• Polymer(Korea)
• /
• v.26 no.3
• /
• pp.300-306
• /
• 2002

To study the effect of polymer compositions on the cell adhesion, copolymers of 3-(S)-[(dodecyloxycarbonyl) methyl]-1,4-dioxane-2,5-dione (DMD) and L-lactide were made, where DMD was synthesized form L-malic acid (L-MA) and glycolic acid. Furthermore, the copolymerization of DMD and L-lactide was performed using tin(II) octanoate as a catalyst. As a result of fixing RGD on the copolymer films, the cell adhesive peptide was fixable on the surface of the film. It was found out that the amount of fixation of RGD also increases by the increase in the amount of MA unit introduction. Since it is gradually decomposed over a long period and neither remains nor accumulation occurs, glycolic acid-$\beta$-dodecylmalate -lactic acid (D-PGML) is greatly expected as a potential biomaterial with improved slow degradability.

• Journal of Life Science
• /
• v.22 no.3
• /
• pp.306-311
• /
• 2012

A gene encoding a lipase, lipT, was cloned from the psychrotrophic bacterium Pseudomonas mandelii and sequenced. An open reading frame of 1,686 bp was found that encodes a polypeptide consisting of 562 amino acid residues. Sequence analysis revealed a Gly-His-Ser-Leu-Gly sequence, which matches the consensus Gly-X-Ser-X-Gly motif conserved among lipolytic enzymes. The recombinant LipT protein was predominantly expressed as inclusion bodies in Escherichia coli and subsequently purified by nickel-chelate affinity chromatography. A small fraction of LipT was refolded, and the subsequent LipT exhibited substrate preferences for p-nitrophenyl butyrate (C4) and p-nitrophenyl octanoate (C8).

• Analytical Science and Technology
• /
• v.7 no.4
• /
• pp.435-440
• /
• 1994

Qualitative and quantitative analysis for the anionic surfactants used in the metal washing fluid (brand names are BFA and BCA) was performed by the capillary electrophoresis. Acetonitrile and sodium benzoate were mixed with the buffer solution which controlled at pH 10. Under the 18kV applied voltage, the electropherograms have shown the theoretical plates more than $10^4$. Determined as the concentration at the S/N~3, the typical detection limit was ~5 ppm and the calibration curves have shown the correlation coefficients higher than ~0.99. Based on these results, it was concluded that each components were octanoate, decanoate, dodecanoate, tetradecanoate, hexadecanoate and the relative ratio was 1.0 : 1.0 : 6.5 : 2.1 : 0.8 for the BFA.

• Archives of Pharmacal Research
• /
• v.9 no.4
• /
• pp.237-242
• /
• 1986

The Synthesis of E, E, E-12-fluorofarnesol and E, Z-6-fluorofarnesol which are key intermediates for the study of biosynthesis of some sesquiterpenes, is described. E, E-Farnesyl acetate is treated with selenium dioxide to give E, E, E-12-hydroxy farnesyl acetate, whih is transformed by DAST into E, E, E-12-hydroxy farnesyl acetate, which is transformed by DAST into E, E, E,-12-fluorofarnesylacetate. The latter compound is hydrolyzed to E, E, E,-12-fluorofarnesol. The reformatsky reaction of 6-methyl-5-hepten-2-one with ethyl bromofluoroacetate affords ethyl 2-fluoro-3-hydroxy-3, 7 dimethyl-6-octanoate. This ester is acetylated and eliminated to give ethyl (Z)-2-fluoro-3, 7-dimethylocta-2, 6-dienoate, which is transformed to allyl bromide via allylic alcohol. The allyl bromide is treated with dianion of methyl acetate to give-keto ester. The $\beta$-keto ester is converted to diethyl phosphoryloxy compound. The conjugate addition of lithium dimethylcuprate to the latter compound gives fluoro ester, which is treated with DIBAL to afford E, Z-6-fluorofarnesol.

• Macromolecular Research
• /
• v.9 no.2
• /
• pp.84-91
• /
• 2001

Both A-B-A triblock and multiblock copoly(ester-ether)s consisting of poly(L-Lactide) and poly(oxyethylene-co-oxypropylene) were prepared and characterized. The preparation of the triblock copolymer was done by ring-opening copolymerization of L-lactide with a commercially available telechelic copolyether, Pluronic$\^$TM/(PN) by catalysis of stannous octanoate. The molecular weight and unit composition of the produced copolymers were successfully controlled by changing the L-lactide/PN ratio in feed. However, a high molecular weight copolymer incorporating PN in large amount was not obtained because the molecular weight of the resulting copolymer was limited at a high L-lactide/PN composition. The multiblock copolymer was synthesized by the copolycondensation of oligo(L-lactic acid) prepared by thermal dehydration of L-lactic acid, PN, and dodecanedioic acid as carboxyl/hydroxyl adjusting agent. This polycondensation proceeded by catalysis of stannous oxide to give multiblock copolymers with high molecular weight and wide range of compositions.

• Proceedings of the Korean Journal of Food and Nutrition Conference
• /
• 2003.07a
• /
• pp.83-83
• /
• 2003

우리 전통주의 질적인 향상과 저장성이 우수한 무증자 발효주를 제조하기 위하여 쌀과 옥분의 배합 비율을 쌀 100%, 쌀 80%＋옥분 20%, 쌀 60%＋옥분 40%, 쌀 40%＋옥분60%, 쌀 20%＋옥분 80%로 달리하여 무증자로 담금한 발효주와 쌀 100%로 증자하여 발효시킨 주류의 물리화학적인 변화 및 성분함량을 측정하였으며 관능검사를 병행하여 비교 검토하여 다음과 같은 결론을 얻었다. 1) 술덧의 온도변화는 발효 초기 30 에서 시간의 경과에 따라 서서히 감소하여 발효중기 27.5 를 거쳐 발효 종료 시 모두 26.5 였다. 2) 술덧의 주정도 변화는 옥분의 양을 첨가할수록 낮아지는 경향을 보였으며 16∼18.3v/v% 였다. 3) 유기산은 무증자주는 쌀 100%일 때 0.6 g/dl로 증자주 0.49g/dl보다 높았으며 옥분을 첨가한 무증자주에서는 옥분이 첨가될수록 차즘 감소하여 80%일 때 0.34 g/dl 였다. 4) 유리아미노산 함량은 옥분이 40% 첨가되면서부터 leucine의 함량이 쌀 100% 증자주에 비해 2배 이상 증가하였으며 leucine>arginine>lysine의 순이었다. 5) 유리당 함량은 무증자로 옥분을 첨가할수록 증가하여 옥분 80%에서는 9.81mg/dl였다. 6) 휴젤유는 278.6ppm∼441.6ppm으로 쌀100% 무증자에 비해 옥분이 첨가될수록 감소하여 옥분 80%일때 가장 적은 278.6ppm이었다. 7) 휘발성 향기성분중 ester함량은 100% 무증자주에서 총 9종류가 검출되었으나 옥분이 첨가되면서 10∼12 종으로 많아졌다. Ethyl octanoate는 옥분 60%첨가 무증자주에서 19.26%로 많이 나타났으며 ethyl acetate는 옥분이 첨가되면서 증가하였다. 특히 옥분 80% 무증자주는 총 ester류함량은 적었으나 isoamyl acetate, phenylethyl acetate, ethyl octanoate, ethyl acetate의 함량이 비교적 많이 검출되어 독특한 향기를 기대할 수 있었다. 8) GC/O를 사용하여 향기성분을 동정한 결과 무증자 발효주 시험구에서는 옥분을 첨가할수록 sweet 및 warm note가 강하게 나타나는 현상을 보였다. 9) 발효주의 색도를 측정한 결과 밝기에서는 무증자구가, 적색도에서는 옥분 첨가량이 증가할수록 강하였으며 황색은 증자주보다는 무증자주의 옥분 첨가량의 증가에 따라 높아지는 경향을 보였다. 10) 관능검사 결과 쓴맛, 미묘한 맛, 좋은 맛, 떫은 맛, 신맛 그리고 좋은 맛에 대한 전체 적인 평가를 종합하면 쌀 100% 증자발효주가 가장 점수가 낮아 무증자 발효주에 비하여 기호도가 떨어지는 것으로 나타났으며 특히 옥분 첨가량 80%와 60%의 무증자주가 기호도 면에서 유의적으로 가장 높게 평가되었다.

• Microbiology and Biotechnology Letters
• /
• v.40 no.2
• /
• pp.98-103
• /
• 2012

For screening of useful enzymes producing microorganisms from Meju, we isolated high lipase producing strains and their lipolytic enzyme activities were then tested. The lipolytic enzyme activities of isolated microorganisms were therefore tested on the Y124 strain. The gene sequence analysis of ITS from Y124 strain revealed Yarrowia lipolytica. Lipase production by the Y124 strain was studied in media containing various carbon sources. The Y124 strain drastically increased lipolytic enzyme activity in YPO media containing olive oil, as well as in YPDO media containing both olive oil and glucose. Maximal lipase production was achieved in YPD (yeast extract-peptone-D-glucose) media containing 0.7% olive oil when cultured at $30^{\circ}C$ for 8 hrs. The lipase produced from the Y124 strain showed the highest activity in p-NPO (p-nitrophenyl octanoate ($C_8$)), amongst the various p-nitrophenyl esters.

• Korean Journal of Food Science and Technology
• /
• v.46 no.4
• /
• pp.425-431
• /
• 2014

In this study, the volatile compounds in 24 commercial Korean black raspberry wines were isolated by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 43 volatile components, including 15 esters, 12 terpenes, 7 alcohols, 4 acids, 3 ketones, and 2 aldehydes, were identified. Ethyl esters and alcohols such as ethyl acetate, ethyl octanoate, isoamyl alcohol, and phenethyl alcohol were the most represented groups among the quantified volatiles. In particular, various terpenes such as DL-limonene, linalool, alpha-terpineol, and myrtenol were identified. The differences in volatile components among the 24 black raspberry wines and possible sample grouping were examined by applying principal component analyses to the GC-MS data sets. The first and second principal components explained 43.9% of the total variation across the samples. No apparent sample groupings were observed according to manufacturing locations. The samples KU, BH, SR, and MO showed higher overall levels in the concentrations of terpenes originating from black raspberry, while other samples such as BB and HB, showed higher in ethyl ester and alcohol contents produced by yeast fermentation, respectively.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.207-210
• /
• 2000

Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHA) fram octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate concentration of the culture broth was maintained below 4 g/L by feeding the mixture of octanoic acid and ammonium nitrate when the culture pH rose above high limit. The effect of the ratio of octanoic acid to ammonium nitrate (C/N ratio) in the feed on the PHA production was examined. The final cell concentrations of 62.5, 54.7, and 9.5 g/L, PHA contents of 62.9, 75.1, and 67.6% of dry cell weight, and productivities of 1.03, 0.632, and 0.161 g/L/h were obtained when the C/N ratio in the feed were 10, 20, and 100 g octanoic acid/g ammonium nitrate, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.12
• /
• pp.2024-2033
• /
• 2015

A gene encoding lipolytic enzyme, lip7-3, was isolated from Bacillus sp. W130-35 isolated from a tidal mud flat. The gene encoded a protein of 215 amino acids with a signal peptide composed of 34 amino acid residues. Lip7-3 belonged to the family I.4 lipase and showed its maximal activity at pH 9.0 and 60℃. Its activity increased in the presence of 30% methanol and, remarkably, increased as well to 154.6% in the presence of Ca²⁺. Lip7-3 preferred p-nitrophenyl octanoate (C8) as a substrate and exhibited broad specificity for short- to long- chain fatty acid esters. Additionally, Lip7-3 showed a low degree of enantioselectivity for an S-enantiomer (e.g., (S)-methyl-3-hydroxy-2-methylpropionate). It efficiently hydrolyzed glyceryl tributyrate, but did not hydrolyze glyceryl trioleate, fish oil, or olive oil. Its substrate specificity and activation by the solvent might offer a merit to the biotechnological enzyme applications like transesterification in the production of biodiesel.