• Journal of the Korean Chemical Society
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• v.37 no.5
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• pp.523-526
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• 1993

Absorption spectra of photochromic spironaphthoxazine dye in various solvents were examined and exhibited a positive solvatochromism. The positive solvatochromism of this dye strongly suggests that the structure of open chain forms is keto type structure, 4a. The effect of structural change on the electronic spectra, on replacement of the C=C bond by C=N bond, is discussed.

• Journal of the Korean Chemical Society
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• v.40 no.2
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• pp.122-127
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• 1996

The PPP-MO method has been used to calculate the $\pi$ electronic excitation energy of fluorane dyes. A good correlation between the absorbed and calculated values for the ${\pi}{\rightarrow}\pi*$ transition was found for fluorane dyes. The effect of substituents on the color of fluorane dye was studied on the basis of these calculated results, i.e. HOMO-LUMO energy levels and $\pi-electron-density$ changes accompanying the first excitation.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1184-1187
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• 1999

The Gardenia jasminoides yellow pigment and converted pigments were completely separated by Amberlite XAD-4 column chromatography. These Pigments were gel filtrated on Sephadex LH-20 column chromatography. The characteristics of absorption spectra of eluate and fractionated pigments were investigated. The pigment converted by Lactobacillus plantarum showed a single blue color with an absorption peak at 588 nm and its molecular size was bigger than that of crocetin. The pigment, converted by Staphylococcus epidermidis, Showed blue-green color, which was composed of yellow color with an absorption peak at 418 nm and blue color at 588 nm. Molecular size of the yellow pigment was smaller than crocetin and that of blue color.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.114-120
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• 1981

A rapid and simple method for detecting colors was attempted on the basis of absorption and emission spectra of reflected light at $45^{\circ}$ angle from color-adsorbed filter paper illuminated by ultraviolet light through interference filter. Absorption spectra of prepared samples revealed more characteristic patterns than emission spectra. Detection of colors was readily accomplished by the investigation of wave length range, distribution pattern, the number of absorption bands and the degree of quenching.

• Textile Coloration and Finishing
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• v.6 no.1
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• pp.28-32
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• 1994

The synthesis and absorption spectra of squarvlium(SQ) dyes and croconium(CR) dyes were .studied. Absorption spectra of SQ dye in various solvents exhibited a negative solvatochrornism. Thus, it was suggested that the structure of SQ dye may be a highly polar structure. The λ$_{max}$ of CR dyes undergoes a bathochromic shift of about 100nm compared with the corresponding SQ dyes. This shift can be calculated by the Pariser-Parr-Pople molecular orbital method. From the PPP MO calculation results, we found that SQ dye and CR dye have a almost same Highest Occupied Molecular Orbital(HOMO) level(SQ : -8.0eV, CR : -8.09eV). On the other hand, energy levels of Lowest Unoccupied Molecular Orbital(LUMO) of SQ and CR dyes are -4.09eV and -4.13eV respectively. Thus, replacement of five membered ring by four membered ring in SQ dye causes a large bathochromic shift.t.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.599-605
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• 2016

Serratia marcescens, a Gram-negative bacterium characterized by production of a nondiffusible red pigment. Serratia marcescens 2354 (ATCC 25419) was production and purification a high concentration of red pigments when growing on Cang's soytone (CS) culture broth with soytone and ethanol. The optimal temperature and intial pH range for the production of the red pigments were $28^{\circ}C$ and pH 7.5, respectively. The red pigments was separated and purified through organic solvents extraction. Characterization of the red pigments is studied by UV-spectrophotometer at ${\lambda}_{max}$ 537 nm. The HPLC-Mass analysis of the partially purified compounds showed two major peaks with the molecular masses of 537 and 565 g. The red pigments were stable at room temperature under the acidic pH (up to pH 6) but were unstable at the strong alkaline condition. And red pigments were stable at sun light.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.53-59
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• 1973

The anthocyanins in Santa rosa plum (widely growing var. in Korea) were extracted with 0.5% methanolic HCl and purified with Amberlite IRC-50 cation exchange resin. The individual pigments were separated by paper chromatography. The two pigments were identified as cyanidin-3-monoglucoside and cyanidin-3-xyloglucoside based on the following evidence: Rf values in various solvents, partical acid hydrolysis, stepwise hydrolysis, sugar moiety, alkaline degradation, and absorption spectra in the visible region. Cyanicin-3-monoglucoside was the abundant pigment of the plum.

• Journal of the Korean Chemical Society
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• v.40 no.12
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• pp.741-747
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• 1996

The syntheses and absorption spectra of squarylium and croconium dyes were studied. IR data and negative solvatochromism revealed that squarylium dyes have symmetrical 1,3-bonded squarylium rings. A new class of unsymmetrical squarylium dyes and their precursor have also been synthesized. The λmax of croconium dyes undergoes a bathochromic shift of about 100 nm compared with corresponding squarylium dyes. This shift can he calculated by the Pariser-Parr-Pople molecular orbital method.

• Journal of the Korean Chemical Society
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• v.38 no.11
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• pp.792-799
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• 1994

The spectral changes of 3,3'-diethyl oxacarbocyanine(DOC) in the aqueous solution and in the presence of polyacrylic acid(PAA) were studied by means of absorption and fluorescence spectroscopy. The spectral change of DOC in the aqueous solution with concentration changes is attributed to the formation of dimer. In the presence of PAA, the characteristic changes of metachromatic band with changes of P/D (the ratio between available binding site and the dye concentration) are found and the discussions are made in terms of stacking theory. A kinetic study of the interaction between DOC and PAA was also investigated by the absorption and fluorescence stopped-flow spectroscopy. The observed relaxation effect in PAA-DOC system can be described quantitatively by assuming two relaxation processes occur.

• Applied Biological Chemistry
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• v.18 no.4
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• pp.188-193
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• 1975

The studies on the structure of anthocyanins in wild vines have beer carried out. The pigments were extracted with 0.5% HCl in methanol from the wild vines which were wildly grown in the mountain area of Korea and purified with Amberlite IRC-50 canon exchange resin. The individual pigments were separated by paper chromatography. Sever. pigments were identified by partial acid hydrolysis, sugar moiety, alkaline degradation, $R_f$ values of paper chromatography in various solvents and absorption spectra in the visible region. The identified pigments were delphinidin 3-monoglucoside, petunidin 3-monoglucoside, cyanidin 3-monoglucoside, delphinidin 3, 5-diglucoside, malvidin 3-monoglucoside, petunidin 3, 5 diglucoside and malvidin 3, 5-diglucoside.