Synthesis of Indigo-Dyes from Indole Derivatives by Unspecific Peroxygenases and Their Application for In-Situ Dyeing

Tyrian purple (also known as royal or imperial purple) is the oldest known commercial pigment and still one of the most expensive dyes, often associated with the wardrobes of clergy and royalty. It is a brominated derivative of indigo, a natural dye that has been used since 4000 BC. Moreover, just recently, the therapeutic value of indigoids for the treatment of several disorders was discovered. The manufacturing of indigo derivatives by the existing chemical routes has become increasingly uninteresting due to the use of aggressive reagents, expensive starting materials and high-energy costs. Thus, both dyestuff manufacturers and the pharmaceutical industry are interested in the development of gentle preparation methods of indigoids from simple precursors. Here, we describe a simple enzymatic method for the one-step synthesis of Tyrian purple and other indigo derivatives with fungal peroxygenases (UPO, EC 1.11.2.1). The reaction does not require complex co-substrates and works well in phosphate buffers with H2O2 (<0.1 wt%) and less than 5% (v/v) acetonitrile as co-solvent. We demonstrate the scaling up of the reaction to 10 Liters and established thereupon an environmentally friendly combined synthesis and in-situ dyeing process, further simplifying the manufacturing of vat-dyed fabrics. Eventually, we screened a number of halogen-substituted indoles in the search for novel indigo derivatives, which may be of interest for pharmaceutical and/or dyeing purposes.

Thermodynamic properties of cotton dyeing with indigo dyes in non-aqueous media of liquid paraffin and D5

On the basis of investigation into the dyeing equilibrium of cotton fibers with indigo dyes in decamethylcyclopentasiloxane (D5), liquid paraffin and water, the thermodynamic properties of cotton dyeing with indigo dyes in non-aqueous medium systems were studied in comparison with aqueous dyeing. The main works involved are as follows: firstly, the adsorption isotherms were created; then, the three theoretical adsorption models of Nernst, Langmuir and Freundlich were used to fit the adsorption isotherms created; finally, the thermodynamic parameters were calculated. The results showed that the adsorption isotherms were all in line with the Freundlich model. The order of dyeing affinity was in the sequence: liquid paraffin > D5 > water. The dyeing entropy in the three media showed positive values, which is mainly attributed to the adsorption of both indigo-leuco and water onto cotton fibers, thus reducing the ice-like structure formed among the water molecules in the dyeing system and the hydrophobic bonding structure formed among the non-aqueous medium molecules, then leading to an increase in the system disorder. The dyeing heat in the three media also showed positive values, due mainly to the absorption of thermal energy to “melt” the ice-like structure and to “break” the hydrophobic bonding structure. These dyeing thermodynamic properties are conducive to understanding and interpreting the dyeing performance and behavior of indigo dyes in non-aqueous dyeing systems.

EXAMINING THE UTILISATION OF LOCAL AND SYNTHETIC INDIGO DYES AND QUALITTY OF DYED FABRICS IN ÌTÒKÚ MARKET, ABẸ́ÒKÚTA , ÒGÙN STATE, NIGERIA

Africans had been producing fabrics locally before the advent of Western fabrics. Àdìrẹ fabrics are purely African textile concepts; dyed with local/indigenous materials and readymade synthetic materials in Abẹ́òkúta, Òṣogbo, Ìbàdàn, Kánò, Ṣókótó, and other parts of Nigeria, and Africa at large. The study focuses on how leaves, bark of plants, and trees are utilised in producing colours of dyes. For example, shade of red can be obtained from leaves of guinea corn (sorghum village), leave of teak wood (tectona grands), leaves of henna law (Sonia intermis), bark and roots of African rose wood (ptrocerpus erinaceus), and wood of the came wood “osùn” (baphia nitida). The sap of old physic nut tree (fatopha curca) produces a black dye. Likewise, many other colours are produced when the need arises. When yellow is desired, afromosia taxifora or a root wood (Morinda lucida) or group grand are used. The mango tree bark, when dried and boiled with water gives a brown dye. Two other fruits Kigelia African and vitex grandifolia are also used for dye. There is an argument on which of the colour registered fast, is it the natural dye or the imported synthetic dye? The answer probably lies in the method of preparing and implementing the dye and the skill/creativity of the dyer. The study examines the utilisation of local and synthetic indigo dyes and quality of dyed cotton fabric in Ìtòkú market, Abẹ́òkúta , Ògùn State. Some participants were interviewed, and questionnaires were administered to respondents for data collection. The result of hypothesis tested justify that there is no significant difference between utilisation of local and imported dye in the quality of textile in relation to colours. Results and findings were discussed, comparism between the local and synthetic dyes was concluded and recommendations were made.

The Establishment and Management of Indigo Weaving Groups in Sakon Nakhon Province of Thailand

Objective - The objectives of this research are to study the establishment and management of indigo weaving groups in Sakon Nakhon Province. Methodology/Technique – The study is comprised of qualitative research. The data was collected from focus group discussions with participants from the District Community Development Office of Sakon Nakhon Province and an in-depth interview with the villagers and members of indigo weaving groups. The data was analyzed using content analysis and descriptive analysis. Finding - The results indicate that indigo weaving groups have been established in a variety of ways such as the informal gathering of indigo-dyed weavers, more formal groups on the advice of local administrative organizations and on the recommendation of governmental organizations. The indigo weaving groups’ management consisted of many aspects including the group administration, production planning, producing, product development, marketing, public relations, financing, and accounting. Novelty - To reduce the fixed-cost of buying indigo dyes and to increase the depth of the colour, an indigo weaving group dyed its fabric by mixing indigo dye with Marsdenia tinctoria R. Br.. The study also found that traditional beliefs complicated the weavers’ decision making about the dyeing, especially the belief that colour does not bind to the fabric if the dyeing is performed on Buddhist Holy Days. Type of Paper: Empirical. JEL Classification: D00, O12, Z1, Z13. Keywords: Community Economy; Community Enterprise; Group Management; Indigo; Sakon Nakhon Province. Reference to this paper should be made as follows: Lordko, U; Grisanaputi, W. 2020. The Establishment and Management of Indigo Weaving Groups in Sakon Nakhon Province of Thailand, Global J. Bus. Soc. Sci. Review 8(3): 170 – 180. https://doi.org/10.35609/gjbssr.2020.8.3(4)

Decoction as an Alternative to Producing Indigo Tarum Areuy (Marsdenia tinctoria) Dyes and Its Role on Fiber Coloration from Cellulose

Indigo natural dyes are generally made by maceration-fermentation for 24 - 72 hours impacting on productivity. A faster extraction method is needed by decoction methods. The faster production of indigo tarum areuy dyes is done by decoction at temperatures of 60ºC, 70ºC and 80ºC for 5 minutes, 10 minutes and 15 minutes. The extract was adjusted to reach pH 11. Aeration was carried out 30 minutes and then deposited for 24 hours. Indigo dyes are determined yield, purity of indigo, and evaluation of the quality of the staining results using spectrophotometric methods and color fastness testing of washing. Increased yield of indigo dyes occurs at temperatures of 60ºC and 70ºC. At 80ºC, the yield decreases with increasing decoction time. The best temperature and decoction time for pure indigo yield and the quality of the dyeing results in cotton were at 70ºC for 15 minutes with a yield of 3.625 grams per 500 grams of leaves. The dyeing color of the cotton fabric has increased along with the increase in yield and the purity of the dye. The highest color determination is achieved by a cloth dyed by indigo dyes from the decoction process at 70ºC for 15 minutes, with a<em> </em>K / S value of 3.8754. The extraction time and temperature did not affect the washing fastness.