• 제목/요약/키워드: NaB$H_{4}$

검색결과 643건 처리시간 0.031초

Synthesis and Molecular Structure of Calix[4]arene Butanoate 1,2-Alternate Conformer

  • 노광현;박영자;김근희;신정미
    • Bulletin of the Korean Chemical Society
    • /
    • 제17권5호
    • /
    • pp.447-452
    • /
    • 1996
  • Three conformational isomers of calix[4]arene butanoate were isolated from the reaction of calix[4]arene and butanoyl chloride in the presence of NaH and their structures were determined by NMR spectra as 1,2-alternate 2a, partial cone 2b and 1,3-alternate conformer 2c, respectively. The crystal structure of 2a has been determined by X-ray diffraction method. The crystals are monoclinic, space group C2/c, a=18.435 (4), b=13.774 (2), c=16.941 (3) Å, β=116.23 (1)°, Z=4, V=3858.8 (12)Å3, Dc=1.21 g cm-3, Dm=1.21 g cm-3. The molecule is in the 1,2-alternate conformation. It has two-fold symmetry axis along the line connecting between C (7AA') and C (7BB') parallel to the b axis of crystal lattice.

해수산 rotifer, Brachionus rotundiformis의 $\alpha$-amylase, total alkaline Protease, trypsin 및 triacylglycerol-lipase 활성 특성 (Characterization of $\alpha$-amylase, Total Alkaline Pretense, Trypsin and Triacylglycerol-lipase Activity of the Euryhaline Rotifer Brachionus rotundiformis)

  • 권오남;박흠기
    • 한국양식학회지
    • /
    • 제18권4호
    • /
    • pp.245-251
    • /
    • 2005
  • 본 연구는 rotifer, B. rotundiformis를 대상으로 소화효소 실험을 하기 위해 이들이 가지고 있는 소화효소의 최고 활성 조건을 확인하기 위해 수행하였다. rotifer, B. rotundiformis의 $\alpha$-amylase, total alkaline Protease, trypsin 및 TG-lipase는 Tris-HCl buffer 보다 phosphate-NaOH buffer 안정적인 효소활성을 보였다. $\alpha$-amylase, trypsin 및 TG-lipase는 pH 8.0에서, total alkaline proteaset pH 7.0에서 높은 효소 활성을 나타내었다. $\alpha$-amylase 활성은 $40^{\circ}C$에서 가장 높은 활성을 보였으며, total alkaline pretense와 trypsin은 $55{\~}60^{\circ}C$의 온도에서 높은 활성을 나타내었다. 반면 TG-lipase 활성은 $25{\~}30^{\circ}C$의 낮은 온도에서 활성이 높았다. $\alpha$-amylase, total alkaline pretense, trypsin 및 TG-lipase의 활성의 적정 기질 농도는 $3.5\%$ starch, $\0.6%$ azo-casein, $87.5{\mu}M$ BApNA and 81.2 mM olive oil이었다. $\alpha$-amylase, total alkaline protease, trypsin 및 TG-lipase의 활성의 적정 반응시간은 40, 60, 30 and 25 min으로 나타났다. 본 연구 결과에서 얻어진 자료는 rotifer, B. rotundiformis의 소화효소 연구를 위한 기초 자료로 이용될 것이다.

Conformations of Tetrahomodioxa-p0phenylcalix[4]arene Alkyl Ethers

  • No, Kwang-Hyun;Park, Young-Ja
    • Bulletin of the Korean Chemical Society
    • /
    • 제23권11호
    • /
    • pp.1629-1634
    • /
    • 2002
  • Reaction of tetrahomodioxa p-phenylcalix[4]arene with alkyl halide and NaH in DMF leads to the title tetra-alkylated derivatives, 7,13,21,27-tetra-phenyl-29,30,31,32-tetraalkyloxy-2,3,16,17-tetrahomo-3,17-dioxacalix [4]arenes, their preferred conformations were determined by NMR spectra as C-1,2-alternate. The molecular structure of allyl derivative has been solved by X-ray diffraction methods. The molecules have a conformation with pseudo center of symmetry. The benzene ring A is up, ring C is down, B and D rings are flat with respect to the plane of the macrocyclic ring.

Neuraminidase Inhibitors from the Fruiting Body of Glaziella splendens

  • Kim, Ji-Yul;Woo, E-Eum;Ha, Lee Su;Ki, Dae-Won;Lee, In-Kyoung;Yun, Bong-Sik
    • Mycobiology
    • /
    • 제47권2호
    • /
    • pp.256-260
    • /
    • 2019
  • Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1-5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2-5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the $IC_{50}$ values of 30.9, 41.8, and $35.7{\mu}M$ for 3 and 46.5, 50.4, and $29.9{\mu}M$ for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.

[1,3] Oxazine 유도체 합성을 위한 효율적인 One-Pot 합성 (An Efficient One-Pot Strategies for the Synthesis of [1,3] Oxazine Derivatives)

  • Sapkal, Suryakant B.;Shelke, Kiran F.;Shingate, Bapurao B.;Shingare, Murlidhar S.
    • 대한화학회지
    • /
    • 제54권4호
    • /
    • pp.437-442
    • /
    • 2010
  • 수용액 속에서 $NaHSO_4$, TBAB (phase transfer catalyst), ionic liquid (IL) (1-butyl-3-methyl imidazolium hydrogen sulphate [bmim]$HSO_4$)를 사용하여, formalin, ${\beta}$-naphthol, aromatic amines을 반응시켜서 대응하는 2,3-dihydro-2-phenyl-1Hnaphtho-[1,2-e] [1,3] oxazine 유도체를 합성할 수 있는 보다 친환경적이고, 수율이 좋고, 크로마토그래피 분리 방법을 사용하지 않는 합성 방법을 개발하였다.

알칼리 활성 슬래그 결합재의 미소수화열 분석 (Isothermal Conduction Calorimetry Analysis of Alkali Activated Slag Binder)

  • 최영철;조현우;오성우;문규돈
    • 한국건설순환자원학회논문집
    • /
    • 제3권3호
    • /
    • pp.237-243
    • /
    • 2015
  • 본 연구에서는 알칼리 활성화 슬래그 결합재의 반응성을 정량적으로 살펴보기 위해 미소수화열을 분석을 수행하였다. 알칼리 활성화 슬래그 결합재의 반응성 및 작업성 확보를 위해 다양한 알칼리 자극제의 종류 및 농도에 대해서 실험을 수행하였다. 알칼리 자극제 및 $SO_3$ 질량비를 변화하면서 미소수화열을 측정하였으며, 응결시간 제어를 위해 sodium tripolyphosphate ($Na_2P_3O_{10}$)와 hydrated sodium borate ($Na_2B_4O_710H_2O$)를 적용하였다. 그 결과, 알칼리 활성화 슬래그 결합재는 알칼리 활성에 의해 calcium silicate hydrate(C-S-H)를 촉진하는데 4~5% 농도의 알칼리가 필요한 것으로 나타났으며, $SO_3$ 함량이 높아질수록 누적 발열량이 작아지면서 전반적으로 발열이 지연되는 것으로 나타났다. 또한, 응결 지연제로서 hydrated sodium borate를 사용하였을 경우 발열을 억제하여 지연된 효과를 나타내며, 전체적인 누적 발열을 지연시키는 효과를 보이는 것을 확인할 수 있었다.

Crown Ether를 이용한 탐침형 납 이온선택성 전극 (Coated Wire Lead(Ⅱ) Ion-Selective Electrodes based on Crown Ethers)

  • 장미경;하광수;서무룡
    • 대한화학회지
    • /
    • 제41권7호
    • /
    • pp.337-342
    • /
    • 1997
  • 본 연구에서는 benzo-15-crown-5(B15C5)와 poly(acryloylmethylbenzo-15-crown-5)[poly(AMB15C5)] 화합물을 이온선택성 물질로 이용해서 $Pb^{2+}$를 전위차법으로 정량할 수 있는 탐침형 이온선택성 전극(coated wire-ion-selec-tive electrode[CWISE])을 개발하였다. 각각 감지막의 최적 조성은 B15C5의 경우에는 리간드 20 mg, 가소제인 tris(2-ethylhexyl) ester 165 mg, 지지체인 polyvinylchloride 75 mg 및 용매인 THF 0.7 mL이었으며 poly(AMB15C5) 경우에는 리간드 35 mg, 가소제인 tris(2-ethylhexyl) ester 160 mg, 지지체인 PVC [Polyvinyl Chloride] 70 mg 및 용매인 THF 2 mL이었다. 이 때 코팅용액의 리간드에 대한 무게함량은 각각 7.7%와 13.1%이었다. 각각의 전극은 $10^{-5} M{\sim}10^{-1}$ M 농도 범위에서 기울기가 28{\pm}1$ mV/decade인 직선성이 잘 성립하는 감응을 나타내었다. 또한 전극의 감응시간은 poly(AMB15C5) 경우에는 5분 이내였으며 B15C5의 경우에는 3분이내로 비교적 빠른 편이었다. 전극의 안정성은 크라운 에테르의 물에 대한 용해도 때문에 좋은 편은 아니었다. 최적 pH 조건은 pH 3~6이었으며 $Mg^{2+},\; Ca^{2+},\; Co^{2+},\; Ni^{2+},\; Cu^{2+},\; Zn^{2+}$$Cd^{2+}$는 방해가 거의 없었으나 $Na^+$$K^+$는 방해효과가 컸다. 그리고 본 연구에서 제조한 탐침형 이온선택성 전극을 이용하여 $Pb^{2+}$ 이온을 전위차 적정법으로 정량분석해 보았을 때 이론적인 당량점과 종말점이 잘 일키하는 결과를 얻었다.

  • PDF

Sunflower Seed Sprout의 성분조성에 관한 연구 (A Study on the Composition of Sunflower Seed Sprout)

  • 이영근
    • 동아시아식생활학회지
    • /
    • 제9권1호
    • /
    • pp.74-80
    • /
    • 1999
  • The proximate composition, pH, vitamins and minerals in sunflower seed sprout were investigated to furnish basic data for utilization in health food or processed food. The pH of sunflower seed sprout was 5.70. The contents of moisture, crude protein, crude fat, crude ash and crude fiber of sunflower seed sprout were 94.7%, 1.3%, 0.3%, 1.3% and 1.6%, respectively. The vitamin A, vitamin B$_1$, vitamin B$_2$, vitamin C and niacin contents in sunflower seed sprout were 114.411. U%, 0.06mg%, 0.05mg%. 5.90mg% and 0.80mg%, respectively. The contents of Ca, P, Fe, Na, K, Mn, Cu, Zn and Mg in sunflower seed sprout per 100g were 80.00mg, 4.85mg, 3.63mg, 8.25mg, 180.90mg, 1.35mg, 0.43mg, 1.85mgand 66.35mg, respectively. The crude ash and crude fiber content of sunflower seed sprout were 3 or 4 times higher than those in the sprout of radish seed, mung bean, soybean or alfalfa, respectively.

  • PDF

Statistical Optimization of Medium Components for Milk-Clotting Enzyme Production by Bacillus amyloliquefaciens D4 Using Wheat Bran-an Agro-Industry Waste

  • Zhang, Weibing;He, Xiaoling;Liu, Hongna;Guo, Huiyuan;Ren, Fazheng;Gao, Weidong;Wen, Pengcheng
    • Journal of Microbiology and Biotechnology
    • /
    • 제23권8호
    • /
    • pp.1084-1091
    • /
    • 2013
  • In this paper, two statistical methods were applied to optimize medium components to improve the production of the milk-clotting enzyme by Bacillus amyloliquefaciens D4. First, wheat bran juice, skim milk powder, and $Na_2HPO_4$ were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, an optimal medium was obtained using the Box-Behnken method, which consisted of 3.31 g/l of skim milk powder, 5.0 g/l of sucrose, 0.1 g/l of $FeSO_4{\cdot}7H_2O$, 0.1 g/l of $MgSO_4{\cdot}7H_2O$, 0.1 g/l of $MnSO_4{\cdot}2H_2O$, 0.1 g/l of $ZnSO_4{\cdot}7H_2O$, 1.52 g/l of $Na_2HPO_4$, and 172.45 g/l of wheat bran juice. With this optimal medium, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 3,326.7 SU/ml after incubation of 48 h, which was 1.76-fold higher than that of the basic medium, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize medium components, and B. amyloliquefaciens D4 possessed a high rennet-producing capacity in the optimal medium.

2005년 우리나라 습성강하물의 특성과 분포 (A Characteristics and Distributions of Wet Deposition in Korea, 2005)

  • 한진석;이상덕;홍유덕;공부주;신선아;정일록
    • 한국대기환경학회지
    • /
    • 제22권4호
    • /
    • pp.459-467
    • /
    • 2006
  • This study was carried out to characteristics and distributions of acid deposition in Korea. Precipitation was collected by acid deposition monitoring networks and analyzed for pH, conductivity, and following major ionic components $SO_4^{2-}$, $CI^-$, $NO_3^-$, $NH_4^+$, $Na^+$, $K^+$, $Ca^{2+}$, $Mg{2+}$. During the investigation period, Volume weighted annual mean pH of precipitation in Korea is 4.8, showing slightly acidic level. The amount of rainfall in the range of pH 5.1$\sim$5.5 charged approximately 28% of annual precipitation,23.4% in pH 4.6$\sim$5.0, and contributed 16.2% under pH 4.5. Among seasons, alkaline precipitation has occurred more often in spring, meanwhile acidic precipitation in which pH is under 4.5 has frequently occurred in autumn. Volume weighted annual mean concentrations of $SO_4^{2-}$, $NO_3^-$, $CI^-$ are 2.558 mg/L, 1.590 mg/L, 1.286 mg/L respectively, and provided that $SO_4^{2-}$, is the major contributor, followed by $NO_3^-$, $CI^-$. In case of cation, annual mean concentration for $NH_4^+$, $Na^+$, $K^+$, $Ca^{2+}$, $Mg{2+}$, $H^+$ are 0.693 mg/L, 0.528 mg/L, 0.439 mg/L, 0.455 mg/L, 0.089 mg/L,0.015 mg/L, and $NH_4$ were decided as the main contributor, followed by $Na^+$, $K^+$, $Ca^{2+}$, $Mg{2+}$, $H^+$. Annual wet deposition rate for sulfate, nitrate and ammonia are $3.316gm^{-2}yr^{-1}$, $2.057gm^{-2}yr{-1}$, $0.894gm^{-2}yr{-1}$, respectively, and it was founded that the deposition flux in summer contributes about 38.42% to 67.62% to total deposition.