• Journal of Conservation Science
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• v.3 no.1 s.3
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• pp.23-30
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• 1994

This thesis researched for the conservation of a suit of armor that General Jung, Choong Sin had been worn in the 17th century, and of military uniform that was in perfect condition even though it had been underground for over 300years since 1676. As the armor was made with silk and cotton, it was treated by the dry cleaning method and the mild charge system. In the dry cleaning method, the used solvents were n-hexane and n-decane. And the percentage of the dry soap was 2 in the mild charge system. As the military uniform was made with only silk, it was treated by the dry cleaning method through the solvent of n-hexane and n-decane. Armor was repaired by scoured hemp partially, but military uniform became too deteriorated seriously to repair.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.521-527
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• 2000

The root of Heracleum moellendorffii was extracted with methanol and extract was fractionated with n-hexane, $CHCI_3$ and n-BuOH. Repaeated column chromatography of silica gel, sephadex LH 20 and ODS led to the isolation of ten compounds from n-hexane fraction and n-BuOH fraction. On the basis of spectroscopic evidences, the structures of isolated compounds were identified as isobergapten, psoralen, angelicin, sphondin, xanthotoxin, skimmin, cichoriin, $heratomol-6-O-{\beta}-D-glucopyranoside$, scopolin and apterin.

• Journal of Aquaculture
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• v.15 no.3
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• pp.139-143
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• 2002

Saringosterols have been isolated from the sponge Penares incrustans. The structure of these compounds have been determined by extensive 2-D NMR experiments such as $ ^1 H$ COSY, HMQC, and HMBC and by comparison with published data. Assignment for carbons of saringosterols for the first time has been done.

• The Korean Journal of Food & Health Convergence
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• v.4 no.2
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• pp.17-23
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• 2018

Carica papaya is an important medicinal plant used in the management of different disease conditions. Phytochemical screening was carried out using different chemical test, Percentage yield and total phenolic content was evaluated using Folin Ciocalteu method in different solvent system; methanol, ethanol, ethyl acetate, n-butanol and n-hexane respectively. The phytochemical screening of the studies showed the presence of flavonoids, saponins, tannins, terpenoids, glycosides, steroids, carbonhydrate, anthraquinone and alkaloids. The percentage yield of crude extract and total polyphenol content was high in methanol, ethanol and ethyl acetate when compared with n-butanol and n-hexane. The studies show that Carica papaya leave extracts is a potent source of secondary metabolites. The use of the plant in the management of diseases is justified.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.283-286
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• 2010

A sensitive and reproducible method for the flotation-spectrophotometric determination of zirconium is reported. The method is based on the complex formation zirconium and xylenol orange (XO) which is floated in the interface of aqueous phase and n-hexane by vigorous shaking. By discarding the aqueous solution and n-hexane, the adsorbed complex on to the wall of a separating funnel was dissolved in a small volume of methanol solvent and its absorbance was measured at 429 nm. The effect of different parameters such as pH, concentrations of HCl, and XO, and volume of n-hexane flotation dissolvent, standing and shaking time were studied. The calibration curve was linear in the range of 7-120 ng $mL^{-1}$ of zirconium with a correlation coefficient of 0.9991. The limit of detection (LOD) was 5.8 ng $mL^{-1}$. The relative standard deviation (RSD) for seven replicate measurements of 50 and 110 ng $mL^{-1}$ of zirconium were 4.4 and 3.0%, respectively. The method was successfully applied to the determination of zirconium in water samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1640-1648
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• 2009

This study was carried out to investigate the antioxidant activity of bamboo (Sasa borealis) leaf extract by measuring electron donating ability, superoxide dismutase (SOD)-like activity, reducing power, and lipid peroxidation inhibitory activity. Two crude extracts by water or 70% EtOH and five fractions of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous from the crude extract of 70% EtOH were prepared for this study. The crude extracts of water and 70% EtOH yielded 8.5% and 11.4%, respectively and the yields of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous fractions were 5.1% to 0.6%. Total polyphenol contents of the water and the 70% EtOH crude extracts were not significantly different; however, their total flavonoid contents were significantly greater in the 70% EtOH than in the water crude extract. Total polyphenol contents were the highest in chloroform fraction followed by ethyl acetate and n-butanol fractions and total flavonoid contents were the highest in ethyl acetate fraction followed by chloroform and n-hexane fractions. The two crude extracts as well as the five fractions showed election donating ability, SOD-like ability, reducing power, and lipid peroxidation inhibitory activity. Most of the antioxidant activities of each crude extract or fractions increased proportionally with the concentration. These results indicate that bamboo (Sasa borealis) leaf extracts show antioxidant activities due to its substantial content of polyphenol including flavonoid. Thus, it could be concluded that crude extracts by water or 70% EtOH and the fractions from the 70% EtOH extract, especially chloroform, ethyl acetate and n-butanol, would be useful as natural antioxidant substances.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.317-326
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• 2017

The wood and bark of Hawthorn tree (Crataegus pinnatifida Bunge) were immersed with 70% aqueous acetone for 3 days. After filtering, the wood extracts were fractionated with n-hexane, chloroform ($CHCl_3$), n-butanol (n-BuOH) and $H_2O$, and the bark extracts were fractionated with n-hexane, $CHCl_3$, ethylacetate (EtOAc) and $H_2O$. Then antioxidative and anti-inflammatory activities were evaluated on each fraction. Antioxidative activity indicated high activity in the n-butanol soluble fraction of wood and in the EtOAc soluble fraction of bark. Especially, the EtOAc soluble fraction of bark showed much higher antioxidative value compared to the controls, buthylated hydroxytoluene (BHT) and ${\alpha}$-tocopherol. In the anti-inflammatory activity, all of the tested fractions except the $H_2O$ soluble fraction of wood showed high inhibitory effect on nitric oxide (NO) production. Based on the above results, the extracts of hawthorn tree may be applied for one of the natural biomass sources that can be used as an antioxidant and an anti-inflammatory substance.

• Journal of Life Science
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• v.26 no.10
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• pp.1196-1201
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• 2016

The ovary parts of Nelumbo nucifera were extracted in 80% methanol (MeOH), and the concentrated extract was then partitioned using n-hexane, ethyl acetate (EtOAc), n-butanol (n-BuOH), and H₂O, successively. Using an octadecyl silica gel (ODS) column, silica gel (SiO₂) column chromatography, and a HPLC purification system, five compounds were isolated from the n-hexane fraction obtained from the extract of N. nucifera ovary. The chemical structures of the metabolites were determined using several spectroscopic methods, including NMR and GC/MS and MS of 1-eicosanol (1), cycloartenol (2), trans-squalene (3), pentadecanoic acid (4), and β-sitosterol (5). This study is a first attempt to isolate and identify secondary metabolites from the ovary of N. nucifera. The results indicated that the extract of N. nucifera ovary has biological effects, such as antibacterial and -tumor activity. Therefore, it could decrease the risk of HIV transmission through breastfeeding.

• Korean Journal of Crystallography
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• v.6 no.1
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• pp.36-42
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• 1995

Two types of single crystals of the title compound [6-(2-pyridyl)-3, 5-hexadiyn-ol, PyHxD] were obtained by solution of n-hexane/CH2C12 and n-hexane/Et2O, and their molecular conformations are proved identical in spite of different of space groups; C22H18N2O2 (I), Mr=343.70, Monoclinic, Pa, a=14.595(2), b=5.413(2), c=12.218(2)Å, β=96.86(1)°, V=958.3Å3, Z=2, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=292K, R=0.104 for 756 unique observed reflections. An asymmetric unit contains a dimer connected by two N-H…O intermolecular hydrogen bonds. C11H9NO (II), Mr=171.85, Monoclinic, P21/a, a=14.611(2), b=5.423(6), c=12.191(2)Å, β=96.89(1)°, V=959.0Å3, Z=4, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=293K, R=0.066 for 824 unique observed reflection. The structural asymmetric unit contains a molecule, but two N-H…O hydrogen bonds related by controsymmetry make the molecules form a dimer. In both structure, the dihedral angle between the planar pyridyl ring and the plane defined by C(10)-C(11)-O connected by linear diyne chain is approximately normal, and the molecules are stacked along b-axis with the unit repeat of b-axis.

• Bulletin of the Korean Chemical Society
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• v.3 no.2
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• pp.81-82
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• 1982

Lithium n-butylborohydride generated from n-butyllithium and borane-dimethyl sulfide complex in equimolar ratio in toluene-n-hexane is exceedingly effective for selective 1,2 reductions of enones.