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Indigo is widely used in textile industries for denim garments dyeing and is mainly produced by chemical synthesis which, however, raises environmental sustainability issues. Bio-indigo may be produced by fermentation of metabolically engineering bacteria, but current methods are economically incompetent due to low titer and the need for an inducer. To address these problems, we first characterized several synthetic promoters in E. coli and demonstrated the feasibility of inducer-free indigo production from tryptophan using the inducer-free promoter. We next coupled the tryptophan-to-indigo and glucose-to-tryptophan pathways to generate a de novo glucose-to-indigo pathway. By rational design and combinatorial screening, we identified the optimal promoter-gene combinations, which underscored the importance of promoter choice and expression levels of pathway genes. We thus created a new E. coli strain that exploited an indole pathway to enhance the indigo titer to 123 mg/L. We further assessed a panel of heterologous tryptophan synthase homologs and identified a plant indole lyase (TaIGL), which along with modified pathway design, improved the indigo titer to 235 mg/L while reducing the tryptophan byproduct accumulation. The optimal E. coli strain expressed 8 genes essential for rewiring carbon flux from glucose to indole and then to indigo: mFMO, ppsA, tktA, trpD, trpC, TaIGL and feedback-resistant aroG and trpE. Fed-batch fermentation in a 3-L bioreactor with glucose feeding further increased the indigo titer (≈965 mg/L) and total quantity (≈2183 mg) at 72 h. This new synthetic glucose-to-indigo pathway enables high-titer indigo production without the need of inducer and holds promise for bio-indigo production.
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Escherichia coli , Glucose , Índigo Carmim , Engenharia Metabólica , Escherichia coli/genética , Escherichia coli/metabolismo , Glucose/metabolismo , Glucose/genética , Índigo Carmim/metabolismo , Triptofano/metabolismo , Triptofano/genética , Triptofano/biossínteseRESUMO
BACKGROUND: At present, conventional endoscopy and chromoendoscopy using indigo carmine (IC) is a very useful method to determine the demarcation line (DL) of early gastric cancer lesions, but it is not suitable for all lesions. AIMS: This study aimed to determine the applicable conditions for IC chromoendoscopy. METHODS: We retrospectively evaluated 187 lesions in 181 patients who had an endoscopic diagnosis of EGC and were treated with endoscopic submucosal dissection (ESD). According to the existence of the DL between the lesion mucosa and normal mucosa with IC chromoendoscopy, the lesions were divided into two groups: clear group and unclear group. Clinicopathological characteristics were evaluated in each group. From January 2022 to March 2023, the postoperative pathological sections of 19 lesions (81 slices) in the clear group and 19 lesions (80 slices) in unclear group were scanned with high definition, and the crypt structure between the two groups was evaluated. RESULTS: There was no significant difference in clinical factors between the clear group and unclear group. There were significant differences in crypt area, crypt length, and crypt opening diameter between the two groups. In the clear group, there were significant differences in crypt area, crypt length, and crypt opening diameter between the normal area and cancer area, but there was no significant difference in the unclear group. CONCLUSIONS: The margins of lesions with fused or absent crypt structures, a small crypt area, a short crypt length, and a short crypt opening diameter can be easily determined with IC chromoendoscopy.
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Ressecção Endoscópica de Mucosa , Índigo Carmim , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/diagnóstico por imagem , Estudos Retrospectivos , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Corantes , Mucosa Gástrica/patologia , Mucosa Gástrica/diagnóstico por imagem , Mucosa Gástrica/cirurgia , Coloração e Rotulagem/métodos , Detecção Precoce de Câncer/métodos , Adulto , Gastroscopia/métodos , Idoso de 80 Anos ou maisRESUMO
Liver injury during arsenic treatment for acute promyelocytic leukemia was previously reported in adults, but not comprehensively in children until now. This study aims to investigate liver injury in pediatric patients with APL, changes in liver function during treatment, and compare the effects of Arsenic trioxide (ATO) and Realgar-Indigo naturalis formula (RIF) on liver function. One hundred and eighty-six patients with 3076 patient tests were analyzed, who were enrolled in the Chinese Children's Leukemia Group (CCLG)-APL2016 Protocol database between November 2016 and November 2018 in 38 hospitals across China(ChiCTR-OIN-17011227). Twenty of 164 patients (12.2%) suffered from liver injury after treatment with arsenic. In addition, sixteen (80%) cases of liver injury occurred during the induction period of treatment. What's not disheartening was that 18 (90%) cases of liver injury were transient, occurring at a median time of 17 days after exposure to arsenic. More importantly, the risk of liver injury associated with RIF was not higher than that associated with ATO (RR = 0.854, 95% CI: 0.292-2.495). Otherwise, the ALP of 18 cases of liver injury was not higher than the ULN of ALP. Thus, the incidence of liver injury associated with arsenic in pediatric patients with APL was similar to that in adult patients and the risk of liver injury associated with RIF was not higher than that associated with ATO. Since ALP was not higher in pediatric APL patients with liver injury, further research is needed to explore whether ALP is an index of liver injury in children.
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Trióxido de Arsênio , Doença Hepática Induzida por Substâncias e Drogas , Leucemia Promielocítica Aguda , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Criança , Masculino , Feminino , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Trióxido de Arsênio/efeitos adversos , Trióxido de Arsênio/uso terapêutico , Pré-Escolar , Adolescente , Medicamentos de Ervas Chinesas/efeitos adversos , Medicamentos de Ervas Chinesas/uso terapêutico , Lactente , Fígado/efeitos dos fármacos , Fígado/patologia , Testes de Função Hepática , China/epidemiologia , Arsênio/efeitos adversosRESUMO
PURPOSE OF REVIEW: The identification of isocitrate dehydrogenase (IDH) mutations has led to a transformation in our understanding of gliomas and has paved the way to a new era of targeted therapy. In this article, we review the classification of IDH-mutant glioma, standard of care treatment options, clinical evidence for mutant IDH (mIDH) inhibitors, and practical implications of the recent landmark INDIGO trial. RECENT FINDINGS: In the phase 3 randomized placebo-controlled INDIGO trial, mIDH1/2 inhibitor vorasidenib increased progression-free survival among non-enhancing grade 2 IDH-mutant gliomas following surgery. This marks the first positive randomized trial of targeted therapy in IDH-mutant glioma, and led to the US Food and Drug Administration's approval of vorasidenib in August 2024 for grade 2 IDH-mutant glioma. Vorasidenib is a well-tolerated treatment that can benefit a subset of patients with IDH-mutant glioma. Targeting mIDH also remains a promising strategy for select groups of patients excluded from the INDIGO trial. Ongoing and future studies, including with new agents and with combination therapy approaches, may expand the benefit and unlock the potential of mIDH inhibitors.
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Neoplasias Encefálicas , Glioma , Isocitrato Desidrogenase , Mutação , Humanos , Glioma/tratamento farmacológico , Glioma/genética , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/antagonistas & inibidores , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Inibidores Enzimáticos/uso terapêutico , Antineoplásicos/uso terapêuticoRESUMO
The development of visible light-regulated polymerizations for precision synthesis of polymers has drawn considerable attention in the past years. In this study, an ancient dye, indigo, is successfully identified as a new and efficient photoacid catalyst, which can readily promote the ring-opening polymerization of lactones under visible light irradiation in a well-controlled manner, affording the desired polyester products with predictable molecular weights and narrow dispersity. The enhanced acidity of indigos by excitation is crucial to the H-bonding activation of the lactone monomers. Chain extension and block copolymer synthesis are also demonstrated with this method.
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Índigo Carmim , Lactonas , Luz , Polimerização , Lactonas/química , Catálise , Índigo Carmim/química , Estrutura Molecular , Processos Fotoquímicos , Polímeros/química , Polímeros/síntese químicaRESUMO
BACKGROUND AND AIM: Chromoendoscopy with the use of indigo carmine (IC) dye is a crucial endoscopic technique to identify gastrointestinal neoplasms. However, its performance is limited by the endoscopist's skill, and no standards are available for lesion identification. Thus, we developed an artificial intelligence (AI) model to replace chromoendoscopy. METHODS: This pilot study assessed the feasibility of our novel AI model in the conversion of white-light images (WLI) into virtual IC-dyed images based on a generative adversarial network. The predictions of our AI model were evaluated against the assessments of five endoscopic experts who were blinded to the purpose of this study with a staining quality rating from 1 (unacceptable) to 4 (excellent). RESULTS: The AI model successfully transformed the WLI of polyps with different morphologies and different types of lesions in the gastrointestinal tract into virtual IC-dyed images. The quality ratings of the real IC-dyed and AI images did not significantly differ concerning surface structure (AI vs IC: 3.08 vs 3.00), lesion border (3.04 vs 2.98), and overall contrast (3.14 vs 3.02) from 10 sets of images (10 AI images and 10 real IC-dyed images). Although the score depended significantly on the evaluator, the staining methods (AI or real IC) and evaluators had no significant interaction (P > 0.05) with each other. CONCLUSION: Our results demonstrated the feasibility of employing AI model's virtual IC staining, increasing the possibility of being employed in daily practice. This novel technology may facilitate gastrointestinal lesion identification in the future.
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Inteligência Artificial , Lesões Pré-Cancerosas , Humanos , Projetos Piloto , Endoscopia/métodos , Índigo Carmim , Carmim , Lesões Pré-Cancerosas/diagnóstico por imagemRESUMO
Indigo naturalis (IN), derived from the leaves of the indigo plant, is a traditional Chinese medicine that has historically been used for its anti-inflammatory properties in the treatment of various diseases, including ulcerative colitis (UC). However, long-term use of IN in UC patients is incontrovertibly associated with the onset of pulmonary arterial hypertension (PAH). To investigate the mechanisms by which IN induces PAH, we focused on the raw material of IN, indigo leaves (IL). Only the condition of long-term chronic (6 months) and high-dose (containing 5% IL in the control diet) administration of IL induced medial thickening in the pulmonary arteries without right ventricular hypertrophy in our rat model. IL administration for a month did not induce pulmonary arterial remodeling but increased endothelin-1 (ET-1) expression levels within endothelial cell (EC) layers in the lungs. Gene Expression Omnibus analysis showed that ET-1 is a key regulator of PAH and that the IL component indican and its metabolite IS induced ET-1 mRNA expression via reactive oxygen species-dependent mechanism. We identified the roles of indican and IS in ET-1 expression in ECs, which were linked to pulmonary arterial remodeling in an animal model.
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Endotelina-1 , Hipertrofia Ventricular Direita , Folhas de Planta , Artéria Pulmonar , Ratos Sprague-Dawley , Remodelação Vascular , Animais , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Masculino , Endotelina-1/metabolismo , Remodelação Vascular/efeitos dos fármacos , Hipertrofia Ventricular Direita/metabolismo , Hipertrofia Ventricular Direita/fisiopatologia , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/metabolismo , Ratos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/metabolismoRESUMO
In recent years, with the increasing global focus on environmental protection, the issue of microfiber release from denim during the washing process has gained attention. In this study, a programmable washing device simulating household drum washing was designed and developed, microfibers and indigo dyes released from denim washing were quantitatively detected, and we have also developed a novel method for estimating the release of microfibers during washing. The effects of washing time, washing temperature, and washing load on microfiber and indigo dye release from denim were explored. The results showed that the effect of washing load on microfiber and indigo dye release was greater than washing temperature and washing time. The research findings indicate that with an increase in washing time (35-95 min) and washing load (100-250 g), the shedding of microfibers and indigo dye significantly increases, reaching peak release levels of 343.6 µg/g fabric and 0.027 mg/L, respectively. However, there is a decreasing trend in the release of microfibers and indigo dye when the washing temperature exceeds 50 °C. Furthermore, our data suggests that an increase in washing load leads to a significant change in the number of microfibers (from 978 items/g fabric to 1997 items/g fabric) and their mass (from 156.87 µg/g fabric to 343.56 µg/g fabric). The influence of washing time, washing temperature, and washing load on microfiber length shows relatively small fluctuations within the range of 600-900 µm. This study provides new ideas and methods for estimating the release of microfiber and indigo dye in denim washing around the world.
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Índigo Carmim , TêxteisRESUMO
Sustainable BiOI/sulfated TiO2 nanocomposites were created for the present study utilizing the environmentally friendly dispersion-ultrasonication technique. Then, their ability to degrade the medication ciprofloxacin (CIP) and indigo carmine coloring (IC) in aquatic water was evaluated. The optimized catalyst 10%BiOI/ST, denoted as 10BOST together with 5BOST, is subjected to thorough characterization together with that of sulfate-free TiO2 (10BOT) to assess their physiochemical, morphological, textural, structural, and elemental composition properties. It is noteworthy that the 10BOST composite achieves remarkable degradation and performs exceptionally well in photocatalytic IC and CIP degradation. In 35 min, it degrades IC to 100%, with a rate constant of 0.066 min-1, which is superior to that of 10BOT (0.054 min-1) in the incidence of visible light and without an oxidizing agent. In CIP, 10BOST yields 85.6% degradation with a rate constant of 0.027 min-1 preceding 0.024 min-1 for 10BOT when potassium persulfate oxidizing agent is present. This exceptional performance is ascribed to the composite's diminished particle diameter, largest pore radius, hydrophilicity, improved light absorption, and the developed heterojunction between ST and BiOI, as demonstrated by XPS, TEM, XRD, EDX and IR data. The effect of sulfation concentration, pH, Ti3+/Ti4+ ratio, and pollutant concentration were studied together with the active species determinations, which revealed that active radicals like SO4â¢-, â¢OH, and h+ were well participated in the pollutant's decomposition. Testing for toxicity shows that during CIP breakdown, innocuous hazardous intermediates evolve with a notable 70% mineralization rate in their TOC. Furthermore, 10BOST showed strong stability and reusability. Using DFT simulations, profound insights into the principles underlying the adsorption sites of pollutants, their chemical reactivity, and the arrangement of their electrical charges, and how these factors affect the reaction mechanism on BOST photocatalysts.
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The textile industry is an important economic sector; however, its wastewater generates a great impact on the environment. A heterogeneous solar Fenton (HSF) process was evaluated for denim wastewater treatment. The catalyst was obtained through ultrasonic modification of recycled polyethylene terephthalate (PET) with Fe nanoparticles (PET/NPs- Fe3O4). The SFH process was optimized using surface response methodology with a face-centered central composite design considering the effects of the hydraulic retention time (10, 25, and 40 min), hydrogen peroxide dosage (500, 1000, and 1500 mg/L), and mass of the packed catalyst (4, 6 and 8 g) on the color, COD, and turbidity removal efficiencies. The operating conditions for maximum COD removal were H2O2 541.7 mg/L, HRT 33.9 min, and PET/NPs- Fe3O4 dose 7.9 g with solar radiation. The removal of 91.2% COD, 86.2% color, 90.4% turbidity, and 81.9% TOC was obtained at 14.2 kJ/L QUva. PET modification yielded 1.6 mg Fe/g PET, and the modification method does not allow Fe leaching. The effluent obtained from the SFH process complies with the maximum permissible limits in Mexican legislation in terms of COD, TOC, turbidity, and color and allows the reuse of PET.
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Poluentes Químicos da Água , Purificação da Água , Eliminação de Resíduos Líquidos/métodos , Polietilenotereftalatos , Ultrassom , Peróxido de Hidrogênio , Ferro , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , OxirreduçãoRESUMO
We present the synthesis of a cross-linking enzyme aggregate (CLEAS) of a peroxidase from Megathyrsus maximus (Guinea Grass) (GGP). The biocatalyst was produced using 50%v/v ethanol and 0.88%w/v glutaraldehyde for 1 h under stirring. The immobilization yield was 93.74% and the specific activity was 36.75 U mg-1. The biocatalyst surpassed by 61% the free enzyme activity at the optimal pH value (pH 6 for both preparations), becoming this increase in activity almost 10-fold at pH 9. GGP-CLEAS exhibited a higher thermal stability (2-4 folds) and was more stable towards hydrogen peroxide than the free enzyme (2-3 folds). GGP-CLEAS removes over 80% of 0.05 mM indigo carmine at pH 5, in the presence of 0.55 mM H2O2 after 60 min of reaction, a much higher value than when using the free enzyme. The operational stability showed a decrease of enzyme activity (over 60% in 4 cycles), very likely related to suicide inhibition.
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Enzimas Imobilizadas , Peróxido de Hidrogênio , Índigo Carmim , Peroxidase , Índigo Carmim/química , Peroxidase/metabolismo , Peroxidase/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Peróxido de Hidrogênio/química , Estabilidade Enzimática , Reagentes de Ligações Cruzadas/química , Temperatura , Glutaral/químicaRESUMO
The reaction of indigo with two equivalents of the electrophile ethyl bromoacetate with caesium carbonate as a base result in the formation of structurally complex polyheterocyclics, including a fused spiroimidazole and a spiro[1,3]oxazino derivative, together with a biindigoid-type derivative, through a convenient one-pot reaction. Further assessment of the reaction using five equivalents of the electrophile gave rise to other molecules incorporating the 2-(7,13,14-trioxo-6,7,13,14-tetrahydropyrazino[1,2-a:4,3-a']diindol-6-yl) scaffold. The reaction of ethyl bromoacetate with the less reactive indirubin resulted in the synthesis of three derivatives of a new class of polyheterocyclic system via a cascade process, although yields were low. These compounds were derived from the parent indolo[1,2-b]pyrrolo[4,3,2-de]isoquinoline skeleton. Despite the modest yields of the reactions, they represent quick cascade routes to a variety of heterocycles from cheap starting materials, with these structures otherwise being difficult to synthesise in a traditional stepwise manner. These outcomes also contribute significantly to the detailed understanding of the indigo/indirubin cascade reaction pathways initiated by base-catalysed N-alkylation.
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The production of indigo, primarily used by the denim industry, increases year by year, and is mainly of synthetic origin. The textile industry, on which its production depends, is responsible for 10% of greenhouse gases and 20% of water pollution. However, the source of this pigment/colorant, mainly based on petrochemistry, remains a key issue today. Extracting indigo from plants is becoming a popular answer and requires an understanding and evaluation of the entire process, from raw material to pigment recovery. In this study, the indigotin precursor, indoxyl, derived from the hydrolysis of O-glycosides biomass extracted in water, was oxidized to obtain the desired pigment. This step is the most sensitive, as variations have been observed during this phase. Consequently, the standardization of the oxidation process was established to determine the extract capacity to consistently produce the blue dye pigment. Partial hydrolysis of the O-glycosides, the indoxyl precursors, was identified as a factor causing this yield variability in the obtained extracts. Once the precursors were fully chemically hydrolyzed, plants harvested during summer and during a freezing period showed a similar capacity to produce indigotin, with values of 412 ± 25 ppm and 379 ± 0 ppm, respectively. This result showed that in freezing conditions, the enzymatic material was not available, resulting in the lack of indigotin formation. To address the use of oxidation in an alkaline medium, a spontaneous oxidation method was proposed. This method produced a purer indigotin pigment, with a 21.6% purity compared to 5.9% purity using air-mediated oxidation in an alkaline medium.
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Corantes , Índigo Carmim , Indóis , Isatis , Oxirredução , Índigo Carmim/química , Cromatografia Líquida de Alta Pressão/métodos , Indóis/química , Corantes/química , Isatis/química , Extratos Vegetais/química , HidróliseRESUMO
The present work reports the synthesis of indigo-dye-incorporated polyaniline (Indigo-PANI), poly(1-naphthylamine) (Indigo-PNA), poly(o-phenylenediamine) (Indigo-POPD), polypyrrole (Indigo-PPy), and polythiophene (Indigo-PTh) via an ultrasound-assisted method. The synthesized oligomers were characterized using FTIR, UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence studies, and thermogravimetric analysis (TGA). The experimental data were theoretically compared to analyze the vibrational and electronic spectra via time-dependent density-functional theory (TD-DFT) by applying the Becke, three-parameter, and Lee-Yang-Parr (B3LYP) method with a 6-311G (d,p) basis set. The experimental, theoretical vibrational, and electronic spectra were found to be in close agreement and confirmed the successful incorporation of indigo dye in PANI, PNA, POPD, PPy, and PTh. These studies confirmed that multifunctional oligomers could be synthesized through a facile technique by incorporating dye moieties to enhance their optoelectronic properties, allowing them to be utilized as near-infrared-emitting probes for photodynamic therapy.
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This study presents a comprehensive evaluation of catalytic ozonation as an effective strategy for indigo dye bleaching, particularly examining the performance of four carbon-based catalysts, activated carbon (AC), multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-C3N4), and thermally etched nanosheets (C3N4-TE). The study investigates the efficiency of catalytic ozonation in degrading Potassium indigotrisulfonate (ITS) dye within the constraints of short contact times, aiming to simulate real-world industrial wastewater treatment conditions. The results reveal that all catalysts demonstrated remarkable decolorization efficiency, with over 99% of indigo dye removed within just 120 s of mixing time. Besides, the study delves into the mechanisms underlying catalytic ozonation reactions, elucidating the intricate interactions between the catalysts, ozone, and indigo dye molecules with the processes being influenced by factors such as PZC, pKa, and pH. Furthermore, experiments were conducted to analyze the adsorption characteristics of indigo dye on the surfaces of the materials and its impact on the catalytic ozonation process. MWCNT demonstrated the highest adsorption efficiency, effectively removing 43.4% of the indigo dye color over 60 s. Although the efficiency achieved with C3N4-TE was 21.4%, which is approximately half of that achieved with MWCNT and less than half of that with AC, it is noteworthy given the significantly lower surface area of C3N4-TE.
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The food industry uses indigo carmine (IC) extensively as a blue colorant to make processed food for young children and the general population more attractive. Given that IC can act as a ligand, this raises concerns about its interactions with essential metal ions in the human body. In view of this interest, in the present investigation, the copper(II)/indigo carmine system was thoroughly investigated in aqueous solution and in the solid state, and the detailed structural characterization of the complexes formed between copper(II) and the ligand was performed using spectroscopic methods, complemented with DFT and TD-DFT calculations. NMR and UV/Vis absorption spectroscopy studies of the ligand in the presence of copper(II) show changes that clearly reveal strong complexation. The results point to the formation of complexes of 1:1, 1:2 and 2:1 Cu(II)/IC stoichiometry in aqueous solution, favored in the pH range 6-10 and stable over time. DFT calculations indicate that the coordination of the ligand to the metal occurs through the adjacent carbonyl and amine groups and that the 1:1 and the 2:1 complexes have distorted tetrahedral metal centers, while the 1:2 structure is five-coordinate with a square pyramidal geometry. FTIR results, together with EDS data and DFT calculations, established that the complex obtained in the solid state likely consists of a polymeric arrangement involving repetition of the 1:2 complex unit. These results are relevant in the context of the study of the toxicity of IC and provide crucial data for future studies of its physiological effects. Although the general population does not normally exceed the maximum recommended daily intake, young children are highly exposed to products containing IC and can easily exceed the recommended dose. It is, therefore, extremely important to understand the interactions between the dye and the various metal ions present in the human body, copper(II) being one of the most relevant due to its essential nature and, as shown in this article, the high stability of the complexes it forms with IC at physiological pH.
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Indigo is a widely used dye in various industries, such as textile, cosmetics, and food. However, traditional methods of indigo extraction and processing are associated with environmental and economic challenges. Fermentative production of indigo using microbial strains has emerged as a promising alternative that offers sustainability and cost-effectiveness. This review article provides a critical overview of microbial diversity, metabolic pathways, fermentation strategies, and genetic engineering approaches for fermentative indigo production. The advantages and limitations of different indigo production systems and a critique of the current understanding of indigo biosynthesis are discussed. Finally, the potential application of indigo in other sectors is also discussed. Overall, fermentative production of indigo offers a sustainable and bio-based alternative to synthetic methods and has the potential to contribute to the development of sustainable and circular biomanufacturing.
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Índigo Carmim , Indigofera , Fermentação , Alimentos , Engenharia GenéticaRESUMO
Natural products are attractive components to tailor environmentally friendly advanced new materials. We present surface-confined metallosupramolecular engineering of coordination polymers using natural dyes as molecular building blocks: indigo and the related Tyrian purple. Both building blocks yield identical, well-defined coordination polymers composed of (1 dehydroindigo : 1 Fe) repeat units on two different silver single crystal surfaces. These polymers are characterized atomically by submolecular resolution scanning tunnelling microscopy, bond-resolving atomic force microscopy and X-ray photoelectron spectroscopy. On Ag(100) and on Ag(111), the trans configuration of dehydroindigo results in N,O-chelation in the polymer chains. On the more inert Ag(111) surface, the molecules additionally undergo thermally induced isomerization from the trans to the cis configuration and afford N,N- plus O,O-chelation. Density functional theory calculations confirm that the coordination polymers of the cis-isomers on Ag(111) and of the trans-isomers on Ag(100) are energetically favoured. Our results demonstrate post-synthetic linker isomerization in interfacial metal-organic nanosystems.
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The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor expressed in hematopoietic and non-hematopoietic cells. Activation of the AhR by xenobiotics, microbial metabolites, and natural substances induces immunoregulatory responses. Autoimmune pancreatitis (AIP) is a chronic fibroinflammatory disorder of the pancreas driven by autoimmunity. Although AhR activation generally suppresses pathogenic autoimmune responses, the roles played by the AhR in AIP have been poorly defined. In this study, we examined how AhR activation affected the development of experimental AIP caused by the activation of plasmacytoid dendritic cells producing IFN-α and IL-33. Experimental AIP was induced in MRL/MpJ mice by repeated injections of polyinosinic-polycytidylic acid. Activation of the AhR by indole-3-pyruvic acid and indigo naturalis, which were supplemented in the diet, inhibited the development of experimental AIP, and these effects were independent of the activation of plasmacytoid dendritic cells producing IFN-α and IL-33. Interaction of indole-3-pyruvic acid and indigo naturalis with AhRs robustly augmented the production of IL-22 by pancreatic islet α cells. The blockade of IL-22 signaling pathways completely canceled the beneficial effects of AhR ligands on experimental AIP. Serum IL-22 concentrations were elevated in patients with type 1 AIP after the induction of remission with prednisolone. These data suggest that AhR activation suppresses chronic fibroinflammatory reactions that characterize AIP via IL-22 produced by pancreatic islet α cells.
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Indigo, one of the most ancient and abundant dyes in human history, has recently emerged as a potential functional motif due to its intriguing photochemical properties. This review aims to provide insights into both the preparation of these molecules and their utilization in molecular systems. First, the synthesis of the indigo core as well as available methods to derivatize indigo are described to outline synthetic strategies to build the desired molecular structures. Then, the photochemical behavior of indigos is discussed, with particular focus on E-Z photoisomerization and photoinduced electron transfer. Connections between the molecular structures and their photochemical properties are highlighted and serve as guiding principles for designing indigos to be applied as photoresponsive tools.