• Journal of Life Science
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• v.24 no.3
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• pp.266-273
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• 2014

In the present study, the chemical compositions and antimicrobial and antioxidant activities of commercially available essential oils in Korea were investigated. The essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). The results demonstrated that they exhibit a broad spectrum of antimicrobial activities against gram positive, gram negative, and multidrug resistant (MDR) strains. The antimicrobial activity of five of the essential oils against 40 organisms was assessed using the minimum inhibitory concentration (MIC). The MIC values were in the ranges of 0.0625-0.5% (v/w) for lemongrass and manuka, 0.03125-1.0% (v/w) for tea tree, 0.0625-1.0% (v/w) for thyme, and 1-4% (v/w) for ravensara, depending on the pathogens studied. This study revealed that, among the essential oils tested, lemongrass and thyme oil showed broad antimicrobial activity against infectious bacteria. The antioxidant activities and the reducing power of the essential oils were determined with a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Thyme oil exhibited the strongest antioxidant activity comparing with ascorbic acid. This is the first report on the chemical compositions and antimicrobial activities of commercially available essential oils against infectious bacteria and MDR strains acquired from Korean hospitals.

• 한국패션뷰티학회:학술대회논문집
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• 2005.05a
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• pp.17-18
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• 2005

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.198-205
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• 2021

Objectives: Antibiotics help treat Vaginitis, and prolonged usage of antibiotics can lead to resistance. Methods: This study investigates the antimicrobial activity of two types of lactic acid bacteria using essential oils. After cultivation by adding grapefruit seed extract (GSE), eucalyptus, tea tree, clove bud, cinnamon, lemongrass, thyme, and ginger oils in a specific ratio, pathogenic microorganisms, namely E. coli, C. albicans, and lactic acid bacteria were released. The number of bacteria was measured using a medium suitable for the strains. Results: The essential oils and GSE inhibited pathogenic microorganisms, and the inhibitory concentration of GSE against pathogenic bacteria (E. coli, C. albicans) was confirmed. The non-inhibitory mixing ratio was also confirmed (50 μl of eucalyptus globulus (EG) oil and 50 μl of melaleuca alternifolia oil (tea tree oil, TTO) at 200 ppm GSE (pH 5.0, 5.5, 6.0)). Conclusion: Essential oils can be considered as an alternative to antibiotics because of their antibacterial properties. They are useful as auxiliary antibacterial agents for patients under long-term antibiotic treatment.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.491-499
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• 2000

This study was performed to investigate the antioxidative effects of solvent extracts of eighteen curry spices. Yields of the curry spices extracted by methanol, ethylacetate and hexane were $6.4{\sim}42.9%$, $3.9{\sim}26.2%$ and $1.6{\sim}29.2%$, respectively. Methanol, ethylacetate and hexane extracts of spices were added up to 1,500 ppm in the rice bran oil and antioxidative effects of extracts were tested by Rancimat. Induction periods of spices extracted by methanol were in the order of rosemary(33.5hr)>sage(29.1hr)>ginger(28.6hr)>turmeric(26.9hr)>nutmeg(25.8hr)>oregano(25.6hr)>thyme(25.3hr)>BHT(24.5hr)>control(22.6hr). Those of ethylacetate extracts were as follows: rosemary(43.9hr)>sage(30.9hr)>oregano(29.0hr)>thyme(27.5hr)>ginger(27.1hr)>BHT(24.5hr)>control(22.6hr). Those of hexane extracts were in the order of rosemary(47.4hr)>sage(31.4hr)>oregano(27.3hr)>ginger(25.5hr)>thyme(25.1hr)>control(22.6hr). Solvent extracts of rosemary, sage, oregano, ginger and thyme showed significant antioxidative effects. Two thousands ppm hexane-extract of rosemary was the most effective. Addition of hexane-extracts of rosemary didn't show any synergism with the hexane extracts of sage, oregano, ginger, and thyme.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.419-427
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• 2013

The insecticidal activity of 124 plant essential oils and control efficacy of six experimental spray formulations (SF) containing 0.25, 0.5, 1, 2.5, 5, and 10% of the selected oils was examined against both nymph and adult of the citrus flatid planthopper, Metcalfa pruinosa using direct contact applications (leaf dipping and spray). Reponses varied according to dose (1,000 and 500 mg/L). When exposed at 1,000 mg/L for 24 h using leaf dipping assay, 19 essential oils showed strong mortality (100%) among 124 essential oils screened. At 500 mg/L, 100% mortality was observed in cinnamon technical, cinnamon green leaf, cinnamon #500, cassia tree, citronella java and pennyroyal followed by origanum, thyme white, grapefruit, savory, fennel sweet, aniseed and cinnamon bark showed considerable mortality (93.3-80%) against nymphs of M. pruinosa. The moderate mortality (73.3-60%) was found in thyme red, tagetes, calamus, lemoneucalptus and geranium. Oils applied as SF-10% sprays provided 100 % mortality against adult M. pruinosa. One hundred mortalities were achieved in cinnamon technical at >SF-0.5 formulation, in cinnamon #500, cinnamon green leaf and penny royal at >SF-2.5. To reduce the level of highly toxic synthetic insecticides in the agricultural environment, the active essential oils as potential larvicides could be provided as an alternative to control M. pruinosa populations.

• Research in Plant Disease
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• v.24 no.4
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• pp.292-301
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• 2018

Alternaria leaf spot disease has been a concern during a tomato production in greenhouse. In vitro antifungal activities of vapours of four plant essential oils, cinnamon oil, fennel oil, origanum oil and thyme oil, were investigated during in vitro conidial germination and mycelial growth of Alternaria alternata causing the tomato leaf spots to find eco-friendly alternatives for chemical fungicides. The four plant essential oils showed different antifungal activities against in vitro conidial germination of A. alternata in dose-dependent manners, and cinnamon oil vapour was most effective to suppress the conidial germination. The four plant essential oils showed similar antifungal activities against the in vitro mycelial growth of A. alternata in dose-dependent manners, but low doses of thyme oil vapour slightly increased in vitro mycelial growth of A. alternata. Necrotic lesions on the A. alternata-inoculated tomato leaves were reduced differently depending on kinds and concentrations of plant essential oils. Delayed conidial germination and germ-tube elongation of A. alternata were found on the tomato leaves treated with cinnamon oil and origanum oil vapours at 6 hpi. These results suggest that volatiles from cinnamon oil and origanum oil can be provided as alternatives to manage Alternaria leaf spot during the tomato production eco-friendly.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.935-944
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• 2013

Essential oils have been shown to favorably effect in vitro ruminal fermentation, but there are few in vivo studies that have examined animal responses. The objective of this study was to evaluate the effects of thyme (THY) and cinnamon (CIN) essential oils on feed intake, growth performance, ruminal fermentation and blood metabolites in feedlot calves fed high-concentrate diets. Twelve growing Holstein calves ($213{\pm}17kg$ initial BW) were used in a completely randomized design and received their respective dietary treatments for 45 d. Treatments were: 1-control (no additive), 2-THY (5 g/d/calf) and 3-CIN (5 g/d/calf). Calves were fed ad libitum diets consisting of 15% forage and 85% concentrate, and adapted to the finishing diet by gradually increasing the concentrate ratio with feeding a series of transition diets 5 wk before the experiment started. Supplementation of THY or CIN did not affect DMI and ADG, and feed efficiency was similar between treatment groups. There were no effects of additives on ruminal pH and rumen concentrations of ammonia nitrogen and total VFA; whereas molar proportion of acetate and ratio of acetate to propionate decreased, and the molar proportion of propionate increased with THY and CIN supplementation. Rumen molar concentration of butyrate was significantly increased by adding CIN compared to control; but no change was observed with THY compared with control group. No effects of THY, or CIN were observed on valerate, isobutyrate or isovalerate proportions. Plasma concentrations of glucose, cholesterol, triglyceride, urea-N, ${\beta}$-hydroxybutyrate, alanine aminotransferase and aspartate aminotransferase were not changed by feeding THY or CIN. Results from this study suggest that supplementing a feedlot finishing diet with THY or CIN essential oil might be useful as ruminal fermentation modifiers in beef production systems, but has minor impacts on blood metabolites.

• Journal of the Korean Society of Food Culture
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• v.37 no.5
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• pp.446-453
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• 2022

In this study, we analyzed the antifungal activities of five essential oils (clove, rosemary, thyme, basil, and oregano) against three fungi (Penicillium oxalicum, Penicillium commune, and Cladosporium cladosporioides) isolated from farm-type fermented meat products Though their antifungal activities differed for each fungus, thyme had the greatest effect. Notably, C. cladosporioides showed the highest sensitivity to essential oils, and growth inhibitory effects were greater than for the other two strains. Additionally, ABTS, DPPH, and FRAP analysis confirmed that the five essential oils studied had antioxidant activity. ABTS analysis showed that clove (75%) and oregano (75%) oils had the highest antioxidant activities (both 93.7%). DPPH analysis showed that clove (75%) and rosemary (75%) oils had significantly greater antioxidant activities (both 93.8%) than thyme, basil, or oregano oils. FRAP results indicated that clove and basil oils were the strongest reductants. Comprehensive comparative analysis indicated that clove oil had more antioxidant activity than the other four essential oils. Overall, the study shows that the excellent antifungal properties of clove oil could be harnessed to produce safe fermented meat products by preventing rancidity and mold contamination.

• Journal of Microbiology and Biotechnology
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• v.34 no.10
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• pp.2049-2069
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• 2024

Fungi play a significant role in the deterioration of various types of monuments. Therefore, the protection of ancient monuments from fungal attacks is an important goal that must attract the attention of researchers worldwide. A total of 69 fungal isolates were recovered from 22 deteriorated objects compromising paper, textiles, wood, and stone in the National Museum of Egyptian Civilization (NMEC) storeroom, Cairo, Egypt. The isolates were identified as 12 different species categorized into three different genera, namely, Aspergillus (9 species), Penicillium (2 species) and Trichoderma (1 species). Among them, Aspergillus fumigatus was the most prevalent species. Three essential oils were assessed for antifungal activity and compared with the antifungal effects of five synthetic microcides to identify a natural inhibitory treatment. Thyme oil and sodium azide were found to be the most active growth inhibitors, with minimum inhibitory concentrations (MICs) of 625 and 100 ppm, with inhibition zone diameters of 19.0 ± 0.70 - 23.76 ± 1.15 and 13.30 ± 0.35 -- 19.66 ± 0.54 mm, respectively. An in vitro simulation of the biodeterioration process was conducted using spores of the A. fumigatus strain NMEC-PSTW.1 on model cubes made of paper, textile, wood, and stone materials. The changes in the characteristics of the artificially deteriorated materials were analyzed using environmental scanning electron microscopy/energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The results revealed changes in the morphology, physical properties, and chemical composition induced by A. fumigatus NMEC-PSTW.1. Overall, thyme oil is recommended as a natural inhibitor to protect carbonate and cellulosic monuments in NMEC against fungal attack.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.117-123
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• 2006

Fumigant toxicity of 34 plant essential oils were tested against female adults of Culex pipiens pallens. Seven oils (basil, coriander, fennel, pennyroyal, peppermint, thyme red, thyme white) showed more than 60% mortality at 1 ${\mu}L\;L^{-1}$ air concentration and pennyroyal oil appeared to have the highest adulticidal activity. GC and GC-MS analysis of the seven essential oils and bioassay of their components revealed that pulegone (a major component of pennyroyal oil) and anethole (a major component of fennel and basil oil, $LD_{50}$, ${\mu}L\;L^{-1}$ air =0.49) showed higher adulticidal activities than others. In addition to the above two components, linalool ($LT_{50}$, min=0.91), camphor ($LT_{50}$, min=1.06), fenchone ($LT_{50}$, min=1.16), 1,8-cineole ($LT_{50}$, min=2.93), and geranyl acetate ($LT_{50}$, min=1.60) also showed higher adulticidal activity than empenthrin ($LT_{50}$, min=3.45).