• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.53-59
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• 2001

The needles of torreya(Torreya nucifera S. et Z) were collected, extracted with acetone-$H_2O$(7:3, v/v), fractionated with hexane, chloroform and ethylacetate, and freeze dried to give some dark brown powder. The ethylacetate soluble mixture was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Most of the needle extractives were flavan and its methyl ether compounds such as (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin, 3'-O-methyl-(+)-catechin and 3'-O-methyl-(-)-epicatechin including protocatechuic acid, one of benzoic acids. $^1H$- and $^{13}C$-NMR, NOE and CI-MS analyses were performed to elucidate the structures of the isolated compounds.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.497-503
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• 1992

To study antioxidative activities of Ganoderma lucidum, its extracts were fractionated by various organic solvents with different polarity the extracts were purified by thin chromatography, silicagel column chromatography and preparative liquid chromatography. In antioxidative activity tests using thiocyanate method, TBA method and weighing method, fraction 5 from the hexane extract and fraction II from the methanol extract showed antioxidative activity. When the antioxidative activities were expressed as TBA value using a homogeneous liver extracte of rats, the relative antioxidative activities of fraction 5 and fraction II were increased by 13.0% and 54.6%, respectively.

• Membrane Journal
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• v.3 no.1
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• pp.29-34
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• 1993

Reverse osmosis(RO) and pervaporation(PV) membrane processes were compared with each other theoretically by using Paul and Ebra-Lima model. From this model the concentrations of liquid within the membrane when pressure was applied to the upper compartment(for PV case, the applied pressure is infinite) were calculated for rubber membrane-n-hexane and rubber membrane-benzene systems. The permeabilities of RO and PV were also calculated and compared for polyethylene film-n- hexane and polyethylene film- benzene systems Theoretically, the permeabilities of PV membrane were greater than those of RO membrane.

• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.41-48
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• 2002

The barks of oak trees (Quercus acutissima and Quercus variabilis) were collected, extracted with acetone-$H_2O$ (7:3, v/v), fractionated with hexane, $CH^2C1^2$ EtOAc and -$H_2O$, then freeze dried to give dark brown powder. The EtOAc soluble mixtures of the trees were chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The structures of isolated compounds were characterized by $^1H$, $^13C$ and 2D-NMR spectroscopy and molecular weights were determined by FAB-MS spectra. The isolated compounds from Quercus acutissima were (+)-catechin, (+)-gallocatechin, gallic acid and taxifolin-3-O-$\beta$-D-glucopyranoside and the compounds from Quercus variahilis (+)-catechin, caffeic acid and taxifolin-3-O-$\beta$-D-glucopyranoside.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.865-870
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• 1996

Antitumor effects of hexane, chloroform fractions and tannins from persimmon leaves were studied by using sarcoma-180 tumor cells. The solid tumor growth was inhibited most effectively when 0.5mg/kg of hexane fraction was administerated to the Balb/c mouse. The life prolongation effects were 35.6%, 11.5% and 29.9%, respectively when hexane fraction, chloroform fraction and tannins from the persimmon leaves were administerated to the mouse. Spleen index, a marker for immunological activity, was increased in mice administrated hexane fraction, chloroform fraction and tannins of persimmon loaves, compared with the control group.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.622-628
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• 2014

The aim of this work is to evaluate the potential of oriental melon (Cucumis melo L. var. makuwa Makino) seeds for the management of type 2 diabetes by controlling glucose absorption. The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effects of the hexane extracts from oriental melon seeds were investigated. A bioassay-guided fractionation technique was used to elucidate the principal active components. The results show that the hexane extract from oriental melon seeds exhibited high inhibitory activities against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The hexane extract was further fractionated into four sub-fractions. Among them, the sub-fraction F-1 exhibited the most potent anti-diabetic effect. The active components were isolated and identified by gas chromatography/mass spectroscopy (GC-MS). Free fatty acids showed significant hypoglycemic activity (p < 0.001) and fatty acid composition influenced enzyme inhibitory activities. These results suggest that oriental melon seeds could be used to prevent type 2 diabetes.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.719-724
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• 2018

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for a number of infections in humans that are difficult to treat, and as a result, is a substantial contributor to morbidity and mortality. In the present study, in search of natural products capable of inhibiting this multidrug-resistant bacterium, we investigated the antimicrobial activity of Lysimachia clethroides Duby root. The antibacterial activities of EtOH extract of Lysimachia clethroides Duby root and its n-hexane, EtOAc, n-BuOH and water fractions were evaluated against 15 strains of methicillin-resistant staphylococcus aureus (MRSA) and 1 standard methicillin-susceptible S. aureus (MSSA) strain by using the minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test. Antimicrobial activity of n-hexane fraction of Lysimachia clethroides Duby root was remarkable. Against the 16 strains, the minimum inhibitory concentrations (MICs) were in the range of $31.25-62.5{\mu}g/ml$ and FICI values for n-hexane fraction of Lysimachia clethroides Duby root+AM and n-hexane fraction of Lysimachia clethroides Duby root+OX were checkerboard method performed using the MRSA, MSSA and one clinical isolate strains via MICI 0.12-1 and 0.25-0.75, showing the increase of synergistic effect. When combined together, these antibiotic effects were dramatically increased. These effective combinations could be new promising agents in the management of MRSA.

• Current Photovoltaic Research
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• v.7 no.1
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• pp.21-27
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• 2019

Lifetime of Si photovoltaics modules are about 25 years and a large amount of waste modules are expected to be discharged in the near future. Therefore, the extraction and collection of valuable metals out of discharged Si modules will be one of the important technologies. In this study, we demonstrated that supercritical $CO_2$ extraction method can be effectively used to remove Cu, one of the abundant elements in the module, as well as its oxide form, $Cu_2O$. Especially, we proved that the addition of hexane as co-solvent is effective for the removal of both materials. The optimal ratio of $CO_2$ and hexane was 4:1 at a fixed temperature and pressure of $250^{\circ}C$ and 250 bar, respectively. In addition, it was proven that the removal of $Cu_2O$ was preceded via reduction of $Cu_2O$ to Cu.

• Fisheries and Aquatic Sciences
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• v.25 no.8
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• pp.417-428
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• 2022

This study aimed to determine the antibacterial activity and toxicity of methanol and hexane extracts of Halymenia durvillei red seaweed which were found abundantly in Kayangan island, South Sulawesi. The antibacterial activity of the crude extract was tested against five gram-negative bacteria, namely Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Aeromonas hydrophila, and Vibrio harveyi at a dose of 200 g/disk. Extract toxicity was tested on Artemia salina larvae at concentrations of 1,000, 500, 250, 125, 62.5, and 31.25 ㎍/mL. The results showed that the methanol and hexane extracts of H. durvillei had the highest activity against S. thypi and A. hydrophila, respectively, with inhibition zones of 26.2 mm and 21.0 mm. On the other hand, the two extracts did not show activity against E. coli and P. aeruginosa, respectively. The toxicity of the methanol extract of H. durvillei was twice as high as that of the hexane extract with half-maximal inhibitory concentration of 98.24 and 184.21 ㎍/mL, respectively. Thus, the methanol and hexane extracts of red seaweed H. durvillei have the potential as new antibacterial agents respectively against the pathogenic bacteria S. typhi and A. hydrophila, but also have the opportunity to be developed into antitumor herbal compounds.

• Korean Journal of Agricultural Science
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• v.39 no.3
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• pp.377-386
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• 2012

To reduce the saturation level of lard, solvent fractionation with hexane and acetone was carried out. The fatty acid compositions of lard were 1.5% myristic acid, 26.0% palmitic acid, 2.2%, palmitoleic acid, 12.1% stearic acid, 44.7% oleic acid, and 12.7% linoleic acid. Lard was fractionated by various conditions such as different fractionation temperatures (-15, 5, 10, $15^{\circ}C$), solvent ratios (1:1, 1:3, 1:5, 1:10, lard : solvent, w/v), and fractionation time (3, 6, 24 hr). At $-15^{\circ}C$, acetone was better for reducing the content (11.2%) of saturated fatty acids (SFA) than hexane (10.8%) when the 1:5 solvent ratio was used at 24 hr. Triacylglycerol (TAG) profiles were analyzed by reversed-phase high performance liquid chromatography based on the partition number (PN) of TAG molecules. The PN of major TAG species in lard were 46 (24.4%), 48 (55.7%), and 50 (19.9%). However, after fractionation (1:5, $5^{\circ}C$ and 24 hr), TAG species with a PN of 46 (34.2%), 48 (54.4%), and 50 (6.9%) were major components in acetone-fractionated lard (liquid part), while TAG species with a PN of 46 (26.0%), 48 (50.3%), and 50 (19.0%) were in hexane-fractionated lard, suggesting that fractionation with acetone resulted in maximal reduction of saturation level in lard.