• 분석과학
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• 제31권3호
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• pp.112-121
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• 2018

The hydrothermal carbonization method has received great attention because of the conversion process from biomass. The reaction produces various products in hydrochar, bio-liquid, and gas. Even though its yield cannot be ignored in amount, it is difficult to find research papers on bio-liquid generated from the hydrothermal carbonization reaction of biomass. In particular, the heterogeneity of feedstock composition may make the characterization of bio-liquid different and difficult. In this study, bio-liquid from the hydrothermal carbonization reaction of food wastes at $230^{\circ}C$ for 4 h was investigated. Among various products, fatty acid methyl esters were analyzed using two different extraction methods: liquid-liquid extraction and column chromatography. Different elutions with various solvents enabled us to categorize the various components. The eluents and fractions obtained from two different extraction methods were analyzed by gas chromatography with a mass spectrometer (GC/MS). The composition of the bio-liquid in each fraction was characterized, and seven fatty acid methyl esters were identified using the library installed in GC/MS device.

• 약학회지
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• 제29권5호
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• pp.234-245
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• 1985

To clarify the diffusional behavior of p-aminbenzoic acid esters in the presence of polyethylene glycol 400, cellulose membrane permeation rate, solubility and viscosity of p-aminobenzoic acid methyl ester, benzocaine and butamben were determined with PEG solutions of various concentrations. With an increase in PEG concentrations permeation rates from solutions; decreased due to an increase in viscosity of the solution. From suspensions, however, permeation rates increased due to an increase in solubility and when the initial drug concentration was constant, permeation rates were found to be greatest from the PEG-water system with the PEG concentration which transported from the solution to the suspension. Permeation rate of 4.0mg/ml p-aminobenzoic acid methyl ester was $26.51\mu$g/ml$\cdot$hr from 5g/100ml PEG solution, and that of 4.0mg/ml benzocaine was $13.17{\mu}g/ml{\cdot}hr$ from 15g/100ml PEG, solution, and that of 2.0mg/ml butamben was $3.8{\mu}g/ml{\cdot}hr$ from 10g/100ml PEG solution. Permeation rate was 7.0 fold in p-aminobenzoic acid methyl, ester and 3.5 fold in benzocaine compared to butamben.

• 약학회지
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• 제45권1호
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• pp.46-54
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• 2001

Protein carboxyl Ο-methylation is a kind of enzymatic reaction producing carboxyl methylester catalyzed by protein carboxyl Ο-methyltransferases at the carboxyl group of amino acid residues in polypeptide. Since the finding of carboxyl methylesterl many studies have been focused on the under-standing of biological functions in eukaryotes but still not clear except for roles in Ras attachment to membrane and protein repair. In this study, we investigated the protein carboxyl methylation in porcine liver and testis in respect of identification and characterization of carboxyl methylesters and natural proteinous substrates using pH stability of the esters and electrophoresis under acidic and basic conditions. We detected several kinds of methyl esters, 3 kinds each in cytosolic fractions from liver and testis. Under the treatment of strong acid and base, the ratio between base-stable substrates and unstable ones in liver (4 : 6) was different from the ratio obtained in testis (6 : 4). The methyl accepting capacities were affected by enzymatic proteolysis between the range of 55 to 65% in liver and of 35 to 45% in testis. Separation of the methylated proteins by acidic electrophoresis in the presence of urea and SDS revealed distinctively natural substrates of 26, 33 and 80 kD in the cytosol from liver and of 14, 25, 32 and 86 kD from testis. Most of the labelling, however were lost following electrophoresis under moderate alkaline condition, except for molecules of newly detected 7 and 17 kD in livers and 15, 29, 40 and 80 kD in testis. From these results, it was proposed that protein carboxyl Ο-methylation in each organs may be catalyzed by different classes of protein carboxyl Ο-methyltransferases. In addition, it is suggested that the protein carboxyl methylation in liver and testis may have different patterns in respect of natural substrates.

• 한국식품영양학회지
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• 제12권5호
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• pp.513-517
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• 1999

Theessential oils of anise darkopal lettuce and sweet basils cultivated in Korea were extracted by simulatneous steam distillation and extraction method and were analyzed by GC/MSD. Total 41 com-ponents were identified in essential oils including 11 alcohols, 6 carbonyls 19 hydrocarbons and 5 esters components. The major components were 1,8-cineole linalool $\alpha$-bergamotene $\beta$-elemene methyl chavicol, $\beta$-cubebene methyl cinnamate and eugenol. Darkopal lettuce and sweet basils were rich in linalool(30.1-36.5%) methyl chavicol(8.1-25.5%) and relatively poor in methyl cinnamate(0-2.71%) Anise basil was rich in linalool(28.5%) and methyl cinnamate(23.1%) However methyl chavicol which was known as one of the main components of bisil was not detected.

• 한국식품영양학회지
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• 제12권4호
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• pp.415-420
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• 1999

Petal of Azalea(Rhododendron mucronulatum Turcz) was incubated with Gokja at 3$0^{\circ}C$ for seven days and the essential oil components of petal of Azalea before and after incubated were analyzed using a GC/MSD. Ten or more essential oil components including n-heneicosane n-tricosane n-tetreacosane n-pentacosane n-heptacosane n-nonacosane and n-hentriacontane were identified from the petal of Azal-ea before incubated while oxygen-containng compounds including (E)-heptenal 2-ethoxy-1 -hexanol n-hexadecanoic acid methyl ester 9, 12-octadecadienoic acid methyl ester 9,12,15-octadecatrienoic acid methyl ester, n-octadecanoic acid methyl ester n-eicosanoic acid methyl ester and 9-docosaenoic acid methyl ester as well as n-alkanes such as n-tricosane that n-pentacosane were identified from the petal of Azalea after incubated. These results suggest that n-alkanes in petal of Azalea might be degraded and some oxygen-containing compounds such as aldehyde, esters and /or acids might be produced when pet-al of Azalea is incubated with Gokja.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.143-144
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• 2002

A series of alcohols with perfluorinated segments $F(CF_2)_m(CH_2)_n-OH$, with m=8, 10 and n=4, 6, 10, were synthesized. First, the alcohols were reacted with fatty acid to produce several esters $(F(CF_2)_m(CH_2)-OOC-R$ with m=8, 10 and n=2, 4, 8,) containing perfluoro group by condensation reaction, and characterized by FT-IR, GC, and surface tension. The esters were soluble in ethyl ether, toluene, hexane, ethyl acetate, chloroform, and acetone, but insoluble in methyl alcohol, ethyl alcohol and isopropyl alcohol. Preliminary experiments on 1,2-dichloroethane solutions showed a remarkable decrease of surface tension upon addition of the esters. Also, the esters films ranged from 100 to $122^{\circ}$, depending on the structure of fatty acid esters. As the separate experiment, the water-repellency of coated paper and cotton was evaluated. As a result, the water droplet dropped in surface was not permeated for two weeks.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.459-463
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• 2015

This study evaluated the microbial conversion of coconut oil waste, a major agro-residue in tropical countries, into single cell oil (SCO) feedstock for biodiesel production. Copra cake was used as a low-cost renewable substrate without any prior chemical or enzymatic pretreatment for submerged growth of an oleaginous tropical mangrove fungus, Aspergillus terreus IBB M1. The SCO extracted from fermented biomass was converted into fatty acid methyl esters (FAMEs) by transesterification and evaluated on the basis of fatty acid profiles and key fuel properties for biodiesel. The fungus produced a biomass (8.2 g/l) yielding 257 mg/g copra cake SCO with ~98% FAMEs. The FAMEs were mainly composed of saturated methyl esters (61.2%) of medium-chain fatty acids (C12-C18) with methyl oleate (C18:1; 16.57%) and methyl linoleate (C18:2; 19.97%) making up the unsaturated content. A higher content of both saturated FAMEs and methyl oleate along with the absence of polyunsaturated FAMEs with ≥4 double bonds is expected to impart good fuel quality. This was evident from the predicted and experimentally determined key fuel properties of FAMEs (density, kinematic viscosity, iodine value, acid number, cetane number), which were in accordance with the international (ASTM D6751, EN 14214) and national (IS 15607) biodiesel standards, suggesting their suitability as a biodiesel fuel. The low cost, renewable nature, and easy availability of copra cake, its conversion into SCO without any thermochemical pretreatment, and pelleted fungal growth facilitating easier downstream processing by simple filtration make this process cost effective and environmentally favorable.

• Natural Product Sciences
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• 제25권4호
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• pp.354-357
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• 2019

Toxicodendron vernicifluum, also called as Rhus verniciflua is a deciduous tree belonging to Anacardiaceae family. Two new caffeoyl threonate esters, rhuseols A (1) and B (2), together with 5-O-(E)-caffeoylquinic acid methyl ester (3) were isolated from the leaves of T. vernicifluum. The structures of isolated compounds were established by using 1D and 2D NMR in combination with HR-ESI-MS. Compounds 1 - 3 showed DPPH radical scavenging effects with IC₅₀ values of 47.9, 107.8 and 15.4 μM, respectively. Taken together, these compounds might contribute to the antioxidant properties of the leaves of T. vernicifluum, which will be useful for various oxidative stress mediated diseases.

• Natural Product Sciences
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• 제9권3호
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• pp.200-203
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• 2003

Total lipids extracted from the powdered seeds of Carum roxburghianum were fractionated into hydrocarbons (0.30%), wax esters (0.30%), sterol esters (1.35%), triacylglycerols (72.41%), free fatty acids (6.06%), 1,3-diacylglycerols (4.60%), 1,2- diacylglycerols (0.64%), glycolipids (5.10%), sterols (1.20%), 2-monoacylgylcerols (3.18%), 1-monoacylglycerols (1.46%), phosphatidylethanolamines (1.08%) phosphatidylcholines (0.40%), lysophosphatidylethanolamines (1.48%) and phosphatidylinositols (0.44%) with the help of TLC. The fatty acid composition of all the lipid fractions was determined after converting them into their methyl esters with $BF_3-methanol$ reagent and then analyzing them by GC. Oleic acid was found as a major component in all the lipid classes, whereas palmitic, linoleic and linolenic acids were present in lesser quantities. Arachidic acid was identified as a minor component in only seven out of twelve lipid classes.

• Food Science and Biotechnology
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• 제18권3호
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• pp.700-705
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• 2009

In this study, the volatile compounds in 9 commercial fermented soybean pastes were extracted and analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), respectively. A total of 63 volatile components, including 21 esters, 7 alcohols, 7 acids, 8 pyrazines, 5 volatile phenols, 3 ketones, 6 aldehydes, and 6 miscellaneous compounds, were identified. Esters, acids, and pyrazines were the largest groups among the quantified volatiles. About 50% of the total quantified volatile material was contributed by 5 compounds in 9 soybean paste samples; ethyl hexadecanoate, acetic acid, butanoic acid, 2/3-methyl butanoic acid, and tetramethyl-pyrazine. Three samples (CJW, SIN, and HAE) made by Aspergillus oryzae inoculation showed similar volatile patterns as shown in principal component analyses to GC-MS data sets, which showed higher levels in ethyl esters and 2-methoxy-4-vinylphenol. Traditional fermented soybean pastes showed overall higher levels in pyrazines and acids contents.