• 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.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.249-256
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• 2017

The Monascus azaphilone (MAz) pigment is a well-known food colorant that has yellow, orange and red components. The structures of the yellow and orange MAz differ by two hydride reductions, with yellow MAz being the reduced form. Orange MAz can be non-enzymatically converted to red MAz in the presence of amine derivatives. It was previously demonstrated that mppE and mppG are involved in the biosynthesis of yellow and orange MAz, respectively. However, ${\Delta}mppE$ and ${\Delta}mppG$ knockout mutants maintained residual production of yellow and orange MAz, respectively. In this study, we deleted the region encompassing mppD, mppE and mppG in M. purpureus and compared the phenotype of the resulting mutant (${\Delta}mppDEG$) with that of an mppD knockout mutant (${\Delta}mppD$). It was previously reported that the ${\Delta}mppD$ strain retained the ability to produce MAz but at approximately 10% of the level observed in the wildtype strain. A chemical analysis demonstrated that the ${\Delta}mppDEG$ strain was still capable of producing both yellow and orange MAz, suggesting the presence of minor MAz route(s) not involving mppE or mppG. Unexpectedly, the ${\Delta}mppDEG$ strain was observed to accumulate fast-eluting pigments in a reverse phase high-performance liquid chromatography analysis. A LC-MS analysis identified these pigments as ethanolamine derivatives of red MAz, which had been previously identified in an mppE knockout mutant that produces high amounts of orange MAz. Although the underlying mechanism is largely unknown, this study has yielded an M. purpureus strain that selectively accumulates red MAz.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.416-421
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• 2013

The purpose of this study was to investigate the effects of pH, temperature, light, sugars, and organic acids on the stability of anthocyanin pigments extracted from aronia (Aroniamelanocarpa). Pigments from aronia were most stable at pH 3.0, with maximal absorbance at 514 nm. High temperatures and prolonged heating substantially reduced anthocyanin contents. Anthocyanin levels were as low as approximately 21.70 and 79.63% of normal levels after 300 min of heating at 30 and $100^{\circ}C$, respectively. All of the sugars tested decreased the abundance of aronia pigments, with the levels highest in the presence of maltose, and decreasing progressively in the presence of galactose, sucrose, glucose, and fructose. Among the organic acids tested, citric acid was the most effective in stabilizing the aronia pigment, followed by tartaric acid, malic acid, formic acid, and ascorbic acid. These results provide useful reference data for efforts to use pigments from aronia in processed foods or for developing natural food colorants.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.243-247
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• 1976

A potent intracellular-lipid-producing yeast, Rhodotrorular glutinis var. glutinis sw-17 was studied on the production of carotenoids after shaking the cultures for 8 days at $25^{\circ}C$. The pigments were extracted with solvents and chromatographed with columns for its isolation. The carotonoids were identified by their positions on the column, and by their light-absorption curves. Close agreement was obtained between the absorption maxima of the isolated pigments and published literature values. The characteristic wave length maxima and the extinction values used for quantitative determination. The caroteniod pigments produced by the yeast were composed of torularhodin(28.52%), torulene(38.16%), neurosporene(1.49%), ${\gamma}-carotene(9.88%)$, ${\beta}$-zeacarotene(2.0%), ${\beta}-carotene(19.95%)$ and ${\delta}-carotene(trace)$.

• Journal of the Korean Ceramic Society
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• v.44 no.5 s.300
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• pp.160-165
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• 2007

This research studied the most suitable synthesis condition of mineral pigments of black spinel, which have a stable chromogenic characteristic also ata high temperature of $1400^{\circ}C$ (it is not currently producedin the country) to meet not only functionality of ceramics but also an individual's aesthetic. It was synthesized by the plastic synthetic method on the basis of basic formation of $Fe_2O_3,\;Cr_2O_3$, Quartz, Kaolin, CoO, $MnO_2$, and plasticity was made at $1500^{\circ}C,\;1550^{\circ}C,\;1600^{\circ}C,\;1650^{\circ}C$. We researched the most suitable condition of plasticity and composition which make crystallization of spinel system and chromogenic characteristic close to black in every composition. And for the experiment of application to Zirconia, after adding synthesized pigments to Zirconia and plasticizing them, we analyzed their color and property of matters. The most suitable synthesis conditions of mineral pigments of black spinel system require composition of $Fe_2O_3-32.01%,\;Cr_2O_3-30.47%$, Quartz-9.66%, Kaolin-18.53%, CoO-3.71%, $MnO_2-5.62%$ and condition of plasticity kept for 1 h at $1600^{\circ}C$. When we added pigments synthesized in this way to Zirconia with 5 wt% and plasticized them at $1410^{\circ}C$, the result was that the degree of $strength-32.6kgf/mm^2$, absorptance-0.108%, $luminosity-L^*:37.54,\;color-a^*:1.31,\;b^*:2.61$ and their use suited for artificial jewelry or decoration Zirconia goods.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.450-456
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• 2010

During the process of synthesizing green celsian pigments, attempts were made to replace a given amount of $BaCO_3$ with $SrCO_3$ to accelerate the hexagonal to monoclinic celsian phase transition, which was assumed to promote color development. Monoclinic celsian have been synthesized from Hongkong-Kaolin, $BaCO_3$, $SrCO_3$, $Al(OH)_3$, $SiO_2$ and $SrCO_3$ with 1 to 1.5 wt% of LiF as a mineralizer from 1100 to $1300^{\circ}C$. It was found that replacing $BaCO_3$ with $SrCO_3$ allowed monoclinic celsian to be formed at a lower temperature. While the pigments containing 1 mole of $BaCO_3$ were difficult to synthesize monoclinic celsian with absence of the mineralizer, the formation of monoclinic celsian was successfully achieved even without mineralizer by using 0.25 mole of $SrCO_3$ at $1250^{\circ}C$ for 1 h. The color development was improved from yellowish green to green with increasing amount of $SrCO_3$ being replaced.

• Journal of Photoscience
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• v.12 no.1
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• pp.33-39
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• 2005

Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.2
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• pp.71-76
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• 2017

The cocoon's color of silkworm, Bombyx mori L. is usually white. But some are yellow, flesh and green colors because of modified characteristics. The yellow and flesh cocoons depend on carotenoid pigments, green cocoons are determined by flavonoid pigments. The cocoon's color is affected by the genes controlling penetration process from midgut to coelom and silk gland. Y (Yellow blood, 2-25.6) and I (Yellow-inhibitor, 9-16.2) genes are involved in the penetration process of carotenoid pigments from midgut to coelom, C (Outer-layer yellow cocoon, 12-7.2) and F (Flesh, 6-13.6) genes from coelom to silk gland. Therefore, the carotenoid cocoon's color depends on the genotype Y, I, C and F genes and their combination. Among them, C gene is sympathetic gene, which are known as C, CI and CD. C (Outer-layer yellow cocoon) genes make yellow cocoons on outer-layer and white cocoons on inter-layer, and CI (Inner-layer yellow cocoon) genes do yellow cocoons on inter-layer and dilute yellow cocoons on outer-layer. CD gene is known as making dilute yellow cocoons all layer. In this study, we have checked the dominance relation of C sympathetic genes among carotenoid genes for color cocoons by using strains related to the genes for color cocoons and investigated the aspect that pigments were penetrated in silk gland by action of each gene.

• Korean Journal of Heritage: History & Science
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• v.48 no.1
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• pp.132-147
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• 2015

In this article, the research trends regarding the analysis and restoration of the pigments applied on colored cultural properties during past 25 years are reviewed and the future research direction in this field of study is proposed. There are over 100 different pieces of the colored cultural property samples that have been analyzed in Korea during the time and are increasing numbers of studies on comparative investigations as well. In addition, new analysis techniques have been introduced to surpass the limitation of the current analysis techniques and the database construction has been developed tremendously, which will enhance the analysis reliability, indicating fast growth in the related research areas. There are also studies on finding new materials to replace the traditional ingredients for producing color pigments and related other materials to overcome the limitation of the traditional ingredients on top of the steady number of studies on reproduction and restoration of the traditional pigments. These various research efforts will bring much development in this area of research. One suggestion to be made is that there need to be long term planned research works for certain type of studies. For instance, the effect to the colored cultural properties due to the environmental change is one of important research topics that should be carefully studied, which requires longer time period and also more patience than the research works in the current and past trends.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.989-1002
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• 2022

Cephalopods, in particular octopus (Octopus vulgaris), have the ability to alter their appearance or body pattern by showing a wide range of camouflage by virtue of their chromatophores, which contain nanostructured granules of ommochrome pigments. Recently, the antioxidant and antimicrobial activities of ommochromes have become of great interest; therefore, in this study, the pH-dependent redox effect of the extraction solvent on the antioxidant potential and the structural characterization of the pigments were evaluated. Cell viability was determined by the microdilution method in broth by turbidity, MTT, resazurin, as well as fluorescence microscopy kit assays. A Live/Dead Double Staining Kit and an ROS Kit were used to elucidate the possible inhibitory mechanisms of ommochromes against bacterial and fungal strains. The results obtained revealed that the redox state alters the color changes of the ommochromes and is dependent on the pH in the extraction solvent. Natural phenoxazinone (ommochromes) is moderately toxic to the pathogens Staphylococcus aureus, Bacillus subtilis, Salmonella Typhimurium and Candida albicans, while the species Pseudomonas aeruginosa and Pseudomonas fluorescens, and the filamentous fungi Aspergillus parasiticus, Alternaria spp. and Fusarium verticillioides, were tolerant to these pigments. UV/visible spectral scanning and Fourier- transform infrared spectroscopy (FTIR) suggest the presence of reduced ommatin in methanol/ HCl extract with high intrinsic fluorescence.