• Conservation Science in Museum
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• v.15
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• pp.122-137
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• 2014

The National Museum of Korea own a historical document box ^K976 that was once used to store Joseon Wangjo Sillok ^{Annals of the Joseon Dynasty} of the Joseon Dynasty. The rectangular box has a lid, and the entire surface is varnished with black lacquer. The wood of the box had become warped and the upper part of the wooden frame had been damaged. In some areas, the paint was flaking off, exposing the underlying wood, and an iron ring that connected the lid to the body of the box was missing. Thus, in 2013, Conservation Science Department in National Museum of Korea began to repair and restore the Joseon document box. Before the treatment, analyses were conducted to examine the box's structure, damaged parts, species of wood, and lacquering techniques. The wood was found to be that of a linden tree. As for the lacquering technique, the surface of the box was first coated with a layer of lacquer and bone ash, and then covered with Korean traditional paper. Next, the box was painted with a layer of mud and ashes, followed by a layer of black pigment mixed with soot, and then varnished again with lacquer.

• Conservation Science in Museum
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• v.15
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• pp.96-121
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• 2014

Portrait of Sim Huisu is a seventeenth-century Joseon portrait of a meritorious vassal. The National Museum of Korea currently owns two portraits of Sim Huisu, which are the eldest son's family and by the eldest grandson of the family's second eldest son. Both were donated in 1980. Portraits were still in its original mounting, but the supporting silk had been damaged and stained in a flood. Conservation treatment was undertaken to restore the original style, and scientific analysis, such as, X-ray, XRD, XRF and Graff "C" stain, was conducted to study the materials and painting techniques. The support silk was found to be refined fibroin and a plain weave consisting of two weft threads and one warp thread. The lining papers were found to be bamboo fiber paper of first layer in China and Korean traditional mulberry paper in second. Various pigments were identified in the painting, including white lead, cinnabar, atacamite, ink stick, azurite, silver, and gold. The study also confirmed the use of the back painting, with colors such as white ^{White Lead}, green ^Atacamite, orange ^Minium, black ^{Ink Stick}, and yellow ^Dye. Also, it was found that stick ink or dye was used with white lead.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1523-1523
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• 2001

The wine industry requires practical methods for objectively measuring the composition of both red wine grapes on the vine to determine optimal harvest time; and of freshly harvested grapes for efficient allocation to vinery process streams for particular red wine products, and to determine payment of contract grapegrowers. To be practical for industry application these methods must be rapid, inexpensive and accurate. In most cases this restricts the analyses available to measurement of TSS (total soluble solids, predominantly sugars) by refractometry and pH by electropotentiometry. These two parameters, however, do not provide a comprehensive compositional characterization for the purpose of winemaking. The concentration of anthocyanin pigment in red wine grapes is an accepted indicator of potential wine quality and price. However, routine analysis for total anthocyanins is not considered as a practical option by the wider wine industry because of the high cost and slow turnaround time of this multi-step wet chemical laboratory analysis. Recent work by this ${group}^{l,2}$ has established the capability of near infrared (NIR) spectroscopy to provide rapid, accurate and simultaneous measurement of total anthocyanins, TSS and pH in red wine grapes. The analyses may be carried out equally well using either research grade scanning spectrometers or much simpler reduced spectral range portable diode-array based instrumentation. We have recently expanded on this work by collecting thousands of red wine grape samples in Australia. The sample set spans two vintages (1999 and 2000), five distinct geographical winegrowing regions and three main red wine grape varieties used in Australia (Cabernet Sauvignon, Shiraz and Merlot). Homogenized grape samples were scanned in diffuse reflectance mode on a FOSE NIR Systems6500 spectrometer and subject to laboratory analysis by the traditional methods for total anthocyanins, TSS and pH. We report here an analysis of the correlations between the NIR spectra and the laboratory data using standard chemometric algorithms within The Unscrambler software package. In particular, various subsets of the total data set are considered in turn to elucidate the effects of vintage, geographical area and grape variety on the measurement of grape composition by NIR spectroscopy. The relative ability of discrete calibrations to predict within and across these differences is considered. The results are then used to propose an optimal calibration strategy for red wine grape analysis.

• Toxicological Research
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• v.31 no.4
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• pp.403-414
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• 2015

Lithospermum erythrorhizon has long been used as a traditional oriental medicine. In this study, the acute and 28-day subacute oral dose toxicity studies of hexane extracts of the roots of L. erythrorhizon (LEH) were performed in Sprague-Dawley rats. In the acute toxicity study, LEH was administered once orally to 5 male and 5 female rats at dose levels of 500, 1,000, and 2,000 mg/kg. Mortality, clinical signs, and body weight changes were monitored for 14 days. Salivation, soft stool, soiled perineal region, compound-colored stool, chromaturia and a decrease in body weight were observed in the extract-treated groups, and no deaths occurred during the study. Therefore, the approximate lethal dose (ALD) of LEH in male and female rats was higher than 2,000 mg/kg. In the subacute toxicity study, LEH was administered orally to male and female rats for 28 days at dose levels of 25, 100, and 400 mg/kg/day. There was no LEH-related toxic effect in the body weight, food consumption, ophthalmology, hematology, clinical chemistry and organ weights. Compound-colored (black) stool, chromaturia and increased protein, ketone bodies, bilirubin and occult blood in urine were observed in the male and female rats treated with the test substance. In addition, the necropsy revealed dark red discoloration of the kidneys, and the histopathological examination showed presence of red brown pigment or increased hyaline droplets in the renal tubules of the renal cortex. However, there were no test substance-related toxic effects in the hematology and clinical chemistry, and no morphological changes were observed in the histopathological examination of the kidneys. Therefore, it was determined that there was no significant toxicity because the changes observed were caused by the intrinsic color of the test substance. These results suggest that the no-observed-adverse-effect Level (NOAEL) of LEH is greater than 400 mg/kg/day in both sexes.

• Journal of Conservation Science
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• v.33 no.6
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• pp.485-495
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• 2017

The purpose of this study is to evaluate the functionality and lightfastness of the natural pigments according to the type of Seokganju used as Dancheong. The commercially available red iron-oxide-based natural pigments that are called Seokganju and Daija manufactured by traditional methods in Korea and Japan were selected. The analysis of the constituent minerals and constituents of 8 kinds of collected Seokganju showed that most of them contained hematite. There are two types of Seokganju according to the $Fe_2O_3$ contents. The type of Seokganju can be characterized not only using the main component but also from the burn-out processing. The chromaticity results for Seokganju with a high $Fe_2O_3$ concentration indicate dark red or grayish brown, while those for Seokganju with a low $Fe_2O_3$ concentration indicate yellowish red or yellowish brown. Samples were prepared by mixing with a glue solution and functional properties were evaluated based on the opacity and spreadability. Coated samples were used in the lightfastness test. The spreadability and opacity of the pigments were measured differently depending on the main component. Most Seokganju samples a showed slight color change until $9,000kJ/m^2$ but rapid color changes were detected after $18,000kJ/m^2$. In particular, burnt Seokganju showed superior lightfastness.

• Journal of the Mineralogical Society of Korea
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• v.31 no.2
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• pp.123-135
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• 2018

This study tried to find the clue to Seokrok province by comparing Seokrok used in painting culture properties with Seokrok ore from domestic occurrence and imported Seokrok ore. To this end, chemical and mineralogical characteristics of painting cultural properties were identified with portable X-ray Florescence (p-XRF), micro X-ray diffraction (micro XRD) and SEM/EDS Analysis. To obtain Pb isotopic ratio, the Pb contained in Seokrok has been analyzed with Thermal Ionization Mass Spectrometer. Atacamite (or botallackite) and small quantity of brochantite were identified from Seokrok in Dancheong, and malachite was also identified from Buddhist painting besides those two ingredients. Without distinction of type, most Seokrok used in painting cultural properties is atacamite composed of Cu and Cl. From Pb isotope analysis, it was found that Seokrok in painting cultural properties was closer to that of north Korea, north China and Japan than south Korea as in regional division for East North Asia suggested by Mabuchi. The Pb isotopic ratio of domestic green mineral belongs to the distribution of Seokrok inside the painting cultural properties but imported malachite showed considerably difference. Considering the fact that atacamite, the main mineral of Seokrok in painting cultural properties is rarely produced from southern mine of the Korean Peninsula and the result of Pb isotope analysis.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.7-16
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• 2020

The Fabaceae family are being used as traditional medicine. The aim of this study was to compare the antioxidant effects as well as the cell protecting effects of extracts of 5 species (Astragalus membranaceus, Caesalpinia sappan L., Glycyrrhiza uralensis F., Pueraria lobate O., Pterocarpus santalinus L.) in Fabaceae family. The extracts from 5 species were tested by radical scavenging activity test, total phenolic contents and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on human liver carcinoma (HepG2) cell line. Anti-oxidant effects of the extracts (5 mg/mL) from C. sappan was 93.49% by radical scavenging activity test. In addition, A. membranaceus extracts showed a weak radical scavenging activity. Anti-oxidant effects of the extracts (5 mg/mL) from A. membranaceus was 7.83% by radical scavenging activity test. Total phenolic contents of the extracts from C. sappan and A. membranaceus were 310.93 mg GAE/g extract, 15.33 mg GAE/g extract, respectively. Cell protecting effects against H₂O₂ treatment were observed at 100 ㎍/mL concentration of C. sappan and P. santalinus extracts. These results suggest that C. sappan and P. santalinus might be best anti-oxidant in Fabaceae family.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.152-156
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• 1994

The purplish red pigment from the roots of Lithospermum erythrorhizon, a Korean edible wild plant, has been investigated concerning it's value as a natural colorant for Korean traditional foods. An attempt was made to isolate pigments and define their characteristics. Two compounds of isobutylshikonin and acetylshikonin were identified by melting point determination and spectra of UV, IR, and $^{1}H-NMR$. To examine the utility of these naphthoquinone pigments for foods, the effect of various pH values on stability were determined over a period of storage. Buffered solutions of acetylshikonin and isobutylshikonin at pH 3 and 5 showed stable purplish red. The absorption maxima if acetylshikonin and isobutylshikonin over the range of pH 3 to 7 were 518 nm and 520 nm, respectively. A bathochromic shift to 588 nm at pH 10 was observed on these two naphthoquinone pigments. Sensory evaluation was performed with acetylshikonin and isobutylshikonin of identical absorbance. These two pigments revealed purplish red color in Munsell system.

• Journal of Life Science
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• v.31 no.2
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• pp.192-198
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• 2021

Red yeast rice has been extensively used as food and traditional medicine for thousands of years in East Asian countries. It is produced by the fermentation of a particular yeast (in general, Monascus purpureus) as rice and various cereals (barley, soybean, etc.). Monascus sp. produces many secondary metabolites during its growth, including pigments, monacolins, and γ-aminobutyric acid. Some metabolites―specifically, monacolin K, γ-aminobutyric acid, dimerumic acid, and monascus pigments―have been reported to lower cholesterol and blood pressure while showing anti-obesity effects. In this study, we investigated the anti-obesity effect of ethanol extract from red yeast barley (RYB) fermented with Monascus sp. BHN-MK 2 on 3T3-L1 cells. The anti-obesity effects of RYB extract were examined: its lipid accumulation inhibitory effect was tested by Oil Red O staining, and obesity-related mRNA expression levels were tested by real-time RT-PCR in MDI stimulated 3T3-L1 cells. The intracellular lipid content of MDI-stimulated 3T3-L1 cells decreased significantly to 5.04%, 12.24%, and 23.52% in response to 200, 400, and 800 ㎍/ml RYB, respectively. Moreovers, we evaluated that RYB extract significantly downregulated the expression of C/EBPα, SREBP-1, and PPAR-γ gene in a dose-dependent manner. As a result, red yeast barley ethanol extracts exerted the strongest anti-obesity effects. Also, the results indicate that red yeast barley could be used as a functional anti-obesity food material.

• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.122-147
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• 2012

The Four-guardian statues in Song-gwang buddhist temple, Suncheon, Korea, have been remade in AD 1628 and have been repaired and repainted over several times since then. Therefore, the study of the pigments applied on the statues can provide good chance for investigation about pigments used in the late Chosun Period. Pigments on fragments from Gwang-mok(Virupaksha), one of the Four-guardian statues, have been analyzed by optical microscope, SEM-EDX and XRD in order to identify the components and compounds. Six types of materials were found from the fragments, which are soil layer with brown clay band, soil layer containing a lot of fibers, Korean paper with loose texture, Korean paper with dense texture, silk, and hemp textile. Presumably, the soil layer which have brown clay band is basis layer and the other layers are repaired layers. From comparative study for the components of the pigments, applied on upper and lower parts of the repaired layers, we have concluded that those repaired layers had been applied on the statue by the following order; basis layer ${\rightarrow}$ Korean paper with loose texture ${\rightarrow}$ soil containing a lot of fibers ${\rightarrow}$ silk ${\rightarrow}$ hemp textile and Korean paper with dense texture. In addition, the years that those materials were applied on the statue have been estimated as 1720~1891, 1926, 1946 and 1976, respectively. The distinct features of each age are as the following; lead white and copper chloride hydroxide are major white and green pigments before 1891, zinc white, barium white, emerald green, and ultramarine blue appear after 1926 and titanium white uprises around 1976. Our result presented here, study on pigments applied on traditional statues over several different periods, will provide good database for future study on pigments used for traditional painting in Buddist temples and Dancheong.