• Title/Summary/Keyword: ester

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Biochemical Characterization of a Novel Thermostable Esterase from the Metagenome of Dokdo Islets Marine Sediment (독도 심해토 메타게놈 유래 신규 내열성 에스테라아제의 생화학적 특성규명)

  • Lee, Chang-Muk;Seo, Sohyeon;Kim, Su-Yeon;Song, Jaeeun;Sim, Joon-Soo;Hahn, Bum-Soo;Kim, Dong-Hern;Yoon, Sang-Hong
    • Microbiology and Biotechnology Letters
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    • v.45 no.1
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    • pp.63-70
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    • 2017
  • A functional screen of 60,672 fosmid metagenomic clones amplified from marine sediment obtained from the Dokdo islets in Korea identified the gene EstES1, whose product, EstES1, displayed lipolytic properties on tributyrin-supplemented media. EstES1 is a 576 amino acid protein with a predicted molecular weight of 59.4 kDa including 37 N-terminal leader amino acids. EstES1 exhibited the highest sequence similarity (44%) to a carboxylesterase found in Haliangium ochraceum DSM14365. Phylogenetic analysis indicated that EstES1 belongs to a currently uncharacterized family of lipases. Within the conserved domain, EstES1 retains the catalytic triad that consists of the consensus penta-peptide motif, GESAG. EstES1 demonstrated a broad substrate specificity toward the long acyl group of ethyl esters (C2-C12), and its optimal activity was recorded toward p-Nitrophenyl butyrate (C4) at pH 9.0 and $40^{\circ}C$ (specific activity of 255.4 U/mg). The enzyme remained stable in the ranges of $60-65^{\circ}C$ and pH 9.0-10.5 and in the presence of methanol, ethanol, isopropanol, and dimethyl sulfoxide. Therefore, EstES1 has potential for use in industrial applications involving high temperature, organic solvents, and/or alkaline conditions.

Carotenoid Pigments in Echiurid, Urechis unicinctus (개불의 carotenoid 색소성분)

  • KIM Soo Young;HA Bong Seuk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.2
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    • pp.223-231
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    • 1999
  • Carotenoid pigments of echiurid, Urechis unicinctus were investigated during March, April and May as a part of comparative biochemical studies of carotenoid pigments for the marine organisms other than pisces. Total carotenoid contents were found to be 1.19 mg/100 g in March, 0.98 mg/100 g in April and 0.84 mg/100 g in May, indicating that total carotenoid content was negatively affected by the temperature of sea water that echiurid resided. The carotenoid isolated in March composed of $16.3\%$ diatoxanthin monoester, $14.8\%$ $\beta$-carotene and $12.6\%$ cynthiaxanthin monoester, $8.4\%$ cynthiaxanthin diester, $8.2\%$ zeaxanthin monoester, $7.3\%$ diatoxanthin diester $4.2\%$ astaxanthin $2.9\%$ diatoxanthin, $2.4\%$ triol, $2.3\%$ cynthiaxanthin, $1.7\%$ isocrytoxanthin, $1.5\%$ zeaxanthin diester, $0.8\%$ zeaxanthin and $0.5\%$ lutein. The carotenoid isolated in April composed of $21.9\%$ diatoxanthin monoester, $17.2\%$ cynthiaxanthin monoester and $16.6\%$ $\beta$-carotene $10.9\%$ zeaxanthin monoester, $5.6\%$ cynthiaxanthin diester, $4.9\%$ diatoxanthin diester, $3.1\%$ astaxanthin, $2.4\%$ triol, $2.3\%$ diatoxanthin, $1.7\%$ isocrytoxanthin, $1.5\%$ lutein, $1.1\%$ zeaxanthin, $1.0\%$ cynthiaxanthin and $1.0\%$ zeaxanthin diester. Similarly, the carotenoid isolated in May composed of $25.3\%$ diatoxanthin monoester, $19.7\%$ cynthiaxanthin monoester, $13.0\%$ $\beta$-carotene, and $12.6\%$ zeaxanthin monoester, $5.8\%$ cynthiaxanthin diester, $5.1\%$ diatoxanthin, $3.0\%$ astaxanthin, $2.4\%$ triol, $2.2\%$ diatoxanthin, $1.3\%$ isocrytoxanthin, $1.2\%$ zeaxanthin, $1.1\%$ zeaxanthin diester, $1.0\%$ lutein and $0.9\%$ cynthiaxanthin. Based on these data, monoester-type carotenoids ($37.1\~57.6\%$) and diester-type carotenoids ($11.5\~17.2\%$) of total carotenoids in echiurid were the major carotenoids. Meanwhile, when the sea water temperature was elevated and the contents of total carotenoid in echiurids were decreased, the contents of zeaxanthin monoester, diatoxanthin monoester and cynthiaxanthin monoester were increased, but the contents of zeaxanthin diester, diatoxanthin diester and cynthiaxanthin diseter were decreased, indicating that changes in ester-type caroteoids were differently affected by the sea water temperature.

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Effect of Ginseng Saponin on LDL Receptor Biosynthesis (인삼사포닌의 저밀도지질단백질(LDL)수용체에 미치는 영향)

  • Joo Chung No;Lee Hee Bong;Lee Yong Woo;Kang In Chul
    • Proceedings of the Ginseng society Conference
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    • 1988.08a
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    • pp.47-54
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    • 1988
  • Cholesterol a component of all eucaryotic plasma membranes. is essential for the growth and viability of cells in higher organisms. However. too much cholesterol can be lethal because of atherosclerosis resulting from the deposition of cholesterol ester plaques. It was attempted in this study to understand the preventive effect of ginseng saponin. one of the major components of the roots of Panax ginseng C.A. Meyer. against hypercholesterolemia induced by high cholesterol diet. $^{125}I-LDL$ was injected intravenously to rabbits and rats. which were fed a high cholesterol diet with and/or without ginseng saponin for 12 days. The disappearance of the radioactivity occurred faster in the test group than the control. The effect of saponin fraction from Panax ginseng C.A. Meyer and the purified ginsenosilks. $Rb_1,\;Rb_2,\;Re\;and\;Rg_1,$ on LDL receptor biosynthesis in high cholesterol fed rat has been investigated. Analysis of LDL receptors from various organs such as liver. kidney. adrenal cortex and testis showed that the population of LDL receptors of test group significantly higher than that of the control. It was also found that liver homogenate containing ginsenosides $(10^{-3}-10^{-4}\%)$ stimulated the biosynthesis of bile acid form cholesterol. From the above results. it seemed that ginsenosides lower the cholesterol level by stimulating cholesterol metabolism. which result in the suppression of the inhibitory action of cholesterol on LDL receptor biosynthesis.

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A novel cold-active lipase from Psychrobacter sp. ArcL13: gene identification, expression in E. coli, refolding, and characterization (새로운 Psychrobacter sp. ArcL13 유래 저온활성 지질분해효소 : 유전자 분리동정, 대장균에서의 발현, refolding 및 특성 연구)

  • Koo, Bon-Hun;Moon, Byung-Hern;Shin, Jong-Suh;Yim, Joung-Han
    • Korean Journal of Microbiology
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    • v.52 no.2
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    • pp.192-201
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    • 2016
  • Recently, Psychrobacter sp. ArcL13 strain showing the extracellular lipase activity was isolated from the Chuckchi Sea of the Arctic Ocean. However, due to the low expression levels of the enzyme in the natural strain, the production of recombinant lipase is crucial for various applications. Identification of the gene for the enzyme is prerequisite for the production of the recombinant protein. Therefore, in the present study, a novel lipase gene (ArcL13-Lip) was isolated from Psychrobacter sp. ArcL13 strain by gene prospecting using PCR, and its complete nucleotide sequence was determined. Sequence analysis showed that ArcL13-Lip has high amino acid sequence similarity to lipases from bacteria of some Psychrobacter genus (84-90%) despite low nucleotide sequence similarity. The lipase gene was cloned into the bacterial expression plasmid and expressed in E. coli. SDS-PAGE analysis of the cells showed that ArcL13-Lip was expressed as inclusion bodies with a molecular mass of about 35 kDa. Refolding was achieved by diluting the unfolded protein into refolding buffers containing various additives, and the highest refolding efficiency was seen in the glucose-containing buffer. Refolded ArcL13-Lip showed high hydrolytic activity toward p-nitrophenyl caprylate and p-nitrophenyl decanoate among different p-nitrophenyl esters. Recombinant ArcL13-Lip displayed maximal activity at $40^{\circ}C$ and pH 8.0 with p-nitrophenyl caprylate as a substrate. Activity assays performed at various temperatures showed that ArcL13-Lip is a cold-active lipase with about 40% and 73% of enzymatic activity at $10^{\circ}C$ and $20^{\circ}C$, respectively, compared to its maximal activity at $40^{\circ}C$.

Effects of the Feeding Platycodon grandiflorum and Codonopsis Ianceolata on the Lipid Components of Serum and Liver in Rats (도라지 및 더덕 첨가식이가 흰쥐의 혈청 및 간장의 지질성분에 미치는 영향)

  • 김소영;김한수;서인숙;이호신;김희숙;정승용
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.5
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    • pp.517-523
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    • 1993
  • This study was designed to observe the efforts of the feeding Platycodon grandiflorum, Codonopsis ianceolata, perilla oil and safflower oil on the improvement of the lipids in the serum and liver of dietary hypercholes-terolemic rats. Experimental groups mixed with 5% cellulose+10% lard (group 1, control group), 2% cholestyramine+10% lard (group 2), 5% C. Ianceolata+10% perilla oil (group3). 5% P. grandiflorum+10% perilla oil(group 4), 5% C. ianceolata+10% safflower oil(group 5) and 5% P. grandiflorum+10% safflower oil (group 6) were administered to the male rats of the Sprague Dawley for 3 weeks. Concentrations of total cholesterol in serum were significantly lower in the all experimental groups (2~6 groups) than in the control group, and particularly, the lowest in the group 2 and 6. Concentrations of HDL-cholesterol in serum were remarkably higher in the groups 2 and 4. The ratio of HDL-cholesterol to total cholesterol was the highest in the group 2. Atherosclerotic index was lower in the groups 2, 4 and 6. Concentrations of LDL, phospholipid and triglyceride in serum were remarkably lower in the all experimental groups than in the control group, and particularly, lower in the groups 2, 4 and 6. Concentrations of free cholesterol and cholesteryl ester in serum were significantly lower in the all experimental groups than in the control group, and particularly, the lowest in the group 2. Concentrations of glucose in blood were the lowest in the group 2. And groups 3 and 5 were slgnificantly lower. Contents of total cholesterol and triglyceride in liver were significantly lower in the all experimental groups than in the control group, and particularlyr the lowest in the groups 2 and 3. Phospholipid content was showed little differenre among groups but the lowest in the group 2. From the above research, the feeding 5% Platycodon grandiflorum+10% perilla oil and 5% Platycodon grandiflorum+10% safflower oil were effective on the improvement of the lipid compositions in serum and liver.

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An Experimental Study on the Pore Structure and Thermal Properties of Lightweight Foamed Concrete by Foaming Agent Type (기포제 종류에 따른 경량기포콘크리트의 기포구조 및 열적특성에 관한 실험적 연구)

  • Kim, Jin-Man;Choi, Hun-Gug;Park, Sun-Gyu
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.63-73
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    • 2009
  • Recently, the use of lightweight panels in building structures has been increasing. Of the various lightweight panel types, styrofoam sandwich panels are inexpensive and are excellent in terms of their insulation capacity and their constructability. However, sandwich panels that include organic material are quite vulnerable to fire, and thus can numerous casualties in the event of a fire due to the lack of time to vacate and their emission of poisonous gas. On the other hand, lightweight foamed concrete is excellent, both in terms of its insulation ability and its fire resistance, due to its Inner pores. The properties of lightweight concrete is influenced by foaming agent type. Accordingly, this study investigates the insulation properties by foaming agent type, to evaluate the possibility of using light-weight foamed concrete instead of styrene foam. Our research found thatnon-heating zone temperature of lightweight foamed concrete using AP (Aluminum Powder) and FP (animal protein foaming agent) are lower than that of light-weight foamed concrete using AES (alkyl ether lactic acid ester). Lightweight foamed concrete using AES and FP satisfied fire performance requirements of two hours at a foam ratio 50, 100. Lightweight foamed concrete using AP satisfied fire performance requirements of two hours at AP ratio 0.1, 0.15. The insulation properties were better in closed pore foamed concrete by made AP, FP than with open pore foamed concrete made using AES.

Lipids and Free Sugar Composition in Ginseng Classified by Years (한국(韓國) 인삼(人蔘)의 연근별(年根別) 지질(脂質) 및 유리당조성(遊離糖組成))

  • Sohn, K.M.;Sung, T.S.;Cho, Y.J.;Lee, K.S.;Choi, C.
    • Applied Biological Chemistry
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    • v.31 no.2
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    • pp.169-176
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    • 1988
  • Lipid contents, fatty acid compositions and free sugar contents of dried ginsengs grown for different years were studied. The lipid and free sugar were separated and quantified by silicic acid column chromatography, thin layer chromatography, gas liquid chromatography and high performance liquid chromatography. Ginseng contained $1.07{\sim}67%$ crude lipid and the hightest lipid content was shown in 3 year old root. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid$(51.35{\sim}72.30%)$. The contents of phospholipid and glycolipid in total lipids were $15.03{\sim}34.59%$ and $11.83{\sim}20.72%$, respectively. As the ginseng grew, neutral lipid content increased gradually but glycolipid decreased to the half of the one year old root. Seven components of neutral lipid separated by thin layer chromatography were identified but the other two components were not able to be identified. Triglyceride content was $14.42{\sim}23.91%$, sterol ester and unidentified material(II) were $13.58{\sim}21.26%$ and $7.13{\sim}15.83%$ respectively. The major fatty acids were linoleic acid, palmitic acid, oleic acid and linolenic acid. Linoleic acid content of total and neutral lipid was $61{\sim}65%$ palmitic acid content in phospholipid was $26{\sim}39%$ and one year old root showed the hightest contents. The fatty acid composition of neutral lipid was similar to the pattern of total lipid. Linolenic acid content of glycolipid decreased gradually. Free sugars were composed of rhamnose, fructose, glucose, sucrose, maltose and an unidentified material. The content of sucrose was $92{\sim}94%$ of total free sugars. Two year old root showed the highest sugar content and it decreased since then.

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Immunogenicity of Synthetic Peptide Specific for Major Immunogenic Determinat of Hepatitis B Surface Antigen (B형간염(型肝炎) 표면항원(表面抗原)의 주면역원(主免疫原) 결정기(決定基)에 특이(特異)한 합성(合成) Peptide의 면역원성(免疫原性)에 관한 연구(硏究))

  • Shin, Kwang-soon;Han, Su-nam
    • Korean Journal of Veterinary Research
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    • v.25 no.1
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    • pp.7-17
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    • 1985
  • Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

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Studies on the Lipid Components of Korean Rapeseed Oil (한국산(韓國産) 평지씨 기름의 지방질(脂肪質) 성분(成分)에 관한 연구)

  • Kang, Sook;Lee, Kang-Hyon;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.12 no.2
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    • pp.115-121
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    • 1980
  • The oils extracted with n-hexane from 6 samples of rapeseed (5 Korean samples and 1 Canadian sample) and samples of rapeseed salad oil at the market in Korea were examined. The physical and chemical characteristics of the oils were determined, and the lipid components of the oils were determined by column, thin layer-and gas liquid chromatography. The results obtained were as follows 1. The average crude fat contents in rapeseed was 43.3 % and the content of Korean was higher than that of Canadian by about 3 %. 2. The average values of specific gravity-, refractive-index, saponification value, iodine value, acid value and nonsaponifiable content of the crude oils extracted from Korean rapeseed were 0.9133, 1.4726, 103.6, 0.51 and 1.17%, respectively. 3. The average content of polar and nonpolar in total lipids were 2.7 % and 97.3 % respectively. Triglyceride was the predominant in nonpolar fraction, averaging 92.7 % of total lipids while sterol esters and diglycerides constituted 1.5 % and 1.2 % of the total. Monoglycerides, free fatty acids and free sterols were minor components of the nonpolar fraction. The polar lipids were primarily phospholipids(1.8%), but a significant amount of glycolipid (0.7%) was also found in each oil. 4. The fatty acid compositions in the total lipids showed the Korean rapeseeds averaged 46.7 % erucic, 15 % oleic, 13.4 % linoleic, 9.3 % eicosenoic and 4.3 % palmitic acids. The Canadian rapeseed, however, contained only 0.7 % of erucic acid. 5. The fatty acid compositions in nonpolar lipid fractions was similar to the pattern in those of the total lipids. But phospholipid and glycolipid fractions were lower in erucic acid content than nonpolar lipid fractions.

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Identification of Fatty Acids in the Pulp Oils of Jujube and Their Compsitional Changes in the Ripening Period (대추의 과육지질(果肉脂質)에 존재(存在)하는 지방산(脂肪酸)의 동정(同定)과 숙성(熟成)에 따른 그 조성(組成)의 변화(變化))

  • Woo, Hyo-Kyeng;Kim, Seong-Jin;Park, Sung-Hea;Joh, Yong-Goe
    • Journal of the Korean Applied Science and Technology
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    • v.18 no.1
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    • pp.67-77
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    • 2001
  • In search for several fatty acid with unusual structure in vegetable oils, we have found that unknown peaks were shown on GLC in the analysis of fatty acids of the lipids from the pulp of ripened jujube (Zizypus jujuba var. inermis) fruits. These fatty acids were identified as a series of cis-monoenoic acids with ${\omega}-5$ double bond system such as $C_{14:1{\omega}5}$, $C_{16:1{\omega}5}$ and $C_{18:1{\omega}5}$, including ${\omega}-7$ fatty acid as $C_{16:1{\omega}7}$ and $C_{18:1{\omega}7}$, by GLC, solid-phase extraction silver ion-column chromatographic, GLC-mass spectrometric and IR techniques. First of all, total fatty acid methyl esters were resolved into saturated and branched fatty acid, monoenoic acid, dienoic acid, and trienoic acid fraction, respectively, with 100% dichloromethane (DCM), DCM/acetone (9:1, v/v) 100% acetone, and acetone/ acetonitrile (97:3, v/v) solvent system. Unknown fatty acids were included in the monoenoic fraction and were confirmed to have cis-configuration by IR. Picolinyl esters of monoenoic fatty acids gave distinct molecular ion peak and dominant diagnostic peaks, for example, m/z 317, 220 and 260 fragment for $cis-C_{14:1{\omega}5}$, m/z 345, m/z 248 and 288 fragment for $cis-C_{16:1{\omega}5}$ and m/z 373, m/z 276 and 316 fragment for $cis-C_{18:1{\omega}5}$. In this way the occurrence of $cis-C_{16:1{\omega}7}$ and $cis-C_{18:1{\omega}7}$ could be deduced from the appearance of prominent fragments as m/z 345, 220 and 260, and m/z 373, 248 and 280. Level of total ${\omega}-5$ fatty acids amounted to about 30% in the fatty acid composition with the predominance of $C_{16:1{\omega}5}$ $ (18.7{\sim}25.0%)$, in the semi-ripened and/or ripened samples collected in September 14 ($C_{16:1{\omega}5}$ ; 18.7%, $C_{14:1{\omega}5}$ ; 3.6% and $C_{18:1{\omega}5}$ ; 3.0%), September 22 ($C_{16:1{\omega}5}$ ; 25.0%, $C_{14:1{\omega}5}$ ; 1.4% and $C_{18:1{\omega}5}$ ; 2.6%), and October $7 (C_{16:1{\omega}5}$ ; 24.7%, $C_{14:1{\omega}5}$ ; 7.7% and $C_{18:1{\omega}5}$ ; 2.5%). However, the lipids extracted from unripened jujube in July and August contain these unusual fatty acids as low as negligible. It could be observed that the level of ${\omega}-5$ fatty acids in the pulps increased sharply with an elapse of ripening time of jujube fruits. Other monoenoic fatty acids with ${\omega}-7$ series, $C_{16:1{\omega}7}$ (palmitoleic acid) and $C_{18:1{\omega}7}$ (cis-vaccenic acid) could be detected. And in the lipids of the kernel and leaf of jujube, none of ${\omega}-5$ fatty acids could be detected.