• Korean Journal of Human Ecology
• /
• v.1 no.2
• /
• pp.89-99
• /
• 1998

This study was carried out to investigate some antioxidative effects of stewed pumpkin juice (SPJ) and the SPJs added with ginger (SPJ-G), onion (SPJ-O), jujube (SPJ-J) or boxthorn (SPJ-B), respectively, on the lipid oxidation of soybean oil (S) and mackerel pike boiled ground (MPBG). Antioxidative substances of SPJ were extracted by using the two solvent layers of n-hexane:acetone (1:1)(H) and methanol:water (7:3)M. The antioxidative effects of the extracts were observed by the peroxide value (P.O.V.) and thiobabituric acid (T.B.A.) value. The P.O.V. and T.B.A. value of two solvent extracts of S and MPBG showed significantly lower than those of S and MPBG. The SPJ showed very distingnished antioxidative effects. It was considered that melanoidine extracted by using methanol:water (7:3) solvent as well as carotenoid extracted by using n-hexane:acetone (1:1) solvent had an antioxidative effect. During storage, T.B.A. value of MPBG significantly increased, while that of MPBG-SPJ significantly decreased more than that of MPBG. T.B.A. value of MPBG-SPJs decreased much than that of MPBG-SPJ, SPJ-O, SPJ-G, SPJ-J and SPJ-B, in order of abundance, showed higher level of antioxidative effects than SPJ. (Korean J Human Ecology 1(2):89∼99, 1998)

• Journal of the Korean Chemical Society
• /
• v.29 no.5
• /
• pp.465-471
• /
• 1985

The rate constants for the solvolysis of anthraquinone-2-carbonyl chloride in binary solvent mixtures, methanol-acetonitrile, methanol-acetone, ethanol-acetonitrile and ethanol-acetone, have been studied by means of conductometry. Maximum rate phenomena were observed at the methanol mole fraction, $X_{MeOH}$ = 0.73~0.81 for methanol-acetonitrile and at $X_{MeOH}$ = 0.83 for methanol-acetone mixtures. The Kivinen and Grunwald-Winstein plots indicated that the reaction proceeds via $S_N2$ type mechanism. Application of Taft's solvatochromic correlation on the solvolysis rate revealed that both $\alpha$ and ${\pi}^*$ are important for reactions in methanol-acetonitrile and methanol-acetone mixtures, while only ${\alpha}$ influences significantly on the rate in ethanol-acetonitrile and ethanol-acetone mixtures.

• Applied Biological Chemistry
• /
• v.39 no.4
• /
• pp.315-319
• /
• 1996

The yields of methanol extracts of several Chrysanthemum spp.(5 species, 9 parts) and their solvent fractions were investigated. The yields of methanol extracts ranged from 16.9%(for flower of C. indium, Cultivated) to 31.5%(for whole plant of C. indium). In the tests of the antibacterial activity. the methanol extracts from flower of C. zawadskii and C. boreale, whole plant of C. zawadskii, and flower of C. coronarium showed excellent antibacterial activity. Generally, the chloroform fractions exhibited stronger antibacterial activity against all the bacteria tested when compared with other solvent fractions. In case of C. boreale, the chloroform fraction of the whole plant was shown stronger antibacterial activity against all four bacterial strains tested when compared with that of the flower. The chloroform fractions from flower and whole plant of C. boreale and C .zawadskii, and flower of C. coronarium were shown a similar TLC pattern.

• Korean Journal of Medicinal Crop Science
• /
• v.12 no.5
• /
• pp.349-354
• /
• 2004

The extracts of Pinus densiflora sawdust by n hexane, ethyl acetate and methanol solvent were investigated to identify their mycelial growth inhibition against Lentinus edodes. The yields of n hexane soluble fraction, ethyl acetate-soluble fraction, and methanol soluble fraction from P. densiflora sawdust were obtained 1.36%, 2.21% and 4.03% using organic solvent, respectively. The mycelial growth inhibition of L. edodes was the greatest for n hexane extract, ranging from 36.5% to 47.6% at concentrations of 125 ppm to 1,000 ppm, with the values for all concentrations significantly different from one another. After direct extraction of P. densiflora sawdust using n hexane, ethyl acetate and methanol, each extract was separated into three fractions by silica gel column chromatography and then the fractions were isolated on the values of $R_f$ by thin layer chromatography. The mycelial growth inhibition against L. edodes was recognized in the fractions II (33.5%) and III (37.6%) of n hexane extract, the fraction II (21.4%) of ethyl acetate extract and the fraction II (26.4%) of methanol extract. The fractions III of n-hexane extract showed the highest growth inhibition among the nine fractions of the organic solvent extract.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.1
• /
• pp.20-29
• /
• 2016

Objectives: The purpose of this study is to simplify and standardize analytical method of polar solvents(methanol, isopropanol, n-butanol, acetone, methylene chloride and MIBK) in the working environmental by GC. Because NIOSH methods are various and complicated. Methods: The method is using the same stationary phase(5% phenyl 95% dimethylpolysiloxane), absorbent(silica gel) and desorption solvent(DMSO) for above 6 solvents. For the 6 solvents desorption efficiency, calibration curve, and limit of detection were studied Results: As the results, 6 solvents{2 groups ; first group(methanol/isopropanol/butanol) and second group(acetone/methylene chloride/MIBK)} could be separated and quantified within 10 minutes. Desorption efficiency from silica gell of 6 solvents using dimethylsulfoxide(DMSO) was methanol 86.2%, isopropanol 103.2%, n-butanol 101.8%, acetone 98.2%, methylene chloride 103.9% and MIBK 106.2% in the range of 0.2, 0.5, 2.0 times of TWA, consequently, satisfied NIOSH estimation level(beyond 75%). Correlation coefficient(r)in the range of 0.2~2.0 times of TWA, was above 0.999 for 6 solvent. LOD(mg/DMSO ml) using calibration curve in the range of 0.2~2 times of TWA was methanol 0.11, isopropyl alcohol 0.20, n-butanol 0.03, acetone 0.50, methylene chloride 0.05, MIBK 0.04 respectably. Conclusions: This method can be used at the sampling and analytical method for polar solvents by GC. Also, will be able to be applied with NIOSH methods.

• Journal of Soil and Groundwater Environment
• /
• v.17 no.1
• /
• pp.42-46
• /
• 2012

The ISO document of ISO/TC/190/SC3/WG11/N11 is a working draft of international standard (WD) dealing with analytical method for the determination of explosives and related compounds using high performance liquid chromatography. The scope of this WD covers the storage of samples, preparing test portion, extraction and instrumentation. The main purpose of this study was to improve the extraction conditions which were already adopted in the WD. For this purpose, mechanical shaking method could be corresponded up to 18 hours of ultrasonic bath extraction in the WD was tested. Methanol was also tested with the intention of being added as an extracting solvent other than acetonitrile in the WD. According to the results, 16 hours of mechanical shaking method showed statistically the same effectiveness as that of 18 hours of ultrasonic bath extraction. In case of extracting solvent, methanol also showed statistically the same extraction capability as acetonitrile for DNB, TNT, 2-A-DNT and 2,4-DNT. However, the recovery rate of TNB with methanol extraction was 40% higher than that of acetonitrile extraction. Through adding mechanical shaking method into committee draft (cf. the next stage draft of the WD during the process for making international standard), ISO standard of analyzing explosives and related compounds in soil would become more useful in dealing with huge number of field samples in the laboratory. In other aspect, adopting methanol as an alternative extracting solvent would be very effective in the terms of exchangeability with GC-ECD/MS method which is being developed by German experts.

• Journal of Life Science
• /
• v.6 no.1
• /
• pp.66-71
• /
• 1996

Antioxidative activity of various solvent extracts from freeze dried Kimchi was studied during the oxidation process of linoleic acid mixture system. The aqueous model systems were used for the evaluation of antioxidative activity of solvent extracts during the oxidative reaction at 37$^{\circ}C$ by the determination of peroxide value. The linoleic acid mixture for the aqueous model systems was consisted of linoleic acid (64.6%), oleic acid(27.4%), and other acids in ethanolic phosphate buffer (pH 7.0). Water and methanol extracts of Kimchi had a considerable antioxidative activity with the inhibition of peroxides formation during the autoxidation of linoleic acid mixture in aqueous model systems. Antioxidative activity of 75% methanol extract of 7 day-fermented-Kimchi was relatively higher than that of others, however lower than alpa-tocopherol and butylated hydroxyanisol. The antioxidative effect of 75% methanol extract of 7 day-fermented-Kimchi was increased by the its concentration from 0.5% to 2.5% in the oxidation reactions of aqueous model systems.

• Korean Journal of Medicinal Crop Science
• /
• v.18 no.1
• /
• pp.28-33
• /
• 2010

Glycyrrhiza uralensis (Leguminosae) is a well-known herbal medicine that has long been valued as a demulcent to relieve inflammatory disorders. To compare the influence of different solvents on the anti-inflammatory efficacy of G. uralensis, we measured the inhibition of pro-inflammatory mediators such as NO, TNF-$\alpha$, and $PGE_2$ in lipopolysaccharide (LPS)-stimulated mouse macrophage RAW 264.7 cells by extracts produced using different solvents (water, methanol, ethanol, or n-hexane). The results showed that methanol was the most effective solvent for the inhibition of both NO and $PGE_2$ production in RAW 264.7 cells. However, there was no difference among the extracts for inhibition of TNF-$\alpha$. Further study must be performed for the analysis of correlation between the anti-inflammatory activity of extracts produced using different solvents and the content of major bioactive compounds in G. uralensis, such as glycyrrhizin and liquiritin. The present study suggests that methanol may be a more appropriate solvent of G. uralensis than other solvents (water, ethanol, and n-hexane) to yield the greatest anti-inflammatory activity for food additives and medicine.

• Bulletin of the Korean Chemical Society
• /
• v.21 no.6
• /
• pp.653-655
• /
• 2000

• Korean Journal of Microbiology
• /
• v.31 no.4
• /
• pp.306-311
• /
• 1993

The effects of methanol. used as a solvent for the hydrophobic substrate progesterone. on the morphology of Rhizopus nigricans and 11$\alpha$-hydroxylation of progesterone was investigated. The methanol tolerance of the 11$\alpha$-hydroxylase system in polyacrylamide immobilized R. nigricans mycelia as well as in free mycelia has been induced by adding various unsaturated fatty acids. biotin and ions into the cultivation medium. Immobilization of the cell seemed to protect the cells from denaturation by methanol. It gave higher reaction rate of progesterone than the free mycelia in the presence of methanol.500 $\mu$g/l of biotin was found to be the most effective induction agent for the methanol tolerance among tested chemicals. R. nixricans cells sustained its enzymatic activity at higher methanol concentrations as a result of accumulation of unsaturated fatty acids. especially oleic acid. in the membrane phospholipid.