• Korean Journal of Weed Science
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• v.14 no.2
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• pp.156-162
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• 1994

To better understand the exact nature of the major toxic compound responsible for phytotoxicity of sorghum stem, the most toxic compound from the stem extract was isolated by rapid chromatography and subsequently purified by thin-layer chromatography(TLC) and high pressure liquid chromatography(HPLC). Of the eight fractions isolated by rapid chromatography, the fraction with solvent combinations of butanol (8) : acetic acid (1) : water (1) had the highest toxicity. Further separation of the fraction by TLC in a solvent mixture of butanol (24) : acetic acid (16.4) : water (7) : propanol (1) showed that the spot with an $R_f$ 0.71 had one major peak with retention time of 20.40 minutes. Upon subjecting gas chromatography and the HPLC fraction to the mass spectrometry, the toxic compound is probably one of the four compounds ; 1-methyl-1-(2-propynyl)-hydrazine, 1-aziridineethanol, 5-chloro-2-pentanone, and 2-(methylseleno)-ethanamine.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.591-607
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• 2020

This study was aimed to investigate the changes of chemical composition of the volatile organic compounds (VOCs) emitted from red pine needles in the process of needle abscission or senescence. The VOCs in intact, senescent, and litter red pine needle samples were analyzed by headspace-solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS). And then, multivariate statistical interpretation of the processed data sets was conducted to investigate similarities and dissimilarities of the needle samples. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the dataset structure and discrimination between samples, respectively. From the data preview, the levels of major components of VOCs from needles were not significantly different between needle samples. By PCA investigation, the data reduction according to classification based on the chlorophyll a / chlorophyll b (Ca/Cb) ratio were found to be ideal for differentiating intact, senescent, and litter needles. The following OPLS-DA taking Ca/Cb ratio as y-variables showed that needle samples were well grouped on score plot and had the significant discriminant compounds, respectively. Several compounds had significantly correlated with Ca/Cb ratio in a bivariate correlation analysis. Notably, the litter needles had a higher content of oxidized compounds than the intact needles. In summary, we found that chemical compositions of VOCs between intact, senescent, and litter needles are different each other and several compounds reflect characteristic of needle.

• Journal of Chitin and Chitosan
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• v.22 no.3
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• pp.185-193
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• 2017

Red tide Heterosigma akashiwo (H. akashiwo), a microscopic alga of the class Raphidophyceae, causes extensive damage to all marine ecosystems. It is essential to reduce the damage to marine ecosystems for them to be used as a resource. In this study, we used organic solvent fractionation to obtain an ethyl acetate-methanol extract from H. akashiwo (HAEM80) and then evaluated its anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and a zebrafish model. HAME80 markedly inhibited the production of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$). It also down-regulated the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and decreased the secretion of interleukin-$1{\beta}$ ($IL-1{\beta}$) in LPS-stimulated RAW 264.7 cells. HAME80 reduced yolk edema and improved the survival rate of LPS-stimulated zebrafish embryos; in addition, the extract significantly reduced the production of ROS and NO and attenuated cell death in this model. Gas chromatography-mass spectrometry (GC-MS) of the extract was used to confirm the identity of peaks 1-20. Taken together, our data suggest that H. akashiwo is a beneficial anti-inflammatory agent.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.66-78
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• 2019

In this study, strain KNU17Pc1 was tested for its antifungal activity against Rhizoctonia solani AG-1(IA), which causes banded leaf and sheath blight (BLSB) of maize. KNU17Pc1 was tested further for its broad-spectrum antifungal activity and in vitro plant growth promoting (PGP) traits. In addition, the in vivo effects of KNU17Pc1 on reduction of BLSB severity and seedling growth promotion of two maize cultivars under greenhouse conditions were investigated. On the basis of multilocus sequence analysis (MLSA), KNU17Pc1 was confirmed as P. chlororaphis subsp. aurantiaca. The study revealed that KNU17Pc1 had strong in vitro antifungal activity and was effective toward all in vitro PGP traits except phosphate solubilization. In this study, for the first time, a strain of P. chlororaphis against Colletotrichum dematium, Colletotrichum gloeosporioides, Fusarium oxysporum f.sp. melonis, Fusarium subglutinans and Stemphylium lycopersici has been reported. Further biochemical studies showed that KNU17Pc1 was able to produce both types of phenazine derivatives, PCA and 2-OH-PCA. In addition, solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis identified 13 volatile organic compounds (VOCs) in the TSB culture of KNU17Pc1, 1-undecene being the most abundant volatile. Moreover, for the first time, Octamethylcyclotetrasiloxan (D4), dimethyl disulfide, 2-methyl-1,3-butadiene and 1-undecene were detected in P. chlororaphis. Furthermore, this study reported for the first time the effectiveness of P. chlororaphis to control BLSB of maize. Hence, further studies are necessary to test the effectiveness of KNU17Pc1 under different environmental conditions so that it can be exploited further for biocontrol and plant growth promotion.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.55-62
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• 2021

This study aims to reduce the rancid odor generated during the fermentation process of kimchi by inserting zinc oxide (ZnO) into an inorganic porous material with a high surface area to decompose or adsorb the fermentation odor. ZnO activated by the presence of moisture exhibits decomposition of rancid odors. Mixed with Titanium dioxide (TiO₂), a photocatalyst. To manufacture the packaging liner used in this study, NaOH, ZnCl₂, and TiO₂ powder were placed in a tank with diatomite and water. The sludge obtained via a hydrothermal ultrasonication synthesis was sintered in an oven. After being pin-milled and melt-blended, the powders were mixed with linear low-density polyethylene (L-LDPE) to make a masterbatch (M/B), which was further used to manufacture liners. A gas detector (GasTiger 2000) was used to investigate the total amount of sulfur compounds during fermentation and determine the reduction rate of the odor-causing compounds. The packaging liner cross-section and surface were investigated using a scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDS) to observe the adsorption of sulfur compounds. A variety of sulfur compounds associated with the perceived unpleasant odor of kimchi were analyzed using gas chromatography-mass spectrometry (GC-MS). For the analyses, kimchi was homogenized at room temperature and divided into several sample dishes. The performance of the liner was evaluated by comparing the total area of the GC-MS signals of major off-flavor sulfur compounds during the five days of fermentation at 20℃. As a result, Nano-grade inorganic compound liners reduced the sulfur content by 67 % on average, compared to ordinary polyethylene (PE) foam liners. Afterwards SEM-EDS was used to analyze the sulfur content adsorbed by the liners. The findings of this study strongly suggest that decomposition and adsorption of the odor-generating compounds occur more effectively in the newly-developed inorganic nanocomposite liners.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.2
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• pp.153-162
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• 2022

Objectives: Fused deposition modeling (FDM) 3D printer which is one of the material extrusion (MEX) technologies is an additive manufacturing (AM) process. 3D printers have been distributed widely in Korea, particularly in school and office, even at home. Several studies have shown that nanoparticles and volatile organic compounds (VOCs) were emitted from an FDM 3D printing process. The objective of this study was to identify types of chemicals possibly emitted from FDM 3D printing materials such as PLA (polylactic acid), ABS (acrylonitrile butadiene styrene), nylon, PETG (polyethylene terephthalate glycol), PVA (polyvinyl alcohol), PC (polycarbonate) filaments. Methods: 19 FDM 3D printing filaments which have been distributed in Korea were selected and analyzed VOCs emitted of 3D printing materials by headspace gas chromatography mass spectrometry (headspace GC-MS). Subsamples were put into a vial and heated up to 200℃ (500 rpm) during 20 minutes before analyzing FDM 3D printing filaments. Results: In the case of PLA filament, lactide and methyl methacrylate, the monomer components of one, were detected, and the volume ratio ranged 27~93%, 0.5~37% respectively. In the case of ABS filaments, styrene (50.5~59.1%), the monomer components of one, was detected. Several VOCs among acetaldehyde, toluene, ethylbenzene, xylene, etc were detected from each FDM 3D printing filaments. Conclusions: Several VOCs, semi-VOCs were emitted from FDM 3D printing filaments in this study and previous studies. Users were possibly exposed to ones so that we strongly believe that we recommend to install the ventilation system such as a local exhaust ventilation (LEV) when they operate the FDM 3D printers in a workplace.

• Analytical Science and Technology
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• v.21 no.6
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• pp.526-534
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• 2008

To determine the trace level of synthetic and natural hormones in food, the improvement of official analytical method and new development of simultaneous determination of hormones were established. On the basis of developed analytical method, the background level of natural hormones and distribution of residual hormones were monitored in meat. Target hormones were six natural hormones such as estrogens ($17{\beta}$-estradiol, $17{\alpha}$-estradiol, estrone), androgens ($17{\beta}$-testosterone, $17{\alpha}$-testosterone), and gestagens (progesterone) and three synthetic hormones such as DES, zeranol, and taleranol. These hormones were analyzed by gas chromatographymass spectrometry. Newly developed multi-residue analysis method was applied for meat sample which were collected from market in the capital region and monitored the presence of residues of synthetic and natural steroid hormones. No residue of synthetic hormones were detected and endogenous level of progesterone was detected in cattle, pig and liver samples tested.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.529-532
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• 2005

Volatile compounds, isolated from Chopi (Zanthoxylum piperitum A.P. DC.) using steam distillation, were analyzed by gas chromatography/mass spectrometry-olfactometry (GC-MS-O). Forty-six volatile compounds, consisting of 12 hydrocarbons, 8 aldehydes, 5 esters, 12 alcohols, 4 ketones, 4 oxides and 1 acid, were tentatively identified from the essential oil of Chopi. Unidentified compounds constituted 7.2% of the total peak area. Limonene was the most abundant compound, followed by geranyl acetate, citronellal, cryptone and ${\beta}$-myrcene. In addition, aroma-active compounds, in particular citronellal and limonene, which are related to the citrus and Chopi flavors of Chopi essential oil, were detected. The aroma of Chopi essential oil had a score of 4.8 on the preference test (neither like nor dislike) and a score of 5.97 on the intensity test (slightly strong) using the 9-point hedonic scale.

• The Korean Journal of Ecology
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• v.20 no.6
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• pp.397-403
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• 1997

The monoterpenes and sesquiterpenes are analysed in the leaf and stem of Chrysanthemum boreale using gas chromaltography-mass spectrometry (GC-MS). The total amount of sesquiterpenes are always higher than monoterpenes in both leaf (2.0-3.4 times) and stem (1.6-8.3 times). The mono- and sesquiterpenes yields of the leaf are higher than the stem. There was no significant difference among the leaf developmental stages, while those of stem were varied. Seventeen monoterpenes and 9 sesquiterpenes compound in this plants comprised more than 5% of the mean total monoterpenes and the total sesquiterpenes in each dates. Among leaf monoterpenes, the concentration of (+)-Limonene and unknown compound no. 13 (Retention time, R.T.=17.28) varied significantly during leaf growing season, and the concentrafion of unknown compound no. 7 (R.T.=35.04) and no. 9(R.T.=35.71) varied in the leaf sesquiterpenes. Similarly the results from the leaf, the concentration of five monoterpenes in stem also varied significantly during maturing period, and much varied in seven compounds of stem sesquiterpene. The major sesquiterpenes of leaf and stem were ${\alpha}-Humulene$ and compound no. 2(R.T.=26.19).

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.18-22
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• 2008

Volatile components in field bean (Dolichos lablab) were collected by simultaneous steam distillation and solvent extraction and analyzed by gas chromatography-mass spectrometry. One hundred and five components were identified including alcohols (32), ketones (18), aldehydes (9), acid (1), alkanes (5), aromatics compounds (4), esters (2), furans (2), naphthalene (1), pyrazines (4), pyridine (3), sulfur-containing compounds (4) and terpenes (7) and miscellaneous compounds (13). Relatively high concentration of n-hexanal found in the field bean might be undesirable to some consumers.