (p < 0.01). The significantly increased catalase (CAT) activity was recorded in MIC50 treated strains (p < 0.01). Apoptosis-like process and cellular oxidative stress were also monitored with acridine orange/ethidium bromide (Ao/Eb) dual staining and 2′,7′-dichlorodihydrofluorescein diacetate (DCF-DA) staining. The genomic template stability (GTS) percentages were calculated as 79% for PH-1 and 71% for FcUK99 via random amplified polymorphic DNA (RAPD). Methylation polymorphism values were calculated as 53.8% and 50.6% in PH-1 and 40.4% and 39% in FcUK99 for HapII and MspI, respectively by coupled restriction enzyme digestion-random amplification (CRED-RA). Methylation-sensitive amplified polymorphism (MSAP) revealed that myrcene caused both type I and type III epigenetic modifications in both genomes. MIC50 dose caused up to 13.86 ± 0.42-fold changes in the expressions of cat, mst20, and stuA, whereas downregulation in tri5 was recorded. Myrcene application did not change the retrotransposon movement in both species by the amplifying of idiomorphic retrotransposon patterns through inter-retrotransposon polymorphism-polymerase chain reaction (IRAP-PCR). This study demonstrated that myrcene is an effective compound in the management of phytopathogenic Fusarium species by causing morphological, genetic, epigenetic, and cellular alterations, and has a potential to utilize as an antifungal agent. [ABSTRACT FROM AUTHOR]

Hedyosmum purpurascens is an endemic species found in the Andes of Ecuador and it is characterized by its pleasant smell. In this study, essential oil (EO) from H. purpurascens was obtained by the hydro-distillation method with a Clevenger-type apparatus. The identification of the chemical composition was carried out by GC–MS and GC–FID in two capillary columns, DB-5ms and HP-INNOWax. A total of 90 compounds were identified, representing more than 98% of the total chemical composition. Germacrene-D, ϒ-terpinene, α-phellandrene, sabinene, O-cymene, 1,8-cineole and α-pinene accounted for more than 59% of the EO composition. The enantioselective analysis of the EO revealed the occurrence of (+)-α-pinene as a pure enantiomer; in addition, four pairs of enantiomers were found (α-phellandrene, o-cymene, limonene and myrcene). The biological activity against microbiological strains and antioxidants and the anticholinesterase properties were also evaluated and the EO showed a moderate anticholinesterase and antioxidant effect, with an IC50 value of 95.62 ± 1.03 µg/mL and a SC50 value of 56.38 ± 1.96. A poor antimicrobial effect was observed for all the strains, with MIC values over 1000 µg/mL. Based on our results, the H. purpurasens EO presented remarkable antioxidant and AChE activities. Despite these promising results, further research seems essential to validate the safety of this medicinal species as a function of dose and time. Experimental studies on the mechanisms of action are essential to validate its pharmacological properties. [ABSTRACT FROM AUTHOR]

Mastic oil (MO) is extracted from the resin of the bark of Pistacia lentiscus var. chia, a tree abundantly grown in the Greek island of Chios. Various biological activities, such as antimicrobial, anticancer and antioxidant, have been associated with the dietary intake of MO. However, little is known about MO's potential anti-inflammatory effects, while some of its main chemical constituents were reported to exert significant anti-inflammatory activity. This study aims to assay the bioactivity of MO on in vitro and in vivo experimental inflammation models, in particular on LPS-stimulated RAW264.7 macrophages, murine primary peritoneal macrophages and a model of zymosan-induced peritonitis in BALB/c mice. The per os administration of MO inhibited the recruitment of macrophages into the peritoneal cavity of zymosan-treated mice, but did not affect neutrophil mobilisation or the levels of IL-6 or TNF-α in the peritoneal fluid. Similarly, IL-6 and TNF-α secretion in primary LPS-stimulated macrophages was not affected by MO, but the levels of phosphoproteins that activate inflammation in macrophages were differentially regulated. Finally, MO and some of its individual constituents reduced nitric oxide (NO), prostaglandin E2 and TNF-α levels in supernatants of LPS-stimulated RAW264.7 cells and inhibited their phagocytosis rate. Our data imply that MO may promote an anti-inflammatory transition in macrophages due to the combined bioactivities of its individual constituents. Thus, as a mixture of various compounds, MO seems to affect multiple molecular mechanisms that are involved in the development of inflammation. Therefore, more research, focusing on MO's individual constituents and employing various pre-clinical inflammation models that activate different mechanisms, is required for a detailed investigation of the oil's potential anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

Ultrafine fiber membranes of polylactic acid (PLA) 8% (w/v) loaded with pink pepper essential oil (PPEO) in 10, 20 and 30% (w/v) were produced and evaluated for antimicrobial potential against the bacteria Escherichia coli, Salmonella enteritidis, Listeria monocytogenes and Staphylococcus aureus. The membranes were applied in simulated cream cheese packaging and characterized by morphological, thermal, structural, antimicrobial and wettability analysis. The addition of PPEO reduced the diameter of fibers and increased the initial degradation temperature in relation to pure PPEO. The PPEO presented myrcene as major component and had antimicrobial action for S. aureus and L. monocytogenes. The membranes applied to the cream cheese packaging showed inhibitory effect on the 21st day of storage, for L. monocytogenes. For S. aureus, the membranes inhibited the growth of the colonies on days 14 and 21, with reductions of 30 and 62%, respectively. Finally, the ultrafine membranes had hydrophobic character. Highlights: Protective thermal effect of PLA on PPEO Membranes of ultrafine fibers showed hydrophobicity Potential action of PPEO volatile compounds in reducing bacteria Antimicrobial effect of membranes in simulated cream cheese packaging [ABSTRACT FROM AUTHOR]

The development of PVC materials grafted with mannich base originated from myrcene (P-MAM-g, where the mannich base derived from myrcene is abbreviated as MAM) via green and effective synthetic methods is a good strategy to avoid unacceptable discoloration and deterioration of thermal and mechanical properties caused by autocatalytic dehydrochlorination (DHC) during PVC processing. In this study, MAM with double bonds, amino groups, ester groups, and phospholipid groups was introduced into the chains of PVC to improve the thermal stability of PVC. The experimental results showed that the covalent attachment of MAM to PVC enhanced both the initial and the long-term stability of PVC. The enhanced performance of P-MAM-g compared with unmodified PVC is attributed to the simultaneous introduction of double bonds and amino groups into the PVC structure. The double bonds trapped the unstable chlorine atoms originated from the degradation of the PVC chain and reacted with the labile macromolecular radicals originated from PVC, thus inhibiting the radical degradation of the PVC chain. Furthermore, the amino groups absorbed the HCl produced in the degradation of PVC, inhibiting the adverse effects of HCl. P-MAM-g displayed better intrinsic flexibility and anti-migration ability of organic functional components compared with the control PVC materials. A possible stabilizing mechanism of the P-MAM-g was also presented. [ABSTRACT FROM AUTHOR]

Background and Objectives: Nutraceuticals are gaining more and more importance as a knee osteoarthritis (KOA) complementary treatment. Among nutraceuticals, hemp seed oil and terpenes are proving to be very useful as therapeutic support for many chronic diseases, but there are still few studies regarding their effectiveness for treating KOA, both in combination and separately. The aim of this study is thus to compare the effect of two dietary supplements, both containing hemp seed oil, but of which only one also contains terpenes, in relieving pain and improving joint function in patients suffering from KOA. Materials and Methods: Thirty-eight patients were recruited and divided into two groups. The control group underwent a 45 day treatment with a hemp seed oil-based dietary supplement, while the treatment group assumed a hemp seed oil and terpenes dietary supplement for the same period. Patients were evaluated at the enrollment (T0) and at the end of treatment (T1). Outcome measures were: Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), Short-Form-12 (SF-12), Knee Injury Osteoarthritis Outcome Score (KOOS), and Oxford Knee Score (OKS). Results: All outcome measures improved at T1 in both groups, but NRS, KOOS and OKS had a greater significant improvement in the treatment group only. Conclusions: Hemp seed oil and terpenes resulted a more effective integrative treatment option in KOA, improving joint pain and function and representing a good complementary option for patients suffering from osteoarthritis. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, resulting in motor deficits. The exact etiology of PD is currently unknown; however, the pathological hallmarks of PD include excessive production of reactive oxygen species, enhanced neuroinflammation, and overproduction of α-synuclein. Under normal physiological conditions, aggregated α-synuclein is degraded via the autophagy lysosomal pathway. However, impairment of the autophagy lysosomal pathway results in α-synuclein accumulation, thereby facilitating the pathogenesis of PD. Current medications only manage the symptoms, but are unable to delay, prevent, or cure the disease. Collectively, oxidative stress, inflammation, apoptosis, and autophagy play crucial roles in PD; therefore, there is an enormous interest in exploring novel bioactive agents of natural origin for their protective roles in PD. The present study evaluated the role of myrcene, a monoterpene, in preventing the loss of dopaminergic neurons in a rotenone (ROT)-induced rodent model of PD, and elucidated the underlying mechanisms. Myrcene was administered at a dose of 50 mg/kg, 30 min prior to the intraperitoneal injections of ROT (2.5 mg/kg). Administration of ROT caused a considerable loss of dopaminergic neurons, subsequent to a significant reduction in the antioxidant defense systems, increased lipid peroxidation, and activation of microglia and astrocytes, along with the production of pro-inflammatory cytokines (IL-6, TNF-α, IL-1β) and matrix metalloproteinase-9. Rotenone also resulted in impairment of the autophagy lysosomal pathway, as evidenced by increased expression of LC3, p62, and beclin-1 with decreased expression in the phosphorylation of mTOR protein. Collectively, these factors result in the loss of dopaminergic neurons. However, myrcene treatment has been observed to restore antioxidant defenses and attenuate the increase in concentrations of lipid peroxidation products, pro-inflammatory cytokines, diminished microglia, and astrocyte activation. Myrcene treatment also enhanced the phosphorylation of mTOR, reinstated neuronal homeostasis, restored autophagy-lysosomal degradation, and prevented the increased expression of α-synuclein following the rescue of dopaminergic neurons. Taken together, our study clearly revealed the mitigating effect of myrcene on dopaminergic neuronal loss, attributed to its potent antioxidant, anti-inflammatory, and anti-apoptotic properties, and favorable modulation of autophagic flux. This study suggests that myrcene may be a potential candidate for therapeutic benefits in PD. [ABSTRACT FROM AUTHOR]

The combination of Nd(BH4)3(THF)3 and dialkyl magnesium has enabled a notable achievement in the copolymerization process, with potential for new materials with diverse properties. The copolymerization of myrcene and isoprene has been achieved through statistical copolymerization, with yields of up to 84%. This process allows the insertion of isoprene into poly(1,4-trans-myrcene) while maintaining the regio and stereoselectivity of the reaction, even in the presence of high quantities of isoprene. These findings have important implications for the development of new materials with enhanced properties and demonstrate the potential of this copolymerization method for future applications. [ABSTRACT FROM AUTHOR]

Iron catalyst has been encountered with low activity and stereoselectivity sensitive to the operational conditions for diene polymerization. In this study, diphenylphosphite has been proved as an efficient donor in iron‐based tertiary catalyst for butadiene, isoprene and myrcene stereopolymerizations. Thermal robustness of active species has been demonstrated as the high activity and 1,2 stereoselectivity are survived in a wide temperature scope ranging from 5°C to 80°C. The resultant polybutadienes are found to have 1,2 incorporation up to 92.8% with syndiotactic conformation (rrrr: 95.1%), and more than 65% of irregular 3,4 enchainments are generated for polyisoprene and polymyrcene. The active species are formed preferably following addition sequence of iron compound, donor and activator in the presence of monomer. The development of this highly active and stable catalyst combining cost‐efficient components and mild operation parameters could provide accessible catalyst recipe to produce new types of polydienes. [ABSTRACT FROM AUTHOR]

The reliance of both our life and industry on fossil resource and the alarming accumulation of polymeric materials in the environment have presented huge challenges to sustainable society. Nowadays, utilization of renewable monomers as building blocks for polymeric materials has emerged as a hot topic and increasingly gained attention from chemists. As a class of biomass with abundance and low cost, terpenes are typical hydrocarbon‐rich natural compounds, and some of them, such as myrcene and farnesene, are inherently suitable for coordination polymerization. In this review, we focus on the rare‐earth metal catalyzed highly regio‐ and stereoselective polymerization of bio‐based conjugated dienes, especially the ones from terpene‐derived compounds with or without modifications. This review also discusses the future direction on the modification of these bio‐based conjugated dienes. [ABSTRACT FROM AUTHOR]

In this work, we report a new facile method for the preparation of myrcene-limonene copolymers and nanocomposites using a Lewis acid as a catalyst (AlCl3) and organo-modified clay as a nano-reinforcing filler. The copolymer (myr-co-lim) was prepared by cationic copolymerization using AlCl3 as a catalyst. The structure of the obtained copolymer is studied and confirmed by Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance spectroscopy, and Differential Scanning Calorimetry. By improving the dispersion of the matrix polymer in sheets of the organoclay, Maghnite-CTA+ (Mag-CTA+), an Algerian natural organophilic clay, was used to preparenanocomposites of linear copolymer (myr-co-lim). In order to identify and assess their structural, morphological, and thermal properties, the effect of the organoclay, used in varyingamounts (1, 4, 7, and 10% by weight), and the preparation process were investigated. The Mag-CTA+ is an organophylic montmorillonite silicate clay prepared through a direct exchange process in which they were used as green nano-reinforcing filler. The X-ray diffraction of the resulting nanocomposites revealed a considerable alteration in the interlayer spacing of Mag-CTA+. As a result, interlayer expansion and myr-co-lim exfoliation between layers of Mag-CTA+ were observed. Thermogravimetric analysis provided information on the synthesized nanocomposites' thermal properties. Fourier transform infrared spectroscopy and scanning electronic microscopy, respectively, were used to determine the structure and morphology of the produced nanocomposites (myr-co-lim/Mag). The intercalation of myr-co-lim in the Mag-CTA+ sheets has been supported by the results, and the optimum amount of organoclay needed to create a nanocomposite with high thermal stability is 10% by weight. Finally, a new method for the preparation of copolymer and nanocomposites from myrcene and limonene in a short reaction time was developed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Key aroma substances of 21 types of frankincense from 9 global production regions have been identified. • The relationship between frankincense flavor substances and sensory characteristics were shown. • Establishing an OICS for evaluating the odor quality of frankincense. • A new model was established to distinguish the origin of frankincense. Frankincense is an important seasoning and spice known for its distinctive and intricate flavor profile. Considering the considerable variation in the aromatic quality of frankincense due to geographical origin, species diversity and cultivation conditions, frankincense from major global origins was characterized holistically for the first time. The electronic nose (E-nose) with headspace solid-phase microextraction gas chromatography–mass spectrometry (HS–SPME–GC–MS) and sensory evaluation were implemented to characterize the aroma components of 21 commercial varieties of frankincense from around the world. The results showed that a total of 149 volatile organic compounds (VOCs) of 10 categories were identified in frankincense, among which the numbers of alcohols, terpenes and esters compounds accounted for 22.15 %, 18.79 % and 15.44 % of the total VOCs of frankincense, respectively. The PLS-DA model effectively distinguished frankincense from Oman/Somalia and other origins. Furthermore, the study identified two differential VOCs with VIP > 1 in three Asian countries and five in six African countries. The total VOCs content and sensory characteristic score of "Lemon/Citrus" in Oman frankincense is significantly higher than other regions. The OAV results showed that 61 substances (e.g., Diacety, alpha-Pinene, Camphene, Myrcene) as key aroma compounds and OICS model indicated that p-Cymenol was found to contribute significantly to the citrus aroma in frankincense. This study identified the fundamental components of frankincense flavor and revealed different flavor descriptors of frankincense, which are crucial for reconstructing frankincense flavor and improving flavor quality. [ABSTRACT FROM AUTHOR]

γ-terpinene, α-terpinene, p-cymene, and myrcene are monoterpenes found in many essential oils extracted from a variety of plants and spices. Myrcene also occurs naturally in plants such as hops, cannabis, lemongrass, and verbena and is used as a flavoring agent in food and beverage manufacturing. In this research, the biological efficacy of γ-terpinene, α-terpinene, p-cymene, and myrcene was studied in human cell lines (HeLa, SH-SY5Y, and HDFa). Cytotoxicity, cell proliferation, cell migration, and morphology assays were performed to obtain detailed information on the anticancer properties. Our results show that myrcene has potential biological activity, especially in HeLa cells. In this cell line, it leads to an arrest of proliferation, a decrease in motility and morphological changes with loss of sphericity and thickness, and DNA damage. In addition, the interaction of γ-terpinene, α-terpinene, p-terpinene, and myrcene with calf thymus DNA (ct-DNA) was studied by UV-visible spectrophotometry. DNA binding experiments show that only myrcene can interact with DNA with an apparent dissociation constant (Kd) of 29 × 10−6 M.

The present work aimed to evaluate the insecticidal activity of Cymbopogon citratus essential oil and its major compounds (citral and myrcene) on Anticarsia gemmatalis. The essential oil, citral, myrcene, and a mixture of citral and myrcene were tested at the concentrations of 0.1, 0.3, 0.5, 0.7, and 0.9 % v/v, plus two negative controls (distilled water and Tween-80® 0.5 % v/v) and a positive control (novaluron 0.075 % w/v). Insect mortality was evaluated in 24, 48, 72, and 96 h. According to the results, C. citratus essential oil and the citral-myrcene mixture at 0.9 % v/v were effective in the control of A. gemmatalis, with 96 % and 88 % mortality, respectively, in the first 24 h. At this concentration, citral caused 100 % mortality after 72 h, whereas myrcene had no effect on the caterpillars even after 96 h of exposure. Thus, C. citratus essential oil can be a potential option for the alternative control of A. gemmatalis.

Brewing recipe design is mainly based on brewer’s expertise, information available in catalogs and certificates of analysis (CoA’s). Hop schedule design and formulation has become an essential topic since hoppy craft beers took the scene. But how accurate is the flavor profile information provided in catalogs? How useful is the chemical composition profile information in CoA’s? Besides current research and tons of reported experiences, hops impact is still a mystery, and topics like biotransformation are black-boxes for brewers. In this study, nine single hopped beers were brewed, and a trained panel conducted sensorial beer analysis. Then, to asses hop impact, qualitative and process-related-quantitative beer characteristics were contrasted to find valuable correlations and trends between hop catalogs and final beers. Discrepancies with catalog qualitative data were reported. In addition to what is already described in the literature, here we describe how α-acids, linalool, myrcene, and geraniol (despite the classical use for these compounds) could predict positive and negative hop impact of nine different hop varieties on bitterness, flavor, and aroma, when they are applied in different brewing process steps. Also, with this pipeline we stand the basis of a tool to be improved, available for brewers, to better predict their brews and assess new hop varieties in real-life pilot brewing set ups.

Microbial resistance has become a worrying problem in recent decades after the abusive use of antibiotics causing the selection of resistant microorganisms. In order to circumvent such resistance, researchers have invested efforts in the search for promising natural substances, such as essential oils. Thus, the objective of this work was to determine the chemical composition of the essential oil of Acritopappus confertus leaves, to evaluate its intrinsic effect and its effects in combination with drugs against pathogenic fungi and bacteria, in addition to verifying the inhibition of virulence in Candida strains. To this end, the oil was verified by gas chromatography coupled with mass spectrometry (GC/MS). Candida strains were used for antifungal assays by means of the serial microdilution technique, in order to determine the average inhibitory concentration (IC50), and for the modification assays, sub-inhibitory concentrations (MIC/8) were used. Finally, the natural product's ability to inhibit the formation of filamentous structures was evaluated. In antibacterial tests, the MIC of the oil against strains of Staphylococcus aureus and Escherichia coli and its modifying effects in association with gentamicin, erythromycin, and norfloxacin were determined. The major constituent of the essential oil was the monoterpene myrcene (54.71%). The results show that the essential oil has an antifungal effect, with C. albicans strains being the most susceptible. Furthermore, the oil can potentiate the effect of fluconazole against strains of C. tropicalis and C. albicans. Regarding its effect on micromorphology, the oil was also able to inhibit the filaments in all strains. In combination with antibiotics, the oil potentiated the drug's action by reducing the MIC against E. coli and S. aureus. It can be concluded that the essential oil of A. confertus has potential against pathogenic fungi and bacteria, making it a target for the development of an antimicrobial drug. [ABSTRACT FROM AUTHOR]

This study examines the action of light modifications by different shade nets (pearl, red and blue color nets with a shade index of 50%) in relation to unshaded plants from the open field on the relative effects on changing basil aroma profile and antioxidant activity. The most abundant components were linalool, 1,8-cineole and myrcene. Aqueous extracts were isolated from basil leaves using maceration and ultrasound-assisted extraction. Yield of total extractive matters depends on both the extraction technique applied and the growing conditions used. The highest yield of total extractive matter (30.50 g/100g) was obtained by maceration from open field-grown basil. The highest content of total phenols (106.52 mg GAE/g), flavonoids (19.74 mg RE/g) and antioxidant activity (EC50 - 7 µg/mL) was found under a red net. The isolated water extracts are a source of natural antioxidants with potential application in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Cannabis-infused product manufacturers often add terpenes to enhance flavor. Meanwhile, labeling requirements for these same products necessitate testing for residual solvent levels. We have found that heating terpene samples containing an oxygen or air atmosphere results in the detection of significantly higher levels of acetone when compared to the same compound in argon atmosphere using temperature regimes common to headspace autosampler routines. This formation was statistically significant (p = 0.05) for most of the predominant terpenes found in cannabis. The largest increase in acetone formation was seen for terpinolene which showed an 885% increase in oxygen atmosphere (4603.6 PPM) when compared to analysis under argon (519.9 PPM). Cannabinoids were shown to reduce this formation and explain why high levels of acetone are not reported in cannabis extracts, even though these can contain up to 40% terpenes. [ABSTRACT FROM AUTHOR]

In addition to phytocannabinoids, cannabis contains terpenoids that are claimed to have a myriad of effects on the body. We tested a panel of five common cannabis terpenoids, myrcene, linalool, limonene, α-pinene and nerolidol, in two neuronal models, autaptic hippocampal neurons and dorsal root ganglion (DRG) neurons. Autaptic neurons express a form of cannabinoid CB1 receptor-dependent retrograde plasticity while DRGs express a variety of transient receptor potential (TRP) channels. Most terpenoids had little or no effect on neuronal cannabinoid signaling. The exception was nerolidol, which inhibited endocannabinoid signaling. Notably, this is not via inhibition of CB1 receptors but by inhibiting some aspect of 2-arachidonoylglycerol (2-AG) production/delivery; the mechanism does not involve reducing the activity of the 2-AG-synthesizing diacylglycerol lipases (DAGLs). Nerolidol was also the only terpenoid that activated a sustained calcium response in a small (7%) subpopulation of DRGs. In summary, we found that only one of five terpenoids tested had notable effects on cannabinoid signaling in two neuronal models. Our results suggest that a few terpenoids may indeed interact with some components of the cannabinoid signaling system and may therefore offer interesting insights upon further study. [ABSTRACT FROM AUTHOR]