Purple Compound Research Articles

Additive Manufacturing of Halochromic Polylactic Acid (PLA)

With increasing concerns regarding plastic waste and pollution, researchers have been looking to develop advanced materials from biodegradable plastics. This study features a halochromic biodegradable polymer produced using additive manufacturing. The purpose of this research is to fabricate halochromic polylactic acid (PLA) filaments and assess its halochromic behaviour, mechanical and chemical properties of the 3D printed PLA specimens. PLA/polyethylene glycol (PEG)/bromocresol purple (BCP) compound was prepared and added in extrusion to produce a 3D printing filament. Dumbbell-shaped and rectangular specimens were fabricated from the filament through 3D printing. The halochromic responsiveness and colour reversibility were tested by exposing the samples to liquid and vaporized hydrochloric acid (strong acid), acetic acid (weak acid) and ammonia (strong alkali). The tensile properties, fracture surface morphology and chemical species of the specimens were tested and analyzed through tensile test, scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy. The halochromic responsiveness shows obvious colour changes from yellow to blue when exposed to strong alkali. The tensile strength and modulus were found to be higher in comparison to plasticized PLA but the elongation at break was lower. SEM morphology show brittle fracture characteristics in the printed specimens. Overall, the 3D printed halochromic PLA specimens show promising results and have proven their functionality as pH sensors which offers wide applications in many industries such as medical, environmental and packaging.

Preparation, analysis and toxicity characterisation of the redox metabolites of the azo food dye tartrazine

Tartrazine (E102, FD&C Yellow 5) is a vibrant yellow azo dye added to many processed foods. The safety of this ubiquitous chemical has not been fully elucidated, and it has been linked to allergic reactions and ADHD in some individuals. In our study, bacterial species isolated from human stool decolourised tartrazine and, upon exposure to air, a purple compound formed. Tartrazine is known to undergo reduction in the gut to sulfanilic acid and 4-amino-3-carboxy-5-hydroxy-1-(4-sulfophenyl)pyrazole (SCAP). These metabolites and their derivatives are relevant to the toxicology of tartrazine. The toxicity of sulfanilic acid has been studied before, but the oxidative instability of SCAP has previously prevented full characterisation. We have verified the chemical identity of SCAP and confirmed that the purple-coloured oxidation derivative is 4-(3-carboxy-5-hydroxy-1-(4-sulfophenyl)-1H-pyrazol-4-yl)imino-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid (purpurazoic acid, PPA), as proposed by Westöö in 1965. A yellow derivative of SCAP is proposed to be the hydrolysed oxidation product, 4,5-dioxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid. SCAP and PPA are moderately toxic to human cells (IC50 89 and 78 μM against HEK-293, respectively), but had no apparent effect on Escherichia coli and Bacillus subtilis bacteria. These results prompt further analyses of the toxicology of tartrazine and its derivatives.

PENGARUH JAHE TERHADAP AKTIVITAS ANTIOKSIDAN DAN SIFAT ORGANOLEPTIK MINUMAN EKSTRAK JAGUNG UNGU (Zea mays L.)

One of the cultivable food crops, corn also serves a strategic purpose and has economic worth. Corn, as the primary source of carbs, is utilized as a rice alternative. Beverage goods are one alternative that can be made from corn. Anthocyanins found in purple corn work as antioxidants to stop atherosclerosis in the body. One sort of spice that offers numerous health advantages is ginger. Antioxidants are substances that can limit oxidation reactions by attaching to free radicals and highly reactive molecules. Antioxidants in food can minimize food spoiling processes, free radical oxidation, slow down the oxidation of lipids and oils, increase shelf life in the food sector, increase the storage of fat contained in food and prevent sensor and nutritional quality degradation. This study used the DPPH method (1,1-diphenyl-2,-picrylhydrazyl) which is a purple compound that will turn yellow when reacted with antioxidant activity and used a completely randomized design (CRD) method in the form of a single factor ratio of corn: ginger extract ( 100 g : 2 g, 3 g, 4 g, and 5 g) using 5 treatments and 3 replications. The organoleptic test used is the hedonic test, namely the level of preference test for the taste, texture, color, color of the purple corn extract drink. The score used is 1 – 5 (very dislike, dislike, somewhat like, like, and like very much). The data obtained were then analyzed and processed using SPSS with one way ANOVA. The purpose of this study was to determine the antioxidant activity and the panelists' preference level of purple corn extract drink.

Technological exploration and antioxidant activity determination of purple compound fruit wine

When it comes to processing, purple pepper and purple corn are poorly utilised even though they are rich in anthocyanins and other nutrients. Therefore, studies focusing on their processing are vital for resolving their underutilisation. In the present work, purple pepper and corn were used to prepare a compound fruit wine. The fermentation process parameters were optimised using single factor tests and response surface design. The sensory characteristics of the compound fruit wine were used as an indicator. The antioxidant potential of the purple compound fruit wine was also assessed using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) and hydroxyl radical (·OH) scavenging rates. A purple compound fruit wine with a sensory score of 94.2 and 8.6% alcohol by volume was obtained using a combination of 72.0% purple pepper juice and 28.0% purple corn juice (with an initial sugar content of 23.3%), followed by inoculation with 6.2% Saccharomyces cerevisiae and fermentation for 7.8 d at 23°C. The resulting purple compound fruit wine had a typical harmonious fruit aroma and a mellow taste. Furthermore, the content of anthocyanins in purple compound fruit wine was 1.38 ± 0.14 mg/mL, and the half inhibitory concentration (IC50) values against DPPH· and ·OH were 51.31 and 49.08 mg/mL, respectively. This optimised fermentation process could serve as a theoretical basis for the industrial utilisation of purple pepper and corn.

Histocompatibility of Light-Curing Composites Used in Pediatric Dentistry in Human Oral Fibroblast Cells.

Tooth-colored composites are used to repair caries lesions and other dental defects, particularly in anterior regions in children. Although a wide range of composites is using, little attention has been paid to the important indicators such as biological profiles or products released from these materials. The current study aimed to compare the histocompatibility and cytotoxicity of light-curing resin used to repair children's teeth with different brands (3M, DenFil, and Opallis) in curing times of 20 and 40 seconds in human oral fibroblast cells (HGF1). In this in vitro study, Three types of flow composites (3M, Opallis, and DenFil), all at A2 shade, were used. The composites were at 4×2mm with separate exposure times of 20 and 40 seconds. MTT test was used to determine the cytotoxicity of composites on oral fibroblast cells. This test is based on the conversion of tetrazolium bromide to a purple compound known as formazan that its color intensity can be evaluated using the ELISA. The higher intensity of the color reveals the higher survival rate of the mitochondria, which indicates less toxicity. One-way variance analysis and unpaired t-test were used to compare the cytotoxicity of each brand in two conditions of 20 and 40 seconds of curing. Statistical significance was considered when p< 0.05. 3M and Opallis composites were significantly reduced vitality of cells compared to control group in both 20s and 40s curing status. While DenFil brand did not show marked cytotoxicity. In each brand, there are no significant deference between 20s and 40s curing times. Histocompatibility depends on the type of composite resin. In the current study, DenFil brand showed the highest histocompatibility, followed by 3M and Opallis.

Fabrication of halochromic polylactic acid filament for 3D Printing

With increasing concerns regarding plastic waste and pollution, researchers have been looking to develop advanced materials from biodegradable plastics. This study features the additive manufacturing of halochromic polylactic acid (PLA) filaments and the testing of halochromic properties of the specimens. PLA/polyethylene glycol (PEG)/bromocresol purple (BCP) compound was extruded and wound to produce a 3D printing filament. The halochromic responsiveness and colour reversibility were tested by exposing the samples to liquid and vaporized pH solutions for 30 min and then placing them back into ambient conditions for 48 h. The compatibility of PLA, PEG and BCP were found to be good, and the halochromic compound formed was homogenous. Dumbbell-shaped and rectangular specimens were successfully fabricated from the compound through 3D printing. Overall, the 3D printed halochromic PLA specimens show promising results and have proven their functionality as pH sensors which offers wide applications in many industries such as medical, environmental and packaging.

Characterization of Anti-Cancer Activities of Violacein: Actions on Tumor Cells and the Tumor Microenvironment.

Natural products have been shown to serve as promising starting points for novel anti-cancer drugs. In this study, the anti-cancer activities of the purple compound violacein, initially isolated from Chromobacterium violaceum, were investigated. To highlight the crucial role of the tumor microenvironment on the effectiveness of cancer therapies, this study includes effects on macrophages as prototypic cells of the microenvironment in addition to the investigation of tumor-centric activities. Using 2D and 3D cell culture models, automated live-cell microscopy, and biochemical analyses, violacein was demonstrated to inhibit tumor cell proliferation and migration. The violacein-triggered tumor cell death was further associated with caspase 3-like activation and ATP release. Stimuli released from dead cells resulted in inflammatory activation of macrophages, as shown by NF-κB reporter cell assays, macrophage morphology, and gene expression analysis. Moreover, macrophages deficient in the inflammasome component Nlrp3 were found to be significantly less sensitive towards treatment with violacein and doxorubicin. Taken together, this study provides new insights into the biological activity of violacein against cancer. In addition, the in vitro data suggest immunogenic features of induced cell death, making violacein an interesting candidate for further studies investigating the compound as an inducer of immunogenic cell death.

A reliable fluorescent and colorimetric dual-readout assay for Ag+ tracing

Silver ion pollution is a great threat to global environment and public healthcare today. Thus, quick, portable and sensitive assays for Ag+ tracing are highly needed. Herein, a reliable fluorescent and colorimetric dual-channel assay has been constructed for Ag+ detection by utilizing a terbium-based fluorescent nanomaterial (named as Tb-DPA) and a Pt/Pd nanoflower (Pt/Pd NF)-triggered reaction between N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt (TOPS) and 4-amino-antipyrine (4-AAP). Initially, in the sensing system containing 4-AAP, TOPS, Tb-DPA and Pt/Pd NF, TOPS and 4-AAP is catalyzed by Pt/Pd NF to produce a purple compound (called as PC1), which endows a broad UV absorption that can fully cover the emission band of Tb-DPA. Thus, the system exhibits a high UV absorption (originating from PC1) and a low fluorescence intensity (originating from Tb-DPA) which has been quenched by PC1 through a filtering effect. However, when the system meets Ag+, the oxidase-like activity of Pt/Pd NF will be inhibited, leading less amount of PC1. As a result, the system exhibits a decreased UV absorption and a recovered fluorescence intensity, both of which can be used for Ag+ detection, reporting low detection limits of 3.63 nM and 1.63 nM, respectively. Specially, results from the dual-channel assay can mutually validate each other, improving the detection reliability. Moreover, this dual-mode assay shows good capability toward Ag+ detection in real samples, illustrating the potential for practical applications.

Sintesis antigen AFB1-BSA dan konjugasi antibodi anti AFB1-BSA dengan nanopartikel emas sebagai pereaksi imunostrip

Aflatoksin B1 (AFB1) often contaminates a great variety of foods and animal feeds that will be dangerous if con-sumed by humans or animals. Rapid detection techniques that can be used in the field is really needed to monitor AFB1 contamination. The aims of this study were to perform synthesis of AFB1-BSA antigen and conjugation of antibody against AFB1-BSA to gold nanoparticle as immunostrip-test reagents. The AFB1-CMO was identified on TLC and AFB1-BSA was characterized using SDS PAGE. The AFB1-CMO formation indicated as a blue spot at 0.45 retention factor (Rf) on TLC and the AFB1-BSA antigen revealed as a single band protein at about 72 kDa molecular weight on the SDS PAGE. Conjugation of antibody against AFB1-BSA to gold nanoparticle resulted in the formation of red-dish purple compound which can be used for the detection of AFB1 on immunostrip. The optimum composition achieved in concentration of AFB1-BSA 1-1.5 mg/ml, IgG anti rabbit 0.1 mg/ml, and antibody against AFB1-BSA-gold nanoparticle conjugate in 0.5x0.5 cm² area characterized by the establishment of two reddish purple lines in the test and control zone.

Fabrication of Zinc Protoporphyrin-Modified Gold Electrode for Sensitive and Fast Detection of Vascular Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) is directly related to cancer growth and its distant spread, and thus, it is considered a promising biomarker for diagnosis and post-treatment monitoring of patients with malignancies. Zinc protoporphyrin (ZnPP) is a zinc-centered raw purple compound (protoporphyrin) that has unique optical and electrochemical characteristics. In this study, we used a ZnPP-modified gold electrode to generate a chemical bond with Avastin by self-assembly and fabricate a Au/ZnPP/Avastin electrode. Bovine serum protein (BSA) was added to the electrode to prevent non-specific linkage with biomolecules. The prepared Au/ZnPP/Avastin/BSA electrodes were used for the detection of VEGF by cyclic voltammetry and amperometry. The optical properties of ZnPP were analyzed with an ultraviolet/visible/near-infrared spectrometer and a photoluminescence spectrometer. The structural and hydrophilic/hydrophobic properties of the ZnPP-modified gold electrodes were investigated by Fourier-transform infrared spectroscopy and contact angle gauge, respectively. VEGF was detected with the Au/ZnPP/Avastin/BSA electrodes prepared either with (w/LT) or without light treatment (w/o LT). The w/LT electrode showed a linear range and a sensitivity of 0.1 pg/mL–10 ng/mL and 6.52 μA/log(pg/mL)-cm2, respectively; the corresponding values for the w/o LT electrode were 10 pg/mL–10 ng/mL and 3.15 μA/log(pg/mL)-cm2, respectively. The w/LT electrode had good specificity for VEGF and was minimally influenced by other molecules. The excellent detection range, high sensitivity, and high selectivity for VEGF detection indicate that Au/ZnPP/Avastin electrodes have great potential for diagnostic and prognostic applications in patients with malignancies.

A specific antioxidant peptide: Its properties in controlling oxidation and possible action mechanism

Marine byproducts have become popular research themes due to their biological significance. The black sharkskin protein hydrolysate-based antioxidant peptides were firstly investigated in this study. The black sharkskin-derived novel antioxidant peptide demonstrating 81.05% free radical scavenging activity to ABTS at 500 μg/mL, was identified to be Ala-Thr-Val-Tyr (ATVY). The crucially antioxidant interaction site of ATVY action on ABTS was determined to be Tyr in the N-terminal. ATVY reacted with ABTS to generate polyphenol-derived adducts which subsequently degraded into a purple compound. The MS/MS showed it was formed by covalently bonding through the phenol group of ATVY to the N group of ABTS. The free radical scavenging kinetics of ATVY on ABTS demonstrated a two-phase reaction process. These findings reveal the action mechanism of ATVY on ABTS, implying ATVY can be incorporated in the production of antioxidant food additives.

Formation Reactivity of Ruhemann’s Purple Compound and Their Metal Ion Complexes as Dual Latent Fingerprint Reagent, and DNA Molecule Protection Potential

Formation Reactivity of Ruhemann’s Purple Compound and Their Metal Ion Complexes as Dual Latent Fingerprint Reagent, and DNA Molecule Protection Potential

Characterization of a new gel based on alanine–ninhydrin for possible use in radiation dosimetry

Ninhydrin reacts with alanine forming a Ruhemann’s purple (RP) compound. RP and chloral hydrate (CH) were introduced into gelatin to form a tissue equivalent RP gel for radiation dose measurements, 5–450 Gy. The gel color fades proportionally with the absorbed dose. Addition of CH to the gel improved its radiation sensitivity and fading. RP was analyzed by FTIR spectrometer and the gel by UV–Vis spectrophotometer at 404 and 572 nm. Dose–response is nearly temperature independent from 22 to 30 °C but it is a time dependent after irradiation. Uncertainty (2σ) in dose estimation is less than 6.0%.

A versatile and greener multicommuted flow-based system for exploiting relatively slow chemical reactions

A multi-commuted flow system was designed for implementing spectrophotometric methods based on relatively slow chemical reaction. It comprised six-way solenoid valves with reaction coils coupled to each port, which provided long sample zone residence times in the analytical path yet maintaining the sampling rate. Potentialities of the system were demonstrated by selecting the reaction of iodate (IO3−) with p-aminophenol (PAP) in acidic medium, which yielded a purple compound with absorption maximum at 540nm. Although more than 40min were needed for reaching chemical equilibrium, sampling rate of the proposed flow system was 70h−1. The innovation was applied to iodate determination in table-salts, and favorable features such as a linear response from 2.28×10−5 to 3.65×10−4mol L−1 iodate, a detection limit (99.7% confidence level) of 8.2×10−6mol L−1, and a coefficient of variation (n=20; IO3−=1.37×10−4mol L−1) of 0.42% were attained. Furthermore, pronounced lessening in reagent consumption and effluent generation, estimated at 1.05mg PAP and 0.7mL of waste per determination. The results agreed with those obtained by a titrimetric procedure at 95% confidence level.

Biodecoloration of Reactive Black 5 by the methylotrophic yeast Candida boidinii MM 4035

Azo dyes are extensively used in textile dyeing and other industries. Effluents of dying industries are specially colored and could cause severe damage to the environment. The anaerobic treatment of textile dying effluents is nowadays the preferred option, but it could generate carcinogenic aromatic amines. Recently, yeasts have become a promising alternative, combining unicellular growth with oxidative mechanisms. This work reports the characterization of the first methylotrophic yeast with dye decolorizing ability, Candida boidinii MM 4035 and some insights into its decoloration mechanism. The analysis of two selected media revealed a possible two stages mechanism of Reactive Black 5 decoloration. In glucose poor media, decoloration is incomplete and only the first stage proceeds, leading to the accumulation of a purple compound. In media with higher glucose concentrations, the yeast is able to decolorize totally an initial concentration of 200mg/L. The entire process is co-metabolic, being largely dependent on glucose concentration but being able to proceed with several nitrogen sources. Manganese dependent peroxidase but not laccase activity could be detected during decoloration. Aromatic amines do not accumulate in culture media, supporting an oxidative decoloration mechanism of unknown ecophysiological relevance.

Structural, spectroscopic and theoretical studies of a diruthenium(II,II) tetraformamidinate that reversibly binds dioxygen

The reaction of Ru2(O2CMe)4 with N,N′-bis(3,5-dimethoxyphenyl)formamidine (Hdmof) in refluxing toluene solutions yields Ru2(dmof)4 as a diamagnetic red solid that is extremely air-sensitive. The crystal structure reveals the expected paddlewheel arrangement of ligands around the Ru24+ core, with a relatively long Ru–Ru bond (2.4999(8)Å) that is consistent with a σ2π4δ2π∗4 electronic configuration. This is supported DFT calculations that show this electronic structure results from destabilization of the δ∗ orbital due to antibonding interactions with the formamidinate ligands. The cyclic voltammogram of Ru2(dmof)4 in a 0.1M nBu4NPF6/CH2Cl2 solution shows two redox processes, assigned as successive oxidations corresponding to the Ru24+/5+ and Ru25+/6 redox couples. Changes in the electronic absorption spectra associated with these oxidation processes were probed using a UV–Vis spectroelectrochemical study. Ru2(dmof)4 reacts with dioxygen in solution to generate a purple compound that decomposes within an hour at room temperature. Bubbling N2 gas through the purple solution regenerates Ru2(dmof)4, as evidenced by UV–Vis spectrometry and cyclic voltammetry, suggesting that the dioxygen reversibly binds to the diruthenium core.

Formulation and Quality Control of Readily Dissolving Drink Powder from Antidesma ghaesembilla Fruits

Antidesma ghaesembilla Gaertn, known as in Thai, is a plant with edible purple compound fruits. This experiment was conducted to investigate the 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activities of extracts from the fruits of mamao prepared by different methods of extraction and drying, and to quantitatively analyze the total phenolic content and the total anthocy- anin content. Decoction and drying by evaporating the extract of mamao ripe fruits promoted the extract with the strongest free radical scavenging activity (IC 50 = 72.42 ± 3.52 µg/ml), with high amounts of total phenolic content and total anthocyanin content of 1.22 ± 0.36 g gallic acid equivalent in 100 g extract (g%GAE) and 7.09 ± 0.24 g cyanidin-3-glucoside equivalent in 100 g extract (g%C-3-GE), respectively. This extract was developed as a readily dissolving drink powder by a wet granulation method and qualitatively controlled by evaluations of loss on drying, thin layer chromatographic (TLC) and infrared spectroscopic (IR) fingerprints. The obtained product was observed to be a pinkish-red pow - der that contained 3.08 ± 0.81 g%C-3-GE in 1 sachet (14 g) and exhibited free radical scavenging activity equivalent to 0.004 g of vitamin C.

Determination of Thiocyanate in Desulfurization Waste Solution by Spectrophotometry

Affects of thiosulfate (S2O32-) and sulfate (SO42-) on determination of thiocyanate (SCN-) in desulfurization waste solution (DWS) by spectrophotometry were investigated. The experiment results suggested that S2O32-and Fe3+ generated purple compound [Fe(S2O3)2]-which has a strong absorption at 450nm, but the purple soon fades in this process. As long as the reacting time is longer than 120s, the impact of S2O32-can be eliminated. In addition, sulfate has no effect. At 450nm wavelength, linear relationship between concentration of SCN-and absorbance was C=19.7272A-0.2774, which conformed to the Beer Law in the range of 2.00 ~ 19.45μg•ml-1, the correlation coefficients was 0.9996. The Fe3+-SCN-spectrophotometric method of monitoring SCN- in desulfurization waste solution was feasible.

Porphyrias: implications for anaesthesia, critical care, and pain medicine

The porphyrias are a heterogeneous group of inherited disorders of haem biosynthesis. The name porphyria is derived from the Greek word for purple, ‘porphyros’. This was the name given to the purple compound formed when blood was treated with concentrated sulphuric acid; the disease was probably named porphyria due to the red discolouration of urine in affected patients. Multiple classification systems exist; the most relevant to anaesthetists is acute and nonacute (Table 1). All acute porphyrias have the potential to develop acute neurovisceral crises. Precipitating factors are commonly encountered in the perioperative period; therefore, anaesthetists must be aware of the triggers and the management of an acute crisis. Non-acute porphyrias do not deteriorate into acute crises, are less relevant for anaesthetists, and will not be mentioned further in this article.

The co-ordination chemistry of tris(3,5-dimethylpyrazolyl)methane manganese carbonyl complexes: Synthetic, electrochemical and DFT studies

The tricarbonyl [Mn(CO)(3){HC(pz')(3)}][PF(6)] 1(+)[PF(6)](-) (pz' = 3,5-dimethylpyrazolyl) reacts with a range of P-, N- and C-donor ligands, L, in the presence of trimethylamine oxide to give [Mn(CO)(2)L{HC(pz')(3)}](+) {L = PEt(3)3(+), P(OEt)(3)4(+), P(OCH(2))(3)CEt 5(+), py 6(+), MeCN 7(+), CNBu(t)8(+) and CNXyl 9(+)}. The complex [Mn(CO)(2)(PMe(3)){HC(pz')(3)}](+)2(+) is formed by reaction of 7(+) with PMe(3). Complexes 2(+) and 6(+) were structurally characterised by X-ray diffraction methods. Reaction of 7(+) with half a molar equivalent of 4,4'-bipyridine gives a purple compound assumed to be the bridged dimer [{HC(pz')(3)}Mn(CO)(2)(μ-4,4'-bipy)Mn(CO)(2){HC(pz')(3)}](2+)10(2+). The relative electron donating ability of HC(pz')(3) has been established by comparison with the cyclopentadienyl and tris(pyrazolyl)borate analogues. Cyclic voltammetry shows that each of the complexes undergoes an irreversible oxidation. The correlation between the average carbonyl stretching frequency and the oxidation potential for complexes of P- and C-donor ligands is coincident with the correlation observed for [Mn(CO)(3-m)L(m)(η-C(5)H(5-n)Me(n))]. The data for complexes of N-donor ligands, however, are not coincident due to the presence of a node (and phase change) between the metal and the N-donor in the HOMO of the complex as suggested by preliminary DFT calculations.