• Bulletin of the Korean Chemical Society
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• v.9 no.4
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• pp.202-206
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• 1988

In order to investigate the oligomerization state of the plasma membrane proteolipid apoprotein purified from the bovine kidney, fluorescence polarization experiment was carried out in the two different solvent systems, i.e., water and organic solvent(chloroform-methanol). The molecular volumes of the proteins estimated from the Perrin equation, were to be 45,258$A^3$ and 17,608$A^3$ in water and organic solvent, respectively. These values indicate that a trimerization is possibly occurring in the aqueous environment. As an auxiliary experiment for the calculation of the molecular volume using Perrin equation, fluorescence quenching constants ($K_q$) with the quencher acrylamide and fluorescence lifetimes (${\tau}_F$) of the intrinsic fluorophore tryptophan residue were estimated in the two different solvent systems. $K_q$ in water was 18.21$M^{-1}$ and it was 46.24$M^{-1}$ in organic solvent. Fluorescence lifetimes of tryptophan residue were calculated to be 2.80 nsec. in water and 3.81 nsec. in organic solvent, respectively.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1289-1289
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• 2001

Water-methanol and water-acetonitrile mixtures are frequently used as HPLC solvent system and strong hydrogen bonding is well-known. But a detailed aspect of water-methanol and/or water-acetonitrile mixtures have not been shown with direct spectral evidence. Recently, near infrared spectroscopy and chemometric data refinery have been successfully combined in many applications. On the basis of factor analytical methods, the spectral features of water-methanol and water-acetonitrile mixtures were studied to reveal the detail of mixtures. Water-methanol and water-acetonitrile mixtures were prepared with varying concentration of each constituent and near infrared spectral data were acquired in the range of 1100-2500nm with 2-nm interval. The data matrices were analysed with ITTFA(Iterative Target Transform Factor Analysis) algorithm implemented as MATLAB codes. As a result, the concentration profiles of water, methanol and water-methanol complex were resolved and the spectra of water-methanol complexes were calculated, which cannot be acquired with pure complexes. A similar result was obtained with NIR spectral data of water-acetonitrile mixtures. Moreover, pure spectra of hydrogen-bonding complexes of water-methanol and water-acetonitrile can be computed, while any other usual physical methods cannot isolated those complexes for acquiring pure component spectra.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.88-91
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• 2014

In this study, oil as a source of biodiesel from Nannochloropsis oceanica was extracted using organic solvent. The oil extraction yield and efficiency from dry and wet microalgae were investigated. The initial fatty acids content of the N. oceanica was 317.8 mg/g cell showing a high oil content over 30%. The yield from dry microalgae was higher than that from wet microalgae due to the inhibition of water. The yield by chloroform-methanol was the highest and the yield by hexane was the lowest. However, the total fatty acids contents with the chloroform-methanol were 678.7 and 778.2 mg/g oil under dry and wet conditions, respectively. The high oil extraction yield by chloroform-methanol reflected the fact that the extracted oil contained a high level of impurity. The hexane-methanol extraction from dry N. oceanica showed high oil extraction efficiency, 82.6%. The chloroform-methanol extraction under wet condition also showed high efficiency, 88.0%. While the hexane-methanol extraction from dry microalgae is desirable under low drying cost, the chloroform-methanol extraction from wet microalgae is desirable under high drying cost.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.54-59
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• 1997

After extracting Caridina denticulata denticulata, the raw material of salt-fermented Toha, with the use of water, ether, acetone and methanol in order, we had the antimicrobial activity test for nine strains of bacteria which are harmful to the human body and food. It is as follows; solvent extract yield of the powder of vacuum freeze dried Caridina denticulata denticulata was 52% of water fraction, 7.4% of ether fraction, 1.0% of acetone fraction and 0.8% of methanol fraction. The result of solvent extract antimicrobial search of Caridina denticulata denticulata said that with the sample of 20$\mu\textrm{g}$/disk, ether fraction resulted in clear one of 8~12mm, acetone fraction 8~12mm, methanol fraction 7~9mm and water fraction didn't have antimicrobial effect. The minimal inhibitory concentration of solvent extract of Caridina denticulata denticulata per area was that ether fraction was 250~500$\mu\textrm{g}$/$m\ell$, acetone fraction 125~500$\mu\textrm{g}$/$m\ell$ and methanol fraction 250~500$\mu\textrm{g}$/$m\ell$. The minimal bactericidal concentration of solvent extract per area of Caridina denticulata denticulata showed that ether fraction was 2, 500~10, 000$\mu\textrm{g}$/$m\ell$, acetone fraction 1, 250~10, 000$\mu\textrm{g}$/$m\ell$ and methanol fraction 5, 000~10, 000$\mu\textrm{g}$/$m\ell$.

• Journal of Electrochemical Science and Technology
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• v.1 no.1
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• pp.19-24
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• 2010

Alloying degree is an important structural factor of PtRu catalysts for direct methanol fuel cells (DMFC). In this work, carbon supported PtRu catalysts were synthesized by reduction method using anhydrous ethanol as a solvent and $NaBH_4$ as a reducing agent. Using anhydrous ethanol as a solvent resulted in high alloying degree and good dispersion. The morphological structure and crystallanity of synthesized catalysts were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM). CO stripping and methanol oxidation reaction were measured. Due to high alloying degree catalyst prepared in anhydrous ethanol, exhibited low onset potential for methanol oxidation and negative peak shift of CO oxidation than commercial sample. Consequently, samples, applying ethanol as a solvent, exhibited not only enhanced CO oxidation, but also increased methanol oxidation reaction (MOR) activity compared with commercial PtRu/C (40 wt%, E-tek) and 40 wt% PtRu/C prepared in water solution.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.1094-1103
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• 2017

The purpose of this study was to measure the bioactivity and antioxidant activity of seed from Gardenia jasminoides Ellis fructus (GJE). We determined tannin content ($1.517{\pm}0.003mg\;CE/g$, mg of catechin equivalents). The extraction yields of the GJE seed solvent were distilled water (DW) 36.61%, 70% methanol 30.10% and ethyl acetate (EA) 20.40%. The antioxidant activities of the extracts were significantly increased (0.2, 0.4, 0.6 mg/mL). Flavonoid contents (mg QE/g, mg of quercetin equivalents) were observed in the order of 70% methanol (0.799), DW (0.565) and EA (0.117). Antioxidant activities (DPPH, OH, ferrous ion-chelating capacity) were similar to the flavonoid content of each solvent. But ABTS scavenging activity and SOD like ability of DW extract were higher than 70% methanol extract. Comparing the yield and the antioxidant activity of each solvent of GJE seed, it seems to be preferable to use DW and 70% methanol solvent for extraction. As a result of this experiment, it has high antioxidant activity and physiological activity, which is expected to be highly valuable as a functional food and a natural antioxidant.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.82-90
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• 1997

This study was conducted to establish an ideal condition for obtaining maximum extraction efficiencies using an array of soil types and under a wide variety of conditions. Nine characteristic compounds were studied: benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, n-propylbenzene, 1,2,4-trimethylbenzene, and n-butylbenzene which were found in gasoline. Increasing the moisture content resulted in decreased recovery, and recovery of hydrocarbons from wet soils was significantly lower than from dry soils. For the batch extraction process, 4 hours of extraction time was sufficient to give optimum recovery of the contaminants. With methanol as an extraction solvent, maximum recovery time appeared to be reached quicker for BTEX components than with 2-propanol. The 2 to 1 ratio of solvent/soil was chosen as a compromise to provide for the indicated minimum solvent use and high extraction efficiency. The 0.4 mg/g soil contamination was adequate to show quantitative recovery. The percent recovery of BTEX was concentration dependent more than the semivolatile compounds. Methanol and 2-propanol consistently gave higher efficiency than water. Methanol was superior to 2-propanol in removing contaminants from silty clay loam soil. Using the most efficient extraction procedure, the average recovery of the light hydrocarbons from the three soils was 66 percent. Recoveries were also dependent on soil type, solvent type, extraction time, solvent amount, contaminant concentration, and compounds volatility. This study provided a useful screening technique for procedures that can be used to remediate soils contaminated with light hydrocarbons.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.685-690
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• 2010

Rubiadin, a major compound of noni ($Morinda$ $citrifolia$) adventitious root, is highly valued in pharmaceutical industry due to hepatoprotective activity. To dissect rubiadin's effective extraction condition, extraction process of noni adventitious roots was performed with different solvent types, ratio of water to methanol (water, 20, 40, 60, 80, and 100% of methanol), extraction time, and extraction method. In contrast, we also developed a reverse- phase HPLC assay method to determine rubiadin from noni adventitious roots. The HPLC assay of rubiadin was performed by C-18 column using a gradient solvent system of methanol and water with UV detector at 280 nm. The extraction efficiency of different types of solvents were increased in order of methanol (0.08%) > ethanol (0.05%) > acetonitrile (0.03%) > acetone (0.02%) and methylene chloride (0.02%). The results of rubiadin extraction using different solvents showed that 1 hour of ultrasonic extraction was effective in order of 60% methanol (0.21%) > 80% methanol (0.13%) > 100% methanol (0.07%), 40% methanol (0.07%) and 2 hours of reflux extraction was effective in order of 60% methanol (0.21%) > 40% methanol (0.17%) > 80% methanol (0.14%). To compare the extraction efficiency of rubiadin according to the extraction methods and time for high rubiadin content, the extracts of rubiadin in noni adventitious roots were isolated with the methods of ultrasonic extraction, shaking extraction and reflux extraction. Rubiadin extracted from the methods of ultrasonic waves and shaking displayed the highest contents at 8 and 24 hours, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.3
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• pp.392-399
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• 2014

Haw(Crataegus pinnatifida Bunge) belongs to the rose family and has beneficial health effects such as anti-obesity and gastroprotective activities. This study compared the antioxidative activities of various solvent extracts from haw. After removing seeds, pulpy was extracted with 70% methanol, 70% ethanol, chloroform :methanol(CM, 2:1, v/v), n-butanol, and ethyl acetate(EA). Total phenol contents were 71.46, 70.41, 47.63, 47.49 and 45.95 mg/g in the 70% methanol, 70% ethanol, CM, n-butanol and EA extracts, respectively. Total flavonoid contents of CM and n-butanol extracts were higher compared to other extracts at 1.63 mg/g and 1.59 mg/g, respectively, whereas EA extract had the lowest flavonoid content at 1.12 mg/g. Corresponding to total phenol contents, among $NO_2$ radical scavenging activity, antioxidant activity by ${\beta}$-carotene bleaching assay, and superoxide dismutase(SOD)-like ability, 70% methanol and 70% ethanol extracts showed higher antioxidative activities than the other extracts. However, the lowest activities were n-butanol extract in $NO_2$ radical scavenging activity as well as EA extract in antioxidant activity by ${\beta}$-carotene bleaching assay and SOD-like ability. These results suggest that haw extracts are available as a new natural antioxidant, and its activities are attributed to antioxidant substances such as phenolic compounds and flavonoids.

• Food Science and Preservation
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• v.7 no.1
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• pp.113-116
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• 2000

The antimicrobial activities of three parts of Korean sword bean , such as whole seed, dotyledon and hull were investigated . Yields were higher hull other parts in water and methanol extract. Methanol extract in seed parts was fractionated with different solvents, such as hexane, chloroform, ethyl acetate, butanol and water, yields of water fractino showed 3.3% , 2.5% and 0.3% in whole seed, 채쇼ledon and hull, respectively. In solvent extracts using methanol, hexane, chloroform, and water , methanol extract showed the most effective antimicrobial activities. Antimicrobial activities of ethyl acetate fraction of methanol extractwas higher than those of other fractions.