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Presented herein is a switchable synthesis of naphthalenone spiroindanediones or 4‐acyl‐1‐naphthols via condition‐controlled divergent cascade reactions of aryl enaminones with diazoindanediones. When the reaction was carried out in the presence of an oxidative additive, naphthalenone spiroindanedione was formed through C(sp2)−H alkylation followed by simultaneous spiroannulation and elimination of dimethylamine. When the reaction was carried out in the presence of an acid additive, on the other hand, 4‐acyl‐1‐naphthol was formed through ring opening of the spiroindanedione moiety attacked by the in situ released dimethylamine. In addition, the reactions are suitable for gram‐scale applications and compatible with a variety of substrates. Moreover, the naphthol products allow structural elaborations and hybridization with a drug, thus further enhancing the value of this developed method. [ABSTRACT FROM AUTHOR]

Rapid and visual detection of SARS‐CoV‐2 variants is vital for timely assessment of variant transmission in resource‐limited settings. Here, a closed‐tube, two‐stage, mixed‐dye‐based isothermal amplification method with ribonuclease‐cleavable enhanced probes (REP), termed REP‐TMAP, for dual‐visualization detection of SARS‐CoV‐2 variants including JN.1, BA.2, BA.4/5, and Delta is introduced. The first stage of REP‐TMAP is reverse transcription recombinase polymerase amplification and the second stage is dual‐visualization detection synergistically mediated by the REP and the mixed dyes of cresol red and hydroxy naphthol blue. In REP‐TMAP reaction, the color change under ambient light indicates SARS‐CoV‐2 infection, while the fluorescence change under blue light excitation specifies variant type. On detecting transcribed RNA of SARS‐CoV‐2 spike gene, this assay is rapid (within 40 min), highly sensitive (10–200 copies per reaction), and highly specific (identification of single‐base mutations). Furthermore, the assay has been clinically validated to accurately detect JN.1, BA.2, and BA.4/5 variants from 102 human oropharyngeal swabs. The proposed assay therefore holds great potentials to provide a rapid, dual‐visualization, sensitive, specific, point‐of‐care detection of SARS‐CoV‐2 variants and beyond. [ABSTRACT FROM AUTHOR]

Iridium catalyzed electrochemical coupling of naphthols with acrylates for the syntheses of naphtho[1,8‐bc]furan derivatives are herein reported. Ir‐catalyzed electrochemical C−H annulation is accomplished within a supportive catalysis manifold, paving the way for electrooxidative C−H acrylation via weak O‐coordination. The merge of iridium catalysts and electric current not only minimizes the need for a stoichiometric amount of chemical oxidants but also confirms broad reaction compatibility with a variety of electronically and sterically diverse substrates. This utility provides a valuable method for producing a wide range of naphtho[1,8‐bc]furan derivatives in good to moderate yields. [ABSTRACT FROM AUTHOR]

A flame atomic absorption spectrophotometric technique was studied for the preconcentration and determination of Co2+ ions in trace amounts after ultrasound enhanced enrichment of its 1-(2-pyridylazo)-2-naphthol (PAN) complexes by cloud point extraction. The Co2+ ions were firstly complexed with PAN molecules at pH 4 and the complex transferred to a surfactant Tergitol NP-7 (TNP-7) rich phase with a very small volume under ultrasound waves. The surfactant rich phase was separated and dissolved by 1 mL, 1.0 M HNO3 in ethanol prior to determination of Co2+ concentration by flame atomic absorption spectrophotometry. The optimization steps of ultrasound interaction time, solution pH and surfactant volumes were achieved by response surface methodology (RSM) which is a combination of statistical approaches. PAN concentration and possible interfering ions were optimized conventionally. The Co2+ ions were extracted only in 150 s at pH 4 quantitatively under optimum conditions (˃95%). The accuracy and validity of developed ultrasound assisted cloud point extraction (UA-CPE) was granted by employing a certified reference material wastewater UME CRM 1204. The technique was applied to wastewater and natural water with satisfactory results. [ABSTRACT FROM AUTHOR]

Cyclic annulation involving diaryliodonium salts is an efficient tool for the construction of two or more chemical bonds in a one-pot process. Ortho-functionalized diaryliodonium salts have showcased distinct reactivity in the exploration of benzocyclization or arylocyclization. With this strategy of ortho-ester-substituted diaryliodonium salts, herein, we utilized a copper catalyst to activate the C–I bond of diaryliodonium salts in the generation of aryl radicals, thus resulting in an annulation reaction with naphthols and substituted phenols. This approach yielded a diverse array of 3,4-benzocoumarin derivatives bearing various substituents.

Developing suitable electrode materials for sodium-ion batteries (SIBs) is important to improve the electrochemical performance. Herein, we prepare n-type carbonaceous anodes via pyrolysis of naphthol-functionalized polytriarylamine that manifests rapid Na+ storage. During pyrolysis, gas evolution from poly(DNap-OH) triggers structural rearrangement to form a disordered microstructure with a high char-yield of 72%. When utilizing PDNOH as anodes in SIBs, PDNOH-800 delivered the specific capacity of 212 mA h g−1 at 0.05 A g−1 and stable cycling behavior with C.E. of 99.7%. The n-type characteristics attributed to N- and O-moieties played a critical role to enhance the electrochemical performance of SIBs via surface-induced Na+ storage with fast kinetics. [ABSTRACT FROM AUTHOR]

In the future, it is necessary to discover natural resources with no or less toxicity and side effects instead of synthetic drugs. Therefore, it is crucial to recognize, isolate, measure, and reveal the biological activities of substances in the structure of natural resources. In this study, the two extracts prepared from the plant (Hibiscus sabdariffa) and the insect (Dactylopius coccus) were examined. Sampling of the released substances was performed using Gas-ChromatographyMass Spectrometry (GC-MS). In addition, viability, apoptosis, and oxidative stress of the derivatized samples were determined. Due to the biological differences between the samples, the chemical structures observed in the GC-MS analysis were not the same. It was observed that stigmasterol and its derivatives were found in the pomegranate sample, whereas naphthol and its derivatives were more abundant in the Cochineal insect sample. The cell viability increased with increasing concentrations of stigmasterol, which is present in large amounts in the structure of the pomegranate flower. However, the cell viability decreased with the Cochineal insect sample. Apoptosis and oxidative stress test results were also found to be different and contrasted for both samples. Therefore, the present study presents a new, natural, and different source that can be used as an antiviral and anticancer agent. [ABSTRACT FROM AUTHOR]

In this study, TiO2 nanospheres (TiO2-NS) were synthesized by the solvothermal method. Firstly, the synthesized nanomaterial was characterized by X-ray diffraction (XRD), Fourier Transformed Infrared (FTIR), scanning electron microscopy (SEM) and UV-Vis Diffuse Reflectance Spectroscopy (DRS). To study the photocatalytic degradation of Tartrazine (TTZ) and Naphthol Blue Black (NBB) in a binary mixture, the influence of some key parameters such as pH, pollutant concentration and catalyst dose was taken into account under visible and UV light. The results show a 100% degradation efficiency for TTZ after 150 min of UV irradiation and 57% under visible irradiation at 180 min. The kinetic study showed a good pseudo-first-order fit to the Langmuir–Hinshelwood model. Furthermore, in order to get closer to the real conditions of textile wastewater, the influence of the presence of salt on TiO2-NS's photocatalytic performance was explored by employing NaCl as an inorganic ion. The optimum conditions provided by the Response Surface Methodology (RSM) were low concentrations of TTZ (2 ppm) and NBB (2.33 ppm) and negligible salt (NaCl) interference. The percentage of photodegradation was high at low pollutant and NaCl concentrations. However, this yield became very low as NaCl concentrations increased. The photocatalytic treatment leads to 31% and 53% of mineralization yield after 1 and 3 h of visible light irradiation. The synthesis of TiO2-NS provides new insights that will help to develop an efficient photocatalysts for the remediation of contaminated water. [ABSTRACT FROM AUTHOR]

The significance of utilizing photocatalysts to degrade toxic dyes and microbes has grown in recent years. It has been demonstrated as a successful method for utilizing light through hybrid photocatalysts to break down harmful organic molecules. This study aims to investigate the potential applications of CuO–Ag/rGO nanocomposites in environmental remediation. The nanocomposites were synthesized by incorporating Ag and CuO nanoparticles onto rGO nanosheets via hydrothermal method. The nanocomposites that resulted were thoroughly characterized using various analytical techniques to determine their chemical structure, morphology, crystallinity, and photocatalytic application. The degradation efficiency of naphthol black blue (NBB) dye under visible light irradiation was used to assess the photocatalytic performance of the nanocomposites. It was revealed that 80.2%, 90.3%, and 97.3% of NBB dye degraded as a result of enhanced photocatalytic activity of synthesized CuO–Ag/rGO. The research provides valuable insights into the design and development of advanced nanomaterials for efficient and sustainable wastewater treatment applications. [ABSTRACT FROM AUTHOR]

The current study aims to evaluate the effectiveness of undoped (CoFe2O4) and aluminium-doped cobalt spinel ferrite (CoFe1.1Al0.9O4) nanoparticles as photocatalysts in the process of photocatalytic degradation of organic naphthol blue black (NBB) dye. In the sol-gel auto combustion method, a combination of metal nitrates, citric acid, sodium hydroxide, and liquid ammonia was utilized as the raw chemical ingredients for synthesizing nanoparticles of CoFe2-xAlxO4 (x=0.0, 0.3, 0.6, 0.9, 1.2, 1.5) spinel ferrites. The nanoparticles were subjected to various characterization techniques including thermal analysis (TGA/DTA), X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy for comprehensive analysis. The XRD analysis confirmed the presence of a spinel cubic structure in the synthesized spinel ferrite nanoparticles. The interplanar distance (d) and crystalline size (D) were determined using Bragg's equation and Scherrer's relationship, respectively. The morphological characteristics and elemental composition of the spinel ferrites were confirmed through FE-SEM and EDS. Furthermore, the UV spectrum of the synthesized photocatalyst was investigated to compare the energy band gap between undoped and Al-doped cobalt spinel ferrites. The analysis of photoluminescence (PL) spectra was conducted to investigate the dynamics of charge carriers, focusing on their transfer, relocation, and recombination processes. The surface area of the synthesized photocatalyst ranged from 3.525 to 16.113m²/g. Photocatalytic degradation of naphthol blue black (NBB) dye was carried out under visible light exposure utilizing both cobalt spinel ferrite nanoparticles without doping and those doped with aluminium. Several factors, including pH level, H2O2 concentration, amount of photocatalyst (spinel ferrite) and initial dye concentration, were considered through the photocatalytic degradation of NBB dye. The highest percentage degradation (%) of NBB dye was determined at pH 11. For NBB dye with an initial concentration of 20ppm, the maximum degradation was achieved using 200mg of spinel ferrite nanoparticles per 100 mL dye solution under visible light irradiation for 40 min. [ABSTRACT FROM AUTHOR]

A catalytic, regioselective Friedel–Crafts alkylation of beta-naphthol with allylic alcohols has been developed. This procedure allows for selective α-alkylation of β-naphthol with a p-toluenesulfonic acid catalyst. This transformation demonstrated functionalized naphthol synthesis under mild reaction conditions with high product yields – 20 examples with up to 96% yields. The synthetic utility further proved the versatility of the allyl naphthol products. [ABSTRACT FROM AUTHOR]

Reactions of o‐alkyl naphthol compounds with ReCl3(PMePh2)3 produced naphtho‐rhenafuran complexes, which adapted different ground states (singlet S0 and triplet T0). These polycyclic structures have been characterized experimentally and theoretically. Their electronic behaviors have been studied by UV‐Vis absorption and DFT calculations. [ABSTRACT FROM AUTHOR]

The sonochemical‐assisted multicomponent reaction catalyzed by ionic liquid, solvent‐free synthesis, improving chemical structure, computational calculations, and nonlinear optical properties (NLO) assessment of a new amidoalkyl naphthol derivative 4, that is, [N‐((2‐hydroxynaphthalen‐1‐yl)(4‐nitrophenyl)methyl)‐2‐phenylhydrazinecarbothioamide (C24H20N4O3S), are introduced. The corrected structure of the synthesized derivative 4 is confirmed by different spectroscopic techniques viz. (1H and 13C) NMR, Infrared radiation (IR), Mass spectra, and UV‐vis. spectra. To obtain geometrical structure and confirm the experimental findings, DFT‐assisted B3LYP/6‐31G* method is used. The NLO properties of the synthesized derivative are studied using two visible laser beams where its nonlinear refraction index (NLRI) at 473 nm cw laser beam is obtained using diffraction patterns (DPs) and the Z‐scan techniques. As high as 5.312×10−11 m2/W of NLRI is obtained. The all‐optical switching (AOS) which is usually carried out utilizing two laser beams, the controlling and controlled, is generalized by the use of three laser beams, controlling, 473 nm beam and two controlled 532 nm and 635 nm beams. [ABSTRACT FROM AUTHOR]

To address the separation problems and produce the reusable adsorbent, cassava peel magnetic activated carbon (MAC) prepared via microwave-assisted activation has been proposed to replace activated carbon (AC) for naphthol blue-black removal. To create MACs, ACs were embedded with nano-sized magnetite particles using co-precipitation methods. In this sense, 2 different activating agents (i.e., H3PO4 and KOH) have been used. H3PO4 activation provides a larger pore size and more functional groups, while KOH activation provides a larger surface area and higher porosity. The increase of H3PO4 concentration from 40 to 60 % leads to an increase in porosity as well as an increase in the weight ratio of KOH to char from 1 to 3. Impregnation magnetite to the ACs reduces surface area from 457.76 to 337.94 m² g-1 for KOH activation, and from 360.65 to 232.74 m² g-1 for H3PO4 activation, decreasing adsorption capacity from 97.5 to 97 % for KOH activation and from 99 to 98 % for H3PO4 activation. However, the adsorbent is easy to separate under the magnetic influence. The adsorption data of MAC by H3PO4 activation show suitability with the Redlich-Peterson isotherm model, suggesting that naphthol blue-black removal is not ideal monolayer adsorption, but a combination of physisorption and chemisorption processes that exhibit heterogeneity of naphthol blue-black adsorption on the surface of adsorbent. Meanwhile, for MAC by KOH activation, the Langmuir isotherm is more suitable. [ABSTRACT FROM AUTHOR]

Objective. Yak is found in the Qinghai-Tibet Plateau and represents a meat of high nutritional value and good flavor. However, the production of yak is limited, and yak meat adulteration is a growing concern in the marketplace. To protect consumer rights and prevent unfair competition, it is necessary to use an efficient assay to identify the species of yak meat rapidly and accurately being sold. Methods. Loop-mediated isothermal amplification (LAMP) combined with hydroxy naphthol blue (HNB) was used to identify potential adulterants. The specificity and sensitivity tests of yak-derived components were carried out to achieve the monitoring of yak-derived components. Results. The optimal color development was achieved with an external primer-to-internal primer ratio of 400 nmol/L : 1200 nmol/L, 1.5 mmol/L dNTP, and 0.32 U/μL Bst DNA polymerase with 5 mmol/L MgSO4 at 62°C amplification temperature. The detection sensitivity of LAMP-HNB for yak-derived DNA was up to 1 pg/μL. Conclusion. The LAMP-HNB assays provided a valuable tool for the identification of yak gene from adulterated meat. This further enabled the LAMP-HNB assay to be applicable in the identification of other meat products. [ABSTRACT FROM AUTHOR]

We disclosed the dual role of neutral [Hmim]Br towards the direct conversion of arylsulfonic anhydride into arylthiol surrogate for the controlled and regioselective synthesis of 3‐sulfenylindoles from indole derivatives at rt. In addition, 2‐bromo‐3‐sulfenylindoles were synthesized in the presence of catalytic water at 50 °C in a cascade manner i. e. sulfenylation and bromination through de‐oxygenative reduction with [Hmim]Br in the absence of any additional brominating agent. The present method was also utilized for the sulfenylation of other heterocycles including azaindole, coumarin, naphthol, and pyrrole in good to excellent yields. Moreover, mechanistic investigations revealed this reaction was driven by imidazolium cation of neutral ionic liquid i. e. [Hmim]Br, which converts arylsulfonic anhydride into sulfenyl group for sulfenylation/bromination of sp2 C−H bond wherein an acidic ionic liquid [Hmim]pTSA is released as a by‐product. [ABSTRACT FROM AUTHOR]

Selective dehydrogenative silylation is one of the most valuable tools for synthesizing organosilicon compounds. In this study, a regio- and stereoselective ruthenium-catalyzed dehydrogenative intermolecular silylation was firstly developed to access (E)-alkenyl silyl-ether derivatives and silyl-ether heterocycles with good functional group tolerance. Furthermore, two pathways for RuH2(CO)(PPh3)3/NBE-catalyzed dehydrogenative intermolecular silylation of alcohols and alkenes as well as intermolecular silylation of naphthol derivatives were investigated with H2SiEt2 as the hydrosilane reagent. [ABSTRACT FROM AUTHOR]

BACKGROUND: To improve the quality of wastewater and thereby to meet the standards as per environmental production agency in US and UK. In the present work, Malachite green (MG) and Naphthol Green B (NGB) has been taken as model dyes in wastewater. Solvent extraction process was carried out using deep eutectic solvents (DESs) as an alternative solvent for organic and ionic liquids. RESULTS: The possible molecular interaction between DESs and selective dyes in water were analyzed and discussed in details using volumetric properties including excess molar volume VmE, partial molar volume Vi¯, excess partial molar volume V¯iE, apparent molar volume V∅i, isobaric thermal expansion (α) and excess isobaric thermal expansion (αE). Further, the extraction of selective dyes was conducted and characterized in terms of extraction efficiency (η), effect of temperature on extraction efficiency, effect of shaking time on extraction efficiency, effect of concentration on extraction efficiency, effect of HBD on extraction efficiency, distribution coefficient (D). Finally, the thermodynamic extraction feasibility was analysed by means of Gibbs free energy ΔGT0, change in enthalpy ΔHT0, and change in entropy ΔST0. CONCLUSION: There is possible molecular interaction between hydrophilic DESs and NGB/MG in water at molecular level. 96% of extraction efficiency was obtained for NGB using hydrophobic DESs like {[TBAB][DA]} and {[TBAB][OA]} whereas {[TBAB][DA]} and {[TBAB][OA]} gave above 72% removal efficiency of MG. Finally the thermodynamic feasibility of extraction process was analyzed and discussed. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles have been successfully synthesized using water extract of red dragon fruit (Hylocereus polyrhizus) stem with zinc acetate dihydrate as a precursor of ZnO. Chemical compounds contained in the red dragon fruit stem extract, such as phenolics, terpenoids, and steroids, acted as reducing agents, stabilizers, and capping agents. The phase structure, crystallite size, functional groups, shape, and morphology of ZnO nanoparticles were determined by X-ray diffraction (XRD), Fourier Transform infrared (FTIR) Spectroscopy, and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The XRD pattern confirmed the crystallinity of synthesized zinc oxide was in the zincite (ZnO) phase with an average crystallite size of 79.09 nm. Spectroscopy FTIR analysis showed that the synthesized ZnO nanoparticles had characteristics similar to the ZnO standard/commercial. SEM-EDX analysis revealed that the synthesized ZnO nanoparticles were spherical, evenly distributed, and homogeneous particle size. The photocatalytic activity of synthesized ZnO nanoparticles was evaluated on the photodegradation of naphthol blue black (NBB) dye. The results showed that the synthesized ZnO nanoparticles have high photocatalytic activity that can degrade NBB dye up to 98.82%. This high photocatalytic activity was obtained at operating parameter conditions with the initial pH of NBB at 2, the dosage of ZnO nanoparticles at 250 mg, and the initial dye concentration at 10 ppm. [ABSTRACT FROM AUTHOR]

The carbon nanotubes (CNT) have great potential as a metal intelligent anti-corrosion additive due to its excellent conductivity, mechanical property and large specific area. However, their uniform dispersion in the matrix without chemical modification still remains a great challenge, not to mention the corresponding potential mechanism. Herein, a novel hyperdispersant, polymethyl naphthol sulfonate (PMNS), is developed to improve the dispersivity of CNT in a polymer matrix according to the high adsorption energy (− 0.919 eV) of PMNS on the CNT surface calculated by the density functional theory (DFT). This resulting aqueous CNT/acrylate grafted epoxy nanocoating has a conductivity percolation value as low as 0.175 wt%. The CNT(0.25 wt%) nanocoating presents the best both in seawater immersion resistance and in the salt spray resistance improved by 75% in comparison with unfilled coating. The metal corrosion prevention mechanism is revealed to be good dispersibility in polymer matrix and the effective cathode suppression effect caused by the formation of CNT conductive networks revealed by Tafel polarization curves and electrochemical impedance tests. [ABSTRACT FROM AUTHOR]

To prevent the serious threat of textile wastewater, researchers have developed adsorption-based wastewater treatment using cheap, yet effective, adsorbent materials. Of which is natural bentonite, that has the advantages for adsorption due to its porous structure and functional groups but still suffers from its low affinity against anionic and hydrophilic azo dyes. Herein, we aimed of improving the affinity by amino acid tryptophan embedment into the locally isolated natural bentonite collected from Aceh Province, Indonesia. The prepared bentonite samples were characterized using Fourier transform infrared, X-ray diffraction, and scanning electron microscopy. Adsorptive removal was performed on naphthol blue black (NBB) in a batch system with variations of contact time, pH, and adsorbent dosage. The isotherm studies were carried out at optimum conditions (contact time=15 minutes; pH 1; adsorbent dosage=0.2 g) with several models including Langmuir, Freundlich, Sips, and Redlich-Peterson isotherm models. The characterization results revealed that the modification altered its functional group, crystallinity, and micro-surface morphology that add more benefits for adsorption. At optimum conditions, 99.2% NBB has been successfully removed from the aqueous solution. The isotherm studies suggested that the NBB adsorption onto the tryptophane-modified natural bentonite was dependent on Sips isotherm model (R2=0.999; root-meansquare-errors=1.11×10-4 mg/g). [ABSTRACT FROM AUTHOR]

In search of new active molecules, a small focused library of new 1,2,3-triazoles derived from naphthols were efficiently prepared via the click chemistry approach. The synthesized triazole derivatives were evaluated for their antifungal, antioxidant and antitubercular activities. Furthermore, to rationalize the observed biological activity data, the molecular docking study has also been carried out against the active site of cytochrome P450 lanosterol 14α-demethylase of C. albicans to understand the binding affinity and binding interactions of enzyme and synthesized derivatives, which revealed a significant correlation between the binding score and biological activity for these compounds. The results of the in vitro and In Silico study suggest that the 1,2,3-triazole derivatives may possess the ideal structural requirements for the further development of novel therapeutic agents. [ABSTRACT FROM AUTHOR]

Summary Molisch's test is a test for carbohydrates which has the feature to differentiate between pentoses (arabinose, ribose, xylose), hexoses (e.g. glucose, galactose, fructose) and rhamnose, a deoxy sugar, via the colour shown. The use of α‐Naphthol as a solid has to be regarded as questionable. The risk potential of the experiment can be lowered via a reduced amount of applied chemicals thus leading to a thoroughly mixed solution instead of the normally formed ring in the test tube indicating a positive reaction. To further lower the risk potential of the reaction solid α‐Naphthol can be replaced by its ethanolic solution or the use of the natural compound Carvacrol. The implementation of these modifications yields a "new" colorful and meaningful Molisch test which can be used as an experiment for students with simple materials. [ABSTRACT FROM AUTHOR]

A while ago, this journal (Canadian Journal of Chemistry) published a set of seminal studies that revealed the underlying mechanism supporting the widely used 4-aminoantipyrine (4-AAP)-based analytical technique for detecting phenols at low levels in domestic water supplies. The current paper revisits these studies, but with a primary focus on an aspect of the mechanism that synthesizes a 6- and a 7-membered heterocyclic ring containing both N and O in a single step. Here we report a rather unusual outcome of this aspect in which, while the same naphthoquinonimide product is produced in the oxidative coupling of 4-AAP to 1-naphthol in aqueous solution and in the condensation of 4-AAP with 1,4-naphthoquinone in chloroform, a similar pair of reactions with 2-naphthol and 1,2-naphthoquinone produces two oxazepine isomers instead. In one isomer, the 4-AAP/naphthol C–N and C–O linkages are at positions 1 and 2 of the naphthyl ring, respectively; in the other isomer, these linkages are at positions 2 and 1, respectively. This unexpected difference in a one-pot reaction at ambient temperature is potentially the flexibility needed to synthesize families of pharmaceutically relevant oxazepines. Spectroscopic features useful for identifying 12 heterocyclic compounds synthesized here, nine of which are new, are also provided. [ABSTRACT FROM AUTHOR]

A novel peripherally tetra naphthol substituted Co(II) phthalocyanine (NCoPc) was synthesized by the reaction of naphthol linked phthalonitrile, and cobalt chloride, in the presence of catalytic amount of DMF, DBU, and K2CO3. The NCoPc and its composite with MWCNTs were characterized by FTIR, NMR, UV–Vis, XRD, TGA, and mass spectroscopic techniques. The NCoPc and NCoPc-MWCNTs-coated glassy carbon electrodes (GCEs) were used to electrochemically detect and quantify ortho amino phenol (oAP) oAP in aqueous solutions. Cyclic voltammetric data established a linear response between the oAP oxidation current (ipa) and its molar concentration (10–190 μM). The limit of detection (LoD) of the two modified electrodes was comparable (1.5 μM and 25 nM, respectively). The NCoPc and NCoPc-MWCNTs-GCEs (in the concentration range of 10–160 μM) were both low and comparable. The LoD values for oAP at the NCoPc-GCE and NCoPc-MWCNTs by DPV were 1.2 µM and 42 nM and CA were 10 nM and 6.5 nM, respectively. They are exhibited good electrocatalytic activity towards the oxidation of oAP, and this was aided by the improved conductivity of the composite modifiers. [ABSTRACT FROM AUTHOR]

Along with the depletion of petroleum-based fuels, the development of renewable energy resources is a must. One of them is through DSSC (Dye Sensitized Solar Cells) technology, which has a dye sensitizer and semiconductor as the main components. The aim of this research is to investigating the photovoltaic performance of complexes series from metals (Mn(II); Fe(II); Co(II) and Ni(II)) and naphthol blue-black (NB) as a ligand. This investigation also successfully revealed factors that are highly influencing photovoltaic efficiency, namely the band-gap energy and the conductance of metal-NB complexes. The Fe(II)-NB complex has performed the highest photovoltaic activity as a result of the d-d electron transition and MLCT (Metal to Ligand Change Transfer) character which are covered by vivid color from the ligand. The bonding between metal and ligand was shown at a wavenumber of 316.33 cm-1 for M-N bonding and 486.06 cm-1 for M-O bonding. Fe(II)-NB complex had the narrowest band gap energy which is 5.86 eV and had the highest value of conductance and the highest efficiency, namely 0.0925%. This experiment successfully demonstrates that the narrower the energy gap of a molecule, the ability to transfer electrons is faster. Thus, the efficiency of the solar cell becomes higher. This investigation has proven that the narrow band gap makes the electron transfer becomes easier. [ABSTRACT FROM AUTHOR]

Naphthol is a widely used chemical and medical detection biomarker, but it is harmful to human health and the environment. Therefore, a highly sensitive detection method for naphthol is urgently required. Herein, an electrochemical microsensor for the simultaneous detection of naphthol isomers was fabricated by the in situ growth of a three-dimensional graphene network (3DGN) on screen-printed electrodes. The microsensor exhibited good electrochemical sensing responses to typical isomers of naphthol (1-NAP and 2-NAP). Using the differential pulse voltammetry (DPV) method, the microsensor successfully realized the electrochemical detection of 1-NAP, 2-NAP, and naphthol isomer mixtures. Whether detecting naphthol isomers individually or simultaneously, the microsensor exhibited a good linear relationship for 1-NAP and 2-NAP in a wide range of concentrations. For the simultaneous detection of naphthol isomers, the limit of detection (LOD) of the microsensor to 1-NAP reached 10 nM, and the LOD for 2-NAP was about 20 nM. The microsensor also showed good selectivity, reproducibility, and stability. The simultaneous quantitative detection of 1-NAP and 2-NAP was also successfully achieved in synthetic urine samples. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A copper‐catalyzed [5+1] cycloaddition reaction of terminal alkynes with diazo esters for the rapid construction of protected naphthalen‐1(2H)‐one derivatives in moderate to good yields has been disclosed along with good functional group compatibility and a broad substrate scope. The mechanistic investigations reveal that this tandem cyclization process proceeds through a Cu(I)‐catalyzed coupling of terminal alkyne with diazoacetate, a 1,5‐H shift process and a thermally induced pericyclic reaction via an allene intermediate. The synthetic utility and the further transformations of the obtained cycloadduct to naphthalenone, naphthol and dihydronaphthol have been also presented in this paper. [ABSTRACT FROM AUTHOR]

The title compound, C16H11N3O3, belongs to the family of azo dyes. In the light of a single-crystal X-ray study, it is evident that of the tautomeric forms (azo-hydrazone), the hydrazone form is the predominant form in the solid state, namely, (1E)-1-[2-(3-nitro­phen­yl)hydrazin-1-yl­idene]-1,2-di­hydro­naphthalen-2-one. The naphthol and benzene fragments attached to the -N=N-moiety adopt the s-trans conformation. Furthermore, the mol­ecules are nearly coplanar, subtending a dihedral angle of 2.63 (5)°. An intra­molecular N--H⋯O hydrogen bond occurs. There are only two types of inter­molecular inter­actions in the crystal structure: strong hydrogen-bonding C--H⋯O inter­actions and π-π stacking inter­actions. The importance of C--H⋯O inter­actions in the mol­ecular packing is reflected by the relatively high contributions (28.5%) made by O⋯H/H⋯O contacts to the Hirshfeld surface. [ABSTRACT FROM AUTHOR]

A green multi‐component approach for the synthesis of a new series of bis‐Betti base derivatives via Mannich‐type reaction was developed based on the one‐pot pseudo five‐component reaction of 5,5′‐methylenebis(thiazol‐2‐amine), aromatic aldehydes and 2‐naphthol in the presence of p‐toluenesulfonic acid as organocatalyst under solvent‐free conditions. The attractive features of this method are operational simplicity, metal‐free conditions, environmentally friendly, high atom‐economy, shorter reaction time, broad substrate scope, easy workup procedure, purification of products by nonchromatographic methods and good to high yields. [ABSTRACT FROM AUTHOR]

The naphthol reds are a family of intermediate performance monoazo organic pigments and three of its members, C.I. Pigment Red 148, C.I. Pigment Red 170 (Naphthol Red), and C.I. Pigment Red 188, have been cited as having original automotive paint applications. This study sought to determine which were used in North American vehicle original finishes (1974 to 2019) and how they can be differentiated and identified in situ in paint infrared spectra. Naphthol Red was the only such pigment found and based on a comprehensive survey, absorptions of this pigment were identified in spectra of 12 of the 373 (3%) red or maroon nonmetallic original finishes examined. Identification of Naphthol Red in an unknown finish can thus serve to limit the number of possible source vehicles and spectra of the twelve are presented to facilitate this examination, along with a list of the vehicles that the twelve were used on. For a comparative analysis, identification of this pigment in questioned and known specimens may provide some means of assessing the significance of the finding. Two Inmont red nonmetallic acrylic melamine basecoats, one of which contains Naphthol Red, were found to have quite unusual infrared spectra that are readily distinguished from those of the other 371 finishes examined, and they are discussed. Naphthol Red was also identified in some color‐coordinated automotive paint primers and its use appears to be more common in these than in the finish layers. [ABSTRACT FROM AUTHOR]

We have measured the intermolecular dissociation energies D0 of supersonically cooled 1-naphthol (1NpOH) complexes with solvents S = furan, thiophene, 2,5-dimethylfuran, and tetrahydrofuran. The naphthol OH forms non-classical H-bonds with the aromatic π-electrons of furan, thiophene, and 2,5-dimethylfuran and a classical H-bond with the tetrahydrofuran O atom. Using the stimulated-emission pumping resonant two-photon ionization method, the ground-state D0(S0) values were bracketed as 21.8 ± 0.3 kJ/mol for furan, 26.6 ± 0.6 kJ/mol for thiophene, 36.5 ± 2.3 kJ/mol for 2,5-dimethylfuran, and 37.6 ± 1.3 kJ/mol for tetrahydrofuran. The dispersion-corrected density functional theory methods B97-D3, B3LYP-D3 (using the def2-TZVPP basis set), and ωB97X-D [using the 6-311++G(d,p) basis set] predict that the H-bonded (edge) isomers are more stable than the face isomers bound by dispersion; experimentally, we only observe edge isomers. We compare the calculated and experimental D0 values and extend the comparison to the previously measured 1NpOH complexes with cyclopropane, benzene, water, alcohols, and cyclic ethers. The dissociation energies of the nonclassically H-bonded complexes increase roughly linearly with the average polarizability of the solvent, α ¯ (S). By contrast, the D0 values of the classically H-bonded complexes are larger, increase more rapidly at low α ¯ (S), but saturate for large α ¯ (S). The calculated D0(S0) values for the cyclopropane, benzene, furan, and tetrahydrofuran complexes agree with experiment to within 1 kJ/mol and those of thiophene and 2,5-dimethylfuran are ∼3 kJ/mol smaller than experiment. The B3LYP-D3 calculated D0 values exhibit the lowest mean absolute deviation (MAD) relative to experiment (MAD = 1.7 kJ/mol), and the B97-D3 and ωB97X-D MADs are 2.2 and 2.6 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

The venerable axially chiral biaryl skeletons used widely in asymmetric catalysis such as BINOLs, NOBINs, QUINOLs, and CPAs possess a 2-naphthol moiety or are derived from the naphthol precursor. The hydroxy functionality offers the interaction point or serves as functional handle for synthetic elaboration. This prevalence and significance drive our studies to incorporate this nucleophile class to fabricate an assortment of atropisomers. By activating the reacting partners via distinctive mechanisms, the arylation of quinones, azo- or nitroso-naphthalenes, VQM intermediates, 1,2,4-triazole-3,5-diones, isoquinolines, and 1-bromo-2-naphthols with 2-naphthols were successfully attained. A concise account of these developments is provided in this article. 1 Introduction 2 Asymmetric Arylation with Quinones 3 Asymmetric Arylation with Electron-Deficient Arenes 4 Asymmetric Synthesis of Atropisomers with other Electrophiles 5 Conclusion [ABSTRACT FROM AUTHOR]

Naphthopyranopyrimidine derivatives are an important class of naturally occurring tetraheterocyclic organic compounds that are used as dyes, fluorescent materials for visualization of biomolecules, and in laser technology. Moreover, they are known for biological and pharmaceutical activities. Herein, we briefly reviewed the history of synthesis approaches of naphthopyranopyrimidine and spironaphthopyranopyrimidine derivatives from naphthols, aldehydes/isatins, and barbituric acid/1,3-dimethylbarbituric acid/thiobarbituric acid/1,3-dimethyl-2-thiobarbituric acid/6-amino-1,3-dimethyluracil in the presence of both homogeneous and heterogeneous catalysts reported by research groups. [ABSTRACT FROM AUTHOR]

A cascade cyclization from Weinreb amide‐tethered methylenecyclopropanes and alkynes has been disclosed in this paper, which extends the umpolung ring opening of methylenecyclopropanes, giving a synthetic approach for the construction of polycyclic cyclopenta[b]naphthalenol framework. In the protocol, four carbon‐carbon bonds and two carbocycles are formed without the use of transition metals, providing a tool for constructing the structure‐related polycyclic compounds. [ABSTRACT FROM AUTHOR]

6-Hydroxyquinoline and 3-hydroxyisoquinoline as N-containing naphthol analogues were tested in modified Mannich reactions (mMr's). In the case of 6-hydroxyquinoline, the outcomes of the attempted Mannich reactions were strongly influenced by the amine components. Aminoalkylation of this substrate with reagents 1-naphthaldehyde and N-benzylmethylamine led to the isolation of a diol regarded as a stabilised water adduct of an ortho-quinone methide (o-QM), of which formation can be ascribed to the presence of a hydroxide ion in a relatively higher concentration generated by the bulky and basic amine component with decreased nucleophilicity. The classical Mannich base was isolated as a single product when the amine component was replaced for morpholine, featuring nucleophilicity rather than basic character under the applied reaction conditions. Starting from the isomer substrate 3-hydroxyisoquinoline, independently on the nucleophile (methanol or morpholine) besides the formation of the classical Mannich base, the nucleophilic attack at position one of the heterocyclic substrate was also observed. The DFT analysis of the acceptor molecular orbitals of the potential electrophilic components and the thermodynamics of the assumed-possible transformations demonstrated that this regioselective addition is a feasible process on the investigated heterocyclic skeleton. DFT modelling studies also suggest that besides the steric bulk, the orbital-controlled electronic properties of the aryl group, originating from the aldehyde components, have a strong influence on the ratios and the NMR-monitored interconversions of the C-1-substituted 3-hydroxyisoquinolines and the classical Mannich bases formed in multistep reaction sequences. On the basis of the DFT analysis of the thermodynamics of alternative pathways, a reaction mechanism was proposed for the rationalization of these characteristic substrate-controlled interconversions. [ABSTRACT FROM AUTHOR]

Nearly half of the world's population have been infected with Helicobacter pylori (H. pylori) which is known as the main cause of chronic gastritis, duodenal ulcer illness as well as stomach carcinoma. In this work, an efficient, one-pot synthesis of amidoalkyl naphthol derivatives and their in vitro anti-Helicobacter pylori activity are reported. The reaction proceeds via multi-component condensation of 2-naphthol, (hetero) aromatic aldehydes and urea/thiourea/acetamide/2-aminothiazole/4-nitrothiazol-2-amine/2-aminopyridine under solvent-free condition. This protocol includes some salient features, such as using triethanolammonium acetate ([OHCH2CH2)3NH][OAc]) ionic liquid as a green, clean and reusable catalyst, high yields, no column chromatography, and low cost. By comparing the inhibition zone of the target compounds, 6e and 6j could be considered as the best anti-helicobacter agent. [ABSTRACT FROM AUTHOR]

The naphthofuran and its derivatives are important biological compounds so we have focused on the synthesis of naphthofuran derivatives. The synthesized compounds of ethyl 1-(acetylamino)-5-nitronaphtho[2,1-b]furan-2- carboxylate (3), and N-[2-(hydrazinylcarbonyl)-5-nitronaphtho[2,1-b]furan-1-yl]acetamide (4) used for the synthesis of N-(2-{[(2Z)-2-benzylidenehydrazinyl]carbonyl}-5-nitronaphtho[2,1-b]furan-1-yl)acetamide compounds of four derivatives 5 (a-d) and 1-acetamido-5-nitro-N-(5-oxo-2-phenylthiazolidin-3-yl)naphtha[2,1-b]furan-2-carboxamide compounds of four derivatives 6 (a-d). The prepared compounds were confirmed by FTIR NMR, and mass methods. The prepared naphthofuran derivatives used for the antibacterial activity versus both Gram(+ve) and Gram(-ve) bacteria show excellent results. Therefore the synthesized compounds are used for further antibacterial studies in the medical field. [ABSTRACT FROM AUTHOR]

In this manuscript, the application of cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC) for the removal of Naphthol Green B (NGB) as a synthetic effluent has been studied. The solubilization of NGB by a single and mixed micellar system using Triton X-100 (TX-100) as a nonionic surfactant has been performed to establish both the extent of the partitioning (kx) of NGB and ultimately their respective Gibbs free energies ΔGp as well. An applied methodology, micellar-enhanced ultrafiltration (MEUF), has also been studied in different micellar media of cationic surfactants by variation in some selective parameters, such as the concentration of surfactant, electrolyte, pressure, pH, and RPM to obtain optimum conditions. The results have been analyzed by a UV/visible double beam spectrophotometer. ΔGp was found to be −39.65 kJ/mol and −47.94 kJ/mol by CTAB and CPC, respectively, in the presence of a nonionic surfactant. The maximum value of Gibbs free energy (ΔGp) of the partition was obtained by CPC. The values of the rejection coefficient (R%) and permeate flux (J) are also calculated. A maximum removal of 99.77% and 98.53% by CTAB and CPC, respectively, was obtained. It has been observed that both of the surfactants are strong candidates for NGB removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structural dependent Fenton activity catalyzed by natural magnetite is studied. • Main influence factor of magnetite Fenton activity is probed by redundancy analysis. • Naphthol degradation is closely associated with Ti and V content. • H 2 O 2 accelerate e−−h+ separation of ilmenite resulting in high O 2 − generation. • Naphthol degradation is a detoxification process as revealed by GC–MS and ECOSAR. Magnetite is a ubiquitous iron mineral in nature and its iron ions are usually isomorphically substituted by Ti and V cations, which shows a high ability for degradation of organic contaminants via the photo-Fenton process. However, numerous reports pay more attention to the activity of synthetic magnetite rather than natural magnetite. Here, three types of natural magnetite (HG01, HG02, and GCL01) with different Ti and V contents were investigated from the perspective of the difference in structural property, catalytic activity, H 2 O 2 decomposition, and reactive oxygen species generation. Structural characterization exhibited that the purity of natural magnetite obeyed the order: GCL01 > HG02 > HG01. HG01 contained the highest Ti content in the form of ilmenite, followed by HG02 and GCL01. Moreover, HG01 yielded the highest photo-Fenton catalytic activity with 99.5 % of naphthol degradation and 96.0 % of H 2 O 2 decomposition after 60 min reaction. The superior activity of HG01 was attributed to the relatively high Ti and V content as demonstrated by redundancy analysis. Mechanistic investigation implied that the Ti and V in the octahedral sites of the magnetite surface can accelerate the electron transfer from Fe(III) to Fe(II), resulting in higher Fenton activity. Besides, ilmenite in HG01 enhanced naphthol degradation because H 2 O 2 accelerated the separation of photoelectron-holes pairs to promote O 2 − production. Furthermore, as revealed by gas chromatography-mass spectrometry and the toxicity of identified products predicted by the ECOSAR model, the toxicity of naphthol can effectively reduce accompanied by the harmless products generated. The high reusability, low iron ions residual in water, harmless end products, and easily recycled with magnetic separation suggest that natural magnetite has a promising application prospect for wastewater purification. [ABSTRACT FROM AUTHOR]

V-Ce/Ti catalysts were prepared for the removal of naphthalene and NO x in the flue gas. The adverse effects of NH 3 and NO on the naphthalene degradation were weakened on V-Ce/Ti, resulting in a decrease of only 2.5 % in CO x selectivity. The formation of high molecular weight byproducts was also reduced. Besides the acid sites on the catalysts, Ce introduced new Brønsted basic sites, which could also adsorb and degrade naphthalene into naphthol effectively. With the separated active sites for naphthalene degradation and NO removal, the reaction between NH 3 and the intermediates during the naphthalene degradation was also inhibited, decreasing the formation and accumulation of phthalimide. The oxidation of the intermediates was promoted by active V5+ introduced by Ce, inhibiting the transformation of the intermediates to higher molecular weight byproducts. Nearly 100 % conversion of naphthalene and NO, as well as 40.1 % of the CO x selectivity were obtained on V-Ce/Ti. [Display omitted] • V-Ce/Ti catalysts weakened the adverse effect of SCR reaction on Nap degradation. • Ce built separated active sites for Nap degradation and SCR reaction. • Ce-OH worked as Brønsted basic sites avoided the competitive adsorption between Nap and NH 3 on the active sites. • The enhanced the redox property of V-Ce/Ti inhibited the transformation of Nap to higher molecular PAHs. • The interaction between V and Ce led to effective oxidation of by-products. [ABSTRACT FROM AUTHOR]

The main chain of the inorganic polymer polyphosphazene exhibits good alkaline stability, but its poor film-forming properties and excessive water uptake have led to its limited application in the field of anion exchange membranes. In this study, naphthol-substituted polyphosphazene anion exchange membranes demonstrate good film-forming properties and conductivity. When the degree of naphthol substitution reaches around 33%, the hydrophobic main chain and hydrophilic side chain can form a well-defined hydrophilic and hydrophobic phase separation structure. Its ionic conductivity can reach 59.1 mS cm−1 at 80 °C, with a swelling ratio of only 23.5%. Observation under atomic force microscopy reveals that this is due to the introduction of naphthol, which enhances the π-π stacking effect between the main chains, forming a more stable hydrophobic region. Furthermore, when exposed to 4 mol L−1 NaOH at 80 °C for 1000 h, the ionic conductivity of NapP2N-4 decreased by only 19%, and the elongation at break did not significantly decrease, reflecting its good alkaline stability. • Synthesized a multisubstituted polyphosphazene anion exchange membrane. • Quaternary ammonium polyphosphazenes with naphthol substitution have good phase separation structure. • Effectively enhancing polysubstituted polyphosphazenes with naphthol substituted groups. [ABSTRACT FROM AUTHOR]

A diphenyl prolinol TMS ether-catalyzed stereoselective reaction of 1-bromo-2-naphthols with enals has been developed. The organocatalyzed cross coupling-like reaction servers an efficient approach to sterically congested (E)-α-naphthyl enals. The formal C(sp2)-C(sp2) cross-coupling products are obtained in good yields and with excellent stereoselectivities in favor of E-isomers. A broad range of aromatic enals and 1-bromo-2-naphthols are tolerated. The synthetic strategy significantly expands the scope of the organocatalytic cross-coupling-like reactions by enabling sterically demanding 1-bromo-2-naphthols as viable substrates.

Novel green natural composites comprising of BF immobilized in CS (BF-i-CS) were prepared and characterized by means of Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). It was observed that BF is not grafted to but widely dispersed and immobilized within the CS matrix by physical mean. The effect of pH on the controlled-release behavior of BF-i-CS was investigated using 1- and 2-naphthol as model pesticides. The results revealed that the release amount was found higher in acidic medium followed by neutral and basic medium. On average, the release behavior of 1- and 2-naphthol was found controlled, consistent and prolonged over a period of 36 and 30 h, respectively.

In this project, Sn(II)/nano silica has been prepared using a simple deposition of SnCl2.2.H2O on nano-silica. The prepared catalyst has been used as a green and reusable catalyst for synthesis of 14H-dibenzoxanthenes through a one-pot condensation reaction of β-naphthol with various aliphatic and aromatic aldehydes. Several xanthene derivatives have been synthesized using ethanol as the solvent, 10 mol percent of the catalyst, at reflux condition, in 3 h, and by 48%–94% yield. The structures of the synthesized derivatives are confirmed by melting point, FT-IR, 13C-NMR, and 1H-NMR analyses. Additionally, the nanocatalyst composition was confirmed by SEM, EDX, FT-IR, and XRD.

Using the stimulated-emission-pumping/resonant 2-photon ionization (SEP-R2PI) method, we have determined accurate intermolecular dissociation energies D0 of supersonic jet-cooled intermolecular complexes of 1-naphthol (1NpOH) with alkanes, 1NpOH·S, with S = methane, ethane, propane, and n-butane. Experimentally, the smaller alkanes form a single minimum-energy structure, while 1-naphthol·n-butane forms three different isomers. The ground-state dissociation energies D0(S0) for the complexes with propane and n-butane (isomers A and B) were bracketed within ±0.5%, being 16.71 ± 0.08 kJ/mol for S = propane and 20.5 ± 0.1 kJ/mol for isomer A and 20.2 ± 0.1 kJ/mol for isomer B of n-butane. All 1NpOH·S complexes measured previously exhibit a clear dissociation threshold in their hot-band detected SEP-R2PI spectra, but weak SEP-R2PI bands are observed above the putative dissociation onset for the methane and ethane complexes. We attribute these bands to long-lived complexes that retain energy in rotation-type intermolecular vibrations, which couple only weakly to the dissociation coordinates. Accounting for this, we find dissociation energies of D0(S0) = 7.98 ± 0.55 kJ/mol (±7%) for S = methane and 14.5 ± 0.28 kJ/mol (±2%) for S = ethane. The D0 values increase by only 1% upon S0 → S1 excitation of 1-naphthol. The dispersion-corrected density functional theory methods B97-D3, B3LYP-D3, and ωB97X-D predict that the n-alkanes bind dispersively to the naphthalene “Face.” The assignment of the complexes to Face structures is supported by the small spectral shifts of the S0 → S1 electronic origins, which range from +0.5 to −15 cm−1. Agreement with the calculated dissociation energies D0(S0) is quite uneven, the B97-D3 values agree within 5% for propane and n-butane, but differ by up to 20% for methane and ethane. The ωB97X-D method shows good agreement for methane and ethane but overestimates the D0(S0) values for the larger n-alkanes by up to 20%. The agreement of the B3LYP-D3 D0 values is intermediate between the other two methods. [ABSTRACT FROM AUTHOR]

Gummy stem blight (GSB) caused by Didymella bryoniae (D. bryoniae) is a worldwide fungal soil-borne disease that can cause severe yield reduction of watermelon. To shorten the monitoring time of carbendazim-resistant strains of D. bryoniae in the field, in this study, we developed a loop-mediated isothermal amplification (LAMP) assay for rapid detection of carbendazim-resistant strains of D. bryoniae. The β-tubulin gene of carbendazim-resistant strains was selected as the target for primer design. Based on the color change of hydroxy naphthol blue (HNB) and gel electrophoresis, the optimal reaction conditions for LAMP were determined at 65 °C for 50 min. In specificity tests, the LAMP assay was able to distinguish between carbendazim-resistant and sensitive strains of D. bryoniae. Moreover, in sensitivity tests, the detection limit was 1 ng/μL D. bryoniae DNA of the carbendazim-resistant strain. In addition, the LAMP method was successfully applied to detect carbendazim-resistant strains in D. bryoniae-infested samples. Therefore, the developed LAMP assay provides a new method for the rapid detection of carbendazim-resistant strains of D. bryoniae. [ABSTRACT FROM AUTHOR]