• 제목/요약/키워드: amino alcohols

검색결과 99건 처리시간 0.023초

Studies on the Regioselective of Chlorosulfonyl Isocyanate with Cyclic ethers

  • Lim, Seung-Yong;Jung, Young-Hoon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.183.1-183.1
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    • 2003
  • The synthesis of various cyclic carbamate compounds and amino alcohols has attracted attention in the past because of their potential as antibiotics, antitumor, analgenics, anticonvulsants. Several methods for the preparation of cyclic carbamate compounds have previously been reported including the use of heterocumulenes. We have recently described the novel synthetic method for N-protected amines from various ethers using Chlorosulfonyl isocyanate(CSI) and found that the mechanism of our CSI reaction is a competitive reaction of $S_N1$ and $S_ Ni$ mechanisms according to the stability of carbocation intermediates. (omitted)

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Highly Efficient Microwave-assisted Aminolysis of Epoxides in Water

  • Zuo, Hua;Li, Zhu-Bo;Zhao, Bao-Xiang;Miao, Jun-Ying;Meng, Li-Juan;Jang, Ki-Wan;Ahn, Chul-Jin;Lee, Dong-Ha;Shin, Dong-Soo
    • Bulletin of the Korean Chemical Society
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    • 제32권spc8호
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    • pp.2965-2969
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    • 2011
  • Highly efficient and rapid aminolysis of epoxides with various amines in water under microwave irradiation in the absence of catalyst was developed. Chiral ${\beta}$-amino alcohols were formed in a short time with excellent yields.

A Simple, Efficient, Catalyst-Free and Solvent-Less Microwave-Assisted Process for N-Cbz Protection of Several Amines

  • Aouf, Zineb;Mansouri, Rachida;Lakrout, Salah;Berredjem, Malika;Aouf, Nour-Eddine
    • 대한화학회지
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    • 제61권4호
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    • pp.151-156
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    • 2017
  • A simple, green and chemo-selective method for the N-benzyloxycarbonylation of amines, ${\beta}$-amino alcohols, ${\alpha}$-amino esters and sulfonamides has been developed under microwave irradiation. Good to excellent yields of the N-benzyloxycarbamates compounds were obtained in short times without any side products.

Anti-Selective Dihydroxylation Reactions of Monosubstituted and (E)-Ester Conjugated Allylic Amines by Bulky Alkyl Groups

  • Jeon, Jong-Ho;Kim, So-Hee;Lee, Jong-Hyup;Oh, Joon-Seok;Park, Doh-Yeon;Kim, Young-Gyu
    • Bulletin of the Korean Chemical Society
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    • 제30권5호
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    • pp.1003-1008
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    • 2009
  • The $O_sO_4$-catalyzed dihydroxylations of a monosubstituted allylic amine and $\gamma-amino-\alpha,\;\beta-unsaturated$ (E)-esters with bulky alkyl groups showed a high anti-selectivity. Since the acyclic conformation of N-acyloxy protected allylic amines was efficiently controlled by a bulky t-Bu or OBO ester group, the anti diastereoselectivity of >12.5:1 was obtained without applying a chiral reagent. The synthetic utility of the present method was demonstrated by a stereoselective and efficient synthesis of an $\alpha$-glucosidase inhibitor 15 from commercially available N-Cbz-L-serine 6 in 11 steps and 31% yield.

Influence of preserved brewing yeast strains on fermentation behavior and flocculation capacity

  • Cheong, Chul;Wackerbauer, Karl;Beckmann, Martin;Kang, Soon-Ah
    • Nutrition Research and Practice
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    • 제1권4호
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    • pp.260-265
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    • 2007
  • Preservation methods on the physiological and brewing technical characters in bottom and top brewing yeast strains were investigated. The preserved yeasts were reactivated after 24 months storage and grown up to stationary phase. The samples of filter paper storage indicated a higher cell growth and viability during propagation than those of nitrogen and lyophilization storage independent on propagation temperature. In addition, the filter paper storage demonstrated a faster absorption of free amino nitrogen and a highest level of higher aliphatic alcohols production during propagation than other preservation methods, which can be attributed to intensive cell growth during propagation. Moreover, the filter paper storage showed a faster accumulation for glycogen and trehalose during propagation, whereas, in particular, lyophilization storage noted a longer adaptation time regarding synthesis of glycogen and trehalose with delayed cell growth. In beer analysis, the filter paper storage formed an increased higher aliphatic alcohols than control. In conclusion, the preservation of filter paper affected positively on yeast growth, viability and beer quality independent on propagation temperature. In addition, in this study, it was obtained that the HICF and Helm-test can be involved as rapid methods for determination of flocculation capacity.

Varying Inocula Permutations (Aspergillus oryzae and Bacillus amyloliquefaciens) affect Enzyme Activities and Metabolite Levels in Koji

  • Gil, Hye Jeong;Lee, Sunmin;Singh, Digar;Lee, Choong Hwan
    • Journal of Microbiology and Biotechnology
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    • 제28권12호
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    • pp.1971-1981
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    • 2018
  • In this study, we investigated the altered enzymatic activities and metabolite profiles of koji fermented using varying permutations of Aspergillus oryzae and/or Bacillus amyloliquefaciens. Notably, the protease and ${\beta}$-glucosidase activities were manifold increased in co-inoculated (CO) koji samples (co-inoculation of A. oryzae and B. amyloliquefaciens). Furthermore, gas chromatography-mass spectrometry (GC-MS)-based metabolite profiling indicates that levels of amino acids, organic acids, sugars, sugar alcohols, fatty acids, nucleosides, and vitamins were distinctly higher in CO, SA (sequential inoculation of A. oryzae, followed by B. amyloliquefaciens), and SB (sequential inoculation of B. amyloliquefaciens, followed by A. oryzae). The multivariate principal component analysis (PCA) plot based on GC-MS datasets indicated a clustered pattern for MA and MB (koji samples inoculated either with A. oryzae or B. amyloliquefaciens) across PC2 (20.0%). In contrast, the CO, SA, and SB metabolite profiles displayed segregated patterns across PLS1 (22.2%) and PLS2 (21.1%) in the partial least-square discriminant analysis (PLS-DA) model. Intriguingly, the observed disparity in the levels of primary metabolites was engendered largely by higher relative levels of sugars and sugar alcohols in MA, SA, and CO koji samples, which was commensurate with the relative amylase activities in respective samples. Collectively, the present study emphasizes the utility of integrated biochemical and metabolomic approaches for achieving the optimal permutation of fermentative inocula for industrial koji preparation.

향미 개선 저식염 우렁쉥이(Halocynthia roretzi) 젓갈의 휘발성 향기성분 (Volatile Flavor Compounds in Low Salt-Fermented Ascidians Halocynthia roretzi Made by Flavor Enhancing)

  • 차용준;정은정;유대웅
    • 한국수산과학회지
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    • 제53권3호
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    • pp.273-280
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    • 2020
  • Volatile compounds in fermented ascidians Halocynthia roretzi were analyzed to identify key flavor compounds using SPME/GC/MSD (solid phase microextraction/gas chromatography/mass selective detector) after 60 days of fermentation at 5℃. The control was chopped ascidians subject to anti-browning and 4% salt treatment. product A was made from product C by adding an alcohol extract of red peppers and onion peel, 0.1% of glucose, and 0.55% of mixed amino acids (MAA; 0.05% Glu, 0.1% Pro, 0.3% Ala, and 0.1% Gly). After blanching and anti-browning treatment of chopped ascidians, Product B1 was made by adding 3% anchovy sauce and 6% sorbitol. Product B2 was made by adding 0.1% glucose and 0.55% MAA to Product B1. In total, 78 compounds were identified, including 31 alcohols, 15 aldehydes, and 10 ketones. The alcohols included 12 compounds from the C8-C10 series with floral and fruit odors, including octanol, 3-methyloctanol, 2,6-dimethyl-1-heptanol, (E)-5-octen-1-ol, 6-methyloctanol, (E)-3-octen-1-ol, (E)-3-decen-1-ol, (Z)-1,5-octadien-3-ol, and nonanol. These were detected in high amounts in ascidians and all fermented products. Aldehydes (octanal, (E)-2-octenal, 2,4-heptadienal, and nonanal) and ketones (1-oten-3-one and 2-heptanone) with fatty and mushroom odors were detected as major compounds, whereas nine ethyl esters were detected only in product A.

콩 품종에 따른 발효물의 아미노산과 향기성분 특성 (Properties of Amino Acid and Volatile Flavor Compounds of Fermented Soybean Products by Soybean Cultivar)

  • 신동선;최인덕;이석기;박지영;김남걸;박장환;최혜선
    • 한국식품영양학회지
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    • 제32권5호
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    • pp.434-441
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    • 2019
  • In this study, we analyzed the nutritional composition properties of soybeans and the organic acids, amino acids and volatile flavor compounds of fermented soybean products. We used five soybean cultivars including Pyeongwon, Jinpung, Saedanbaek, Saeolkong and Cheonga for this experiment. Physicochemical analysis of soybeans, showed that the cured protein and fat contents were 35.12~45.12 and 14.26~20.14%, respectively. The rank order of major organic acids was lactic acid > acetic acid > fumaric acid, with Saedanbaek being the highest. Total amino acid content of the samples was 358.12~657.28 mg/100 g, and glutamic acid, alanine, cysteine, valine, leucine, histidine and arginine were the major amino acids. We identified a total of 34 volatile aroma-compounds, including 7 alcohols, 7 acids, 7 ketones, 5 phenols, 2 esters, 1 furan, 4 pyrazines, and 1 miscellaneous compounds. As a result of this, could be applied to determine the suitability of cultivars and the quality for the process of the fermented soybean products.

The Impact of Proteolytic Pork Hydrolysate on Microbial, Flavor and Free Amino Acids Compounds of Yogurt

  • Lin, Jinzhong;Hua, Baozhen;Xu, Zhiping;Li, Sha;Ma, Chengjie
    • 한국축산식품학회지
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    • 제36권4호
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    • pp.558-565
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    • 2016
  • The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth.

유연한 곁가지 말단에 이온성 작용기를 가지는 양이온성 수분산 PU의 제조와 물성 (Preparation and Properties of Water-borne PU Having Ionic Center onto Flexible Side Chain)

  • 김동민;방문수;김형중
    • 접착 및 계면
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    • 제7권1호
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    • pp.3-9
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    • 2006
  • 세 개의 isocyanate작용기를 가지는 IP-$75^{(R)}$와 하나의 hydroxyl작용기를 가지는 여러 가지 amino alcohol을 ionomer로 이용하여 수분산에 필요한 ionic center가 측쇄에 위치하는 양이온성 수분산 polyurethane (PU)을 합성하였다. NCO/OH몰 비, ionomer의 종류 및 중화제의 종류에 따라 수분산 PU의 입도, 점도, 분산안정성, 접촉각, 표면에너지, $T_g$, 그리고 접착강도의 변화를 알아보았다. 제조된 수분산 PU는 주쇄에 ionic center를 가지는 양이온 수분산 PU보다 더 작은 입도를 가지며 분산안정성도 우수함을 확인하였다.

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