• Korean Journal of Pharmacognosy
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• v.21 no.2
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• pp.121-125
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• 1990

Essential oil of the root of Angelica dahurica Benth et Hook(Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain eleven monoterpenes such as ${\alpha}-pinene(4.74%),\;campben, {\beta}-pinene,\;myrcene,\;{\alpha}-phellandrene,\;{\delta}-3-carene(39.4%),\;{\alpha}-terpinene,\;{\rho}-cymene,\;{\beta}-phellandrene,\;{\alpha}-terpinene,\;terpinolene\;and\;also\;found\;to\;contain\;4-vinylguaiacol,\;iso-elemicin,\;{\beta}-elemene$, caryophyllene, ligustilide, osthol and seven tentatively identified sesquiterpenes.

• Korean Journal of Pharmacognosy
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• v.19 no.4
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• pp.239-247
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• 1988

Essential oil of the root of Angelica gigas Nakai (Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain eleven monoterpenes such as ${\alpha}-pinene,\;camphene,\;{\beta}-pinene,\;myrcene,\;{\alpha}-phellandrene,\;{\Delta}-3-carene,\;{\alpha}-terpinene,\;p-symene,\;limonene,\;{\gamma}-terpinene$ and terpinolene and also found to contain 4-vinylguauacol, myristicin, elemol, ${\beta}-eudesmol,\;{\alpha}-eudesmol,\;four\;sesquiterpenes\;involving\;{\Delta}-elemene$. Four sesquiterpenes and five sesquiterpene alcohols were tentatively identified by comparison of their mass spectra.

• Journal of Environmental Science International
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• v.11 no.8
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• pp.811-818
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• 2002

The concentration levels of monoterpenes, including ${\alpha}$- and ${\beta}$-pinene, were measured in a pine forest in Florida, USA, over about one year. Based on this measurement data, the current study then investigated the factors affecting the environmental behavior of monoterpenes. Despite a moderately weak temperature variability in the study area, the temperature dependence of the concentration variations was still evident. The concentrations of the two pinenes were significantly affected by changes in the air temperature, as indicated by strong correlations with temperature. A close relation among the measured parameters was also found between the ${\beta}$-pinene and ozone concentrations, which is also in line with previous findings from other studies. In addition, it was interesting to note that the ${\beta}$/${\alpha}$ pinene concentration ratio exhibited a strong inverse correlation to temperature, with the seasonal mean ranging from 0.51(summer) to 0.93(winter). Accordingly, the current results indicate that, in a forest environment, the major terpene species concentrations are affected by both meteorological conditions and chemical reactions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.59-68
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• 2001

Essential oils extracted from Chamaecyparis obtusa were applied to make antibacterial corrugating liner. The quantitative analysis of the essential oils was carried out by GC-MS, which showed that the monoterpenes as a basic component of the essential oils extracted from Chamaecyparis obtusa in the domestic mountain were greater in amount than those in China. The antibacterial activity was then examined with Tyromyces palustris and gram-negative/positive bacteria. The papers treated with the essential oils desplayed great resistance against T. Palustris and gram bacteria but the best results were obtained with the handsheet formed by softwood bleached kraft pulp rather than the liner by OCC. The low antibacterial activity of the liner was considered to be due to starch components which could be readily attacked by the fungi.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.698-705
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• 2010

The concentration of monoterpenes (12 species) was measured from spring to fall in 2008 in ambient air at six different forests located in the southern parts of Korea. Sampling - using a Solid Adsorption Tube - was conducted at 2-hour-interval a day (24 hours) of each season. The highest annual average concentration of total monoterpene was 0.715 ppbv, which occurred at Mt. Baega. ${\alpha}$-Pinene, sabinene and ${\beta}$-pinene were the most abundant compounds throughout the sampling periods and areas. The concentrations of monoterpene were higher in spring than in any other seasons. The compositions and concentrations of monoterpene displayed a distinct pattern by area. Most of monoterpenes had diurnal variations with higher concentrations during the daytime, and lower during the nighttime. This may be due to the fact that the amount of monoterpenes emitted increases at elevated ambient temperatures and increased sunlight intensity. The results of this study showed that each area had distinct monoterpene compositions, which depended on the tree species, topography and local climate at each area.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.62-75
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• 2022

Background: Pollinators help plants to reproduce and support economically valuable food for humans and entire ecosystems. However, declines of pollinators along with population growth and increasing agricultural activities hamper this mutual interaction. Nectar and pollen are the major reward for pollinators and flower morphology and volatiles mediate the specialized plant-pollinator interactions. Limited information is available on the volatile profiles attractive to honey bees and bumblebees. In this study we analyzed the volatile organic compounds of the flowers of 9 different plant species that are predominantly visited by honey bees and bumblebees. The chemical compositions of the volatiles were determined using a head space gas chromatography-mass spectrometry (GC-MS) method, designed to understand the plant-pollinator chemical interaction. Results: Results showed the monoterpene 1,3,6-octatriene, 3,7-dimethyl-, (E) (E-𝞫-ocimene) was the dominating compound in most flowers analyzed, e.g., in proportion of 60.3% in Lonicera japonica, 48.8% in Diospyros lotus, 38.4% Amorpha fruticosa and 23.7% in Robinia pseudoacacia. Ailanthus altissima exhibited other monoterpenes such as 3,7-dimethyl-1,6-octadien-3-ol (𝞫-linalool) (39.1%) and (5E)-3,5-dimethylocta-1,5,7-trien-3-ol (hotrienol) (32.1%) as predominant compounds. Nitrogen containing volatile organic compounds (VOCs) were occurring principally in Corydalis speciosa; 1H-pyrrole, 2,3-dimethyl- (50.0%) and pyrimidine, 2-methyl- (40.2%), and in Diospyros kaki; 1-triazene, 3,3-dimethyl-1-phenyl (40.5%). Ligustrum obtusifolium flower scent contains isopropoxycarbamic acid, ethyl ester (21.1%) and n-octane (13.4%) as major compounds. In Castanea crenata the preeminent compound is 1-phenylethanone (acetophenone) (46.7%). Conclusions: Olfactory cues are important for pollinators to locate their floral resources. Based on our results we conclude monoterpenes might be used as major chemical mediators attractive to both honey bees and bumblebees to their host flowers. However, the mode of action of these chemicals and possible synergistic effects for olfaction need further investigation.

• Journal of the Korean Wood Science and Technology
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• v.34 no.3
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• pp.46-55
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• 2006

This study was to compare the antifungal activitiy of monoterpenes with that of sesquiterpenes, which were major constituents of antifungal active essential oil of Chamaecyparis obtusa, to investigate which constituents had more effective against dermatophytes, and to evaluate the synergistic effect of combination of the antifungal active constituents. The antifungal activities of seven fractions (A, B, C, D, E, F, and G) from C obtusa essential oil by column chromatography were tested against Trichophyton mentagrophytes. Fraction D, E, F, and G were more active than fraction A, B, and C, and their major compounds were mono- and sesquiterpenes analyzed by GC/MS. Borneol, linalool, and ${\alpha}$-terpineol were selected as monoterpenes, and ${\alpha}$-cedrol, nerolidol, and ${\beta}$-eudesmol as sesquiterpenes, respectively. The antifungal activities of the constituents were respectively examined against Trichophyton mentagrophytes (KCTC6077), Microsporum canis (KCTC6591), and Microsporum gypseum. The constituents of sesquiterpenes were more active than those of monoterpenes. By comparing single and combined sesquiterpenes with fraction F containing the higher ratio of sesquiterpenes, combined sesquiterpenes were the most active. This result indicated that there was the synergistic antifungal effect against dermatophytes when sesquiterpenes were combined together.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.17-21
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• 2017

BACKGROUND: Castor oil and wormseed extract are important active ingredients for biopesticide, and ricinoleic acid in castor oil and three monoterpenes (ascaridole, carvacrol and p-cymene) in wormseed extract are known bioactive substances. However, their stabilities had not been studied, even though the stability was the core property for estimation of shelf-life of biopesticide. Aimed to investigate the thermal stabilities of the bioactive substances in castor oil and wormseed extracts. METHODS AND RESULTS: The contents of ricinoleic acid and three monoterpenes (ascaridole, carvacrol and p-cymene) were analyzed by gas chromatography (GC). The thermal stabilities of the bioactive substance were measured at $0^{\circ}C$, $23^{\circ}C$, $30^{\circ}C$, $40^{\circ}C$, $45^{\circ}C$ and $54^{\circ}C$ for 84 d. The half-lives of ricinoleic acid in biopesticides was ranged from 28.9 d to 57.8 d at $30^{\circ}C$, and the stability of pure castor oil were located in the range ($t_{1/2}$=46.2d for Indian product and 27.7 d for Korean product) at the same temperature. The half-lives of the total monoterpenes in biopesticides were ranged from 3.9 d to 27.7 d at $30^{\circ}C$. Among the monoterpenes, the stability ascaridole and p-cymene were decreased in acidic condition. All the bioactive substances showed similar stability on the different thermal conditions. CONCLUSION:The half-lives of most bioactive substance from castor oil and wormseed extracts were less than 100 d. To increase the stability of bioactive substance in biopesticide, stabilizing additives like antioxidant and oxygen remover should be considered to extend of the shelf-life.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.347-349
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• 2008

• Journal of Environmental Science International
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• v.16 no.2
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• pp.151-158
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• 2007

In order to investigate the compositions and the emission rates of monoterpenes emitted from coniferous trees, those from Larix leptoleis (Sieb, et Zucc.) Gordon were measured. In spring and summer, the major monoterpenes were ${\alpha}-terpinene,\;{\alpha}-pinene$, myrcene; however, ${\alpha}-pinene\;and\;{\alpha}-terpinene$ were most abundant in fall. The total mean monoterpene emission rates were $0.455\;({\mu}gC/gdw/hr)$ during the whole period. The higher monoterpene emission rates were found in fall compared to those in spring and summer. In addition, the slopes (${\beta}\;value$) between emission rate and temperature were two times lower in fall than those in spring and summer. It was also found that Larix leptoleis (Sieb. et Zucc.) Cordon had lower monoterpene emission rates than P. densiflora and P. rigida.