• KSBB Journal
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• v.28 no.1
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• pp.60-64
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• 2013

Two strains were isolated from the traditional Deep Blue Sediment Dye of Polygoum tinctoria, Niram, and temporarily named Niram A and Niram B, respectively. The phylogenetic analysis revealed that strain Niram A and B were closely related to the members of the genus Comamonas and Microbacterium, respectively. Strain Niram A exhibited the highest 16S rRNA gene sequence similarity to C. aquatica LMG $2370^T$ (98.06%). Strain Niram B showed 100% homology with M. oxydans DSM 20578T and M. maritypicum DSM $12512^T$. The growth of the strain Niram A and B was not inhibited in Niram medium containing high calcium concentration without free sugar as carbon source. The reducing Niram is greenish. Therefore, the reducing ability on the Niram of the strains Niram A and B were determined with the color difference of the $a^*$ values of Niram fermented-fluids. The $a^*$ value indicates the level of redness (positive value) or greenness (negative value). The green color is increasing towards the negative value. In all samples fermented for 10 days, the $a^*$ values among samples were no significant difference. However, samples fermented for 15 days have an appreciable change. After fermentation for 15 days, the control Niram sample had $-3.96{\pm}0.02$ of the $a^*$ value. On the other hand, the Niram samples fermented with the strain Niram A and B showed $-4.20{\pm}0.02$ of the $a^*$ value and $-7.86{\pm}0.03$ of the $a^*$ value, respectively. In the reducing ability on the Niram, the strain Niram B was significantly better than the strain Niram A.

• Applied Microscopy
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• v.44 no.2
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• pp.53-60
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• 2014

In the present study, we investigated the effects of Polygonum tinctoria Niram (PTN) on atopic dermatitis (AD) in BALB/c mice induced by 2,4-dinitrochlorobenzene (DNCB). They were divided into four groups; Control, DNCB, DNCB+1%PTN (1% PTN extract) and DNCB+5%PTN (5% PTN extract), for evaluating the change of appearance of skin surface, skin hydration, thickness of epidermis and mast cell numbers during 4 weeks. PTN suppressed symptoms of AD in appearance of skin and increased skin hydration for DNCB+1%PTN and DNCB+5%PTN. Treatment with PTN significantly decreased the levels of eosinophils. In histopathological examination, DNCB+1%PTN and DNCB+5%PTN significantly reduced the thickness of epidermis and number of mast cell in dermis. These results suggested that the PTN improved symptoms of AD in BALB/c mice.

• Herbal Formula Science
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• v.22 no.1
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• pp.141-150
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• 2014

Objectives : The purpose of this study was to investigate the effects of Polygonum tinctoria Niram(PTN) on atopic dermatitis(AD) in hairless mice induced by 2,4-dinitrochlorobenzene(DNCB). Method : They were divided into four group, Nor, Con, 1X and 5X, for evaluating the change of appearance of skin surface, skin hydration, thickness of epidermis and mast cell numbers during 30 days. Results : PTN suppressed symptoms of AD in appearance of skin and increased skin hydration for 1X and 5X. In histopathological examination, 1X and 5X significantly reduced the thickness of epidermis and number of mast cell in dermis. These results suggested that the PTN improved the AD-like symptoms of hairless Mice.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.253-259
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• 2012

In this work, the natural indigo production process from Polygonum tinctorium was balanced based on the traditional Niram method in Korea. A standard procedure was determined considering the conditions of indican extraction from plant material, the amount of alkali for precipitation, storage of extract, etc. The effect of experimental conditions on the yield of crude dye was investigated. The contents of indigo and indirubin of the crude dyes were analyzed by HPLC. Increase of the amount of crude dye was observed within 1-2.5 days of extraction time. Longer extraction beyond 2.5 days resulted in a slight decrease in the amount of crude dye. There was no consistency in terms of indigo content depending on extraction pH. We found that the storage of extract or harvested plants affected adversely to dye yield and dye quality. Based on the lab scale extraction, large scale extraction was performed for 2-2.5 days in water and 2.0-2.5 g/L of $Ca(OH)_2$ was applied for precipitation of indigo dye. We obtained natural indigo dye containing about 15% of pure indigo in scale-up production using whole plant except root.

• Korean Journal of Medicinal Crop Science
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• v.21 no.3
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• pp.213-219
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• 2013

This study was carried out to find out the optimum method of preparation of indigo standard solution and its stability, and to investigate the indigo contents in Niram, blue dye extract, from a total of 7 indigo plants and 34 breeding lines of Persicaria tinctoria H. Gross. Proper solvent for indigo standard was dimethyl sulfoxide (DMSO), and appropriate concentration was 1 mg of indigo in 10 mL of DMSO. Absorbance value of UV/Vis Spectrophotometer at 620 nm of standard solution was changed decreasingly 12 hours after the preparation of standard solution irrespective of the storage conditions such as temperature and light. Average value of absorbance of 8-fold diluted standard solutions prepared daily during 16 days was $0.210{\pm}0.005$, indicating the powder of indigo compound was stable chemically. Calibration curve was made for quantitative analysis of indigo of 7 Niram samples, and indigo contents ranged from 0.69% to 18.76% showing relatively larger variation. Across all 34 breeding lines, the range of indigo content was from 7.9 mg to 56.4 mg per 100 g of fresh leaves, averaging 25.2 mg of indigo content and showing a 47.7% coefficient of variation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.177-184
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• 2013

This study was conducted to determinate the optimum times of transplanting and harvest for enhancing the fresh leaf yield and colorant level of an indigo crop, Persicaria tinctoria H. Gross, containing the blue dye indigo. Two cultivars, Naju Local and a new cultivar, NaramBlue, were transplanted 5 times from May 30 to July 10 at an interval of 10 days, and all of experiment plots harvested on Aug. 23 in Muan, the south area of Korea. As transplanting time was delayed, fresh leaf yield were maximum at earliest transplanting (May 30) and then decreased, while Niram (blue dye extract) and indigo content of fresh leaf remained almost constant though showed a small variation. Also, two cultivars transplanted on May 23 were harvested 5 times from Jul. 20 to Sept. 20 at an interval of 15 days. As harvest time was delayed, plant height, No. of first branches, and fresh leaf yield changed increasingly, while Niram content was increased to Aug. 20 and then decreased slightly. Indigo level increased largely to Aug. 5, and then continuously decreased with more delayed harvest. These tendencies of changes in fresh leaf yield and colorant level with different transplanting and harvest times were shown similarly in both cultivars. The results indicate that early transplanting before May 30 and harvest in early August will be appropriate for improving fresh leaf yield and colorant level.

• Textile Coloration and Finishing
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• v.21 no.3
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• pp.10-18
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• 2009

Dyeing process of the natural indigo powder onto ramie and silk fabrics was investigated by using glucose and calcium hydroxide as a reducing system. Effect of reduction and dyeing conditions such as temperature and time of reduction/dyeing, and concentrations of glucose and calcium hydroxide on the dyeing process were explored. Indigo powder was obtained by drying the conventional niram paste in an oven at $50^{\circ}C$. Color strength of the dyed fabrics was evaluated by K/S value measured at the wavelength of maximum absorption(${\lamda}$max). Munsell color coordinates(H V/C) were used to compare fabric colors of ramie and silk. Ramie fabric showed purple-blue color for all the temperature and time. On the contrary, silk fabric showed wide range of color including brown, brown-green, green at the different temperature. With the increase of K/S value, the coordinate of value(lightness) decreased for both of ramie and silk fabrics. The coordinate of hue(shade) changed drastically with the increase of K/S value for silk fabric, compared with that of ramie fabric which showed nearly constant value at the whole range of K/S value. Optimum concentrations of calcium hydroxide were for 6 g/L for ramie and 4 g/L for silk at $60^{\circ}C$ and 50 min. K/S value increased with the indigo concentration. Maximum K/S value was shown at $10{\sim}12$ g/L of glucose concentration. For both of ramie and silk fabrics, the colorfastness of washing and light was lower than that of rubbing. All the colorfastness values were improved with the increase of color strength.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.191-201
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• 2021

In this study, an eco-friendly indigo reduction system(scale up reduction, use of buffer solution, and pH control) using baker's yeast(Saccharomyces cerevisiae) was applied for natural indigo(Polygonum tinctorium) dyeing of Hanji fabric and Hanji-mixture fabric(Hanji/Cotton, Hanji/Silk). The effect of concentration of baker's yeast, repeat dyeing, and bath reuse was investigated in terms of dye uptake indicating reduction power. And the oxidation-reduction potential(ORP) was monitored. We also evaluated color properties and colorfastness according to the color strength. The yeast concentration did not significantly affect the maximum reduction power. However, the highest yeast concentration was effective in improving the initial dye uptake, and its the reduction retention power was the most excellent. Even on the last reduction day, the effect of increasing the dye uptake by repeat dyeing was observed. And it was confirmed that the reduction bath could be reused for up to 30 days by supplementing yeast at the end of reduction. For all the fabrics used, deeper and darker PB color were obtained by repeat dyeing. As dyeing was repeated, purplish tint got stronger on the Hanji/Silk fabric compared to other fabrics. Regardless of the composition of Hanji fabrics and color strength, washing and dry cleaning fastness were relatively good with above rating 4-5, and fastness to rubbing and light were acceptable with a rating 3-4 ~ 4-5. The eco-friendly natural indigo dyeing process using niram and baker's yeast would offer global marketability and diversity of Hanji product as a sustainable high value-added material.

• Textile Coloration and Finishing
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• v.35 no.2
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• pp.82-96
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• 2023

The purpose of this study is to enhance the usability of hanji fabrics by expanding the color space of hanji fabrics. For the expression of various colors of hanji fabrics, single and combination dyeing were carried out using natural indigo(Niram, Polygonum tinctorium), marigold extract colorant, and madder extract colorant for three types of hanji fabrics with different fiber compositions(hanji, hanji/cotton, hanji/silk). The light, medium, and deep colors obtained through individual single dyeing were shown to be PB Munsell colors in the case of indigo dyeing, Y color for marigold dyeing, and R color for madder dyeing. For combination dyeing, indigo dyeing was first carried out under the conditions for light, medium, and deep colors, respectively, and marigold or madder dyeing was performed thereafter. Indigo and marigold combination dyeing produced PB, B, BG, G, and GY Munsell colors and indigo and madder combination dyeing produced PB, P, RP, and R Munsell colors. Overall, the color change of hanji/silk fabric was more diverse than that of hanji fabric and hanji/cotton fabric. In the indigo, marigold, and madder combination dyeing into individual deep colors, blackish PB and P Munsell colors was obtained. Colorfastness to washing, dry cleaning, rubbing, and light were relatively good with above rating 4. Finally, 9 colors excluding YR color out of 10 Munsell color were obtained. We confirmed that the expansion of the color space of Hanji fabrics by the single and combination dyeing with indigo, marigold, and madder.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.12
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• pp.1963-1970
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• 2008

Natural indigo dye in powder form was prepared by modifying traditional Niram method, using $Ca(OH)_2$ instead of baked oyster powder for precipitating indigo dye. The prepared dye was applied to dyeing Tencel fabrics to investigate the effect of experimental conditions for the optimization of dyeing process. The indigo dye powder contained 15.2%(w/w) of indigo content and 0.757%(w/w) of indirubin content on the basis of HPLC analysis. Maximum dye uptake was obtained at $60^{\circ}C$ for 20min. Almost saturated dye uptake was obtained at 2g/L of sodium hydrosulfite concentration up to 4g/L of indigo dye and then slowly increased for further increase of sodium hydrosulfite. Whereas at higher indigo dye concentration(8g/L) more than 3g/L of reducing agent concentration was required for obtaining the maximum dye uptake. At the same indigo dye and reducing agent concentration, K/S value of the sample dyed without sodium hydroxide(pH 5.75) was 15.19, much higher than one dyed in alkaline condition(K/S 5.76). There was no difference in colorfastness ratings among samples with different color strength. However, more fading was occurred for the sample with low color strength.