• Journal of Korean Society on Water Environment
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• v.40 no.1
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• pp.36-46
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• 2024

Microplastics in water resources have been recognized as a serious problem. The discharge of microplastics from wastewater treatment plants is considered a major contributor to environmental pollution in water resources. However, a reliable analytical method for quantifying microplastics in wastewater treatment plants has not yet been established. This study proposes a reliable, quick, and easy analytical method for quantifying microplastics. For the removal of organic particles, preprocessing steps were applied including oxidation, sonication, washing, and sieving. Nile Red staining was used to visualize microplastics, and quantitative analysis was conducted using fluorescent imaging. The stained microplastics were ultimately quantified through image analysis software. Among the preprocessing steps, sonication and washing stages were particularly effective in efficiently removing interfering substances from wastewater, enhancing the accuracy of the microplastic analysis. Additionally, various solvents (methanol, acetone, and N-hexane) for the Nile Red staining solution were tested. When N-hexane was applied as the solvent, the quantity of stained microplastics was lower compared to methanol and acetone. This suggests that N-hexane has a greater potential of reducing false staining and counting of non-plastic particles. In summary, this research demonstrates a robust method for quantifying microplastics in wastewater treatment plants by employing effective preprocessing steps and optimizing the staining process with Nile Red and N-hexane.

• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.134-144
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• 2024

This study aimed to analyze the anti-termite properties of tamanu (Calophyllum inophyllum L.) stem bark extracts against subterranean termites, specifically, Coptotermes curvignathus. The bark powder of C. inophyllum was extracted using different solvents, such as n-hexane, ethyl acetate, and methanol, using the maceration method. Anti-termite testing was performed using two paper disc methods: no- and two-choice tests. Whatman test paper was dripped with the extract solutions at concentrations of 4%, 6%, 8%, and 10% (w/v). Subsequently, the treated paper disc was placed into an acrylic tube, and the subterranean termite was added. The parameters utilized in the test included termite mortality and the weight loss of the test paper. The results revealed that the total extract yield of C. inophyllum stem bark was 30.24%. Furthermore, the extractive substances from C. inophyllum bark exhibited anti-termite activity. The most favorable outcomes were obtained with the n-hexane and ethyl acetate extracts at a concentration of 10%. The termite mortality and weight loss of the test paper were respectively 66% and 5.67% for the n-hexane extract and 66.67% and 6.19% for the ethyl acetate extract. In addition, the n-hexane extract contained friedelan-3-one, while the ethyl acetate extract contained 1,2-benzene dicarboxylic acid, dinonyl ester, and friedelan-3-one. The results suggested that these compounds are responsible for the observed anti-termite activity.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.5-11
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• 2017

18 flowers of Compositae family were collected and extracted in aqueous methanol (MeOH). The concentrated extract was partitioned into n-hexane, ethyl acetate (EtOAc), n-BuOH, and water fractions. The extract and fractions were evaluated for total phenolics, total flavonoids, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and tyrosinase inhibition activity. n-Hexane and EtOAc fractions of Aster yomena, n-hexane fraction of Cosmos bipinnatus White, n-hexane and EtOAc fractions of C. bipinnatus Pink showed high total phenolics. And EtOAc fractions of A. yomena, C. bipinnatus White, C. bipinnatus Red, C. morifolium Froggy, and C. morifolium Himaya exhibited high total flavonoids. EtOAc fractions of A. yomena, C. bipinnatus White, C. bipinnatus Pink, C. morifolium Yellowmable, and MeOH extract of C. morifolium Rosa significantly scavenged DPPH radical. EtOAc fractions of C. chinensis, C. bipinnatus White, C. bipinnatus Red, C. morifolium Himaya, and C. morifolium Hongsim highly inhibited the tyrosinase activity. A. yomena, C. bipinnatus White, C. bipinnatus Pink, C. bipinnatus Red and C. morifolium Himaya are evaluated as good source for whitening cosmetics materials.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.1-7
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• 1999

Antioxidant activity of a methanol extract of Symphyocladia latiuscula was evaluated by the thiocyanate method in the linoleic acid system. The methanol extract inhibited the peroxidation of linoleic acid in a dose-dependent manner. The MeOH extract was then sequentially partitioned with n-hexane, $CH_2Cl_2$, EtOAc, n-BuOH and H20. The antioxidant activity of the fractions increased in order of $CH_2Cl_2$, n-hexane, EtOAc, and n-BuOH. There was no activity found in $H_2O$ partitoned fraction by the thiocyanate method. Especially, the activities of the fractions of n-hexane and $CH_2Cl_2$ were comparable to that of 2,6-di-tert­butylhydroxytoluene (BHT). Column chromatography of the $CH_2Cl_2$ fraction over silica gel yielded cholesterol (1) and 2,3,6-tribromo 4,5-dihydroxybenzyl methyl ether (2) which were identified by instrumental analysis of MS and $^1H-$ and $^{13}C-NMR$. The latter (2) demonstrated significant antioxidant activity.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.336-340
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• 2011

The aim of this study was to investigate the possible utilization of Zanthoxylum schinifolium as a source of antimicrobial agents. The antimicrobial effects of Zanthoxylum schinifolium extracts were investigated against Acinetobacter baumannii, which is a multi-drug resistant pathogen, and 5 other pathogenic microorganisms. The hexane extract of Zanthoxylum schinifolium was more effective than the ethyl acetate, n-butanol and methanol extracts which were active against Acinetobacter baumannii 25, with minimum inhibitory concentrations(MIC) ranging from 0.8 mg/ml to 1.6 mg/ml. Tetracycline had no effect on Acinetobacter baumanniii. The hexane extract was highly active against Candida albicans IFO 6258, with an MIC of 1.5 mg/ml. In contrast, the ethyl acetate, n-butanol and methanol extracts showed no activity against the 5 pathogenic microorganisms. Furthermore, a combination of hexane extract and ethyl acetate extract was significantly more active against the 5 Acinetobacter baumannii strains than n-butanol and methanol. These results suggest that Zanthoxylum schinifolium extracts have great potential as antimicrobial compounds against multi-drug resistant pathogens, and further studies are warranted.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.36-40
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• 1998

Areca catachu L. which was showed antimicrobial activity against intestinal pathogens through screening herbs related treatments of intestinal diseases, were extracted by methanol and fractionated by n-hexane, ethylether, ethylacetate, and water. Antimicrobial activities of the methanol extract and each fractionates were then investigated under the anaerobic broth system. All fractions of Areca catachu L. except of n-hexane showed antimicrobial activity against all tested pathogens. Especially, ethylacetate fraction of them had the most significant inhibition activity. There is no significant difference of antimicrobial activity among each fractionates. Fraction of Areca catachu L. ethylacetate fractionate, which were fractionated by Sephadex G-200 and Silica gel column chromatography revealed the strongest antimicrobial activity at 5 to 7 and 20 of fraction number, respectively.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.111-114
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• 2004

This study was carried out to evaluate the inhibition of growth and collagenase activity of Salvia miltiorrhiza Bunge against microorganisms causing periodontal diseases. The ethanol extract of Salvia miltiorrhiza showed sig-nificant growth inhibition against microorganisms causing periodontal diseases. Ethanol extract was further fractionated with organic solvents in the order of hexane, chloroform and ethyl acetate. Among the fractions tested, the hexane fraction showed the highest cell growth inhibition. The minimal inhibitory concentration (MIC) of the extract against C. curvus, C. rectus, E. corrodens, F nucleatum, P. gingivalis, P. intermedia and W. succinogenes were 200, 50, 50, 250, 150, 250 and 200 ${\mu}g$/ml, respectively. The inhibition of collagenase activity by organic solvent fractions were higher than that of minocycline, and the inhibition ratio of collagenase activity was $88.2{\pm}2.1$ % in the chloroform fraction.

• Journal of Powder Materials
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• v.10 no.1
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• pp.6-14
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• 2003

The purpose of the present study is to investigate the method decreasing debinding time as well as lowering operation condition than pure supercritical $CO_2$ debinding by using cosolvent or binary mixture of propane + $CO_2$. First method is to add cosolvent, such as n-hexane, DCM, methanol, 1-butanol, in supercritical $CO_2$. In case of adding cosolvent, we were found the addition of non-polar cosolvent (n-hexane) improves dramatically the binder removal rate (more than 2 times) compared with pure supercritical $CO_2$ debinding, second method is to use mixture of supercritical propane + $CO_2$, as solvent. In case of using mixture of supercritical propane + $CO_2$, the rate of debinding speeded up with increasing of pressure and concentration of propane at 348.15 K. It was found that addition of cosolvent (e.g., n-hexane, DCM) and binary mixture propane + $CO_2$ for supercritical solvent remarkably improved binder removal rate for the paraffin wax-based binder system, in comparison with using pure supercritical $CO_2$.

• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.477-482
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• 1997

To investigate the cytotoxicity of Korean traditional fermented soybean products using the MTT assay, we extracted soybean, Kanjang, Doenjang, Kochujang, and Chongkukjang with water, methanol, and hexane. Primary testing of cytotoxicity of 14 extracts was done for P388D1(mouse lympoid neoplasm) and L1210(mouse leukemia) cell lines. Doenjang methanol extract, Kochujang hexane extract, Chongkukjang methanol extract, and Chongkukjang hexane extract showed cytotoxicity of 86.1, 94.3, 83. 6, and 81.1%, respectively against P388D1, and showed cytotoxicity of 69.4, 96.9, 51.4, and 95.1%, respectively against L1210. All the other extracts showed less than 50% cytotoxicity. Methanol extracts of Doenjang and Chongkukjang showed dose-dependent cytotoxicity against P388DI, L1210, SNU-16 (human stomach cancer), HepG2(human hepatic cancer), WiDr(human colon cancer) cell lines, and IC$_{50}$ of Doenjang methanol extract was 67.7, 90.4, 1338.0, 706.4, and 371.2 $\mu$g/ml, respectively, and IC$_{50}$ of Chongkukjang methanol extract was 107.1, 228.3, 756.2, 1346.0, and 327.0 $\mu$g/ml, respectively.

• Membrane Journal
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• v.14 no.2
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• pp.157-165
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• 2004

PU/PDMS(Poly urethane/poly(dimethylsiloxane ) membranes were prepared to enhance chemical resistance over VOCs from 4,4'-diphenylmethane diisocyanate (MDI), poly(dimethylsiloxane) (PDHS). Swelling characteristics and vapor permeation performance of toluene, 1,2-dichloroethane, hexane through PU/PDMS membrane with various feed VOCs concentration were investigated. Swelling ratio of VOCs showed tendency of Toluene > 1,2-dichloroethane > hexane. Fiux of toluene and 1,2-dichloroethane increased with increasing fled concentration while the flux of hexane maintained with increasing feed. VOCs concentration in permeate maintained 50 wt% oi concentration due to high affinity of PU/PDHS membranes to VOCs.