• 제목/요약/키워드: Dichroism

검색결과 294건 처리시간 0.023초

Flurbiprofen과 Cyclodextrin과의 포접화물(包接化物)에 관한 연구(硏究) (Inclusion Compound of Flurbiprofen with Cyclodextrin)

  • 백완숙;용재익;김길수
    • Journal of Pharmaceutical Investigation
    • /
    • 제15권1호
    • /
    • pp.15-21
    • /
    • 1985
  • The inclusion of ${\alpha}-cyclodextrin$ and ${\beta}-cyclodextrin$ with flurbiprofen in aqueous phase was investigated by UV absorption and circular dichroism spectroscopies. The inclusion complex in solid powder form were made by the freeze-drying and coprecipitation methods in molar ratio 1:1. The inclusion complex formation was confirmed by infrared absorption spectroscopy. The freeze-drying method was successful in obtaining the inclusion compounds compared with the coprecipitation method. The dissolution of solid flurbiprofen inclusion complex was examined in comparison with those of flurbiprofen alone. The inclusion complex obtained by freeze-drying method increased the dissolution rate.

  • PDF

The Interaction of Polysaccharides Isolated from Auricularia Polytricha with Human Serum Albumin

  • Wang, Wei;Zhang, Guoguang;Zou, Jinmei
    • Journal of Applied Biological Chemistry
    • /
    • 제57권1호
    • /
    • pp.33-40
    • /
    • 2014
  • Polysaccharides have attracted great attention for their wide range of applications in biological and medical fields. In this paper, the interaction of polysaccharides with human serum albumin (HSA) was systematically investigated by fluorescence (FL) spectroscopy and circular dichroism (CD) spectra under different conditions. The Stern-Volmer quenching constants ($K_a$) at different ionic strength and pH were calculated, and information of the structural features of HSA was discussed. FL and CD results indicate that both hydrophobic and electrostatic interactions play important roles during the binding process. The quenching of the fluorescence resulting the binding of polysaccharides and HSA is static.

Structure studies of Pulmonary Surfactant Protein B(SP-B(3,4)) by NMR Spectroscopy and Molecular Modeling

  • Kim, Yangmee;Dongha Baek;Kang, Joo-Hyun;Shin, Song-Yub;Hahm, Kyung-Soo
    • 한국자기공명학회논문지
    • /
    • 제5권1호
    • /
    • pp.37-45
    • /
    • 2001
  • Synthetic pulmonary surfactants consisting of a mixture of phospholipids with synthetic peptides based on human surfactant-associated protein SP-B were prepared. These surfactants were analyzed f3r their secondary structures by circular dichroism (CD) spectroscopy and NMR spectroscopy. Two synthetic peptides (SP-B(3), SP-B(4)) combined with the phospholipid mixture displayed significant surfactant properties. The CD spectra showed that the u-helical propensities of the peptides in DPC micelles. In the NMR spectroscopy, the tertiary structures of SP-B(3) show that it has $\alpha$-helical structure from Gln5 to Arg13 in DPC micelle and SP-B(4) show that they have $\alpha$-helical structure from Gln5 to Leu12 in DPC micelle. Based on these structures, truncated peptides originated from SP-B protein, can be designed as effective synthetic surfactants for clinical use.

  • PDF

Ag 편광 광도핑에 의한 칼코게나이드 박막의 광유기 이방성(PA) (The photoinduced anisotropy(PA) by Ag polarized-photodoping in amorphous chalcogenide thin films)

  • 장선주;여철호;박정일;정홍배
    • 한국전기전자재료학회논문지
    • /
    • 제13권6호
    • /
    • pp.533-537
    • /
    • 2000
  • It was known that chalcogenide glasses have the superior property of the photoinduced anisotropy(PA). In this study we observed the phenomenon of Ag polarized-photodoping in chalcogenide As$_{40}$ /Ge$_{10}$/Se$_{15}$ /S$_{35}$ and the double-layer of Ag doped As$_{40}$ /Ge$_{10}$/Se$_{15}$ /S$_{35}$ thin film using the irradiation with the polarized He-Ne laser light. The Ag polarized-photodoping results in reducing the time of saturation anisotorpy and increasing the sensitivity of linearly anisotropy intensity up to maximum 220% The Ag polrized-photodoping shows improvement of the photoinduced anisotropy property in polarized photodoping of the chalcogenide thin film. It will offer lots of information for the photodoping mechanism and analysis of chalcogenide thin film.in film.ilm.

  • PDF

Absolute Configuration of ${\beta}$-agarofuran nucleus of euojaponine C by CD exciton chirality method

  • Ryu, Jae-Ha;Ryu, Shi-Yong;Han, Yong-Nam;Han, Byung-Hoon
    • Archives of Pharmacal Research
    • /
    • 제20권1호
    • /
    • pp.76-79
    • /
    • 1997
  • A new celastraceae alkaloid, euojaponine C has been isolated from the methanol extract of the root bark of Euonymus japonica. With the relative stereochemistry of euojaponine C established by NOESY data, the absolute stereochemistry has been determined by circular dichroism (CD) exciton chirality method. The CD of the 2, 5-bis-phenyl benzoate of triacetonide derived from the LiAlH$_{4}$, hydrolysate, euonyminol shows that the configuration of C-2 and C-5 are both R.

  • PDF

Cyclic Oligopyrroles as Sensors for Absolute Configuration Determination of Carboxylic Acids

  • Lintuluoto Juha M.;Nakayama Kana;Setsune Jun-Ichiro
    • 한국고분자학회:학술대회논문집
    • /
    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
    • /
    • pp.241-241
    • /
    • 2006
  • Absolute configuration of carboxylic acids, including amino acids can be determined by circular dichroism (CD) exciton chirality method. This method employs cyclic oligopyrroles able to form stable complexes with carboxylic acids. Addition of carboxylic acids to the oligopyrroles induce CD spectrum at the macrocycle absorption region and in which the sign of the $1^{st}$ Cotton effect is determined solely by the absolute configuration of the carboxylic acid. The basicity of the pyrrole nitrogen can be controlled by macrocycle substitution thus yielding more sensitive chirality sensors.

  • PDF

Synthesis and Chiro-Optical Properties of Water Processable Conducting Poly(diphenylamine) Nanocomposites

  • Showkat, Ali Md;Lee, Kwang-Pill;Gopalan, Anantha Iyengar;Kim, Sang-Ho
    • Macromolecular Research
    • /
    • 제15권6호
    • /
    • pp.575-580
    • /
    • 2007
  • Water-soluble, chiral conducting, poly(diphenylamine) (PDPA) nanocomposites were synthesized by chemical oxidative polymerization of diphenylamine in the presence of poly(acrylic acid) (PAA) as a template and camphor sulphonic acid (CSA) as the chiral inductor, Composites were formed as stable aqueous dispersions under different experimental conditions, such as DPA to PAA molar ratios, PAA molecular weight, etc. Circular dichroism(CD) spectra of the composites indicated the induction of chirality to PDPA. Compared to simple chiral PANI, the PDPA/PAA/CSA nanocomposites showed a different Cotton effect. The appearance of a CD band in the composite was complimentary to the bisignate, exciton-coupled band in the UV-Visible spectrum. FTIR spectra indicated the intimate mixing of PDPA and PAA.

Magnetic Properties of Fe/Ni Thin Films: First Principles Study

  • Kim, Dong-Yoo;Hong, Ji-Sang
    • Journal of Magnetics
    • /
    • 제13권2호
    • /
    • pp.76-80
    • /
    • 2008
  • This study examined the magnetic properties of ultrathin Fe/Ni films on a Cu(001) surface using the full potential linearized augmented plane wave (FLAPW) method. The magnetic moment of Fe/Ni films was found to be insensitive to strain. Nevertheless, strain had a significant influence on the magnetization direction. For example, Fe/Ni films showed a thickness-dependent spin reorientation transition in the presence of strain, while the Fe/Ni films grown pseudomorphically on Cu(001) always showed perpendicular magnetization. In addition, the theoretically calculated X-ray magnetic circular dichroism (XMCD) was examined.

가로 가둠을 통한 자성층간 결합 기여도 조절 (Tailoring Magnetic Interlayer Coupling Contribution via Lateral Confinement)

  • 이동렬
    • 한국자기학회지
    • /
    • 제26권5호
    • /
    • pp.149-153
    • /
    • 2016
  • Fe/Gd 다층박막 내 자성층간 결합에 미치는 패턴의 영향을 연구하였다. 이를 위하여 하나의 다층박막 시료를 나누어서 패턴한 것과 패턴하지 않은 것으로 제작하여 비교하였다. X선 자기 원편광 이색성(X-ray magnetic circular dichrosim: XMCD)을 이용하여 Gd 원소에 선택적인 자화 벡터의 온도 변화를 비교한 결과, 패턴 시료의 경우 Gd 자화 벡터의 온도의존성이 패턴 전에 비해 뚜렷하게 변화했음을 관측하였다. 이는 패턴 효과와 반강자성의 층간 결합 효과가 서로 경쟁하여 나타난 결과이다.

Phospholipid Liposomes과 Bovine Lactoferrin의 상호작용 (Interactions of Phospholipid Liposomes and Bovine Lactoferrin)

  • 김미영;강신원;박장수;남명수
    • 농업과학연구
    • /
    • 제37권3호
    • /
    • pp.543-545
    • /
    • 2010
  • Apo, holo, native-type of lactoferrin showed a similar pattern of circular dichroism(CD) spectra. Lactoferrin appeared to interact more easily with negatively charged liposome than neutral liposome. Holo-type of lactoferrin showed the highest degree of leakage, whereas apo-type of lactoferrin showed the lowest level of leakage. Holo-type lactoferrin could more easily interact with phospholipid liposomes than apo-type lactoferrin, when used as an artificial membrane.