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Pohang, South Korea

Kim S.-A.,Hanyang University | Kim S.H.,Yonsei University | Kim I.S.,Hanyang University | Lee D.,Korea University | And 4 more authors.
Food Chemistry | Year: 2013

A simple, sensitive, and precise reversed-phase liquid chromatographic method was developed for the quantitative determination of 4 bioactive phenolic compounds (gallic acid, fustin, fisetin, and sulfuretin) from the stem extract of Rhus verniciflua stokes. Chromatographic analysis was performed on a Capcell Pak C18 column (150 × 4.6 mm, 3 μm) with a mobile phase consisting of 0.1% formic acid and 90% acetonitrile at a flow rate of 1 mL/min. Quantitation was performed using a UV-vis detector at 260 nm. The method was validated in terms of selectivity, linearity, accuracy, precision, and recovery. Excellent linear behavior was observed over the investigated concentration range (10-500 μ/mL for gallic acid, fustin, and fisetin; 0.5-100 μ/mL for sulfuretin) with correlation coefficient (r2) values >0.99. The intra- and inter-day precision over the concentration range of compounds was less than 6.65% (relative standard deviation) and the accuracy was between 92.42% and 103.62%. The mean recoveries for all the analytes were more than 92.18%. This method was successfully applied for the analysis of bioactive phenolic compounds in the R. verniciflua extracts. © 2013 Elsevier Ltd. All rights reserved. Source


Park J.S.,Hanyang University | Kim I.S.,Hanyang University | Rehman S.U.,Hanyang University | Na C.-S.,Lifetree Biotech Co. | Yoo H.H.,Hanyang University
Journal of Chromatographic Science | Year: 2016

A simple, accurate and reproducible reversed-phase liquid chromatographic method was developed for qualitative and quantitative determination of four bioactive flavonoids (ampelopsin, taxifolin, myricetin and quercetin) from the fruit-stalk extract of Hovenia dulcis Thunb. Chromatographic separation was performed on a C18 column (4.6 × 150 mm, 3.5 μm) with mobile phase consisting of 0.1% acetic acid and 100% acetonitrile at a flow rate of 1.0 mL/min. The analysis was performed using a diode array detector at 365 nm. The method was validated in terms of selectivity, linearity, accuracy, precision and recovery. Good linearity was observed over the investigated concentration range (10-500 μg/mL), with correlation coefficient values greater than 0.99. The intra- and inter-day precisions over the concentration range were <3.91% (relative standard deviation), and the accuracy was between 91.57 and 106.66%. The mean recovery for all the analytes was 100.87%. This method was successfully applied in the quality assessment of bioactive flavonoids in the fruit-stalk extract of H. dulcis. © 2015 The Author 2015. Published by Oxford University Press. Source


Seo S.-M.,Lifetree Biotech Co. | Jung C.-S.,Korea forest Research Institute | Kang J.,Korea Institute of Toxicology | Lee H.-R.,Seoul National UniversitySeoul | And 3 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

This study evaluated the larvicidal activity of 12 Apiaceae plant essential oils and their components against the Asian tiger mosquito, Aedes albopictus, and the inhibition of acetylcholine esterase with their components. Of the 12 plant essential oils tested, ajowan (Trachyspermum ammi), caraway seed (Carum carvi), carrot seed (Daucus carota), celery (Apium graveolens), cumin (Cuminum cyminum), dill (Anethum graveolens), and parsley (Petroselinum sativum) resulted in >90% larval mortality when used at 0.1 mg/mL. Of the compounds identified, α-phellandrene, α-terpinene, p-cymene, (-)-limonene, (+)-limonene, γ-terpinene, cuminaldehyde, neral, (S)-+-carvone, trans-anethole, thymol, carvacrol, myristicin, apiol, and carotol resulted in >80% larval mortality when used at 0.1 mg/mL. Two days after treatment, 24.69, 3.64, and 12.43% of the original amounts of the celery, cumin, and parsley oils, respectively, remained in the water. Less than 50% of the original amounts of α-phellandrene, 1,8-cineole, terpinen-4-ol, cuminaldehyde, and trans-antheole were detected in the water at 2 days after treatment. Carvacrol, α-pinene, and β-pinene inhibited the activity of Ae. albopictus acetylcholinesterase with IC50 values of 0.057, 0.062, and 0.190 mg/mL, respectively. A spherical microemulsion of parsley essential oil-loaded poly(vinyl alcohol) (PVA) was prepared, and the larvicidal activity of this formulation was shown to be similar to that of parsley oil. © 2015 American Chemical Society. Source


Seo S.-M.,Lifetree Biotech Co. | Kim J.,Gyeongsang National University | Kang J.,Korea Institute of Toxicology | Koh S.-H.,Korea forest Research Institute | And 3 more authors.
Pesticide Biochemistry and Physiology | Year: 2014

This study investigated the fumigant toxicity of 4 Asteraceae plant essential oils and their constituents against the Japanese termite Reticulitermes speratus Kolbe. Fumigant toxicity varied with plant essential oils or constituents, exposure time, and concentration. Among the tested essential oils, those from Chamaemelum nobile exhibited the strongest fumigant toxicity, followed by those from Santolina chamaecyparissus, Ormenis multicaulis, and Eriocephalus punctulatus at 2days after treatment. In all, 15, 24, 19, and 9 compounds were identified in the essential oils from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus, respectively, by using gas chromatography, gas chromatography-mass spectrometry, or open-column chromatography. The identified compounds were tested individually for their fumigant toxicity against Japanese termites. Among the test compounds, trans-pinocarveol, caryophyllene oxide, sabinene hydrate, and santolina alcohol showed strong fumigant toxicity against Japanese termites. Acetylcholinesterase (AChE) inhibition activity of the identified compounds from C. nobile, E. punctulatus, O. multicaulis, and S. chamaecyparissus essential oils were tested to determine the mode of their action. The IC50 values of (+)-α-pinene, (-)-limonene, (-)-α-pinene, β-pinene, and β-phellandrene against Japanese termite AChE were 0.03, 0.13, 0.41, 0.42, and 0.67mg/mL, respectively. Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control. © 2014 Elsevier Inc. Source


Seo S.-M.,Lifetree Biotech Co. | Kim J.,Gyeongsang National University | Koh S.-H.,Korea forest Research Institute | Ahn Y.-J.,Seoul National University | Park I.-K.,Seoul National University
Journal of Agricultural and Food Chemistry | Year: 2014

In this study, we evaluated the nematicidal activity of natural ester compounds against the pine wood nematode, Bursaphelenchus xylophilus, to identify candidates for the development of novel, safe nematicides. We also tested the nematicidal activity of synthesized analogues of these ester compounds to determine the structure-activity relationship. Among 28 ester compounds tested, isobutyl 2-methylbutanoate, 3-methylbutyl 2-methylbutanoate, 3-methylbutyl tiglate, 3-methyl-2-butenyl 2- methylbutanoate, and pentyl 2-methylbutanoate showed strong nematicidal activity against the pine wood nematode at a 1 mg/ mL concentration. The other ester compounds showed weak nematicidal activity. The LC50 values of 3-methylbutyl tiglate, isobutyl 2-methylbutanoate, 3-methylbutyl 2-methylbutanoate, 3-methyl-2-butenyl 2-methylbutanoate, and pentyl 2- methylbutanoate were 0.0218, 0.0284, 0.0326, 0.0402, and 0.0480 mg/mL, respectively. The ester compounds described herein merit further study as potential nematicides for pine wood nematode control. © 2014 American Chemical Society. Source

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