Naphthalene Compounds Research Articles

Synthesis and evaluation of naphthalene derivatives as potent STAT3 inhibitors and agents against triple-negative breast cancer growth and metastasis.

Triple-negative breast cancer (TNBC) represents the worst prognostic subtype of breast cancer and lacks targeted therapeutic drugs. Signal transducer and activator of transcription 3 (STAT3) is overexpressed and constitutively activated in TNBCs and associated with poor patient outcomes. However, no agents targeting STAT3 have been successfully developed and marketed. Selective Estrogen Receptor Modulators (SERMs) have been reported as potential inhibitors of the IL-6/STAT3 signaling pathway. Naphthalene compounds have good pharmacological activity and significant anti-cancer activity. In this study, we synthesized a new series of naphthalene derivatives with the general structure of SERM and evaluated their effects on TNBC and STAT3 signals. A new series of compounds based on the scaffold of SERMs and an amino group were designed and screened based on the structure-activity relationship by MTT assay. The binding activity of SMY002 to STAT3 was predicted and validated by docking and SPR. The STAT3 signaling target and anti-cancer effects of SMY002 were evaluated with three TNBC cell lines and the mice transplanted tumor model. Among the compounds, SMY002 displayed the most potent activity, which could directly interact with STAT3 SH2-domain, and strongly inhibit the phosphorylation, dimerization, nuclear distribution, transcriptional activity, and target genes expression of STAT3. Furthermore, SMY002 markedly suppressed migration, invasion, survival, growth, and metastasis of TNBC cells in vitro and in vivo via down-regulating the expression of Cyclin D1 and MMP9. SMY002 can significantly inhibit the growth and metastasis of TNBC cells by targeting the STAT3 signal.

Study on the slurrying properties of semi-coke with dispersants and the interaction between semi-coke particles based on E-DLVO theory

It is essential to prepare the semi-coke water slurry (SCWS) using semi-coke powder in China. The preparation of SCWS can not only alleviate the oil demand, but can also provide a new way to utilize semi-coke powder. In this work, the effects of sodium methylene naphthalene sulfonate (NNO), sodium lignosulfonate (SLS), sodium humate (SH), polycarboxylate (PCE), and compound anion-anion (NNO/PCE), on the slurrying performance of semi-coke water slurry (SCWS) were studied. The results showed that the anionic dispersants increased the concentration of SCWSs, and the slurry exhibited the pseudoplastic rheological behavior of shear thinning. Adding PCE and NNO/PCE in the SCWS could improve its stability and fluidity. The absorbed capacity the microstructure of the particles, surface tension, contact angle, as well as Zeta potential of semi-coke powder were impacted by the addition of anionic dispersants in the SCWS. The results showed that anionic dispersants were adsorbed on the surface of semi-coke by a single-molecular layer. The developments of molecular dynamics simulation indicated that all dispersants should be spontaneously adsorbed on the surface of semi-coke, and the addition of anionic dispersants could reduce the contact angle and surface tension of the semi-char particle surface, increase the hydrophilicity and enhance the electronegativity. Finally, extended Derjaguin–Landau–Verwey –Overbeek (E-DLVO) theory calculations showed that adsorption of dispersants could significantly increase the total interaction energy between semi-coke particles. Finally, a model of the interaction mechanism of the anionic dispersants and semi-coke particles was proposed in this paper.

Synthesis of Naphthalene Natural Products Dehydrocacalohastine and Musizin

AbstractNatural methylated naphthalene compounds, possessing diverse biological activities, remain to be studied because of low content in plants and lacking synthetic methods. Herein, we have disclosed new approaches to methylated naphthalene natural products represented by dehydrocacalohastine and musizin from simple and commercially available naphthalene molecules with the assistance of our reported regioselective C−H methylation. The dehydrocacalohastine has been firstly synthesized from 1‐bromonaphthalen‐2‐ol in overall 8.9% yield with 8 steps. Additionally, the solution to musizin saved 2 steps with comparative yields to previous reported route.

Distinguishing “Through-Space” from “Through-Bonds” Contribution in Indirect Nuclear Spin–Spin Coupling: General Approaches Applied to Complex JPP and JPSe Scalar Couplings

We present herein two complementary theoretical approaches for analyzing the transmission pathways of indirect nuclear spin-spin couplings in high-resolution nuclear magnetic resonance. This phenomenon is notably conceptually poorly understood in complex experimental situations in which both nonbonded ["through-space" (TS)] and more "classical" bonding ("through-bond") spin-spin coupling pathways are potentially involved. The computational approaches we propose allow the visualization and discussion of individual transmission pathways and estimation of their relative weight from numerical contributions to the spin-spin coupling constant J-value. The first approach is based on the analysis of contributions limited to occupied molecular orbitals [focused on occupied molecular orbitals (FOMO)]. The second approach encompasses the consideration of both occupied and vacant orbitals [global molecular orbital contributions (GMOC)], and, besides the contributions from individual pathways, also considers their cross contributions. Both approaches are applicable to large systems with complex interactions of nuclear magnetic moments. Herein, we have first applied the FOMO and GMOC computational approaches to simple diphosphine models and then extended the analysis to JPP and JPSe experimentally measured in a constrained selenated (diphosphino)naphthalene compound. The new computational tools contributed evidence for the importance of the single lone pair not only from phosphorus but also from selenium in TS spin-spin transmission. It evidenced and modeled for the first time the existence of spin-spin transmission pathways mixing classical covalent bonding parts with a lone pair overlap of proximate heteroatoms (P and Se).

Theoretical Determination of Corrosion Inhibitor Activities of Naphthalene and Tetralin

Quantum mechanical methods were used to investigate the corrosion inhibitor activities of tetraline and naphthalene compounds. In this study, some parameters were estimated, including, the energy of the highest occupied molecular orbital (EHOMO), the energy of the lowest occupied molecular orbital (ELUMO), the energy bandgap (ΔE = ELUMO - EHOMO), and the dipole moment (μ). The aforementioned parameters give information about the corrosion efficiency of organic compounds. Furthermore, the density functional theory (DFT) was handled to determine the geometry of the molecules and electronic characteristics of the compounds. B3LYP/6-31G (d, p) was utilized to determine physical parameters such as hardness (ɳ), softness (σ), and electronegativity (χ). We also evaluated quantum chemistry characteristics including the fraction of electrons transported (ΔN) between the iron surface and our title compounds. This study also discusses which parameters have a significant linear relationship with inhibitory performance. The findings suggest that the behavior of organic-based corrosion inhibitors is correlated with the effectiveness of good corrosion inhibitors and the quantum chemical parameters measured from this process. As a result, the behavior of corrosion inhibitors can be determined without the need for an experiment.

Monooxygenase and dioxygenases by bacterial specific enzymes network

Naphthalene, a polycyclic aromatic hydrocarbon (PAH), is present in different industrial sites, including combustion products of fossil products (such as coal tar and petroleum) and biofuels. It is also a chemical with a substantial quantity of commercial manufacturing. Moth repellents and toilet deodorant blocks are among the most common consumer items that include the chemical compound naphthalene. It is also widely used in the production of chemical intermediates (such as phthalic anhydrides) as well as pigments and surfactants, and in the tanning of leather. Naphthalene has critical health impact, inducing mutations and/or cancers. This review focuses on the bacterial enzymes used in the degradation of naphthalene. Naphthalene is an important contaminant of environment that can cause serious health problems. The compound can be bacterial-degraded used specific enzymes networks, such as monooxygenases, dioxygenases, dehydrogenases, etc.

Aqueous Mediated Heterogeneous Catalysis

Pyrolysis atmosphere has significant effect on yield and composition of coal tar. A pyrolysis and gasification integrated reactor in laboratory was used to investigate effects of gasification syngas on yield and composition of coal tar. The results show that tar yield of Naomaohu coal reaches the maximum at 600 °C, and gasification syngas (G-gas) is more beneficial to improve the tar yield at low temperature (550−600 °C). Especially, 550 °C tar yield increases by 4.4% compared with that under N2. With the introduction of G-gas, the yield of tar obtained at high temperature (650−800 °C) decreases, but the quality of tar obtained at 650−700 °C is improved obviously due to the increase of light components. The cracking reaction of aliphatic hydrocarbons and oxygen-containing compounds in volatiles from pyrolysis at 550 and 600 °C is intensified by G-gas, thus substituted benzene and naphthalene compounds in coal tar increase. For the volatiles obtained above 650 °C, the secondary cracking reaction of phenolic compounds is enhanced with the introduction of G-gas, which results in a decrease of phenolic compounds in tar. G-gas is also favorable for the secondary cracking reaction of polycyclic aromatic hydrocarbons in volatiles from pyrolysis at 800 °C, but more favorable for generation of which in the tar obtained below 700 °C

Effects of syngas from semi-coke in situ gasification on yield and quality of tar from pyrolysis of Naomaohu coal

Pyrolysis atmosphere has significant effect on yield and composition of coal tar. A pyrolysis and gasification integrated reactor in laboratory was used to investigate effects of gasification syngas on yield and composition of coal tar. The results show that tar yield of Naomaohu coal reaches the maximum at 600 °C, and gasification syngas (G-gas) is more beneficial to improve the tar yield at low temperature (550−600 °C). Especially, 550 °C tar yield increases by 4.4% compared with that under N2. With the introduction of G-gas, the yield of tar obtained at high temperature (650−800 °C) decreases, but the quality of tar obtained at 650−700 °C is improved obviously due to the increase of light components. The cracking reaction of aliphatic hydrocarbons and oxygen-containing compounds in volatiles from pyrolysis at 550 and 600 °C is intensified by G-gas, thus substituted benzene and naphthalene compounds in coal tar increase. For the volatiles obtained above 650 °C, the secondary cracking reaction of phenolic compounds is enhanced with the introduction of G-gas, which results in a decrease of phenolic compounds in tar. G-gas is also favorable for the secondary cracking reaction of polycyclic aromatic hydrocarbons in volatiles from pyrolysis at 800 °C, but more favorable for generation of which in the tar obtained below 700 °C

Threshold Sooting Index of Sustainable Aviation Fuel Candidates from Composition Input Alone: Progress toward Uncertainty Quantification

A quantitative structure–property relationship model has been developed to predict the threshold sooting index (TSI) of arbitrary mixtures of aliphatic and aromatic hydrocarbons of known composition. The model employs contributions from eight molecular fragments plus a global shift and a penalty factor for naphthenic compounds. For each coefficient, the contributions were determined by a constrained regression to data from five different experimental campaigns, which were stitched together by setting the TSI of methylcyclohexane to 5 and the TSI of 1-methylnaphthalene to 100. Unique to this study; the TSI of 1,3,5-trimethylbenzene was restricted to the range of 54.7 and 63.1, which significantly constrains uncertainty. Within the composite training dataset, which contained 65 molecules and 124 data points, including simple mixtures, the model was found to match 95% of the data within 8.9 TSI. Validation of the model against n-butylcyclohexane, dimethylcyclooctane, and a six-component surrogate jet fuel shows prediction to be well within the 95-percentile confidence band of the experiment. This model is the first to integrate the linear blending rule for the TSI with a linear quantitative structure–property relationship model for the TSI, and the first time that referee controls have been applied to ensure that all datasets, experimental and modeled, are normalized to the same scale.

A Study on the Catalytic Technology for Reduction of Naphthenic Acid Compound from Acidic Crude Oil

The existence of naphthenic acid (NA) in acidic crude oil tends to corrode the oil refinery equipment. In this study, a catalytic deacidification reaction involving the deacidifying agent and the synthesised catalyst was aimed to eliminate NA from acidic crude oil. Diethanolamine-polyethylene glycol (DEA-PEG) was introduced as a deacidifying agent. The wet impregnation method was applied for synthesizing the calcium oxide catalyst doped by copper supported on alumina (Cu/Ca/Al2O3). The potential catalyst was characterised utilising field emission scanning electron microscopy-energy dispersive X-ray (FESEM-EDX), Brunauer-Emmett-Teller (BET), and X-ray diffraction spectroscopy (XRD). The parameters include deacidifying agent dosing, loading dopant ratio and catalyst calcination temperature were performed to enhance the catalytic deacidification process in this study. Data showed that the total acidic number (TAN) value for crude B met the PETRONAS requirement for the TAN value below one using 1500 mg/L of DEA-PEG assisted by Cu/Ca (10:90)/Al2O3 catalyst.

Insights into Ultrasound-Promoted Degradation of Naphthenic Acid Compounds in Oil Sands Process Affected Water. Part Ii: In Silico Quantum Screening of Hydroxyl Radical Initiated and Propagated Degradation of Benzoic Acid

Insights into Ultrasound-Promoted Degradation of Naphthenic Acid Compounds in Oil Sands Process Affected Water. Part Ii: In Silico Quantum Screening of Hydroxyl Radical Initiated and Propagated Degradation of Benzoic Acid

The cobalt(ii)-catalyzed acyloxylation of picolinamides with bifunctional silver carboxylateviaC–H bond activation

The cobalt(ii)-catalyzed C–H bond acyloxylation of picolinamides with bifunctional silver carboxylate has been developed. The mild and practical esterification provides an atom-economic route to access to polysubstituted naphthalene compounds.

Concentration of some Polycyclic Aromatic Hydrocarbons in soil samples of Kirkuk province, Iraq

In order to evaluate the quantity of twelve PAHs (Naphthalene, Tetraphan and Acenaphthylene Fluorene, Phenanthrene, Anthracene, Pyrene, Benzo [a] Anthracene, Ovalene, Chrysene, Benzo [a] fluoranthene and DiBenzo [ah] Anthracene) in the soil samples from Kirkuk province, seven sites (Ras El-Gesr, Benja Ali, Wahed Hozeran, North Oil Company (NOC), Lillan, Kubri and Chimen) were selected using Gas Chromatography (GC) during the autumn 2017 and winter 2018. The results showed that the highest concentration of individual hydrocarbons during the autumn season was for the Acenaphthylene compound in the NOC site 131.19 μg/kg, and for Naphthalene compound, was 100.543μg/kg. The NOC recorded the highest concentration of total hydrocarbons 891.65 μg/kg. For the winter season, the highest concentration of polycyclic aromatic hydrocarbons was recorded for the Fluorene compound at the NOC site 79.19 μg/kg. Fluorene and Naphthalene compounds achieved the highest averages for the season (43.24 and 42.984 μg/kg) respectively, and recorded the location of the NOC, the highest summation of total hydrocarbons amounted to 609.77 μg/kg.

Polycyclic Aromatic Hydrocarbon (PAHs) compound in sea-water of Cimandiri river estuary, Pelabuhan Ratu

Polycyclic Aromatic Hydrocarbon (PAHs) is a polycyclic aromatic organic compound that is toxic to humans and aquatic organisms. This research aims to determine the level of pollution of PAHs compounds in seawater at the estuary of Cimandiri River, Pelabuhan Ratu. This research was conducted in April 2017 by survey method. Seawater samples were taken using a water sampler at 15 research stations. The levels and types of PAHs compounds were determined using Gas Chromatography-Mass Spectrometer (GC-MS), and PAHs sources with individual ratios diagnose. The results showed that seawater in the Cimandiri River Estuary still relatively low from contamination of PAH compounds. The type of PAH in seawater at the estuary of the Cimandiri River is dominated by low molecular weight naphthalene compound. PAH contained in seawater at the estuary of the Cimandiri River possibly comes from various sources, likely oil spills, burning petroleum, and combustion of organic compounds. PAH content in seawater of Cimandiri River estuary relatively small and still within the criteria for marine organism life state by The State Ministry Office for Life Environment.

Naphthalene Endoperoxide Heterodimer Designed for Sustained Singlet Oxygen Release.

Naphthalene endoperoxides undergo thermal cycloreversion reactions to produce singlet oxygen and their parent naphthalene compounds. The rate of the reaction is dependent on the structural features, such as steric and electronic modulators. We believe that achieving a sustained release rate of singlet oxygen is important in potential biological applications. This can be achieved by tethering of two endoperoxides with different singlet oxygen release rates in a single molecular construct. Here, we report the synthesis of such a dimeric endoperoxide. Our data shows that with the biexponential reaction kinetics of singlet oxygen generation from a heterodimeric endoperoxide, it is possible to hold singlet oxygen release rates within a selected range for a longer period of time.

Isolation of isoeleutherol from microwave assisted methanol extract of Eleutherine bulbosa bulbs, its crystal structure elucidation and cytotoxicity evaluation

Different extraction methods (Soxhlet, Serial soxhlet, Cold, and microwave-assisted extraction) were executed for the extraction of phytochemicals from the bulbs of Eleutherine bulbosa Miller (Urban), an important medicinal plant in the family Iridaceae. Among the different methods, most efficient (especially in terms of extraction time) was the microwave-assisted extraction (MAE) using methanol as the extraction solvent. The microwave assisted methanolic extract was subjected to column chromatography and a naphthalene compound, isoeleutherol was isolated. Starting from, about two grams of the crude methanol extract, 21 mg of pure compound (isoeleutherol) was obtained as yellow needle like crystals with an Rf value of 0.53 in TLC. The structural characterization was done by Single crystal X-ray diffraction analysis. The study also tested the cytotoxic activity of the compound against two cancer cell lines (HeLa and MCF-7) and one normal cell (Chang liver cells) line by MTT assay. Results of the cytotoxicity evaluation showed that isoeleutherol has potent activity on both the cancer cell lines with LC 50 values of 35.4 and 23.8 μg/ml against HeLa and MCF-7 cells, respectively. Isoeleutherol exhibitted less cytotoxicity towards normal cells (Chang liver cells). At the highest concentration used (100 μg/ml), 60.99 ± 1.92% normal cells were viable. This is the first report of isolation of a compound from E. bulbosa through microwave-assisted extraction, a faster and environment friendly technique for the phytochemical extraction. The present study also reports detailed structural elucidation of isoeleutherol by X-ray crystallography for the first time.

Drop-in fuel production with plastic waste pyrolysis oil over catalytic separation

The catalytic upgrading of plastic pyrolysis oil was conducted in a 2-kg-scale pyrolysis oil separation system with or without zeolite 4A, Cu-based (MDC-7) and Ni-based catalysts to produce light (F1), middle (F2) and heavy (F3) oil fractions. From the preliminary separation tests without a catalyst, the separation vapor temperature for diesel-like middle fraction (C11 - C22) was determined to be in the range of 107–305 °C. After the pyrolysis oil separation with catalysts, the heavy carbon range (>C23) sharply decreased from 22.1 wt% in the crude plastic pyrolysis oil to 0.1–1.6 wt% and 7.3–8.4 wt% in the F1 and F2, respectively. Among three catalysts, Ni-based catalyst exhibited the highest deoxygenation capacity (1.23% O in F1 and 0.3% O in F2) owing to its strong acid sites concentration (1.115 mmol/g). Accordingly, the order of the deoxygenation capacity was Ni-based > MDC-7 > zeolite 4A > no catalyst. Moreover, the catalytic reactions (deoxygenation) and coke formation mainly occurred on the strong acid sites. MDC-7 catalyst contributed to more production of C6–C10 range (15.8 %) with aromatic and naphthenic compounds. In contrast, the major catalytic mechanisms of Ni-based catalyst were dehydration, decarboxylation and decarbonylation reactions. In addition, the physical properties of catalytically upgraded pyrolysis oil were close to those of the petroleum-based fuels. Finally, the current study suggested that Ni-based catalyst was a suitable catalyst for the production of diesel-like fraction (C11-C12) with the lowest contents of oxygen from the plastic pyrolysis oil.

Lipid peroxidation and antioxidant levels in Anabas testudineus (Bloch) under naphthalene (PAH) stress

Exposure to large concentrations of organic PAH (polycyclic aromatic hydrocarbon) compound naphthalene can potentially accumulate inside the body, damage the cells and causes serious health issues. The current understanding of naphthalene exposure to many food fish species is limited. For a comprehensive understanding of naphthalene toxicity to fish health, dose dependent exposure was carried out in Anabas testudineus, an important food fish of Asia. Fish were exposed to sublethal concentrations of naphthalene (4.2, 4.4, 4.6, 4.8 and 5 mg L−1) for a period of 72 h. Activity analysis of lipid peroxidation and antioxidant enzymes in liver and muscles of the Anabas testudineus showed a marked increase in the lipid peroxidation activity in almost all the experimental groups. In contrast, the enzymatic activity of antioxidants like catalase, glutathione peroxidase and non-enzymatic antioxidant glutathione decreased in both liver and muscle tissue. The results imply that increasing doses of naphthalene induced lipid peroxidation and the decreasing levels of antioxidants were incapable of reducing the stress exerted by naphthalene. This study is beneficial for evaluating the effect of LMW (Low molecular weight) naphthalene on fish and highlights the specific biomarker response signifying PAHs toxicity in fish.

Synthesis and Application of New Multibranched–Linear–Multibranched Fluorinated Copolymer as Demulsifiers for Naphthenic Compounds Stabilized Emulsion

• A series of novel fluorinated copolymer with multibranched–linear–multibranched structure were prepared. • The demulsification process of the copolymers in naphthenic acids and sodium naphthenates stabilized emulsions were evaluated. • The relationship between polymer structure and demulsification performance was discussed. To deal with the demulsification of emulsion stabilized by naphthenic compounds, a series of multibranched–linear–multibranched (MLM) copolymer were designed and synthesized. The hydrophilic core with MLM structure is constructed by anionic ring-opening multibranching polymerization (ROMBP) of glycidol with poly (ethylene glycol). The amphophobic arms are grafted by atom transfer radical polymerization (ATRP) of 2, 2, 2-trifluoroethyl methacrylate (TFEMA). The demulsification performance of the MLM copolymer in n-octane/water emulsion stabilized by naphthenic acids (NAs) and sodium naphthenates (Na-NAs) were evaluated. The influences of copolymer dosage, temperature and Na-NAs/NAs ratio on the demulsification efficiency were investigated in detail. Compared with the blank sample settled for 90 min, the fluorinated MLM copolymer with medium HLB value promoted the demulsification efficiency from 50% to 92%. By analyzing the correlation between the polymer structure and demulsification performance, it can be considered that the PEG segment improved the low solubility of the fluorinated copolymer caused by the solvophobic nature of fluorinated groups. The amphophobic effect of the fluorinated group not only accelerates the diffusion process of polymer molecules from the bulk to the interface, but also reduces the rigidity of the interface film by repelling the original interface active material, and produces effective demulsification.

Remediation and optimization of petroleum hydrocarbons degradation in contaminated water using alkaline activated persulphate

This study investigated the characterization of Nigerian crude oil using gas chromatography-mass spectrometry (GC-MS) and the efficiency of alkaline activated sodium persulphate in degrading petroleum hydrocarbons in crude oil-polluted water. Hydrocarbons (aliphatics and aromatics), non-hydrocarbons, and other constituents were characterized in crude oil samples. The ratio of hydrocarbons:non-hydrocarbons/others and aliphatics:aromatics is 86:14 and 45:55, respectively. Alkylated benzenes, toluene, o-xylene, fluorene, and naphthalenic compounds were the most common aromatic compounds. The majority of aliphatic compounds were n-alkanes and cyclic hydrocarbons, including cyclohexane and heptylcyclohexane. Degradation experiments were performed with different initial concentrations of sodium persulphate (0.3 M, 0.5 M and 0.7 M) with sodium hydroxide as an activator. Runs were carried out within 8 days. The total petroleum hydrocarbons (TPH) extraction was carried out and analyzed using gas chromatography flame ionization detector (GC-FID). From an initial TPH concentration of ~137 mg L−1 in water, near-complete degradation was achieved with 0.3 and 0.5 M oxidant dosage. With 0.7 M sodium persulphate, 76% TPH was degraded within 8 days. Radical quenching using sodium thiosulphate showed that the addition of the scavenger resulted in negligible changes in TPH concentration pre-and post-degradation using all three oxidant dosages. Thus, alkaline activated persulphate is effective for the remediation of petroleum hydrocarbon contamination.