• Journal of dental hygiene science
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• v.21 no.1
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• pp.38-44
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• 2021

Background: Dental caries and periodontal disease are bacterial infectious disease, mainly caused by plaque, a bacterial colony deposited on the tooth surface and gum tissue. Dental plaque disclosants easily stain the dental plaque, making them effective for scaling and tooth brushing education. As the erythrosine typically contained in dental plaque disclosants is highly cytotoxic, a low toxicity additive is needed. In this study, we aimed to examine the natural pigments with negligible cytotoxicity but can effectively stain the dental plaques for use in dental plaque disclosants. Methods: The pigmentation of eight types of natural pigments was tested on bovine tongue and teeth, as well as on head and neck tissue sections of experimental ICR mice. The cytotoxicity of gingival epithelial cells was measured via MTT assay. Pigmentation was performed on the bovine tongue and tooth surface. Pigmentation in the oral environment was observed in four mandibular incisors. A 2 Tone was used as a control. Results: Of the eight types of natural pigments, purple and blue pigments were effective in coloring dental plaques on the enamel surface as well as in the head and neck tissue sections. Additionally, purple and blue pigments were visible on the surface of the bovine tongue. Red, pink, orange, green, purple, and yellow pigments showed strong cytotoxicity, whereas brown and blue pigments had relatively low cytotoxicity. Blue pigment was effective in staining the dental plaque of four mandibular incisors. Conclusion: We suggest that the blue pigment derived from Gardenia jasminoides Ellis (Rubiaceae), which is effective for coloring dental plaques and has low cytotoxicity, is useful as a naturally derived dental disclosant.

• Microbiology and Biotechnology Letters
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• v.52 no.3
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• pp.314-324
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• 2024

Due to the hazardous effects of synthetic pigments, natural pigments are gaining popularity. Among natural sources microorganisms have become a major source of numerous industrially essential items and their use for getting various natural products have expanded dramatically in recent years. In the present study, 9 endophytic fungal strains were isolated from Tagetes erecta. On screening, yeast strain MGI was selected for further study which was identified as Rhodotorula mucilaginosa MGI. The pigment was intracellular, and the color of the crude extract was orange. The extract was subjected to characterization by UV-visible spectrophotometer and was purified by column phase chromatography, after purification two pigmented fractions were obtained. These fractions on characterization by thin layer chromatography (TLC) and Fourier transform infrared (FTIR) spectrophotometer affirms that they belong to carotenoid group of pigments. Orange (F1) and yellow (F2) fractions were anticipated as astaxanthin and beta carotene respectively. Moreover, the bioactive potential of pigmented fractions was investigated which manifested that F1 exhibited a maximum antioxidant activity of about 77% and F2 showed the highest zone of inhibition of 38 mm against Staphylococcus aureus. Thus, this study reflects that an endophytic yeast strain has the potential for the production of bioactive microbial pigments.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.2
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• pp.47-54
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• 2020

To develop the bright-vivid red- and yellow-inorganic fluorescent pigments with high luminescence properties, A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ inorganic pigments were synthesized by a water assisted solid state reaction (WASSR) method and a conventional solid state reaction method. Although impurity peaks corresponding to the AVO₃ and AV₃O₈ (A = K, Rb, and Cs) were observed in all samples prepared, the trigonal structure A₃V₅O₁₄ (A = K and Rb) and orthorhombic structure Cs₂V₄O₁₁ were successfully obtained as a main phase. These inorganic pigments showed the broad absorption band (under 550 nm) originated from CT transitions of VO₄ polyhedron, and the strong broad red- and green-emission bands due to ³T₂ → ¹A₁ and ³T₁ → ¹A₁ transitions of the [VO₄]^3- group. The A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ pigments showed a bright-vivid red- and yellow-body color, where the a* values of the A₃V₅O₁₄ (A = K and Rb) were +35.5 and +45.9, respectively, and b* value of Cs₂V₄O₁₁ pigments was +50.3. The L* values of the A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ inorganic pigments were over +45. These results indicate that the A₃V₅O₁₄ (A = K and Rb) and Cs₂V₄O₁₁ inorganic pigments could be an attractive candidate as a bright-vivid red- and yellow inorganic pigments.

• Conservation Science in Museum
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• v.13
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• pp.13-22
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• 2012

The patterns for Jeogui and Pyeseul (patterns of the queen's ceremonial robe worn and a belt ornament covering knees in the front) as owned by National Museum of Korea were made in the early 20th century and both of them were colored on paper. Through a non-destructive analysis on pigments and dyes used on both the patterns, it was attempted to identify the coloring materials. As for the analysis of the coloring pigments, the XRF was used. As a result of the pigment analysis on the pattern for Jeogui, it is presumed that lead white was used for obtaining the white color, ink stick for black color, orpiment for yellow color, cinnabar and red lead for red color, copper and arsenical or a mixture of copper carbonate and orpiment for green color whereas brass seems to have been used for obtaining other colors. The pigments used for obtaining the colors of white, black, yellow and green on the pattern for Pyeseul are the same as those used on the pattern for Jeogui whereas the red pigments used on each of the two patterns are seen to be different. Although it may be difficult to identify the kinds of blue pigments that were used on the patterns for Jeogui and Pyeseul, a mixture containing lead white is presumed to be used as blue pigment. Also, as a result of the UV-Vis spectroscopic analysis performed on the blue hanji (traditional Korean paper) of the pattern for Jeogui, it was presumed to have been dyed with indigo.

• 보존과학연구
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• s.28
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• pp.121-147
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• 2007

A large variety of mineral pigments has been used for Korean paintings and it has known that organic pigments have been used together on the Buddhist painting and the portrait. Haehakbando-do, which is from Honolulu Academy Museum in the United States, 12-fold screen was commissioned by Court of the late Joseon Dynasty in order to pray for the King's longevity. Therefore, it seems that all material used including pigments were selected very carefully and a great deal of technical effort was gone into its process. The purposes of this research were to estimate the pigments and the contributory elements of each color used on Haehakbando-do, in accordance with the conservation treatment carried out by Gochang Conservation Institute throughout last year. Without extracting sample, property of pigment was measured by nondestructive method, X-ray spectral analysis, and by comparing with the data about ancient pigments. In spite of the limited range of pigment analysis by nondestructive method, it should be noted that this method would not cause damage to the cultural properites. White pigment was found in all colored parts except the background, so it can be suggested that white color was used as a grounding of other color pigments. This would be flake white[$2PbCO_3{\cdot}Pb(OH)_2$] as Pb was found. Pb was the only element could be found in yellow, however, it can be organic pigment like Gamboge as same as background. Red would be Cinnabar (HgS) as hydrargyrum (Hg) was detected. For the light purple in cloud, organic pigments were probably used since any element is not detected except for Pb, which is used for background. It is possible that green color is the mixture of Malachite[$CuCO_3{\cdot}Cu(OH)_2$] and Azurite [$2CuCO_3{\cdot}Cu(OH)_2$], which share Cu as their main element. Azurite[$2CuCO_3{\cdot}Cu(OH)_2$] was used for bluish pigments. Black is carbon compound. For gold, solid gold (Au) was detected. It shows that gold was gilded on the flake white background. Red painted on the frame of screen was identified as Cinnabar (HgS) and the gold pattern was solid gold (Au). The supporting leg of folding screen was made of brass because both copper and zinc were detected. In conclusion, white pigment was used as grounding of all colors of Haehakbando-do, and specific pigments were used for each color. Additionally, result from the analysis of several pigments shows that mineral pigment and organic pigment, or different mineral pigments were mixed to make various colors.

• Food Science and Preservation
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• v.11 no.1
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• pp.42-46
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• 2004

Each pigments were obtained by ethyl alcohol extraction method, blue and yellow pigment from Gardenia as well as dark brown pigment from Kaoliang. Concentration of these pigments are all 60 Brix, the extraction yields were 0.68, 1.97, 0.63 ％(w/w), respectively. Oil soluble natural black pigment (OSNBP) was composed of soybean oil, water, emulsifier, Gardenia blue and yellow, Kaoliang dark brown etc. Blending ratio of these was 8: 22: 42: 10: 15: 13 (w/w), this mixture was carried out homogenized. Solubility of this OSNBP in soybean oil was appeared the maximum level at about 30∼40$^{\circ}C$ range. OSNBP solubilized black oil was not reseparated at below 20$^{\circ}C$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.829-832
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• 2014

This study was conducted to investigate antioxidative and physiological activities of ethanol extracts concentration from Monascus-Fermented Chinese Yam (MFCY). The ethanol extracts from MFCY were measured to examine pigments, DPPH radical scavenging activity, reducing power and monacolin K contents. As a results show that Monascus sp. MK805, with Dioscorea japonica as the substrate can produce pigments (yellow, orange and red), DPPH radical scavenging activity, reducing power and monacolin K content at 29.6 (yellow), 15.1 (orange), 20.4 (red), 72.8%, 1.74(OD at 700nm), 480.6 mg/kg in EtOH extract, respectively. Therefore, fermented chinese yam (Dioscorea japonica) was estimated to be effective biological activity material.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.321-324
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• 2000

The Effect of pH red pigment production by Monascus purpureus ATCC 16365 has been studied in pH-controlled batch fermenter culture. A maximum of yellow and red pigments were detected using UV-Vis spectrophotometer at 385nm and 495nm, respectively. Fungal growth and pigment production were favoured at low pH(pH 4.0-5.5). Especially extracellular formation rate of orange to yellow pigment was decreased compared with that of orange to red pigment at pH 7.0. In addition, the enhancement of ratio of extracellular to intracellular pigment and the red pigment production in pH 7.0-controlled batch fermenter was observed. However, the pH 7.0-controlled batch cultures depressed the total production of pigments. The pH change from 4.0 to 7.0 during batch fermenter cultivations sharply increased both red pigment production and the extracellular composition.

• Journal of the Korean Ceramic Society
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• v.55 no.4
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• pp.368-375
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• 2018

This study deals with the color formation of ceramic pigment in the $TiO_2$-SnO-ZnO system. We designed compounds to control the color formation depending on the composition using the Design of Experiment. The color coordinate values of synthesized pigments, $L^*a^*b^*$ were measured and statistically analyzed color for changing elements depending on its composition. The relationship between the major crystalline phases and chromaticity was examined using XRD, and the oxidation states of each element were analyzed by XPS. The synthesized pigments based on the compound design exhibited various color changes ranging from yellow-orange to green-blue and brown. The statistical analysis on the spectrophotometer results shows that $a^*$ and $b^*$ values decreased with $TiO_2$ content, and increased with SnO content. Yellow-orange color was detected with the main peak of SnO, and the green-blue color developed with the main peak of $Zn_2TiO_4$. The $a^*$ and $b^*$ values increased with increased SnO peak intensity, and decreased with increased $Zn_2TiO_4$ peak intensity. The results revealed that pigment color formation was influenced by changes in the main crystalline phases and crystalline intensity. However, XPS analysis of the oxidation states of each element showed little correlation with the pigment chromaticity result.

• Conservation Science in Museum
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• v.28
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• pp.109-136
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• 2022

This study analyzes the , one of the three panels of 《Welcoming Banquets for the Governor of Pyeong-an》, a documentary painting of the late Joseon Dynasty, with the aim to identify the coloring materials used in the painting. The painting was first imaged at each wavelength in order to minimize the potential problems in the process of analyzing specific parts. This study applied X-rays to identify ink, gold, and organic and inorganic pigments and used infrared rays to find ink and copper-based pigments. It also applied hyperspectral imaging to distinguish organic pigments from black, blue, and green materials. It also analyzed spots selected for each color to identify the following materials: white lead (white), ink/indigo (black), a combination of red lead and cinnabar (red), pink dye, purple dye, iron oxides (brown), orpiment/dye (yellow), malachite/malachite and yellow dye/indigo (green), azurite/white lead and indigo/indigo (blue), indigo and cochineal (violet), and gold leaf (gold). It is expected that more efficient analysis will be made possible by securing a sufficient library for each wavelength.