Myrcene Content Research Articles

Toward new applications of terpenes in polymeric materials: Synthesis and characterization of myrcene‐modified unsaturated polyester resins

Abstractβ‐Myrcene, a terpenic monomer, holds potential for developing sustainable polymer‐based materials with enhanced properties. This study examines the synthesis of a myrcene‐based monomer and its incorporation into unsaturated polyesters, focusing on polymerization, curing, and final properties. Unsaturated polyesters were synthesized with varying myrcene‐based monomer content (6, 12, and 24 mol%), phthalic anhydride, maleic anhydride, propylene glycol, ethylene glycol, and diethylene glycol. Polymerization achieved conversion values of 0.92–0.93, resulting in polyesters with molar masses between 1400 and 1700 g mol−1 and dispersity indices of 2.0 to 2.3. Nuclear magnetic resonance (1H NMR) demonstrated short branch formation in myrcene‐modified polyesters and a high maleate‐to‐fumarate isomerization rate (92.66%–95.7%), affecting carbon–carbon double bonds per polyester mole (2.27 to 4.28) and final resin performance. Rheological analysis in a styrene solution (70/30 wt%) indicated shear‐thinning behavior, with viscosities ranging from 0.59 to 3.8 Pa·s, suggesting branching affects chain entanglement. Differential scanning calorimetry (DSC) revealed decreased curing enthalpy with increasing myrcene content, and it was inferred that myrcene's double bonds did not participate in curing. Glass transition temperatures of cured polyesters (70–107 °C) correlate with enthalpy trends. Thermal stability of myrcene‐modified polyesters is similar to the reference polyester, highlighting myrcene's potential as a sustainable monomer for customizable unsaturated polyesters.

The influence of myrcene on anionic copolymerization of 1,3-pentadiene and styrene

C5-dienes including 1,3-pentadiene (PD) and isoprene (IP) as by-products of naphtha cracking are important industrial raw materials for the production of thermoplastic elastomers, synthetic rubber and resins. The research on living anionic polymerization (LAP) of myrcene (MY) is also of great significance for the development of new bio-based materials and products. Focusing on the optimal utilization of C5 resources and the high-value utilization of biomass resources and the realization of green chemical production, this article reports the synthesizing of a novel terpolymer by LAP of PD, styrene (ST) and the biomass monomer MY. The discovery of the alternating sequence structure of ST and PD inspires us to further explore the development of copolymers containing this unique sequence structure. The special long branched side chain of MY and its low glass transition temperature are also conducive to the synthesis of new integrated rubbers. The 1H NMR tracking analysis indicates that the polymerization pattern changes from alternating sequence to gradient block sequence with the increase of MY content. Combined with FTIR analysis, the PD monomeric units are mainly trans-1,4 structure and MY monomeric units are predominant cis-1,4 structure. Considering the extremely high polymerization activity of MY compared to ST and PD, the copolymerization rate is significantly dependent on the concentration of the PD monomer. Despite this, due to the interactions between ST and PD ([ST¦PD] intermediate), ST still tends to form alternating segments with PD. The ternary copolymerization can be viewed as a “binary gradient copolymerization” of [ST¦PD] and MY (rMY > r[ST¦PD]).

Morphological and phenological characteristic, oil yield, quality and economics of Lemon bee balm (Monarda citriodora Cerv. ex-Lag) at diverse environment condition, India

Lemon bee balm (Monarda citriodora Cerv. ex-Lag) is a noble industrial medicinal and aromatic plant species, which is used as digestive, antifungal, anti-inflammatory and menstrual irregularity remedies in traditional medicine. It is a common source of thymol and other active constituents with recognized antimicrobial properties. A multilocation field trial was performed to evaluate essential oil (EO) yield stability, secondary metabolites and economic returns in eight diverse geographical environment conditions (GEC) in India. The secondary metabolites viz., essential oil content and oil yield were found to be highest in tropical and sub-tropical regions. The essential oil content was found to be higher in inflorescence part at all the experimental sites and found to be highest (0.85±0.21%) at BR-JALAUN. The highest EO yield (130.25±3.25 kg ha−1), net return (Rs. 1,22,125.00±245.21 ha−1) and benefit cost (B:C) ratio (2.67±0.17) was recorded at FFDC-KANNAUJ. The thymol content percentage was found to be highest on physiological maturity (>95% flowering) [PM] and on 75% flowering [FS-II] and it began to decline on seed formation stage at all the experimental sites. The significantly highest thymol content percentage was found on PM (86.65±3.91%) and on FS-II (84.21±3.78%) at TBR-JHANSI. On the basis of the gas chromatography and mass spectrophotometry analysis, twenty constituents were isolated. The inflorescence EO contains more thymol than the EO from leaves with stem which in turn was characterized by a higher content of p-cymene, γ-terpinene, carvacrol, α-phellandrene, α-pinene, myrcene, α-terpinene, citral and β-caryophyllene.

Chemical Variability of the Berry Essential Oil of Two Subspecies of Juniperus Oxycedrus L. from Northwestern Algeria.

The chemical composition of 33 oil samples isolated from the berries of individual trees of two subspecies of Juniperus oxycedrus L., collected in four locations in Tlemcen and Aïn Temouchent provinces, was investigated by GC-FID, GC/MS and 13CNMR. In total, 83 compounds were identified, accounting for 85.9 % to 98.6 % of the total composition. Yields ranged between 0.02 and 0.40 % (w/w). All compositions were submitted to statistical analysis. Combination of hierarchical clustering dendrogram and principal component analysis suggested the existence of two groups, the second group being sub-divided into two sub-groups. Groups and sub-groups were distinguished with respect to their contents of α-pinene, germacrene D, myrcene and, to a lesser extent, of manoyl oxide. The chemical composition of the oils belonging to subsp. oxycedrus was largely dominated by monoterpenes. α-Pinene (23.7-63.2 %) and germacrene D (4.5-25.4 %) were the major components, followed by myrcene (3.1-16.7 %). Conversely, samples oils of subsp. macrocarpa were largely dominated by germacrene D (4.4-30.0 %), followed by a lower content of α-pinene (10.0-24.3 %) and myrcene (1.0-4.3 %) and a significant content of manoyl oxide (4.3-9.9 %).

Variability and stability of essential oil composition in Ukrainian hop varieties

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.

Nopadiene: A Pinene-Derived Cyclic Diene as a Styrene Substitute for Fully Biobased Thermoplastic Elastomers.

The bicyclic 1,2-substituted, 1,3-diene monomer nopadiene (1R,5S)-2-ethenyl-6,6-dimethylbicyclo[3.1.1]hept-2-ene was successfully polymerized by anionic and catalytic polymerization. Nopadiene is produced either through a facile one-step synthesis from myrtenal via Wittig-olefination or via a scalable two-step reaction from nopol (10-hydroxymethylene-2-pinene). Both terpenoids originate from the renewable β-pinene. The living anionic polymerization of nopadiene in apolar and polar solvents at 25 °C using organolithium initiators resulted in homopolymers with well-controlled molar masses in the range of 5.6-103.4 kg·mol-1 (SEC, PS calibration) and low dispersities (Đ) between 1.06 and 1.18. By means of catalytic polymerization with Me4CpSi(Me)2NtBuTiCl2 and (Flu)(Pyr)CH2Lu(CH2TMS)2(THF), the 1,4 and 3,4- microstructures of nopadiene are accessible in excellent selectivity. In pronounced contrast to other 1,3-dienes, the rigid polymers of the sterically demanding nopadiene showed an elevated glass temperature, Tg,∞ = 160 °C (in the limit of very high molar mass, Mn). ABA triblock copolymers with a central polymyrcene block and myrcene content of 60-75 mol %, with molar masses of 100-200 kg/mol were prepared by living anionic polymerization of the pinene-derivable monomers nopadiene and myrcene. This diene copolymerization resulted in thermoplastic elastomers displaying nanophase separation at different molar ratios (DSC, SAXS) and an upper service temperature about 30 K higher than that for traditional petroleum-derived styrenic thermoplastic elastomers due to the high glass temperature of polynopadiene. The materials showed good thermal stability at elevated temperatures under nitrogen (TGA), promising tensile strength and ultimate elongation of up to 1600%.

Study on Production Technology and Volatile Flavor Analysis of Fragrance Zanthoxylum Seasoning Oil.

Dried green pepper and first-grade extracted soybean oil were selected as raw materials to study the effect of the Maillard reaction and cold-pressed compound on the quality of Zanthoxylum seasoning oil and its aroma-enhancing effect. The results showed that the optimal technology was as follows: the ratio of material to liquid was 1:5, the heating temperature was 110 °C, the reaction time was 25 or 30 min, and the addition of reducing sugar was 2%. The optimum ratio of fragrant Zanthoxylum seasoning oil was 1:7 for cold pressing oil and hot dipping oil. Compared with Zanthoxylum seasoning oil, it is based on the Maillard reaction and had a more intense and persistent aroma. The taste of fragrant Zanthoxylum seasoning oil was the best of the three blended oils. The possible types of volatile flavor compounds in the three kinds of Zanthoxylum seasoning oils detected by Heracles II ultra-fast gas phase electronic nose were, respectively, 16, 19, and 15. Among the three kinds of Zanthoxylum seasoning oils, the content of limonene, linalool, Eucalyptol, n-pentane α-Pinene, myrcene, and phellandrene was more abundant, which indicated that olefins and alcohols contributed more to the overall flavor of the three kinds of Zanthoxylum seasoning oils.

Soil parameters and bioclimatic characteristics affecting essential oil composition of leaves of Pistacia lentiscus L. from València (Spain)

The variability of the soils found in an area together with the diversity of the bioclimatic parameters will affect the chemical profile of plant species, in our case <em>Pistacia lentiscus</em> L. The aim of this work is to analyse the bioclimatic characteristics and soil parameters affecting the essential oil (EO) composition of the leaves of the <em>Pistacia lentiscus</em> L. growing in València (Spain). The EO compositions of dried leaves of <em>Pistacia lentiscus</em> L. from five sampling sites with noticeable differences in soil and climate features were analysed by GC(MS) and GD(FID). The main bioclimatic and soil parameters were also determined in order to relate them to oil composition. a-pinene (2.8-39.2%), myrcene (0.6-59.3%), b-phellandrene (0.0-42.8%), germacrene-D (3.9-20.4%) and terpinen-4-ol (0.2-19.0%) were found to be the major compounds showing a high variability. The five sampling sites presented well-defined bioclimatic and edaphic characteristics that could be related to specific EO profiles. The results suggested that the EO composition of <em>P. lentiscus</em> L. depends more on the edaphic factors interacting with bioclimate conditions than on the geographical origin itself. Some general trends could be established based on the results: the Calcaric Arenosol (Saler) with a high evapotranspiration index was associated with a high sesquiterpenic fraction, (germacrene-D and b-caryophyllene, mainly). The Luvisol (Borrell and L’Ull), with high amounts of a + b-pinene, were found to be related to sub-humid bioclimatic conditions and clayey and fertile soils (high CEC and OM levels). This last requirement was also observed to be related to the myrcene content, but with drier climatic conditions and calcareous soils (Haplic Calcisol) with high level of carbonates and active lime (Lliria). The rest of hydrocarbon monoterpene and oxygenated monoterpene (terpinen-4-ol, mainly) fractions could be related to a dry climate and non-calcareous and low fertility soils (Eutric Regosol, Segart). Given the most suitable composition related to specific and useful biological activities, new research of controlled environmental factors (soil features and bioclimatic conditions) should be conducted in order to define the best conditions to manage industrial crops of <em>P. lentiscus </em>L<em>.</em>

Breeding of flavour hops in the Czech Republic

Hop breeding in the Czech Republic develops a number of flavour hops. The Kazbek hop variety was registered in 2008 and the Mimosa variety in 2019. The best 7 hop genotypes were selected from breeding materials between the years 2014 and 2019. Kazbek, 5512 (Ceres) and 5571 (Eris) expressed a clear citrusy flavour. Mimosa, 5495 (Juno) and 5520 (Saturn) could be described as fruity while 5164 (Uran), 5540 (Jupiter) and 5580 (Pluto) as rather spicy. Genotype 5164 showed the highest aroma intensity, content of alpha acids (11.51% w/w) and alpha/beta ratio (2.20). Whereas Mimosa demonstrated the highest content of beta acids (5.56% w/w) and the lowest alpha/beta ratio (0.28), 5571 and 5520 had the highest cohumulone amount (49.19% rel. and 47.35% rel., respectively). In contrast, 5580 were distinguished by the lowest cohumulone (21.28% rel.). The highest amount of hop oils was determined in 5164 (1.77 w/w) and 5520 (1.53 w/w). 5164, 5540 and 5495 show a myrcene level above 40% rel. On the other hand, Kazbek, Mimosa and 5571 indicated a myrcene content below 35%. The highest level of farnesene (12.50% rel.) was detected in 5164; in other samples the values were below 1% rel. Mimosa showed the highest concentration of selinenes (32.75% rel.); other samples demonstrated selinenes below 10% rel. The Kazbek variety is the foundation for the breeding of flavour hops in the Czech Republic, and therefore it is the mother plant of genotypes 5495, 5512, 5520, 5540 and 5571. Harmonie is the mother plant of genotype 5580.

Preparation, characterization and application of polymethacrylate-based monolithic columns for fast and efficient separation of alkanes, alcohols, alkylbenzenes and isomeric mixtures by gas chromatography

Application of monolithic columns in gas chromatography is still considered very limited. In this work, several polymethacrylate-based monolithic capillary columns were fabricated, characterized and used in gas chromatography. The five monomers used were: methyl methacrylate, (MMA), hexyl methacrylate (HMA), glycidyl methacrylate (GMA), 2-butoxyethyl methacrylate (BEMA) and isobornyl methacrylate (IBMA), while ethylene dimethacrylate was the crosslinker. The monoliths were synthesized in 30 cm length capillaries possessing inner diameters (i.d.) of 0.25 mm. The prepared monolithic columns were applied for separation of 3 series of homologous alkanes, alcohols and alkylbenzenes, as well as some isomeric mixtures. Van Deemter plots were used to optimize and compare the columns performance. The smaller methacrylates (MMA and GMA) exhibited higher porosity and permeability with low column backpressure values and poorer efficiency than the larger methacrylate monomers (HMA and BEMA). The columns prepared from IBMA monomer showed the highest pressure and the least separation efficiency. The fastest full separation of alkanes was achieved on HMA-co-EDMA column in about 3.0 min with resolution better than 2.73, while the fastest full separation of alcohols and alkylbenzenes was carried out using BEMA-co-EDMA column in less than 0.8 and 1.75 min with chromatographic resolution better than 1.27 and 1.85, respectively. Again, BEMA-co-EDMA column gave the best performance with the fastest and complete separation of all studied isomeric mixtures. For all tested series of solutes, the better separation efficiency was reached with tridecane, which gave 25,200 plates/m on the HMA-co-EDMA column. Another application was carried out using HMA-co-EDMA column for determination of myrcene and limonene, two monoterpenic isomers, in some fruit peels. Under the optimum GC conditions, a rapid separation of myrcene and limonene was achieved in less than 1.0 min with chromatographic resolution of 2.56. The highest contents of myrcene (0.131 mg/g) and limonene (1.225 mg/g) were measured in the hexane extracts of grapefruit and Egyptian orange, respectively. Finally, a comparison between the prepared columns and a commercial capillary column was performed. Based on the measured run time and HETP values, HMA-co-EDMA and BEMA-co-EDMA monolithic columns exhibited faster separation and higher efficiency for n-alkanes and alkylbenzenes than the TR-5 open tubular column, although they are 100 times shorter.

Chemical composition and cytotoxic activity of the essential oils of Cymbopogon citratus L. Grown in phu tho province

Culms and leaves of Cymbopogon citratus L. were collected from two regions of Phu Tho province (Thanh Son and Phu Ninh) and used as materials for essential oil extraction. Oils obtained were steam-distilled, analyzed for chemical composition and evaluated for cytotoxic activity against three different cancer cell lines. The GC/MS analysis showed that citral is the major content of the steam-distilled essential oils which was found in the range of 64.15-76.22%. Camphene was found only in culm oils of both regions but it was not detected in the leaf oils. Interestingly, the isomer forms of ocimene present at higher content in the culm oils than in the leaf oils whereas myrcene content in the leaf oils is higher than that in the culm oils. In a cytotoxicity test, four essential oils of culms and leaves of C. citratus from Thanh Son and Phu Ninh showed potent activity against A549 (human lung carcinoma) cell line with the IC50 values ranging from 4.01±0.39 to 6.3±0.54 µg/ml. The essential oils (culms and leaves) from Phu Ninh exhibited moderate effects on the Hela (human cervical adenocarcinoma) cells with the IC50 values of 19.43±1.16 and 42±2.41 µg/ml, respectively. However, they were inactive against the human hepatocellular carcinoma Hep3B cell line. The essential oils from Thanh Son exhibited potent cytotoxic activity against Hela and Hep3B cell lines with the IC50 values ranging from 1.18±0.26 to 8.91±0.32 µg/ml. The results indicated that the essential oils of C. citratus from Thanh Son, Phu Tho could be considered as a promising candidate for the natural sources of anticancer agents.

Characterization of volatile compounds in ten Piper species cultivated in Hainan Island, South China

ABSTRACTThe volatile compounds of 10 Piper species cultivated in Hainan Island, China, have been investigated. Eighty compounds were profiled after headspace–solid phase microextraction (HS–SPME) with gas chromatography–mass spectrometry (GC–MS). Mean Bray–Curtis similarity value was only 22.78 ± 1.98% among the different Piper species. The volatile compounds were largely grouped as hydrocarbons, aldehydes, alcohols, acids, ketones, esters, and phenols. The main compounds comprised benzaldehyde, cinnamaldehyde, β-caryophyllene, ocimene, lavandulol, myrcene, cubebene, terpinene, linalool, α-caryophyllene, β-elemene, and germacrene. Principal component analysis revealed that Piper laetispicum, Piper longum, Piper hainanense, Piper betle, and Piper flaviflorum were characterized by high contents of β-caryophyllene, α-caryophyllene, germacrene, and β-pinene. Piper puberulum and Piper cathayanum were associated with high contents of linalool, myrcene, and germacrene D. On the other hand, Piper pseudofuligineum and Piper retrofractum were related with high contents of ocimene. Finally, Piper auritum was associated with high content of cinnamaldehyde. Volatile profiling of Piper species by HS–SPME–GC–MS and the interrelationship investigated among the volatiles can be used as a roadmap for future resource utilization or biotechnological applications.

First insight into the chemical composition of essential oils and head space volatiles obtained from fresh leaves and flowers of Peucedanum longifolium Waldst. & Kit.

For the first time, chemical composition of P. longifolium essential oils (EO) and head space (HS) volatiles obtained from the fresh leaves, harvested in different phases of the plant development, and inflorescences was compared. The major contributor of leaves essential oil in vegetative phase (LD) was β-elemene (44.1%). On the cotrary, β-elemene (22.5%) was the second most abundant component, while ( E )-β-ocimene (26.7%) was the first and cis -lanalool oxide (furanoid, 21.9%) was the third most represented compound in the leaves essential oils collected in blossoming phase (LF). ( E )-β-Ocimene was the major compound in both HS leaf samples but in very varying amounts (LD 81.8% and LF 27.4%). Beside ( E )-β-ocimene, p -cymene and limonene were represented more than 10% (13.6% and 15.2% respectively). The essential oil and HS volatiles of the inflorescences was characterized by a high content of β-phellandrene (16.4% and 20.4% respectively), α-phellandrene (22.5% and 13.9% respectively) and myrcene (23.1% and 22.1% respectively). The presented data showed that there was a significant difference in the composition of volatile components from different plant organs and also from the same organ in different stages of development.

Influence of Environmental Factors on Essential Oil Variability in Origanum compactum Benth. Growing Wild in Morocco.

The present study aimed to evaluate the influence of environmental factors on essential oils (EOs) composition of Origanum compactum populations sampled all over the distribution area of the species in Morocco, and to determine the extent of the chemical profiles throughout the geographical distribution of the species. The chemical compositions were submitted to canonical correlation analysis and canonical discriminant analysis that indicated a significant relationship between oil components and some environmental factors. According to their chemical composition and edapho-climatic characteristics, two major groups of populations were differentiated. The first group was composed of samples growing in regions with humid climate, clayey, sandy, and alkaline soils. These samples showed high thymol, α-terpineol, linalool, and carvacryl methyl oxide content. The second group consisted of plants belonging to semi-arid climate, and growing at high altitudes and silty soils. These samples were characterized by high carvacrol, α-thujene, α-terpinene, and myrcene content. However, populations exposed to sub-humid climate, appeared less homogeneous and belong mainly either to the first or second group. A significant correlation between some edaphic factors (pH, K2 O content, soil texture) and the EOs yield of O.compactum plants was evidenced. In spite of the correlation obtained for the oil composition with edapho-climatic factors and the variance explained by the environmental data set, the observed EO diversity might be also genetically determined.

樟脑型樟叶油成分分析

本文针对实验室用挥发油提取器提取樟脑型樟叶油出现的析脑现象，采用真空抽滤进行初步分离，利用GC-MS联用仪和GC对获得的晶体及脱脑油进行了定性和定量分析。实验结果表明，真空抽滤是纯化樟脑型樟叶油的方法之一，得到的樟脑含量为94.671%；脱脑油中单萜类和倍半单萜类物质分别占88.597%，10.554%，含量大于2%的主要成分为樟脑(50.864%)，D-苧烯(12.490%)，α-蒎烯(3.458%)，β-月桂烯(4.199%)，4-松油醇(2.260%)，α-松油醇(3.915%)，石竹烯(3.973%)，葎草烯(3.036%)等，可通过分馏对其加以利用。 The camphor crystals separate out when the essential oil is extracted with volatile oil extractor from the camphor tree leaves of camphor type. In view of this phenomenon, the camphor crystals and the oil layer were separated preliminarily by vacuum filtration and their chemical composi-tions were analyzed qualitatively and quantitatively by GC-MS and GC. The results showed that the vacuum filtration was one of the ways for purifying the camphor oil of camphor type. After the es-sential oil was separated, the content of camphor reached to 94.671%. In the oil layer, the content of single terpenoids and half the terpenoids substances is 88.597% and 10.554% respectively, and the contents of camphor (50.864%), D-limonene (12.490%), alpha pinene (3.458%), beta myrcene (4.199%), 4-terpineol (2.260%), alpha terpineol (3.915%), caryophyllene (3.973%) and humulene (3.036%) are more than 2%. These main chemical compositions can be used by fractionation.

Characteristics of Essential Oil from Young Shoots of Garden Angelica (Angelica archangelica L.)

The objective of the study was to determine the content and composition of essential oil in the fresh young shoots of garden angelica collected in the first year of plant vegetation and to evaluate the effect of preservation method (convective drying at 35°C and lyophilization) on these parameters. Essential oil content in the fresh, convectively dried, and lyophilized shoots amounted to 0.27, 0.21, and 0.11 mL/100 g dry matter, respectively. In the essential oils obtained from these raw materials 91, 89, and 62 compounds were identified, respectively. In all the investigated essential oils the dominant compounds were: α-pinene (20.4–29.1%) and myrcene (17.0–26.7%). Other constituents included limonene (7.6% in the essential oil from fresh shoots), 6-methylhept-5-enal (3.0%), humulene epoxide II (2.4%), β-pinene (2.1%), perylene (1.9%), and α-humulene (1.8%). Both methods of drying resulted in the decrease in α-pinene content, and the increase in myrcene content. (Z,Z)-undeca-1,3,5-triene and trans-myrtanol were completely lost during drying, irrespective of the method used.

Changes in the essential oil content and terpene composition of rosemary (Rosmarinus officinalis L.) by using plant biostimulants

Plant biostimulants can stimulate the increase of growth, metabolism and the biosynthesis of metabolites in plants. This study investigated the changes of rosemary essential oil and its components composition under use of biostimulants for the possible reduction in use of chemical fertilizers. Treatments included biostimulants based on amino acids in four formulations, Aminolforte, Kadostim, Humiforte, and Fosnutren (each of them at 0.75 and 1.5 L ha-1), and application of N.P.K fertilizer as a control treatment (by applied complete fertilizer at 100 kg per hectar with proportion of 15:8:15 percentage of N:P:K in the fertilizer). Results showed that the essential oil content and its components were significantly affected by biostimulants application. The maximum content of essential oil was obtained at 1.5 L ha-1 Humiforte and both concentrations of Aminolforte. While, the highest content of α-pinene, 1,8-cineole, and camphor as major components of rosemary essential oil were obtained at 1.5 L ha-1 Fosnutren. In addition, the maximum content of linalool, z-pinocamphone, bornyl acetate, and caryophyllene oxide were observed at 1.5 L ha-1 Fosnutren.Although, the highest content of myrcene and verbenone was obtained in the treatment with N.P.K fertilizer, but the maximum contents of β-pinene, camphene, borneol, and α-terpineol were related to the both concentrations of Aminolforte.We can conclude that biostimulants based on amino acids can be an effective alternative in reducing the use of chemical fertilizer and increasing the quantity and quality of rosemary essential oil.

Plant-part anatomy related composition of essential oils and phenolic compounds in Chaerophyllum coloratum, a Balkan endemic species

Chaerophyllum coloratum is an endemic plant for the Western Balkans. Despite of its common occurrence in the Sub-Mediterranean part of Dinaric countries, knowledge about its structure and biologically active compounds is rather poor. The plant material was collected in Montenegro. The structure was studied on paraffin sections, as well as on native sections stained with standard reagents for histochemical analysis. Chemical analyses of the essential oils from its leaves, flowers, roots, stems and fruits were performed. The total phenolic, flavonoid and tannin contents in different plant organs were determined, as well, in order to give an insight in the pattern of secondary metabolites distribution. Although it was shown that morphologically and ecologically Chaerophyllum coloratum differed significantly from other species of the genus native in the flora of the Western Balkans, it shared common structural features of the genus. In a comparative analysis of 33 anatomical characters of C. coloratum and six previously studied Chaerophyllum species, C. coloratum clustered with Chaerophyllum aureum. In addition it was closely linked with two other species of Chrysocarpum section: Chaerophyllum bulbosum and Chaerophyllum aromaticum. Histochemical and chemical analysis of secondary metabolites showed the presence of essential oil in all studied plant organs, but differing both in composition and content of individual compounds. The essential oil from the roots is characterized by a high content of monoterpene myrcene (72.18%). In the case of stem monoterpens β-(E)-ocimene (33.59%), β-(Z)-ocimene (20.43%) and terpinolene (10.77%) were predominant compounds, while the principal constituents in the oil of leaves were identified as spathulenol (10.19%), p-cymene-8-ol (9.45%) and p-cymene (7.6%). Monoterpenes terpinolene (17.08%), p-(Z)-(E)-ocimene (6.96%) were identified as the main constituents of the flower oil, while in the fruits, the constituents with the highest amount were caryophyllene oxide (6.93%), (Z)-β-farnesene (5.92%), (E)-pinocarveol (5.56%) and myrtenol (5.25%).

Renewable thermoset copolymers from tung oil and natural terpenes

ABSTRACTThe cationic copolymerization of tung oil, limonene, and myrcene as comonomers, initiated by boron trifluoride, is presented and discussed in this work. Dynamic mechanical analysis revealed that all copolymers behave as thermosets. FTIR spectra for both copolymers, after extraction with dichloromethane, suggested that the major component of the insoluble fraction was reacted tung oil (a cross‐linked triglyceride network). Likewise, unreacted tung oil was found to be the main component of the soluble phase. Also, all the copolymers showed only one tan δ peak, indicating no phase separation. Glass transition temperature (Tg) increased with the myrcene content and decreased almost linearly as the limonene content increased. Furthermore, the Fox and Loshaek model showed a relatively good prediction of the Tg values of the polymers. The Young's modulus ranged from 33.8 to 4.7 MPa for all tested thermosets. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 41155.

Effect of Growth Stage on Essential‐Oil Yield and Composition of Daucus sahariensis

The essential oils obtained by hydrodistillation from Daucus sahariensis Murb. harvested at three different growth stages were characterized by GC/MS analysis. In total, 88 compounds were identified, with myristicin (29.8-51.7%), myrcene (6.7-31.1%), α-pinene (11.6-14.8%), and limonene (5.3-11.5%) as main constituents. Monoterpene hydrocarbons were the most represented compounds in the oils of the plant samples collected during the flower-budding and full-flowering periods. On the contrary, during the fruiting stage, the oils were dominated by phenylpropanoids. The essential oils were subject of considerable variation in their composition during the various developmental stages, particularly concerning the content of myrcene that decreased significantly passing from the vegetative to the fruiting stage. Conversely, for myristicin, the opposite trend was observed. Furthermore, the essential-oil yields were quite low during the flower-budding phase (0.27%), but rapidly increased during plant development (0.63 and 0.68% for the flowering and fruiting phases, resp.).