Synthesis and characterization of some new Schiff base azo disperse dyes based on chromene moiety for simultaneous dyeing and antimicrobial finishing.

New azo Schiff base disperse dyes based on a chromene moiety were synthesized by reacting (2-amino-7-hydroxy-4-(4-methoxyphenyl)-4 H-chromene-3 carbonitrile) and(2-amino-4-(3,4-dimethoxyphenyl)-7-hydroxy-4 H-chromene-3-carbonitrile), with vanillin and ninhydrin, producing new chromene Schiff base derivatives, which in turn were coupled with 2-chloro-4-nitroaniline diazonium salt to give new 4 azo disperse dyes (1-4). The structures of the prepared dyes were confirmed using elemental analysis, 1HNMR spectroscopy, mass spectrometry, and IR. The synthesized dyes were applied to polyester and nylon fabrics using different dyeing techniques: high temperature- high pressure, and ultrasonic dyeing methods. The highest K/S values for all investigated dyes were achieved usinga high temperature-high pressure dyeing technique. Also, the color reflectance of all synthesized dyes with different dyeing shades (1%, 2%, and 3%) was obtained. The fastness properties of the dyed samples using the investigated dyes showed good color fastness toward light, washing, rubbing, and perspiration fastness. The presence of a chromene moiety and Schiff base in the investigated dyes promotes a higher antimicrobial activity on nylon and polyester fabrics against all tested bacteria (E. coli gram-negative and Staphylococcus aureus gram-positive) and two fungi, Aspergillus Niger and Candida albicans.

Time-Dependent Hydrothermal Synthesis of La2O3 NPs for Effective Catalytic Activity of Ionic Dye.

Lanthanum oxide was successfully synthesized by hydrothermal method by varying the reaction time such as 6, 12, and 24 h. In XRD, study confirms the presence of a hexagonal structure, and the phase remains the same at different times; the main goal is to assess the average crystallite size of prepared La2O3 nanoparticles, which was found in the range of 6 to 8 nm. An interesting observation from the XRD data was the apparent increase in crystalline nature as the synthesis time was extended. The UV-Vis spectroscopic studies show a change in the band gap when the reaction time is changed. The morphology analysis shows that the image revealed that the particles formed were agglomerated and formed a spherical shape, with diameters ranging between 35 and 86 nm. When tested for photocatalytic activity, the La2O3 nanoparticles show a degradation of methylene blue dye when the time varies. Remarkably, the nanoparticles synthesized exhibited a profound ability to degrade the dye, with an efficiency rate hitting as high as 89% under halogen light illumination.

Diesters of monoimide of perylene-3,4,9,10-tetracarboxylic acid - Synthesis, characterization, and application for dyeing polyester fibre, polystyrene, and poly (methyl methacrylate) films.

Three dyes-diesters of monoimides of perylene-3,4,9,10-tetracarboxylic acid were synthesized in three-stage process: esterification, hydrolysis, and monoimidation as potential fluorescent light-stable colorants for high visibility safety wear. The structure of these compounds was confirmed by 1H nuclear magnetic resonance spectroscopy and mass spectrometry, and their spectroscopic and physicochemical properties were determined. Colorants were applied to dyeing polyester fibre and polystyrene and poly (methyl methacrylate) films. The light, wash, and rubbing fastness of the dyeings were determined, and chromaticity coordinates were measured and discussed.

Design, Synthesis, and Characterization of Polyoxotungstate-Decorated Ionic Liquid-Based Hybrid Material, [BmIm]4[SiW12O40] toward Rapid Adsorption of Dye and Antibacterial Activities.

A multifunctional polyoxometalate-ionic liquid (POM-IL)-based hybrid material comprising silicotungstic acid, [BmIm]4[SiW12O40], has been synthesized and demonstrated its efficiency toward methylene blue removal and as an antibacterial agent. Single-crystal XRD analysis confirms that the material crystallizes in monoclinic symmetry (SG: Pn), with lattice parameters a = 13.1396(5) Å, b = 16.9655(8) Å, c = 14.3493(7) Å, and Z = 2. The structure comprises a single polyanionic [SiW12O40]4- moiety surrounded by four cationic [BmIm]+ units of two different conformations, which supported DFT and Hirshfeld surface analysis. The material shows excellent removal efficiency for methylene blue, with a maximum adsorption capacity of 92.47 mg/g and 83.05% reusability after five cycles. On the contrary, FTIR and ζ-potential analyses confirm that electrostatic interactions are the predominant factors governing the adsorption process. The material also acts as a superior antibacterial agent against the opportunistic pathogens Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli with a MIC of 500-700 µg/mL. However, a comparative assessment showed that the material was more effective against P. aeruginosa compared to the other two pathogens. PXRD analysis confirms the phase purity, and FESEM and TEM analyses exhibit block-shaped morphology with particle sizes ∼2-3 µm.

Synthesis and photo-induced anticancer activity of new 2-phenylethenyl-1H-benzo[e]indole dyes.

Herein, a series of new 1,1,2-trimethyl-1H-benzo[e]indole dyes was prepared via Knoevenagel condensation reaction between 1,1,2-trimethyl-1H-benzo[e]indole and benzaldehydes, and characterized using various spectroscopic methods. The obtained compounds showed cytotoxic properties in G361 melanoma cell line upon irradiation with 414 nm blue light at submicromolar doses. The mechanism of action of the most potent compound 15 was further investigated. The treatment induced substantial generation of reactive oxygen species, leading to DNA damage followed by cell death depending on the concentration of the photosensitizer compound and the irradiation intensity.

Nucleic Acid-Templated Synthesis of Cationic Styryl Dyes in Vitro and in Living Cells.

A novel method for synthesizing cationic styryl dyes through a nucleic acid-templated reaction has been developed. This approach overcomes issues associated with traditional synthesis methods, such as harsh conditions, low throughput, and wasteful chemicals. The presence of a nucleic acid template accelerated the styryl dye formation from quaternized heteroaromatic and cationic aldehyde substrates. These styryl dyes show remarkable optical properties change when bound to nucleic acids, hence the success of the synthesis could be readily monitored in situ by UV-Vis and fluorescence spectroscopy and the optical properties data were also observable at the same time. This method provides the desired products from a broad range of coupling partners. By employing different substrates and templates, it is possible to identify new dyes that can bind to a specific type of nucleic acid such as a G-quadruplex. The templated dye synthesis is also successfully demonstrated in live HeLa cells. This approach is a powerful tool for the rapid synthesis and screening of dyes specific for diverse types of nucleic acids or cellular organelles, facilitating new biological discoveries.

Development of Mitochondria-Targeted Small-Molecule Dyes for Myocardial PET and Fluorescence Bimodal Imaging.

Mitochondria-targeting positron emission tomography (PET) and fluorescent dual-modal probes are rarely reported. As one of the most promising lipophilic cations, F16 and its derivatives (F16s) have never been used for myocardial imaging. In this work, 14 F16s are synthesized and evaluated for cardiac imaging. In vitro cell fluorescence imaging revealed that the lead probe 5MEF is precisely localized in the mitochondria of cardiomyocytes. In addition, it shows excellent ex vivo fluorescence imaging quality with the heart-to-muscle and heart-to-liver ratios up to ∼2. Furthermore, the radiofluorinated probe 18F-5MEF is successfully prepared and shows a high initial heart uptake of 8.66 ± 0.34 % ID/g at 5 min post injection. It displays a high heart imaging performance, a long retention time in the heart, and a low background in the most normal tissues as revealed by PET. To our knowledge, this is the first time novel F16 analogues are designed and developed for myocardial dual-modal imaging.

Photoacoustic imaging of elevated glutathione in models of lung cancer for companion diagnostic applications.

Companion diagnostics (CDx) are powerful tests that can provide physicians with crucial biomarker information that can improve treatment outcomes by matching therapies to patients. Here, we report a photoacoustic imaging-based CDx (PACDx) for the selective detection of elevated glutathione (GSH) in a lung cancer model. GSH is abundant in most cells, so we adopted a physical organic chemistry approach to precisely tune the reactivity to distinguish between normal and pathological states. To evaluate the efficacy of PACDx in vivo, we designed a blind study where photoacoustic imaging was used to identify mice bearing lung xenografts. We also employed PACDx in orthotopic lung cancer and liver metastasis models to image GSH. In addition, we designed a matching prodrug, PARx, that uses the same SNAr chemistry to release a chemotherapeutic with an integrated PA readout. Studies demonstrate that PARx can inhibit tumour growth without off-target toxicity in a lung cancer xenograft model.

Construction of self-enhanced photoelectrochemical platform for L-cysteine detection via electron donor-acceptor type coumarin 545 aggregates.

Self-enhanced electron donor-acceptor type coumarin 545 aggregates prepared via an anionic surfactant-assisted reprecipitation method provide an underlying approach for the photoelectrochemical detection of L-cysteine, which can be employed in aqueous solution without the addition of electron donors.

Polycationic Monomeric and Homodimeric Asymmetric Monomethine Cyanine Dyes with Hydroxypropyl Functionality-Strong Affinity Nucleic Acids Binders.

New analogs of the commercial asymmetric monomethine cyanine dyes thiazole orange (TO) and thiazole orange homodimer (TOTO) with hydroxypropyl functionality were synthesized and their properties in the presence of different nucleic acids were studied. The novel compounds showed strong, micromolar and submicromolar affinities to all examined DNA ds-polynucleotides and poly rA-poly rU. The compounds studied showed selectivity towards GC-DNA base pairs over AT-DNA, which included both binding affinity and a strong fluorescence response. CD titrations showed aggregation along the polynucleotide with well-defined supramolecular chirality. The single dipyridinium-bridged dimer showed intercalation at low dye-DNA/RNA ratios. All new cyanine dyes showed potent micromolar antiproliferative activity against cancer cell lines, making them promising theranostic agents.

Synthesis of Catechol Derived Rosamine Dyes and Their Reactivity toward Biogenic Amines.

Functional organic dyes play a key role in many fields, namely in biotechnology and medical diagnosis. Herein, we report two novel 2,3- and 3,4-dihydroxyphenyl substituted rosamines (3 and 4, respectively) that were successfully synthesized through a microwave-assisted protocol. The best reaction yields were obtained for rosamine 4, which also showed the most interesting photophysical properties, specially toward biogenic amines (BAs). Several amines including n- and t-butylamine, cadaverine, and putrescine cause spectral changes of 4, in UV-Vis and fluorescence spectra, which are indicative of their potential application as an effective tool to detect amines in acetonitrile solutions. In the gas phase, the probe response is more expressive for spermine and putrescine. Additionally, we found that methanolic solutions of rosamine 4 and n-butylamine undergo a pink to yellow color change over time, which has been attributed to the formation of a new compound. The latter was isolated and identified as 5 (9-aminopyronin), whose solutions exhibit a remarkable increase in fluorescence intensity together with a shift toward more energetic wavelengths. Other 9-aminopyronins 6a, 6b, 7a, and 7b were obtained from methanolic solutions of 4 with putrescine and cadaverine, demonstrating the potential of this new xanthene entity to react with primary amines.

Applying Bayesian forecasting to predictive toxicology: The probability of innate carcinogenicity to humans of colorants synthesized from benzidine.

The preclinical identification of health hazards relies on the performance (the historic concordance to the respective gold standard) of regulatorily recommended bioassays. However, any testing with less than 100% sensitivity (or 100% specificity) can deliver false results (outcomes discordant to the respective gold standard). Conversely, the predictive values approach (a.k.a. Bayesian forecasting) weighs (1) the performance of the predictive bioassay (battery, or framework) with (2) the prevalence of -positivity to the respective gold standard- in the most representative category to which the test substance can be allocated. Thus, the predictive values approach (PVA) provides the numeric probability for the toxicity to humans of chemicals that, circumstantially, are evaluable only through nonclinical data. Consequently, the PVA improves the predictivity of nonclinical toxicology, and increases the impact of hazard identifications entirely based on preclinical data. This article aimed to introduce the PVA through a worked example. Due to their toxicological homogeneity and public health relevance, the superfamily of colorants synthesized from benzidine (BZ) or some mutagenic congeners was selected (colorings hereafter mentioned as BZ-related-colorants). Through the PVA, the numeric probability of innate carcinogenicity to humans of 259 BZ-related-colorants was either estimated from rodent carcinogenesis bioassays (RCBs) or predicted from methods alternative to the RCB. A discussion was provided on (1) some limitations and implications of the PVA, and (2) the probable significance of the predictive values figured here for 259 BZ-related-colorings.

9-Cyanopyronin probe palette for super-multiplexed vibrational imaging.

Multiplexed optical imaging provides holistic visualization on a vast number of molecular targets, which has become increasingly essential for understanding complex biological processes and interactions. Vibrational microscopy has great potential owing to the sharp linewidth of vibrational spectra. In 2017, we demonstrated the coupling between electronic pre-resonant stimulated Raman scattering (epr-SRS) microscopy with a proposed library of 9-cyanopyronin-based dyes, named Manhattan Raman Scattering (MARS). Herein, we develop robust synthetic methodology to build MARS probes with different core atoms, expansion ring numbers, and stable isotope substitutions. We discover a predictive model to correlate their vibrational frequencies with structures, which guides rational design of MARS dyes with desirable Raman shifts. An expanded library of MARS probes with diverse functionalities is constructed. When coupled with epr-SRS microscopy, these MARS probes allow us to demonstrate not only many versatile labeling modalities but also increased multiplexing capacity. Hence, this work opens up next-generation vibrational imaging with greater utilities.

Efficient Design to Monitor the Site-specific Sustained Release of a Non-Emissive Anticancer Drug.

A pH-responsive smart nanocarrier with significant components was synthesized by conjugating the non-emissive anticancer drug methyl orange and polyethylene glycol derived folate moiety to the backbone of polynorbornene. Complete synthesis procedure and characterization methods of three monomers included in the work: norbornene-derived Chlorambucil (Monomer 1), norbornene grafted with polyethylene glycol, and folic acid (Monomer 2) and norbornene attached methyl orange (Monomer 3) connected to the norbornene backbone through ester linkage were clearly discussed. Finally, the random copolymer CHO PEG FOL METH was synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs' second-generation catalyst. Advanced polymer chromatography (APC) was used to find the final polymer's molecular weight and polydispersity index (PDI). Dynamic light scattering, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to explore the prodrug's size and morphology. Release experiments of the anticancer drug, Chlorambucil and the coloring agent, methyl orange, were performed at different pH and time. Cell viability assay was carried out for determining the rate of survived cells, followed by the treatment of our final polymer named CHO PEG FOL METH.

High concentration acid-induced discoloration polymeric dyes fabricated with UV-curable azobenzene-lignin-based waterborne polyurethane.

A durable and reversible acid-induced discoloration azobenzene UV-curable lignin-based waterborne polyurethane polymeric dye (EDA-ULPD) is prepared from lignin, azobenzene and pentaerythritol triacrylate(PETA) by chemical modification of waterborne polyurethane. Lignin and PETA are chemically bonded to the polyurethane chain to improve thermal stability, UV resistance and color fastness, while also endow the polymeric dye with UV curing performance, which is a green and environmentally friendly fixing way. The acid-induced discoloration property of EDA-ULPD with azobenzene chromophore side chain is comparable to those of 4-ethyl-4-2,2'-dihydroxy diethylamine azobenzene (EDA). As the pH value decreases from 7 to 1, the maximum absorption peak of EDA-ULPD from 420 nm to 530 nm, and the color change from yellow to pink due to the transformation of EDA molecular structure from diazo to hydrazone. Interestingly, when EDA-ULPD is fixed to the fabric in the way of UV curing, its printed fabric exhibits the performance of high concentration acid-induced discoloration (1 mol·L-1 HCl) due to the cross-linked structure formed by EDA-ULPD. The acid-induced discoloration property of EDA-ULPD printed fabrics also presents outstanding repetitious stability. The stimulus response printed fabric with reversible high concentration acid discoloration possesses a broad application prospect in smart textiles.

Production of Rainbow Colorants by Metabolically Engineered Escherichia coli.

There has been much interest in producing natural colorants to replace synthetic colorants of health concerns. Escherichia coli has been employed to produce natural colorants including carotenoids, indigo, anthocyanins, and violacein. However, production of natural green and navy colorants has not been reported. Many natural products are hydrophobic, which are accumulated inside or on the cell membrane. This causes cell growth limitation and consequently reduces production of target chemicals. Here, integrated membrane engineering strategies are reported for the enhanced production of rainbow colorants-three carotenoids and four violacein derivatives-as representative hydrophobic natural products in E. coli. By integration of systems metabolic engineering, cell morphology engineering, inner- and outer-membrane vesicle formation, and fermentation optimization, production of rainbow colorants are significantly enhanced to 322 mg L-1 of astaxanthin (red), 343 mg L-1 of ß-carotene (orange), 218 mg L-1 of zeaxanthin (yellow), 1.42 g L-1 of proviolacein (green), 0.844 g L-1 of prodeoxyviolacein (blue), 6.19 g L-1 of violacein (navy), and 11.26 g L-1 of deoxyviolacein (purple). The membrane engineering strategies reported here are generally applicable to microbial production of a broader range of hydrophobic natural products, contributing to food, cosmetic, chemical, and pharmaceutical industries.

Anisotropic Synthetic Allomelanin Materials via Solid-State Polymerization of Self-Assembled 1,8-Dihydroxynaphthalene Dimers.

Melanosomes in nature have diverse morphologies, including spheres, rods, and platelets. By contrast, shapes of synthetic melanins have been almost entirely limited to spherical nanoparticles with few exceptions produced by complex templated synthetic methods. Here, we report a non-templated method to access synthetic melanins with a variety of architectures including spheres, sheets, and platelets. Three 1,8-dihydroxynaphthalene dimers (4-4', 2-4' and 2-2') were used as self-assembling synthons. These dimers pack to form well-defined structures of varying morphologies depending on the isomer. Specifically, distinctive ellipsoidal platelets can be obtained using 4-4' dimers. Solid-state polymerization of the preorganized dimers generates polymeric synthetic melanins while maintaining the initial particle morphologies. This work provides a new route to anisotropic synthetic melanins, where the building blocks are preorganized into specific shapes, followed by solid-state polymerization.

An anti-aggregation NIR-II heptamethine-cyanine dye with a stereo-specific cyanine for imaging-guided photothermal therapy.

Due to the hydrophobicity of the cyanine dye and the huge conjugated plane, the cyanine dye is prone to H-aggregation in aqueous solution, and the ultraviolet absorption is blue-shifted. Here, a hydrophilic quaternary stereo-specific cyanine (HQS-Cy) dye has been synthesized and polypeptide based nanoparticles have been prepared, which improve the water solubility of the cyanine in two aspects. First, at the molecular level, the sulfonic acid group increases the water solubility of the dye molecule while the dimethyl-ammonium functional group repels the molecule through the charge-charge interaction, destroying the planar characteristics of the cyanine structure, increasing the molecular distance between the dye molecules, and preventing the accumulation of cyanine. Secondly, at the nano-micelle level, the use of amphiphilic polypeptide blocks to encapsulate the dye increases the water solubility of the dye while also increasing its biocompatibility. The HQS-Cy@P NPs prepared by the above methods exhibit the maximum absorption at 985 nm and maximum fluorescence emission at 1050 nm in aqueous solution. HQS-Cy@P exhibits good photothermal stability and significant photothermal conversion efficiency of about 35.5%, and both in vitro and in vivo studies revealed that it is an efficient system for NIR-II imaging-guided photothermal therapy of cancer.

Synthesis of chitosan-based polymeric dyes as colorimetric pH-sensing materials: Potential for food and biomedical applications.

pH-sensitive polymeric dyes were fabricated by grafting phenol red (PR) and rosolic acid (RA) onto chitosan (CS) by a facile method. Successful grafting was confirmed by 1H NMR, FT-IR, UV-vis, XRD, and elemental analysis. The polymeric dyes exhibited no cell toxicity. The colorimetric pH-sensing films were fabricated by blending the polymeric dyes with CS to establish their pH-dependent color properties. The film color changed in the pH range 4-10, which may indicate food spoilage or wound status. Covalently grafting of polymeric dyes in the films led to excellent color stability, leaching resistance, and reversibility. Hence, the synthesized polymeric dyes had potential as pH-indicative colorants for food and biomedical fields.

Comparative analyses of new donor-π-acceptor ferrocenyl-chalcones containing fluoro and methoxy-fluoro acceptor units as synthesized dyes for organic solar cell material.

Two organometallic compounds known as (E)-1-ferrocenyl-(3-fluorophenyl)prop-2-en-1-one (Fc1) and (E)-1-ferrocenyl-(3-fluoro-4-methoxyphenyl)prop-2-en-1-one (Fc2) are designed and synthesized for application in dye-sensitized solar cell (DSSC) based on a donor-π-acceptor (D-π-A) architecture. By strategically introducing a methoxy group into the acceptor side of the compound, Fc2 which has adopted a D-π-A-AD structure are compared with the basic D-π-A structure of Fc1. Both compounds were characterized by utilizing the IR, NMR and UV-Vis methods. Target compounds were further investigated by X-ray analysis and studied computationally using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) approaches to explore their potential performances in DSSCs. An additional methoxy group has been proven in enhancing intramolecular charge transfer (ICT) by improving the planarity of Fc2 backbone. This good electronic communication leads to higher HOMO energy level, larger dipole moment and better short-circuit current density (Jsc) values. Eventually, the presence of methoxy group in Fc2 has improved the conversion efficiency as in comparison to Fc1 under the same conditions.