•Computational methods applied on flavonoids have been described and discussed.•Computational chemistry is an helpful tool to understand the chemistry of flavonoids.•Theoretical calculations result ...accurate in describing the properties of anthocyanins.•Hybrid functionals have been successfully applied to anthocyanidins and anthocyanins.•Metal chelation and co-pigmentation have been computationally described.
Anthocyanins and anthocyanidins are polyphenolic compounds, responsible for the red and blue colours in several fruits, flowers, and leaves. Their colorant properties, bioavailability and antioxidant activity, made anthocyanins and anthocyanidins largely adopted in food and pharmaceutical industries. In this body of work, we firstly introduced structure, photophysical properties, co-pigmentation, antioxidant properties, glycosylation and complexation of anthocyanins and anthocyanidins. Secondly, we reported the computational methods adopted and the main theoretical results involving either anthocyanins and anthocyanidins, ranging from the first theoretical investigation on the structure of flavylium ions to the most recent studies on anthocyanins adsorbed on TiO2. We reviewed the computational contributions to the description of molecular properties of anthocyanins and anthocyanidins, giving a particular attention to the geometries, the spectroscopic features and the complexation properties of such molecules. Nowadays, theoretical calculations represent an essential methodology to understand and predict the chemical and physical properties of anthocyanins and their derivates.
Display omitted
•Natural dyes were in situ identified using SERS method on fibers.•Ag nanoparticles SERS substrate was prepared by laser photoreduction.•Ag dendrites SERS substrate was prepared by ...galvanic displacement.•SERS substrates had characteristics of high sensitivity and reproducibility.•Different dye species were distinguished in one archaeological fiber.
Accurate detection of natural dyes in archaeological textiles is challenging due to limited sample availability. In situ detection of fibers by surface-enhanced Raman scattering (SERS) can overcome this challenge. In this study, we present two methods for the preparation of SERS substrates based on the laser photoreduction reaction and the galvanic displacement reaction, respectively. Our results show that the substrates prepared by these methods, including 450 nm-AgNPs, Cu-based Ag, and Zn-based Ag, offer several advantages such as rapid preparation, easy handling, low cost, high sensitivity and excellent reproducibility. Using these substrates, we successfully detected anthraquinones (alizarin, purpurin), indigoids (indigotin, indirubin), and protoberberine-type dyes in archaeological textiles from the Wei and Jin Dynasties. Notably, we were able to detect both indigo and protoberberine-type dyes in one archaeological fiber. The minimally invasive, in situ analytical approach developed provides a valuable tool for analytical applications where sampling is limited to microscopic amounts.
This research focuses on flavonoid-based natural dyes for the coloration and antibacterial finishing of wool fabrics. In the present study, we accessed the suitability of biocolorants from Gingko ...biloba L. waste/fallen leaves extract to develop colored antibacterial wool fabrics to reduce the environmental pollution and dependency of the textile industry on the synthetic antibacterial agents. Specifically, we present a novel method to counteract the growing antibiotic resistance using G. biloba L. leaves extract as a potent antibacterial agent in conjunction with ampicillin. Natural colorants were extracted in 50% aqueous ethanol at 70 °C for 60 min under acid conditions of pH 3. Before dyeing procedures, the extracted dye powder was assessed for thermal stability by TGA analysis. Structural characterization of the extracted dye was done by UV–visible and FT-IR spectral analysis. Optimal dyeing results were achieved at 90 °C for 70 min with a dye concentration of 50% (o.w.f.). Additionally, dye adsorption (Isotherm constants) and dye performances were effectively reported during this study. Pseudo-second order and sips isotherm model provided the best fitting of experimental data with high regression coefficient (R2 = 0.99). Valuated indicators (color strength (K/S), color characteristics, and fastness properties) of dyed wool fabric were effectively reported in response to washing pretreated with different metallic and natural mordants. The antibacterial potential of extracted natural dye was enhanced in combination with ampicillin (synergism) which can be correlated with the significant reduction in the corresponding MIC values. Fe2+ and Sn2+ salts demonstrated negative effects on the antibacterial performance of the dyed wool fabric, whereas most of the biomordants showed enhanced antibacterial performances. The effective use of the extracted yellow dye from G. biloba L. fallen/waste leaves in textile dyeing and finishing will enhance the industrial applications of the green waste over its normal applications.
Display omitted
•Waste leaves of G. biloba L. have been used for natural dye production.•Natural dye was extracted in 50% aqueous ethanol solution under acidic conditions.•Adsorption kinetic showed pseudo-second-order fitting.•MIC of dye extract was enhanced in conjunction with ampicillin.•Biomordants were more effective in enhancing antibacterial properties.
Microbial pigments are gaining more attention in recent times due to their versatile applications in the pharmaceutical, food, cosmetic, and textile industries. The development of microbial pigments ...is a challenging task due to the presence of inexpensive synthetic dyes in the market. However, the harmful side effects of most of the azo and benzidine synthetic dyes have compelled many scientists and experts to shift their attention to chemically greener routes of dye production. Micro-organisms are endowed with the potential to produce useful natural colorants such as carotenoids on an industrial scale at relatively low costs. This review aims to provide crucial information on the biodiversity, distribution, pathogenicity, ecological and industrial applications of microbial pigments, as well as challenges and future directions for food, textile, pharmaceutical, cosmetic, and biomedical applications. It also highlights the challenges faced by the use and development of food and textile-grade pigments and proposes recommendations to deal with these challenges using advanced techniques, including metabolic engineering and gene editing technologies.
•This review article provides an up-to-date knowledge regarding the biosynthesis of microbial pigments from microorganisms.•The methods to increase the yield of microbial pigment using modern-day technologies have also been reviewed in detail.•This review provides detailed information regrading the applications of microbial pigments in various industries.•This review highlights the challenges faced by the use of food and textile-grade pigments.
Improvement in panchromatic light-harvesting and photovoltaic performance is reported for dye-sensitized solar cells by adopting co-sensitization technique by mixing dyes. Betalain and Anthocyanin ...natural dyes are extracted from beetroot and cranberries. All dyes are characterized by UV–Vis and FTIR spectroscopy. Solar cells are fabricated and electrical characterizations are performed. Solar cell sensitized with mixed dyes demonstrated improved performance compared to cells of individual dyes, and yielded short circuit current density, open circuit voltage and fill factor of 0.36 mA/cm2, 0.42 V and 0.51 respectively. Their maximum efficiency is 5.37 and 1.16 times higher than that of individual beetroot and cranberry dye DSSCs respectively. Charge transfer processes are studied by impedance spectroscopy characterizations. The obtained results are in close agreement with commercially available N3 dye DSSC. The results yield that mixing dyes from different natural sources can be a very effective to further improve the performance of DSSCs.
Chalcones are well-known natural dyes, 18 different derivatives selected from the rational molecular design (i.e. through molecular orbital calculations) were synthesized. If used in conjunction with ...an amine (i.e. ethyl l, 4-(dimethylamino) benzoate, EDB) and an iodonium salt (bis(4-tert-butylphenyl) iodonium hexafluorophosphate, Iod) as photoinitiating systems (PISs), these dyes can initiate both the free radical polymerization of polyethylene glycol diacrylate (PEG-diacrylate) and the cationic polymerization of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (EPOX) via oxidation–reduction reaction mechanisms. Furthermore, among the 18 different suggested structures, except for dyes 9 and 10, which have been synthesized and used in other fields, the remaining 16 dyes have never been synthesized before. The photopolymerization efficiency of acrylates carried out under LED@405 nm are excellent both for thin films (the thickness is about 0.2 mm) and thick films (the thickness is about 2 mm). Furthermore, all of them can also boost the cationic polymerization of EPOX upon LED irradiation at 405 nm, in the presence of an iodonium salt and an amine. More interestingly, stereoscopic 3D patterns were successfully fabricated by the direct laser write (DLW) technique which demonstrated reversible swelling properties and reversible shape-memory effects induced via swelling and dehydration for the access to 4D printing.
Display omitted
•18 new synthetic derivatives selected from in silico molecular design were synthesized.•These dyes can initiate both free radical and cationic polymerizations.•The photopolymerization efficiency are excellent both for thin films and thick films.•3D patterns were successfully fabricated by the direct laser write (DLW) technique.•Swelling and dehydration induced shape-memory polymer network were prepared.
The purpose of this community service is to empower the Family Welfare Empowerment (PKK) group by developing the creativity of natural dye batik products in order that they can become the typical ...batik of Mojorejo Village, Madiun Regency. The method of implementing the service activity is through the stages: 1) observation, 2) counseling, 3) training, and 4) evaluation. The target of service activity is the PKK group. The data collection technique used a questionnaire and an observation rubric. Descriptive data analysis is based on achievement indicators. Based on the questionnaire analysis, it was found that the creativity of the trainees increased by 40%. The motivation of the trainees increased by 70%. The understanding of the training participants about the process of making natural dyed batik increased by 90%. The conclusion of the service activity is that training on making Jumputan batik using natural dyes can increase the creativity of batik production, which is typical of Mojorejo Village, Madiun Regency.
Recent interests of scientists in the natural dyes for not only textile colouration but also clean production of functional fabric materials, has led to the development and application of ancient ...nature-based sources of colourants. Historical textiles are considered as important artefacts that present the culture and society from antient time to contemporary centuries, as well as the database to develop the functional materials. Study of organic colourants in ancient textiles is an effective approach to investigate the historical dyeing science and technology, likewise evolve the bio-colourants for modern applications. Plant-based colouring matters were widely utilized since the early textile civilization until the early 20th century. Currently, several anthraquinone colourants are discovered from vegetation, especially the morindone which was widely used in traditional fabric dyeing techniques of Southeast Asia, India and the Pacific Islands. In this context, the principal focus of this study is anthraquinone-based morindone dye, started from a brief overview of natural anthraquinone dyes in historical textiles, followed by the detailed discussion on biological sources, extraction of morindin, modification to red morindone pigment, as well as the summary of mordanting and dyeing method. For intensive investigation of the practical utilization of organic morindone in historical textiles, some recent works using analytical methods including high performance liquid chromatography (HPLC) and surface-enhanced Raman spectroscopy (SERS), are thoroughly discussed. Furthermore, the potential antimicrobial and ultraviolet protective performances of morindone dye are analysed with respect to effective application of morindone in functional textiles.
•Anthraquinone-based morindone dye extracted from Rubiaceae family.•Morindone in the interaction with metal mordant and textile fibres.•Intensive investigation of morindone in historical textiles by HPLC and SERS.•Antimicrobial and UV protective properties of morindone dyed textiles.•Future perspectives of historical natural colourants for functional textiles.
Natural molecular dye, anthocyanin, is described here as safe sensitizer for TiO
2 particles in photo-degradation of organic contaminants in water. The dye is a promising replacement for the more ...costly and hazardous heavy metal based systems, such as CdS particles and Ru-compounds. TiO
2/anthocyanin effectively catalyzed the photo-degradation of methyl orange contaminant under solar simulator radiation. The new TiO
2/anthocyanin catalyst showed comparable efficiency to earlier systems, while avoiding their hazardous nature. When supported onto activated carbon (AC) particles, the resulting AC/TiO
2/anthocyanin system showed enhanced efficiency and ease of recovery from the catalytic reaction mixture. The natural dye molecules showed the tendency to degrade under photo-degradation conditions, just like earlier hazardous sensitizers. However, complete mineralization of anthocyanin occurred leaving no traces of organic species in solution. Sensitizer degradation caused deactivation of the supported catalyst on recovery. Such a shortcoming was overcome by re-treatment of the recovered catalysts with fresh dye.
Effects of different reaction parameters on the catalyst efficiency were studied. A mechanism, similar to earlier CdS-sensitized catalyst systems, is proposed for the TiO
2/anthocyanin catalyst.
Display omitted
PDF
