• 제목/요약/키워드: A new reagent

검색결과 148건 처리시간 0.039초

Dipeptidyl Carboxypeptidases에 의한 S-Hippuryl Thioglycolyl Glycine의 가수분해 (S-Hippuryl Thioglycolyl Glycine : A New Chromogenic Substrate for Dipeptidyl Carboxypeptidases)

  • 이현재
    • 대한화학회지
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    • 제19권4호
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    • pp.246-251
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    • 1975
  • Dideptidyl carboxypeptidases와 angiotenisn-coverting enzyme의 새로운 기질불질로서 thiol ester 인 S-Hippuryl thioglycolyl glycine을 합성하였으며, 이 기질에 의한 간편하고도 예민한 효소 활성도의 정량방법을 제시하였다. 이 경우 효소반응 생성물인 thioglycolyl glycine은 반응계중에 첨가한 5,5-dithio-bis-(2-nitrobenzoic acid), DTNB와 쉽게 반응하여 410nm에서 강한 흡광스펙트럼을 갖는 5-thio-2-nitrobenzoic acid(${\varepsilon}M=1.36{\times}10^4$)을 형성함으로서 효소의 새로운 미량정량 방법으로 이용 가치가 크다고 본다.

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(Pyridine)(tetrahydroborato)zinc Complex, [Zn(BH4)2(py)], as a New Stable, Efficient and Chemoselective Reducing Agent for Reduction of Carbonyl Compounds

  • Zeynizadeh, Behzad;Faraji, Fariba
    • Bulletin of the Korean Chemical Society
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    • 제24권4호
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    • pp.453-459
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    • 2003
  • (Pyridine)(tetrahydroborato)zinc complex, $[Zn(BH_4)_2(py)]$, as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and a, β-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent.

Reaction of Thexylalkoxyboranes with Selected Orgnic Compounds Containing Representative Functional Groups Comparison of Reducing Characteristics of the Alkoxy Derivatives

  • 차진순;장석원;권오운;전중현
    • Bulletin of the Korean Chemical Society
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    • 제19권2호
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    • pp.243-249
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    • 1998
  • The reaction of alcohol with a solution of thexylborane (ThxBH2) in tetrahydrofuran (THF) provides a new class of mild and selective reducing agents, thexylalkoxyboranes (ThxBHOR: R=Et, i-Pr, i-Bu, s-Bu, t-Bu, Ph). In order to elucidate the effect of the alkoxy group in reduction reactions, the reducing power of ThxBHOR toward selected organic compounds containing representative functional groups under practical conditions (THF, 25°, the quantitative amount of reagent to compound) has been investigated. Generally, the reactivity of ThxBHOR is largely dependent upon the alkoxy substituent. ThxBHOR can be synthesized from a variety of alcohols, thus allowing control of the steric and electronic environment of these reagents.

Synthesis of Calcium Phosphate Minerals from Biowaste Clam Shells Using Microwave Heating

  • Bramhe, Sachin;Ryu, Jae-Kyung;Chu, Min Cheol;Balakrishnan, Avinash;Kim, Taik Nam
    • 한국재료학회지
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    • 제24권12호
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    • pp.700-703
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    • 2014
  • Calcium phosphate minerals are biologically important because of their application in the fields of orthopaedics and dentistry. Herein we have tried to synthesize calcium phosphate minerals from biowaste clam shells. A simple microwave method was used to synthesize a mixture of calcium phosphate minerals such as hydroxyapatite, tri-calcium phosphate, and monetite. The microwave induces vibration of the dipole ions in the reagent. The heating and rearrangement of ions and atoms occurs during the process. The phases obtained in the final powder were ascertained by X-ray diffraction; the morphology of each sample was checked using a scanning electron microscope. We were able to obtain a mixture of calcium phosphate minerals using the microwave method; the calcined powder showed a brick like morphology, which is different from the rod shape morphology of the hydroxyapatite obtained using the hydrothermal process.

光學 活性을 갖는 1-Aminoalkylphosphonic Acid 의 合成 (Synthesis of Optically Active 1-Aminoalkylphosphonic Acids)

  • 조성기;김용준
    • 대한화학회지
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    • 제33권2호
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    • pp.257-262
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    • 1989
  • Diethylaminomethylphosphonate와 chiral 시약인 (S)-(-)-2-hydroxypinan-3-one으로부터 만든 Schiff염기를 알킬화하여 광학 활성을 갖는 (+)-1-aminoalkyphosphonic acid를 합성하였으며, (S)-(-)-2-hydroxypinan-3-one을 광학 분할제로 사용하여 만든 diethylaminomethylphosphonate의 Schiff염기로부터 관 크로마토그래피 방법으로 (${\pm}$)-1-aminobenzylphosphonic acid를 광학분할하였다.

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Simple and Rapid Detection of Potato leafroll virus by Reverse Transcription Loop-mediated Isothermal Amplification

  • Ju, Ho-Jong
    • The Plant Pathology Journal
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    • 제27권4호
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    • pp.385-389
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    • 2011
  • A new reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the Potato leafroll virus (PLRV) was developed and compared with conventional reverse transcription polymerase chain reaction (RT-PCR) to address its advantages over RTPCR. RT-LAMP primers were designed from the open reading frame 3 (ORF3) sequence of PLRV. The RT-LAMP reactions were conducted without or with a set of loop primers. By real-time monitoring using Turbimeter, the RT-LAMP (with loop primers) detects PLRV in less than 30 min, compared to 120 min of RT-PCR. By adding fluorescent reagent during the reaction, final products of the RT-LAMP were fluorescently visualized under UV light or could be differentiated by naked-eye inspection under normal light. The RT-LAMP was extremely sensitive, about 2000-fold more sensitive than RT-PCR. This study presents great potential of the RT-LAMP for diagnosis and PLRV epidemiology because RT-LAMP method is speedy, sensitive, inexpensive, and convenient.

Thirty Six Years of Research on the Selective Reduction and Hydroboration

  • Cha, Jin-Soon
    • Bulletin of the Korean Chemical Society
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    • 제32권6호
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    • pp.1808-1846
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    • 2011
  • From 1975 to 2011, for thirty six years, the author and his collaborators have developed a variety of reducing and hydroborating agents, and applied them to organic synthesis, which involves the 1,2-reduction of ${\alpha}$,${\beta}$-unsaturated carbonyl compounds, stereoselective reduction of cycloalkanones, regioselective ring-opening of epoxides, partial reduction of carboxylic acid derivatives to aldehydes, regioselective addition to carbon-carbon multiple bonds, etc. by utilizing metal hydrides and the newly-devised the Meerwein-Ponndorf-Verley (MPV) type reagents. Such developments provide a new synthetic methodology making possible valuable selective reductions and hydroborations, not practical previously.

카티온화제 처리에 의한 면직물의 염색성 개선 (The Improvement of Dyeing Property of Cotton Fabric by Cationic Agent Treatment)

  • Sung, Woo Kyung;Park, Sang Joo;Lee, Won Chul
    • 한국염색가공학회지
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    • 제9권1호
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    • pp.33-43
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    • 1997
  • This study was carried out to investigate increasing the neutral substantivity of anionic dyes for cationic-modified cotton fabric treatied with cationic agent. In the present study 3-chloro-2-hydroxypropyltrimethyl ammonium chloride for reactive cationic agent was produced by reaction of epichlorohydrine with trimethylamine hydrochloride. 3-chloro-2-hydroxypropyltrimethylammonium chloride was converted in an aqueous solution of sodium hydroxide into glycidyltrimethylammonium chloride. By treating with this epoxy reagent the hydroxyl groups of cotton fabric was modified to trimethylammonium group through ether linkage. The introduction of new cationic sites into cotton fabric by pretreating with cationic agent improves the substantivity of anionic dyes with the cotton in dyebath. Dyeablity of the modified cotton fabric for direct and reactive dyes was much improved in a non-electrolytic or a little electrolytic dyebath and was proportional to the concentration of cationic agent.

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Isonicotinic Acid Hydrazide Sodium Methane Sulfonate의 분광광도정량법(分光光度定量法)(제1보)(第1報) (Spectrophotometric Determination of Isonicotinic Acid Hydrazide Sodium Methane Sulfonate)

  • 박영주;이병찬;서정진;김선녀
    • Journal of Pharmaceutical Investigation
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    • 제2권1호
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    • pp.14-17
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    • 1972
  • Spectrophotometric determination of isonicotinic acid hydrazide sodium methane sulfonate was examined and a new method has been established. Isonicotinic acid hydrazide sodium methane sulfonate reacts with acetylacetone solution (NASH Reagent) to produce a yellow dye, which exhibits absorption maximum at about $412\;m{\mu}$. Limits of masurement of isonicotinic acid hydrazide sodium methane sulfonate was $20-100{\mu}g/ml$. By this method isonicotinic acid hydrazide methane sulfonate can be determined in the presence of isonicotinic acid hydrazide.

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분광광도법에 의한 8-(p-Ethylbenzenesulfonamido) quinoline과 구리와의 착물에 관한 연구 (Spectrophotometric Study on the Complex of the Copper by 8-(p-Ethylbenzenesulfonamido) quinoline)

  • 이흥낙;박영규;이철희
    • 대한화학회지
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    • 제15권6호
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    • pp.378-384
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    • 1971
  • A new analytical reagent 8-(p-ethylbenzenesulfonamido)quinoline(EBSQ) has been synthesized, and identified its structure. EBSQ forms copper chloroform-soluble complex in a basic solution (pH = 7.5∼10.5). The other optimum conditions for the spectrophotometric study of Cu-EBSQ have been established at 380 $m{\mu}$. Beer's law is followed in the concentration range of 0~44.5 ${\mu}g$ per 10 ml of chloroform. The composition of complex has been found to be $Cu(EBSQ-H)_2$and the over-all instability constant is calculated to be $1.22{\times}10^{-7}$. The absorption coefficient of the $Cu(EBSQ-H)_2$ complex is ${\varepsilon}$ = 15,800.

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