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Riboflavin (RF) is one of the necessary vitamins. If human body lacks RF, it will lead to inflammation and dysfunction of mouth, lips and skin. Thus sensitive and accurate determination of RF is necessary. Here, an electroactive covalent-organic framework nanobelt (COFTFPB-Thi) with thickness of 1.4 nm was prepared by amine-aldehyde condensation reaction between thionine and 1, 3, 5-tris (p-formylphenyl) benzene, which was then grown vertically on three-dimensional porous carbon derived from kenaf stem (3D-KSC) for double signal ratiometric electrochemical detection of RF. The resulted 3D-KSC/COFTFPB-Thi showed two reduction peaks at −0.08 V and −0.23 V, which came from the reduction of COFTFPB-Thi and the conjugated structure of COFTFPB-Thi, respectively. In the presence of RF, those RF molecules near the electrode surface were oxidized at 0.6 V. Then some oxidized RF (RFox) adsorbed on COFTFPB-Thi would oxidize COFTFPB-Thi into COFTFPB-Thi(ox) while other RFox adsorbed on 3D-KSC kept unchanged. When the potential was scanned from 0.6 V to −0.6 V, both COFTFPB-Thi(ox) and RFox adsorbed on 3D-KSC were reduced at −0.08 V and −0.45 V accordingly, while the reduction peak of −0.23 V of the conjugated structure of COFTFPB-Thi kept constant. When j-0.45/j-0.23 was used as the response signal, the detection limit was 44 nM and the linear range was 0.13 μM −0.23 mM. By using j-0.08/j-0.23 as the response signal, a detection limit of 90 nM and a linear range of 0.30 μM-0.23 mM (S/N = 3) were obtained. By using double signals, the measurement results can be corrected to make the results more accurate and reliable. The sensor also showed good selectivity, reproducibility and stability, which provided a good application prospects.

Ire1 is an endoplasmic reticulum (ER) transmembrane RNase that cleaves substrate mRNAs to help cells adapt to ER stress. Because there are cell types with physiological ER stress, loss of Ire1 results in metabolic and developmental defects in diverse organisms. In Drosophila, Ire1 mutants show developmental defects at early larval stages and in pupal eye photoreceptor differentiation. These Drosophila studies relied on a single Ire1 loss of function allele with a Piggybac insertion in the coding sequence. Here, we report that an Ire1 allele with a specific impairment in the RNase domain, H890A, unmasks previously unrecognized Ire1 phenotypes in Drosophila eye pigmentation. Specifically, we found that the adult eye pigmentation is altered, and the pigment granules are compromised in Ire1(H890A) homozygous mosaic eyes. Furthermore, the Ire1(H890A) mutant eyes had dramatically reduced Rhodopsin-1 protein levels. Drosophila eye pigment granules are most notably associated with late endosome/lysosomal defects. Our results indicate that the loss of Ire1, which would impair ER homeostasis, also results in altered adult eye pigmentation.

P-glycoprotein, member of the B-subfamily of the ATP-binding cassette (ABC) superfamily (e.g., ABCB1), has been demonstrated to confer resistance to clinically relevant anticancer drugs. Paradoxically, ABCB1-expressing multidrug resistant (MDR) cells are hypersensitivity or collateral sensitivity to non-toxic drugs. In this report, we demonstrate the capacity of trifluoperazine (TFP), a calmodulin inhibitor, to confer a collateral sensitivity onto ABCB1-overexpressing MDR cells. We show TFP-induced collateral sensitivity to be linked to ABCB1 expression and ATPase activity, as such phenotype is abolished in ABCB1-knockout MDR cells (CHORC5ΔABCB1 clones A1-A3) or with inhibitors of ABCB1 ATPase. TFP-induced collateral sensitivity is mediated by apoptotic cell death, due to enhanced oxidative stress. The findings in this study show for first time the use TFP as a collateral sensitivity drug, at clinically relevant concentrations. Moreover, given the use of trifluoperazine in the treatment for symptoms of schizophrenia and the role of ABCB1 transporter in tissue blood barriers and other physiologic functions, the finding in this study may have implications beyond cancer chemotherapy.

The order Odonata (dragonflies and damselflies) comprises diurnal insects with well-developed vision, showing diverse colors in adult wings and bodies. It is one of the most ancestral winged insect groups. Because Odonata species use visual cues to recognize each other, color patterns have been investigated from ecological and evolutionary viewpoints. Here we review the recent progress on molecular mechanisms of pigmentation, especially focused on light-blue coloration. Results from histology and pigment analysis showed that ommochrome pigments on the proximal layer and pteridine pigments on the distal layer of the epidermis are essential for light-blue coloration. We also summarize genes involved in the biosynthesis of three major insect pigments conserved across insects and discuss that gene-functional analysis deserves future studies.

Organic materials with Mechanofluorochromism (MFC) properties have potential application value. Phenothiazine derivatives are a class of substances with MFC properties that have been synthesized and reported in experiments (Dyes and Pigments 172 (2020) 107835). Dual fluorescence of a series of phenothiazine derivatives is observed in the experiment, which proved that the ESIPT process is carried out. In this work, we choose phenothiazine derivatives (C2PAHN, C4PAHN, C8PAHN) as models to theoretically analyze the influence of different alkyl chain lengths on the excited state intramolecular proton transfer (ESIPT). In addition, the shift value of fluorescence spectrum is related to the length of alkyl chain. The fluorescence shift of C2PAHN is the largest (6.31 nm), and that of C8PAHN is the smallest (2.40 nm). The theory of density functional theory (DFT) and time-dependent density functional theory (TD-DFT) are adopted to simulate the molecular dynamics in the ground state and excited state. The analysis of the optimized molecular geometry parameters and infrared vibrational spectroscopy (IR) illustrate the stronger hydrogen bonding of the excited state molecules, which is favorable for the progress of ESIPT. Fluorescence spectroscopy reveals that the appropriate increase or decrease of alkyl chains would change the photophysical properties of the molecules. Frontier molecular orbitals (FMOs) indicate that the rearrangement of electron density from electronic level to is the driving force of the ESIPT process. Reduction density gradient (RDG) surfaces and Natural Population Analysis (NPA) tentatively lead to the conclusion that alkyl chain length is inversely proportional to hydrogen bond strength. Finally, the data are qualitatively analyzed by scanning the potential energy curves, and it is concluded that the longer the alkyl chain, the weaker the hydrogen bonding effect and the more unfavorable the ESIPT process.

Dysfunctional reactive oxygen species (ROS) signaling is considered an important disease mechanism. Therapeutically, non-selective scavenging of ROS by antioxidants, however, has failed in multiple clinical trials to provide patient benefit. Instead, pharmacological modulation of disease-relevant, enzymatic sources of ROS appears to be an alternative, more promising and meanwhile successfully validated approach. With respect to targets, the family of NADPH oxidases (NOX) stands out as main and dedicated ROS sources. Validation of the different NOX isoforms has been mainly through genetically modified rodent models and is lagging behind in other species. It is unclear whether the different NOX isoforms are sufficiently distinct to allow selective pharmacological modulation. Here we show for five widely used NOX inhibitors that isoform selectivity can be achieved, although individual compound specificity is as yet insufficient. NOX1 was most potently (IC50) targeted by ML171 (0.1 mu M); NOX2, by VAS2870 (0.7 mu M); NOX4, by M13 (0.01 mu M) and NOX5, by ML090 (0.01 mu M). In addition, some non-specific antioxidant and assay artefacts may limit the interpretation of data, which included, surprisingly, the clinically advanced NOX inhibitor, GKT136901. In a human ischemic blood-brain barrier hyperpermeability model where genetic target validation is not an option, we provide proof-of-principle that pharmacological target validation for different NOX isoforms is possible by applying an inhibitor panel at IC50 concentrations. Moreover, our findings encourage further lead optimization and development efforts for isoform-selective NOX inhibitors in different indications.

Aim Diode lasers are commonly used for antimicrobial photodynamic therapy (aPDT). This study aimed to assess the feasibility of transgingival laser irradiation during aPDT and evaluate whether the photosensitizer can be activated. Materials and Methods Four diode laser settings were assessed for transgingival irradiation: 120 mW, 80 mW, 60 mW, and 40 mW. Fifteen soft-tissue pieces from a pig’s lower jaw were prepared. The specimens’ thickness was measured and transgingival laser irradiation was performed. A digital power meter measured laser power on the other side of the tissue. The power outcome after staining of the nonbuccal aspect of the tissue with photosensitizer dye was assessed similarly. Results Transgingival laser irradiation (average soft-tissue thickness: 0.84 ± 0.06 mm) resulted in different power transmission depending on the power settings and photosensitizer. The lowest values were observed with the 40 mW setting and photosensitizer (median 3.3 mW, max. 5.0 mW, min. 2.3 mW, interquartile range 1.2), and the highest at 120 mW without photosensitizer (median 41.3 mW, max. 42.7 mW, min. 38.0 mW; interquartile range 1.5). Conclusions This study indicates that transgingival irradiation may be suitable for aPDT, since power transmission through the gingival tissue was observed in all specimens. However, the decrease in laser power caused by both the soft tissue and the photosensitizer has to be taken into account.

In this work, a multiplexed electrochemical aptasensor based on mixed valence Ce-MOF was constructed for the simultaneous determination of malathion and chlorpyrifos. Firstly, Ce(III, IV)-MOF materials with many catalytic sites were synthesized and characterized by SEM, TEM, XPS, FT-IR, XRD, and UV-Vis. Then, the chlorpyrifos and malathion signal markers based on Ce(III, IV)-MOF were prepared using thionine (Thi) and ferrocene (Fc) used as the electrochemical probe. The electrochemical signal was amplified by the reduction of thionine catalyzed by the spontaneous cycle of Ce(III, IV) in Ce(III, IV)-MOF skeleton and the reduction of ferrocene catalyzed by ascorbic acid (AA) in solution. The detection of the two targets did not interfere with each other, and the quantitative detection was realized with high sensitivity. The detection range of chlorpyrifos and malathion were 1.0 μM ∼ 0.1 pM, and the detection limits of chlorpyrifos and malathion were 0.038 and 0.045 pM (S/N = 3), respectively. The sensor provided a new idea for the simultaneous determination of multi-component and had a high application prospect in the field of food safety in the future.

Fluorescence probes, as analytical tools with the ability to perform rapid and sensitive detection of target analytes, have made outstanding contributions to environmental analysis and bioassays. Considering the expanding developments in these areas, fluorophores play a key role in the de-sign of fluorescence probes. Compared to classical fluorophores, phenothiazines with elec-tron-rich characteristics have been widely applied to construct electron donor-acceptor dyes, which exhibit outstanding performance in both fluorimetric and colorimetric analysis. In addition, these probes also exhibit the pronounced ability in both solution and solid-state, achieving portable detection for environmental analysis. In this review, we summarize recent advances in the performance of phenothiazine-based fluorescent probes for detecting various analytes, especially in cations, anions, ROS/RSS, enzyme and other small molecules. The general design rules, response mechanisms and practical applications of the probes are analyzed, followed by a discussion of exiting challenges and future research perspectives. It is hoped that this review will provide a few strategies for the development of phenothiazine-based fluorescent probes.

Background: The emergence of multiple-antibiotic-resistant (MAR) Salmonella has been a serious threat worldwide. Salmonella can invade into host cells and evade the attacks of host humoral defenses and antibiotics. Thus, a new antibacterial agent capable of inhibiting intracellular Salmonella is highly needed. Methods: The anti-intracellular activity and cytotoxicity of drugs on intracellular bacteria and macrophages were assayed using intracellular CFU assay and MTT cell viability assay, respectively. The uptake of gentamicin into macrophage and the effect of autophagy inhibitor on loxapine's anti-intracellular Salmonella activity were assessed by using image-based high-content system. The expression of bacterial genes was measured by real-time PCR. The efflux pump activity of bacteria was measured by Hoechst accumulation assays. Results: With our efforts, an antipsychotic drug, loxapine, was identified to exhibit high potency in suppressing intracellular MAR S. Typhimurium, Staphylococcus aureus, Shigella flexneri or Yersinia enterocolitica. Subsequent investigations indicated that loxapine's anti-intracellular bacteria activity was not associated with increased penetration of gentamicin into bacteria and macrophages. Loxapine didn't inhibit bacterial growth in broth at concentration up to 500 μM and has no effect on Salmonella's type III secretion system genes' expression. Blockage of autophagy also didn't reverse loxapine's anti-intracellular activity. Lastly, loxapine suppressed bacterial efflux pump activity in all bacteria tested. Conclusion: Altogether, our data suggested that loxapine might suppress intracellular bacteria through inhibiting of bacterial efflux pumps. In light of its unique activity, loxapine represents a promising lead compound with translational potential for the development of a new antibacterial agent against intracellular bacteria. Keywords: Phenothiazine, Autophagy, Efflux pump, Type III secretion system, High-content assay

A paper-based electrochemical immunosensor was developed for the detection of cancer antigen 125 (CA125) by screen-printing technique. The reduced graphene oxide/thionine/gold nanoparticles (rGO/Thi/AuNPs) nanocomposites were compounded and coated onto the working electrode of immunosensor for CA125 antibody (anti-CA125) immobilization and detection signal amplification. The detection principle was based on the fact that the immunocomplex formed by specify binding of CA125 antibody and antigen could reduce the current response of thionine, which was proportional to the corresponding concentration of CA125 antigen. The immunoassay results showed that the linear range of CA125 was from 0.1 U mL-1 to 200 U mL-1 with the limit of detection (LOD) of 0.01 U mL-1 at signal to noise of 3. Quality control serum samples measured by our proposed immunosensor showed acceptable agreement with traditional ELISA method with the relative error less than 8.05%. The immunosensor exhibited good electrochemical performance with high reproducibility, reliability, stability and accuracy. The proposed immunosensor could be used for the determination of CA125 and had the potential for point-of-care testing (POCT) of other tumor marker.

The objective of the current study is to synthesize a library consisting of four sets of phenothiazine incorporated 1,2,3-triazole compounds using molecular hybridization approach. In total, 36 new hybrid molecules were synthesized and screened for in vitro growth inhibition activity against Mycobacterium tuberculosis H37Rv strain (ATCC-27294). Among the tested compounds, nineteen compounds exhibited significant activity with MIC value 1.6 μg/mL, which is twofold higher than the MIC value of standard first-line TB drug Pyrazinamide. In addition, all these compounds are proved to be non-toxic (with selective index > 40) against VERO cell lines. However, these compounds did not inhibit significantly the growth of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa strains: the activity profile is similar to that observed for standard anti-TB drugs (isoniazid and pyrazinamide), indicating the specificity of these compounds towards the Mycobacterium tuberculosis strain. Also, we report the molecular docking studies against two target enzymes (Inh A and CYP121) to further validate the antitubercular potency of these molecules. Furthermore, prediction of in silico-ADME and pharmacokinetic parameters indicated that these compounds have good oral bioavailability. The results suggest that these phenothiazine incorporated 1,2,3-triazole compounds are a promising class of molecular entities for the development of new antitubercular leads.

Fusarium keratoplasticum and Fusarium moniliforme are filamentous fungi common in the environment and cause mycosis in both animals and plants. Human infections include mycetoma, keratitis and onychomycosis, while deeper mycosis occurs in immunocompromised patients. Most of the Fusarium spp. are frequently resistant to treatment with currently used antifungals. The frequent occurrence of antifungal resistance has motivated the study of antimicrobial photodynamic therapy as an alternative treatment for fungal infections. Many studies have investigated the in vitro use of antimicrobial photodynamic therapy to kill fungi, but rarely in animal models of infection. Thus, here we employed the invertebrate wax moth Galleria mellonella to study the in vivo effects of antimicrobial photodynamic therapy with three different phenothiazinium photosensitizers, methylene blue, new methylene blue N and the pentacyclic S137 against infection with microconidia of Fusarium keratoplasticum and Fusarium moniliforme. The effect of antimicrobial photodynamic therapy using these photosensitizers and light-emitting diodes with an emission peak at 635 nm and an integrated irradiance from 570 to 670 nm of 9.8 mW cm-2 was investigated regarding the toxicity, fungal burden, larval survival and cellular immune response. The results from this model indicate that antimicrobial photodynamic therapy with methylene blue, new methylene blue N and S137 is efficient for the treatment of infection with F. keratoplasticum and F. moniliforme. The efficiency can be attributed to the fungal cell damage caused by antimicrobial photodynamic therapy which facilitates the action of the host immune response.

[EN] In this work, a molecular hydrogel made of gelator (S)-4-((3-methyl-1-(nonylamino)-1-oxobutan-2-yl)amino)-4-oxobutanoic acid (SVN) has been employed as soft container to modify the photochemical and photophysical behavior of the antipsychotic drug cyamemazine (CMZ). The interaction of CMZ with the gel network has been evidenced by fluorescence spectroscopy through a hypsochromic shift of the emission band (from lambda(max) = 521 nm in solution to lambda(max) = 511 nm in the gel) and an increase of the fluorescence lifetime (5.6 ns in PBS vs. 7.2 ns in the gel). In the laser flash photolysis experiments on CMZ/SVN systems, the CMZ triplet excited state ((3)CMZ*), monitored at lambda = 320 nm, has been more efficiently generated and became much longer-lived than in solution (2.7 mu s vs. 0.7 mu s); besides, photochemical ionization leading to the radical cation CMZ(+center dot) was disfavored. In the steady-state experiments, photooxidation of CMZ to afford the N,S-dioxide derivative CMZ-SONO has been retarded in the gel, which provides a more lipophilic and constrained microenvironment. Both the photophysical properties and the photoreactivity are in agreement with CMZ located in a less polar domain when entrapped in the supramolecular gel, as result of the interaction of the drug with the fibers of the supramolecular SVN gel., Financial support from the Spanish Government (CTQ2016-78875-P and CTQ2015-71004-R), the Generalitat Valenciana (PROMETEO/2017/075) and the European Union is gratefully acknowledged.

Cancer cells often develop the resistance to pro-apoptotic signaling that makes them invulnerable to conventional treatment. Therapeutic strategies that make cancer cells enter the path of apoptosis are desirable due to the avoidance of inflammatory reaction that usually accompanies necrosis. In the present study phenothiazines (fluphenazine and four recently synthesized derivatives) were investigated in order to identify compounds with a potent anticancer activity. Since phenothiazines are known as multidrug resistance modulators the sensitive human colorectal adenocarcinoma cell line (LoVo) and its doxorubicin-resistant, ABCB1 overexpressing, subline (LoVo/Dx) have been employed as a model system. In studied cancer cells cytotoxic effect of the phenothiazine derivatives was accompanied by apoptosis and autophagy induction as well as by the increase of cellular lipid peroxidation and intracellular reactive oxygen species generation. Molecular modelling revealed that reactivity of phenothazines (manifested by their low energy gap) but not lipophilicity was positively correlated with their anticancer potency, pro-oxidant properties and apoptosis induction ability. Additionally, some of the studied compounds turned out to be more potent cytotoxic and pro-apoptotic agents in doxorubicin-resistant (LoVo/Dx) cells than in sensitive ones (LoVo). The hypothesis was assumed that studied phenothiazine derivatives induced apoptotic cell death by increasing the production of reactive oxygen species.

In this study, a molecularly imprinted polymer based chemiluminescence array capable of simultaneous determining phenothiazines and benzodiazepines was first reported. Two polymers were coated in different wells of the conventional 96-well microtiter plate as the recognition reagents, and the added analytes competed with a horseradish peroxidase-labeled bi-hapten conjugate to bind the recognition reagents. The light signal was induced by using a highly effective luminol-H2O2-IMP system. The assay procedure consisted of only one sample-loading step prior to data acquisition. Then, the array was used to determine 4 phenothiazines and 5 benzodiazepines in pork simultaneously. The limits of detection for the 9 drugs were in a range of 0.001–0.01 ng/mL, and the recoveries from the fortified blank pork were in a range of 63.5%–94.1%. Furthermore, the array could be reused for 8 times. The detection results for some real pork samples were consistent with an ultra performance liquid chromatography method.

Neoscytalidium spp. are ascomycetous fungi consisting of pigmented and hyaline varieties both able to cause skin and nail infection. Their colour-based identification is inaccurate and may compromise the outcome of the studies with these fungi. The aim of this study was to genotype 32 isolates morphologically identified as Neoscytalidium dimidiatum or Neoscytalidium dimidiatum var. hyalinum by multilocus sequence typing (MLST), differentiate the two varieties by their sequence types (STs), evaluate their susceptibility to seven commercial antifungal drugs [amphotericin B (AMB), voriconazole (VOR), terbinafine (TER), 5-flucytosine (5FC), ketoconazole (KET), fluconazole (FLU), and caspofungin (CAS)], and also to the antimicrobial photodynamic treatment (APDT) with the phenothiazinium photosensitizers (PSs) methylene blue (MB), new methylene blue (NMBN), toluidine blue O (TBO), and the pentacyclic derivative S137. The efficacy of each PS was determined, initially, based on its minimal inhibitory concentration (MIC). Additionally, the APDT effects with each PS on the survival of ungerminated and germinated arthroconidia of both varieties were evaluated. Seven loci of Neoscytalidium spp. were sequenced on MLST revealing eight polymorphic sites and six STs. All N. dimidiatum var. hyalinum isolates were clustered in a single ST. AMB, VOR, and TER were the most effective antifungal agents against both varieties. The hyaline variety isolates were much less tolerant to the azoles than the isolates of the pigmented variety. APDT with S137 showed the lowest MIC for all the isolates of both varieties. APDT with all the PSs killed both ungerminated and germinated arthroconidia of both varieties reducing the survival up to 5 logs. Isolates of the hyaline variety were also less tolerant to APDT. APDT with the four PSs also increased the plasma membrane permeability of arthroconidia of both varieties but only NMBN and S137 caused peroxidation of the membrane lipids. © 2017 British Mycological Society.

Phase separation in amphiphilic systems is an important phenomenon. The temperature at which an amphiphilic solution phase separates is known as Cloud Point (CP). This article reviews in detail the process of phase separation in various amphiphiles (surfactants, polymers and drugs) and effect of different classes of additives on the CP of these amphiphilic systems. Ions affect the CP of drugs in a different way: kosmotropes and hard bases decrease while chaotropes and soft bases increase the CP of nonionic and cationic surfactants. Anionic surfactants show CP in presence of quaternary salts only. Thus, depending upon the nature and concentration of additive, the CP of an amphiphilic system gets increased or decreased and, hence, properties of the system may be tuned as per the need and use. A system with CP at high concentration can be made to phase separate at lower concentration by simply introducing an appropriate additive in it. This makes the system cost effective. On the other hand, if not required, a low CP can be enhanced with the help of another type of a suitable additive.

A sensitive sandwich assay for hepatitis B virus (HBV) DNA detection based on use of commercial CL-ELISA microplates was developed. To reveal the target the covalent conjugate of reporter oligonucleotide and horseradish peroxidase (HRP) was synthesized. An employment of enhanced chemiluminescence reaction, where 3-(10′-phenothiazinyl)propionic acid/N-morpholinopyridine pair was used as enhancer of HRP-catalyzed chemiluminescence, permitted to measure the enzyme activity of the conjugate with high sensitivity. Under the favorable conditions the limit of detection and a linear range of the assay were 3 pM and 0.07–2.0 nM, respectively. The coefficient of variation (CV) for determination of HBV DNA concentrations within the working range was lower than 4%. The obtained results demonstrated that the developed assay had high sensitivity and precision.

Azaphenothiazines (AZA), modified phenothiazine derivatives, have been reported to exhibit a wide spectrum of biological activities, including anticancer activities, but the mechanisms of their interactions with biomolecules are not fully recognized. In this work, the mode of interaction of selected AZA with calf thymus DNA was investigated using UV–Vis absorption, fluorescence spectroscopy (competition experiment with ethidium bromide, quenching of fluorescence) and molecular docking. The investigated AZA represent dipyrido[3,4-b;3′4′-e][1,4]thiazine, quino[3,2-b]benzo[1,4]thiazine and diquino[3,2-b;2′,3′-e][1,4]thiazine possessing tricyclic, tetracyclic and pentacyclic ring system with the additional N,N-dimethylaminopropyl group at the nitrogen atom in the 1,4 thiazine ring. The results obtained from spectroscopic studies showed that AZA bind to DNA by insertion of a fragment of the fused rings system between the base pair stack in the double helix of DNA. In addition, the number of rings in the AZA structures seemed to be related to the strength of the interaction, because pentacyclic AZA (binding constant Kb = 6.31 × 106 L/mol) demonstrated 10-fold higher affinity towards DNA than the tetracyclic AZA and about 100-fold higher affinity than that of tricyclic AZA. The molecular docking results showed that the binding mode of AZA to DNA helix was an intercalation mode with the partial insertion of one planar part of the AZA structure (the pyridine or quinoline ring) into the neighboring bases of one of the DNA chains with additional hydrogen bonding with the minor groove through the positively charged N,N-dimethylaminopropyl group. Chemical potential (μ), chemical hardness (ƞ), electronegativity (χ) and the value of electrons transferred from one system to another (ΔN) calculated from the HOMO and LUMO energies by the density functional theory method indicated that AZA acted as the electron acceptors to the DNA bases.

Citrinin can cause serious human diseases, thus its detection in foods is necessary. Herein, a molecularly imprinted polymer-based ratiometric electrochemical sensor (MIP-RECS) was presented for citrinin detection. The sensor was fabricated by electropolymerization, using thionine as monomer and citrinin as template. The ionic liquid decorated boron and nitrogen co-doped hierarchical porous carbon (BN-HPC) as supporter, provided large surface for anchoring thionine and citrinin. Poly(thionine) not only acted as MIP, but also acted as reference probe. When [Fe(CN)6] 3-/4- was adopted as indicating probe, the resulting sensor demonstrated a wide linear detection range (i.e. 1 × 10-3–10 ng mL−1) and a low detection limit (i.e. 1 × 10-4 ng mL−1).The sensor was applied to the detection of spiked citrinin in real samples, and satisfactory recovery (i.e. 97% – 110%) was obtained. Hence, it was promising for citrinin detection.

In an effort to identify methylene blue analogues having improved antioxidant activity, a series of new methylene violet analogues have been designed and synthesized. The analogues were prepared following a synthetic route that is more efficient than the previously reported methods, both in terms of yield and purity of the final products. The route involves the Smiles rearrangement as one of the crucial steps. Smiles rearrangement of suitably substituted diphenyl sulfide intermediates afforded the corresponding phenothiazine analogues in high yields, which were subsequently converted to the final products. The methylene violet analogues were evaluated for their ability to preserve mitochondrial function in Friedreich's ataxia (FRDA) lymphocytes. The analogues were shown to be efficient ROS scavengers, and able to protect cultured FRDA lymphocytes from oxidative stress resulting from inhibition of complex I. The analogues also preserved mitochondrial membrane potential and augmented ATP production. The analogues were found to be better antioxidants than the parent compounds methylene blue and methylene violet.

The 3D structures of two dummy templates and four phenothiazine drugs were studied by using computational simulation method. Then the two dummy templates were used to synthesize two molecularly imprinted polymers respectively. Results showed that the recognition abilities of the two polymers were consistent with the theoretical calculation. Then a solid phase extraction column was developed for extraction of the four phenothiazines in meat (pork, chicken) followed by determination with high performance liquid chromatography. The column showed high adsorption capacities (850-962ng analyte per milligram of polymer) and high recoveries (93-98%) to the four drugs, and could be recycled for sixty times. The limits of detection were in the range of 1.0-10ng/g, and the recoveries from the fortified blank samples were in the range of 70.3-96.1%. This is the first study reporting the use of molecularly imprinted polymer-based method for determination of phenothiazines residues in foods.

The exploration of novel adsorption properties of conductive polymers based on hybridization with biocompatible nanomaterials receives an increasing interest. In this regard, hydroxyapatite (HA) bioceramic is of critical importance mainly owing to its facile synthesis, high surface area, economic and low toxicity in biological environments. In this work, we first prepared and characterized a magnetite/hydroxyapatite (Fe 3 O 4 /HA) nanocomposite using the bio-waste chicken eggshell via an attractive green way that involved low cost and irrespective of toxicity. Then, polythionine as a novel class of conductive polymers was in situ coated on the synthesized magnetic bioceramic for the separation and preconcentration of riboflavin (vitamin B 2 ) in human plasma before its fluorimetric determination. Considering the putative role of riboflavin in protecting against cancer and cardiovascular diseases, it is essential to evaluate this vitamin in biological fluids. The described method possesses a linear range of 0.75–262.5 μg L − 1 (R 2 = 0.9985) and a detection limit of 0.20 μg L − 1 (signal-to-noise ratio of 3). The relative standard deviations (RSDs) for single-sorbent repeatability and sorbent-to-sorbent reproducibility were less than 4.0% and 7.6% (n = 5), respectively. The respective enrichment factor and extraction recovery of the method found to be 35.7 and 98.4%. The analytical performance of method for riboflavin was characterized by good consistency of the results with those obtained by the enzyme-linked immunosorbent assay (ELISA) conventional method ( p- value of

A thionine (TH)-doped mesoporous silica nanosphere (MSN)/polydopamine (PDA) nanocomposite was synthesized for developing a new signal transduction strategy of electrochemical immunoassay. This nanocomposite was synthesized through one-pot loading of TH and in situ formation of PDA-coating on MSN. After antibody labeling, the obtained nanoprobe was used for the signal tracing of sandwich immunoassay at a magnetic bead-assay platform. Based on the specific capture of the MSN-TH/PDA nanoprobes through sandwich immunoreaction to form a magnetic immunocomplex and the following treatment of the immunocomplex with a NaOH solution, the PDA film coated on MSN was destroyed to release TH tags from the nanoprobe. The released TH was then electrochemically measured at a carbon nanotube (CNT)-modified electrode for the signal transduction of the method. Due to the high loading of TH on the nanoprobe for tag release and effective electrochemical signal enhancement by the electrode modification of CNTs, ultrahigh sensitivity was achieved. Using human IgG as a model analyte, this method showed a wide linear range over four orders of magnitude and a low detection limit of 5.8 pg/mL. Additionally, the method has excellent specificity, satisfactory reproducibility and stability as well as acceptable reliability. Due to the simple preparation of the nanoprobe and the low cost, convenient operation of the detection strategy, this nonenzymatic immunoassay method possesses great potentials for practical applications.

Hybrid molecules are used as anticancer agents to improve effectiveness and diminish drug resistance. So, the current study aimed to introduce twenty novel phenothiazine sulfonamide hybrids 5–22, 24 and 25 of promising anticancer activity. Compounds 11 and 13 revealed more potent anticancer properties (IC 50 8.1 and 8.8 μM) than that of the reference drug (doxorubicin, IC 50 = 9.8 μM) against human breast cancer cell line (T47D). To determine the mechanism of their anticancer activity, compounds 5, 6, 7, 11, 13, 14, 16, 17, 19 and 22 that showed promising activity on T47D, were evaluated for their aromatase inhibitory effect. The study results disclose that the most potent aromatase inhibitors 11 and 13 showed the lowest IC 50 (5.67 μM and 6.7 μM), respectively on the target enzyme. Accordingly, the apoptotic effect of the most potent compound 11 was extensively investigated and showed a marked increase in Bax level up to 55,000 folds, and down-regulation in Bcl2 to 5.24*10 −4 folds, in comparison to the control. Furthermore, the effect of compound 11 on caspases 3, 8 and 9 was evaluated and was found to increase their levels by 20, 34, and 8.9 folds, respectively, which indicates the activation of both intrinsic and extrinsic pathways. Also, the effect of compound 11 on the cell cycle and its cytotoxic effect were examined. Moreover, a molecular docking and computer aided ADMET studies were adopted to confirm their mechanism of action.

Background Antimicrobial photodynamic therapy (APDT) is a process that generates reactive oxygen species (ROS) in presence of photosensitizer, visible light and oxygen which destroys the bacterial cells. We investigated the photoinactivation efficiency of phenothiazinium dyes and the effect of ROS generation on Gram positive and Gram negative bacterial cell as well as on biofilm. Material and methods Enterococcus faecalis and Klebsiella pneumonia were incubated with all the three phenothiazinium dyes and exposed to 630 nm of light. After PDT, colony forming unit (CFU) were performed to estimate the cell survival fraction. Intracellular reactive oxygen species (ROS) was detected by DCFH-DA. Crystal violet (CV) assay and extracellular polysaccharides (EPS) reduction assay were performed to analyze antibiofilm effect. Confocal laser electron microscope (CLSM) scanning electron microscope (SEM) was performed to assess the disruption of biofilm. Results 8log 10 reduction in bacterial count was observed in Enterococcus faecalis while 3log 10 in Klebsiella pneumoniae . CV and EPS reduction assay revealed that photodynamic inhibition was more pronounced in Enterococcus faecalis . In addition to this CLSM and SEM study showed an increase in cell permeability of propidium iodide and leakage of cellular constituents in treated preformed biofilm which reflects the antibiofilm action of photodynamic therapy. Conclusion We conclude that Gram-positive bacteria ( Enterococcus faecalis ) are more susceptible to APDT due to increased level of ROS generation inside the cell, higher photosensitizer binding efficiency and DNA degradation. Phenothiazinium dyes are proved to be highly efficient against both planktonic and biofilm state of cells.

International audience; Recently, multidrug-resistant tuberculosis (MDR-TB) has become a therapeutic challenge. In addition to drug resistance, drug adverse events, intravenous delivery, cost and availability of some antibiotics in low-income countries have led to a look back to old drugs, especially those efficient against closely related organisms such as Mycobacterium leprae. Here we review the available drugs that respect the conditions above and could be upgraded to first-line therapy for treating MDR-TB and extensively drug-resistant tuberculosis (XDR-TB). (C) 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

In this study, a broadly specific monoclonal antibody was prepared and a sensitive monoclonal-based indirect competitive enzyme linked immunosorbent assay (ic-ELISA) was subsequently developed to determine the phenothiazines in animal feed with a simple sample preparation procedure for the first time. The obtained antibody 3A5 was of the immunoglobulin G1 (IgG1) isotype possessing a kappa light chain, which broadly cross-reacted to nine phenothiazines. The limit of detections of the method ranged from 1.1 μg kg −1 to 15.3 μg kg −1 in the swine feed and the fish feed. The recoveries of the phenothiazines were in the range of 78.2–116.6%. The coefficient of variations were less than 16.7%. A positive correlation (r > 0.9249) between the results of the ic-ELISA and the high-performance liquid chromatography were also observed, which indicated that the developed ic-ELISA is reliable and can be used to monitor phenothiazines in animal feed.

A robust and highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of pericyazine in human plasma. The plasma sample was alkalized with sodium hydroxide solution and handled by liquid-liquid extraction with ethyl acetate after adding perphenazine as an internal standard (IS). The analytes were separated on an Ultimate™ AQ-C18 analytical column at 40°C, with a gradient elution consisting of A (aqueous phase: 5mM ammonium acetate buffer solution containing 0.1% formic acid) and B (organic phase: acetonitrile) at a flow rate of 0.350mL/min. The detection was conducted on an API 4000 tandem mass spectrometer coupled with electrospray ionization (ESI) source in positive ion mode. The multiple reaction monitoring (MRM) transitions, m/z 366.5>142.4 for pericyazine, m/z 382.5>142.4 for its 7-hydroxy and sulphoxide metabolites and m/z 404.3>171.3 for IS were chosen to achieve high selectivity in the simultaneous analyses. The method exhibited great improvement in sensitivity (LLOQ of 0.021ng/mL) and good linearity over the concentration range of 0.021-9.90ng/mL. The intra- and inter-day precision, accuracy, and stability results were within the acceptable limits and no matrix effect was observed. This method was successfully applied in a bioequivalence study to evaluate the pharmacokinetics in 20 healthy male Chinese volunteers. Additional exploratory analyses of 7-hydroxy and sulphoxide metabolites of pericyazine in the same samples suggest that the unchanged drug is predominant in the plasma and suitable for the bioequivalence comparison after a single oral administration of 10mg pericyazine.

RNA targeting through small molecules is an emerging and promising therapeutic route that necessitates identification of small molecules that can selectively target specific RNA structures. In this context a comparative study of the interaction of two phenothiazinium dyes thionine (THN) and toluidine blue O (TBO) with three double stranded RNA polynucleotides (ds RNAs) viz. poly(I).poly(C), poly(A).poly(U) and poly(C).poly(G) was conducted by various biophysical techniques. A higher binding of THN with poly(I).poly(C) over poly(A).poly(U) and poly(C).poly(G) was observed. The intercalative binding and RNA induced fluorescence quenching of the dyes through a static mechanism was confirmed by viscosity studies and steady state polarization anisotropy experiments. Binding induced structural perturbation in the RNA polynucleotides was confirmed from circular dichroism spectroscopy. DSC and thermal melting experiments confirmed that the binding resulted in strong thermal stabilization. The binding affinity of THN with poly(I).poly(C) was the highest followed by that to poly(A).poly(U) and poly(C).poly(G). The trend was the same for TBO also, but THN bound stronger than TBO. The binding of the dyes was characterized by strong negative enthalpy changes with minimum positive entropy changes indicating typical intercalative interaction. The results presented here may be useful to design new types of RNA binding antitumor, antibacterial and anticancer agents.

A mesoporous silica nanoparticle (MSN)-based controlled release system with acid cleavable linkage was developed to fabricate an electrochemical immunosensor for the quantitative detection of the prostate-specific antigen (PSA). 3,9-Bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane functionalized mesoporous silica nanoparticles (MSN-Acetal) were used to immobilize the electron mediator thionine (Th). The encapsulation of Th molecules was achieved by capping the pores of MSN-Acetal with carboxylic acid modified Au nanoparticles (defined as MSN-Th-Au). Under the acidic conditions, the capped Au nanoparticles were removed from MSN-Th-Au through the hydrolysis of the acid-labile acetal linker, resulting in the release of encapsulated Th. In this work, the pH-responsive cargo release system was firstly used as the label of secondary anti-PSA for developing an electrochemical immunosensor, and amination Fe3O4 was used as the sensing matrix for immobilizing primary anti-PSA on magnetic carbon electrode surfaces. The specific recognition of PSA resulted in the attachment of MSN-Th-Au-secondary anti-PSA (MSN-Th-Au-Ab2) onto the electrode surfaces. Subsequently, the released Th was detected by differential pulse voltammetry under the acidic conditions. The developed cargo release system provided an innovative and reliable method for the detection of PSA because the response signal was correlated with the concentration of PSA. Under the optimal conditions, the electrochemical immunosensor exhibited a wide linear range of 0.001-5.0ng/mL with a low detection limit of 0.31pg/mL. Moreover, the developed immunosensor showed superior reproducibility and long-term stability, which has promising applications in bioassay and biosensing.

Hypochlorous acid (HOCl/ClO−), a reactive oxygen species (ROS), plays an indispensable role in the human immune system. In this article, a novel red-emission phenothiazine fluorescent protein chromophore RFP-Ptz was developed for the detection of HOCl in cells. In the presence of HOCl, the fluorescence signal 610 nm rose gradually and reached its plateau with 15-fold enhancement; the fluorescence quantum yield increased from 0.01 to 0.12. The electrophilic substitution of Cl+ towards phenolic hydroxyl group made the probe exhibited a high selective fluorescence response with a limit of detection (LOD) of 6.76 × 10−7 M over other analyte species and ROS. This recognition mechanism of oxygen‒chlorine bond (O–Cl) formation has confirmed by HRMS. Finally, the RFP-Ptz can be used to response HOCl with low cytotoxicity and good biocompatibility (MTT cytotoxicity assay > 89.5%). The biocompatible RFP-Ptz was successfully applied to the fluorescence imaging of HOCl-related in SGC-7901 cells.

In this work, we reported a rather facile method for fabrication of ultrabright, well dispersible and biocompatible fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) properties through combination of esterification and ring-opening reaction. The hydroxyl groups of Pluronic F127 was first reacted with the chloride of trimellitic anhydride chloride (TMAC), and its anhydride groups were further reacted with the amino groups of amino-terminated AIE dye (PhNH2) through ring-opening reaction. The optical properties, biocompatibility as well as cell uptake behavior of these obtained AIE-active nanoparticles (F127-TMAC-PhNH2 FONs) were examined by a series of characterization techniques and assays. We demonstrated that uniform organic nanoparticles with high water dispersibility, strong luminescence and desirable biocompatibility can be facilely obtained, which are promising for biological imaging applications. More importantly, a number of carboxyl groups were introduced into these AIE-active nanoparticles, which can be further utilized for further conjugation reaction and carrying anticancer drugs such as cisplatin. Therefore, the strategy of described in this work should be a simple and useful route for fabrication of multifunctional AIE-active luminescent nanotheranostic systems.

A new strategy to fabricate electrochemical biosensor is reported based on the linkage of enzyme substrate, thereby an electrochemical method to detect aldolase activity is established using pectin-thionine complex (PTC) as recognization element and signal probe. The linkage effect of fructose-1,6-bisphosphate (FBP), the substrate of aldolase, can be achieved via its strong binding to magnetic nanoparticles (MNPs)/aminophenylboronic acid (APBA) and the formation of phosphoramidate bond derived from its reaction with p-phenylenediamine (PDA) on the surface of electrode. Aldolase can reversibly catalyze the substrates into the products which have no binding capacity with MNPs/APBA, resulting in the exposure of the corresponding binding sites and its subsequent recognization on signal probe. Meanwhile, signal amplification can be accomplished by using the firstly prepared PTC which can bind with MNPs/APBA, and accuracy can be strengthened through magnetic separation. With good precision and accuracy, the established sensor may be extended to other proteins with reversible catalyzed ability.

In this work, a novel electrochemical aptasensor was developed for sensitive and specific detection of Hg(2+) based on thymine-Hg(2+)-thymine (T-Hg(2+)-T) structure via application of thionine (Th) as indicator signal. For the fabrication of the aptasensor, streptavidin modified magnetic beads (Fe3O4-SA) was firmly immobilized onto the magnetic glassy carbon electrode (MGCE) benefited from its magnetic character. Then biotin labeled T-riched single stranded DNA (Bio-ssDNA) connected with Fe3O4-SA specifically and steadily because of the specific binding capacity between streptavidin and biotin. The stable structure of T-Hg(2+)-T formed in the present of Hg(2+) provided convenience for the intercalation of Th. The detection of Hg(2+) was achieved by recording the differential pulse voltammetry (DPV) signal of Th. Under optimal experimental conditions, the linear range of the fabricated electrochemical aptasensor was 1-200nmol/L, with a detection limit of 0.33nmol/L. Furthermore, the proposed aptasensor may find a potential application for the detection of Hg(2+) in real water sample analysis.

A label-free and highly sensitive electrochemical aptasensor for Pb(2+) was constructed using thionine (TH) as the signaling molecule and graphene (GR) as the signal-enhancing platform. The electrochemical sensing interface was fabricated by stepwise assembly of GR and TH on the lead (II) specific aptamer (LSA) modified electrode. Upon interaction with Pb(2+), the aptamer probe on the sensor underwent conformational switch from a single-stranded DNA form to the G-quadruplex structure, causing the GR with assembled TH released from the electrode surface into solution. As a result, the electrochemical signal of TH on the aptasensor was substantially reduced. Under the optimal experimental conditions, the attenuation of peak currents presented a good linear relationship with the logarithm of Pb(2+) concentrations over the range from 1.6×10(-13) to 1.6×10(-10)M. The detection limit was estimated to be 3.2×10(-14)M. The aptasensor also exhibited good regenerability, excellent selectivity, and acceptable reproducibility, indicating promising application in environment monitoring of lead.

Phenothiazine-modified redox hydrogels were synthesized and used for the wiring of the aldehyde oxidoreductase PaoABC to electrode surfaces. The effects of the pH value and electrode surface modification on the biocatalytic activity of the layers were studied in the presence of vanillin as the substrate. The enzyme electrodes were successfully employed as bioanodes in vanillin/O-2 biofuel cells in combination with a high potential bilirubin oxidase biocathode. Open circuit voltages of around 700 mV could be obtained in a two compartment biofuel cell setup. Moreover, the use of a rather hydrophobic polymer with a high degree of crosslinking sites ensures the formation of stable polymer/enzyme films which were successfully used as bioanode in membrane-less biofuel cells. (C) 2015 Elsevier B.V. All rights reserved.

A new library of phenothiazine and 1,3,4-thiadiazole hybrid derivatives (5a-u) was designed based on the molecular hybridization approach and the molecules were synthesized in excellent yields using a facile single-step chloro-amine coupling reaction between 2-chloro-1-(10H-phenothiazin-10-yl)ethanones and 2-amino-5-subsituted-1,3,4-thiadiazoles. The compounds were evaluated for their in vitro inhibition activity against Mycobacterium tuberculosis H37Rv (MTB). Compounds 5 g and 5 n were emerged as the most active compounds of the series with MIC of 0.8 μg/mL (∼ 1.9 μM). Also, compounds 5a, 5b, 5c, 5e, 5l and 5m (MIC = 1.6 μg/mL), and compounds 5j, 5k and 5o (MIC = 3.125 μg/mL) showed significant inhibition activity. The structure-activity relationship demonstrated that an alkyl (methyl/n-propyl) or substituted (4-methyl/4-Cl/4-F) phenyl groups on the 1,3,4-thiadiazole ring enhance the inhibition activity of the compounds. The cytotoxicity study revealed that none of the active molecules are toxic to a normal Vero cell line thus proving the lack of general cellular toxicity. Further, the active molecules were subjected to molecular docking studies with target enzymes InhA and CYP121.

A sensitive electrochemical sensor for determination of phenothiazine (PTZ) was introduced based on molecularly imprinted polymer (MIP) film. A computational study was performed to evaluate the template-monomer geometry and interaction energy in the prepolymerization mixture. The electrode was prepared during electropolymerization of pyrrole (Py) on a pencil graphite electrode (PGE) by cyclic voltammetry (CV) technique. The quantitative measurements were performed using differential pulse voltammetry (DPV) in Britton-Robinson (BR) buffer solutions using 60% (v/v) acetonitrile-water (ACN/H2O) binary solvent. The effect of important parameters like pH, monomer concentration, number of cycles, etc on the efficiency of MIP electrode was optimized and the calibration curve was plotted at optimal conditions. Two dynamic linear ranges of 1-300 µmol L(-1) and 0.5-10 mmol L(-1) were observed. The detection limit (based on S/N=3) of PTZ was obtained 3×10(-7) mol L(-1). The MIP/PGE has been successfully applied as a selective sensor for fast and accurate determination of PTZ in some model and real biological samples.

In the incessant search for innovative cancer control strategies, this study was devoted to the design, synthesis and pharmacological evaluation of dual inhibitors of farnesyltransferase and tubulin polymerization (FTI/MTIs). A series of indolizine-phenothiazine hybrids 16 (amides) and 17 (ketones) has been obtained in a 4-step procedure. The combination of the two heterocycles provided potent tubulin polymerization inhibitors with similar efficiency as the reference phenstatin and (-)-desoxypodophyllotoxin. Ketones 17 were also able to inhibit human farnesyltransferase (FTase) in vitro. Interestingly, three molecules 17c, 17d and 17f were very effective against both considered biological targets. Next, nine indolizine-phenothiazine hybrids 16c, 16f, 17a-f and 22b were evaluated for their cell growth inhibition potential on the NCI-60 cancer cell lines panel. Ketones 17a-f were the most active and displayed promising cellular activities. Not only they arrested the cell growth of almost all tested cancer cells, but they displayed cytotoxicity potential with GI50 values in the low nanomolar range. The most sensitive cell lines upon treatment with indolizine-phenothiazine hybrids were NCI-H522 (lung cancer), COLO-205 and HT29 (colon cancer), SF-539 (human glioblastoma), OVCAR-3 (ovarian cancer), A498 (renal cancer) and especially MDA-MB-435 (melanoma). Demonstrating the preclinical effectiveness of these dual inhibitors can be crucial. A single dual molecule could induce a synergy of antitumor activity, while increasing the effectiveness and reducing the toxicity of the classical combo treatments currently used in chemotherapy.

A water quality early-warning instrument for evaluating acute water toxicity based on the electrochemical biosensor, Model ETOX18-01, was developed and manufactured with the features of low current detection (0.1 nA), precise thermostatic control, self-cleaning as well as remote data transmission. A sensitive integrated microbial electrode, made up of a glass carbon electrode that was modified by an active biofilm consisting of Escherichia coli, thionine, carbon nanodots and chitosan, has been fabricated as the biosensor. To validate the performance, multiple real water samples and artificial water samples were tested by Model ETOX18-01, and compared with ISO standardized luminescent bacterial test simultaneously. The correlation between the Model ETOX18-01 and luminescent bacterial test for these water samples showed good determination coefficient (R2 = 0.9827). In addition, Model ETOX18-01 is more sensitive to colored metal ionic samples. With its characteristics of high sensitivity, excellent repeatability and easy operation, the instrument Model ETOX18-01 provides a promising tool for large-scale water environmental assessment, and has a potential application in evaluating the water quality and early risk warning.

Ommochromes are widespread pigments that mediate multiple functions in invertebrates. The two main families of ommochromes are ommatins and ommins, which both originate from the kynurenine pathway but differ in their backbone, thereby in their coloration and function. Despite its broad significance, how the structural diversity of ommochromes arisesin vivohas remained an open question since their first description. In this study, we combined organic synthesis, analytical chemistry and organelle purification to address this issue. From a set of synthesized ommatins, we derived a fragmentation pattern that helped elucidating the structure of new ommochromes. We identified uncyclized xanthommatin as the elusive biological intermediate that links the kynurenine pathway to the ommatin pathway within ommochromasomes, the ommochrome-producing organelles. Due to its unique structure, we propose that uncyclized xanthommatin functions as a key branching metabolite in the biosynthesis and structural diversification of ommatins and ommins, from insects to cephalopods.

Phenothiazines inhibit major antioxidant defense mechanisms in trypanosomatids and exhibit potent cytotoxic effects in vitro. However, the relevance of these drugs in the treatment of Trypanosoma cruzi-induced acute myocarditis is poorly explored, especially in combination with reference trypanocidal drugs. Thus, we compared the antiparasitic and cardioprotective potential of thioridazine (TDZ) and benznidazole (Bz) administered in monotherapy and combined in a murine model of T. cruzi-induced acute myocarditis. Female mice were randomized into six groups: (i) uninfected untreated, (ii) infected untreated, or infected treated with (iii) Bz (100 mg/kg), (iv) TDZ (80 mg/kg), (v) Bz (100 mg/kg) + TDZ (80 mg/kg), or (vi) Bz (50 mg/kg) + TDZ (80 mg/kg). Infected animals were inoculated with 2000 T. cruzi trypomastigotes and treated by gavage for 20 days. Animals that received TDZ alone presented the highest levels of parasitemia, parasitic load and anti-T. cruzi immunoglobulin G titers; cardiac upregulation of N-acetyl-β-D-glucosaminidase activity, nitric oxide, malondialdehyde and cytokines (IFN-γ, TNF-α, IL-10 and IL-17); as well as microstructural damage compared to the other groups (p < 0.05). These parameters were reduced in groups receiving Bz monotherapy compared to the other groups (p < 0.05). The combination of TDZ and Bz attenuated the response to treatment, worsening parasitological control, oxidative heart damage and myocarditis compared to the group treated with Bz alone (p < 0.05). Our results indicate that when administered alone, TDZ potentiated the pathological outcomes in animals infected with T. cruzi. Moreover, TDZ attenuated the antiparasitic effect of Bz when administered together, impairing parasitological control, potentiating inflammation, molecular oxidation and pathological microstructural remodeling of the heart. Thus, our findings indicate that TDZ acts as a pharmacological risk factor and Bz-based monotherapy remains a better cardioprotective drug against Trypanosoma cruzi-induced acute myocarditis.

Human butyrylcholinesterase (HuBChE) is a stoichiometric bioscavenger that protects from the toxicity of nerve agents. Non-human primates are suitable models for toxicity studies that cannot be performed in humans. We evaluated the biochemical properties of native macaque (MaBChE) tetramers, compared to recombinant MaBChE monomers, PEGylated recombinant MaBChE tetramers and monomers, and native HuBChE tetramers. Km and kcat values for butyrylthiocholine were independent of subunit assembly status. The Km for all forms of MaBChE was about 70 μM, compared to 13 μM for HuBChE. The kcat was about 100,000 min−1 for MaBChE and 30,000 min−1 for HuBChE. The reversible inhibitor ethopropazine had similar Ki values of 0.05 μM for all MaBChE forms and HuBChE. The bimolecular rate constant, ki, for inhibition by diisopropylfluorophosphate (DFP), an analog of sarin, was 2.2 to 2.5 × 107 M−1 min−1 for all MaBChE forms and for HuBChE. A major difference between MaBChE and HuBChE was the rate of reactivation by 2-PAM. The second order rate constant for reactivation of DFP-inhibited MaBChE by 2-PAM was 1.4 M−1 min−1, but was 380 fold faster for DFP-inhibited HuBChE (kr 531 M−1 min−1). The acyl pocket of MaBChE has Leu285 in place of Pro285 in HuBChE. The reactivation rate of DFP-inhibited HuBChE mutant P285L by 2-PAM was reduced 5.8-fold (kr 92 M−1 min−1) indicating that P285 determines whether 2-PAM binds in an orientation that favors release of diisopropylphosphate. DFP-inhibited MaBChE treated with 0.2 M 2-PAM recovered 10% of its original activity, whereas DFP-inhibited HuBChE recovered 80% activity. It was concluded that the biochemical properties of MaBChE are similar to those of HuBChE except for the reactivation of DFP-inhibited BChE.

Prion diseases or transmissible spongiform encephalopathies (TSEs) are a group of rare neurodegenerative disorders. TSEs are characterized by the accumulation of prions (PrPSc) that represent pathological isoforms of the physiological cellular prion protein PrPC. Although the conversion of PrPC to PrPSc is still not completely understood, blocking this process may lead to develop new therapies. Here, we have generated a pharmacophore model, based on anti-prion molecules reported in literature to be effective in phenotypic assay. The model was used to conduct a virtual screen of commercial compound databases that selected a small library of ten compounds. These molecules were then screened in mouse neuroblastoma cell line chronically infected with prions (ScN2a) after excluding neurotoxicity. 1 has been identified as the therapeutic hit on the basis of the following evidence: chronic treatments of ScN2a cells using 1 eliminate PrPSc loaded in both Western blotting analysis and Real-Time Quaking-Induced Conversion (RT-QuIC) assay. We also proposed the mechanism of action of 1 by which it has the ability to bind PrPC and consequentially blocks prion conversion. Herein we describe the results of these efforts.

Accurately monitoring of aflatoxin B1 (AFB1), the most hazardous mycotoxin in agricultural products, is essential for the public health, but various testing demands (e.g. detection range, sensitivity) for different samples can be challenging for sensors. Here, we developed a sensitivity-programmable ratiometric electrochemical aptasensor for AFB1 analysis in peanut. Thionine functionalized reduced graphene oxide (THI-rGO) served as reference signal generator, ferrocene-labelled aptamer (Fc-apt) output the response signal. During analysis, the formation of Fc-apt-AFB1 complex led to its stripping from the electrode and faded the current intensity of Fc (IFc), while the current intensity of THI (ITHI) was enhanced. And ratiometric detection of AFB1 was achieved by using the current intensity ratio (ITHI/IFc) as quantitative signal. Compared with ratiometric strategies that highly rely on the labelled aptamers, the proposed strategy could regulate the value of ITHI/IFc by changing the modification of Fc-apt. And the detection sensitivity was found to be closely related to ITHI/IFc. Under the optimal conditions, the fabricated aptasensor with a dynamic range from 0.05–20 ng mL−1 and a detection limit of 0.016 ng mL−1 for AFB1 analysis. Besides, it exhibited excellent selectivity, reliability and reproducibility. The proposed sensitivity-programmable biosensor can be applied to detect various aptamer-recognized mycotoxins in agricultural sensing.

By taking advantage of phenothiazine moiety as an electron-donating group, a novel donor-acceptor (D-A) type coumarin dye, PTZ-Et, was developed. The introduction of phenothiazine moiety not only caused emission red-shifting and Stokes shift enlarging, but also endowed PTZ-Et with significant aggregation-enhanced emission (AEE) features, thereby enabled PTZ-Et as a robust ratiometric fluorescent probe for HClO detection. Upon oxidation of the sulfur atom on phenothiazine into sulfoxide, PTZ-Et displayed remarkable ratiometric fluorescence response (over 150 folds variations of F534/F626) toward HClO with rapid response time (

A novel series of phenothiazine derivatives containing diethanolamine, methoxyethylamine, flavonoids, and a nitric oxide (NO) donor was designed and synthesized for the treatment of breast cancer. Phenothiazine derivatives (l) did not noticeably inhibit the growth of SUM159, MDA-MB-231, MCF-7, and SKBR-3 cells, whereas phenothiazine derivatives (ll) containing the NO donor were more potent or had comparable inhibitory activity to trifluoperazine (TFP) and thioridazine against SUM159, MDA-MB-231, MCF-7, and SKBR-3 cells. Compounds 20a-c and 21a-c showed the strongest activity in SUM159, MDA-MB-231, MCF-7, and SKBR-3 cells, and more potent inhibitory activity than TFP against KG1a cells (IC50 = 1.63, 2.93, 1.14, 1.78, 2.20, and 1.20 vs. 4.58 μM). Compounds 20a and 21a had lower toxicity than compounds 20b-c and 21b-c, and inhibited colony formation in MCF-7 cells, decreased the formation of mammospheres in SUM159 cells, and inhibited the migration of MDA-MB-231 cells. Compounds 20a and 21a could inhibited pNF-κB-p65 as shown by dual-luciferase reporter assays and western blotting in MDA-MB-231 cells.

The phenothiazine-derived antipsychotic drugs, such as chlorpromazine and thioridazine, are bactericidal against drug-sensitive and drug-resistant strains of Mycobacterium tuberculosis, but produce undesirable side effects at clinically relevant doses. We have previously modified four novel phenothiazines and maintained their antimycobacterial activity. This study evaluated the pharmacological and toxicity profiles of these novel non-neuroleptic phenothiazines, PTZ3, PTZ4, PTZ31 and PTZ32, for their metabolic stability, kinetic solubility and potential cytotoxic effects in vitro. To further support the safet use of these drug candidates, the in vivo pharmacological and toxicity profiles were assessed in C57BL/6 mice via single or repeated oral gavage. In acute toxicity studies, all four modified phenothiazines showed favourable safety in mice. When treated daily with 100 mg/kg of PTZ3 and PTZ4 for 2 weeks, mice displayed no signs of toxicity. Alternatively, treatment with PTZ31 resulted in 20% mortality with no toxicity evident in biochemical or histological analysis, while exposure to PTZ32 resulted in a 45% survival with increased serum concentrations of uric acid and alkaline phosphatase. The combined non-neuroleptic and antimycobacterial effects of the novel phenothiazines PTZ3, PTZ4, PTZ31 and PTZ32 demonstrated favourable pharmacological and toxicity profiles in this study, highlight the potential of these compounds as suitable anti-tuberculosis drug candidates.