Anthracene Research Articles

Biodegradation of anthracene and benz[a]anthracene by two Fusarium solani strains isolated from mangrove sediments

An investigation was undertaken on the biodegradation of two kinds of polycyclic aromatic hydrocarbons (PAHs), anthracene (ANT) and benz[a]anthracene (BAA), by fungi isolated from PAH-contaminated mangrove sediments environment in Ma Wan, Hong Kong. ANT (50mg l(-1)) and BAA (20mg l(-1)), respectively, were added to mineral salt medium initially for screening of PAH-degrading fungi, and finally two fungal species capable of using ANT or BAA as the sole carbon source were isolated and identified as Fusariumsolani species. Removal of ANT and BAA reached 40% and 60% of the added amount, respectively, after 40 days of incubation. A total of six metabolites were isolated and characterized by solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC/MS), which indicate that F.solani degraded both ANT and BAA via their respective quinone molecules to generate phthalic acid. Free extracellular laccase was detected during the degradation process without detectable lignin peroxidase (LiP) and manganese-dependent peroxidase (MnP), suggesting that laccase might play an important role in the transformation of PAHs compounds.

ENVIROMENTAL HYDROCARBON CONTAMINATION IN RICOTTA AND MOZZARELLA DI BUFALA CHEESE

Polycyclic aromatic hydrocarbons (PAHs), mainly formed by anthropogenic activities, are ubiquitous environmental contaminants. Due to environmental contamination and their chemical properties they migrate through the human food chain. Aim of this study was the evaluation of PAHs in ricotta and mozzarella di bufala cheese, produced by milk of buffalo collected in three farms, located in a high contaminated area in Campania because of a waste treatment plant and illegal waste incineration. 11 PAHs were identified both in milk and dairy products. Carcinogenic hydrocarbon benzo(a)pyrene were found in a range including 0.42- 12.96 μg/kg and dibenzo(ah)anthracene 0.21-10.08 μg/kg. Anthracene showed higher concentrations than the other PAHs (45.23-436.85 μg/kg).

Active phytochemical and antibacterial potentiality of in-vitro regenerated plantlets of Canscora decurrens (Dalzell)

The present paper deals with in vitro produced phytochemicals of Canscora decurrens (Dalzell) such as alkaloids, flavanoids, phenols, steroids, anthracene glycosides and triterpenoids etc for their antibacterial activities against human pathogenic strains viz. Staphylococcus aureus, Bacillus subtilis, Rhodococci sp., Escherichia coli, Proteus vulgaris, Pseudomonas sp, Salmonella sp. and Bacillus stearothermophilus . The investigation suggests that the plant may be used in therapeutic treatments of gastrointestinal disorders, diarrhoea and skin diseases.

Photocatalytic degradation of polycyclic aromatic hydrocarbons in GaN:ZnO solid solution-assisted process: Direct hole oxidation mechanism

The photooxidation of four polycyclic aromatic hydrocarbons (PAHs), namely phenanthrene (PHE), anthracene (ANT), acenaphthene (ACE), and benz[a]anthracene (BaA), were investigated. The solid solution GaN:ZnO before and after Pt modification were employed as photocatalysts. The intermediates from photodegradation were analyzed by gas chromatography–mass spectrometer. Active species in the present photocatalytic systems were monitored by the electron paramagnetic resonance spin-trap technique and hydrogen peroxide test strip. The effects of radicals and hole scavengers on the photocatalytic degradation of PAHs were also evaluated. The experimental results show that GaN:ZnO exhibits excellent activity for the photodegradation of PAHs, and the activity can be obviously improved by loading Pt. The reactivity of PAHs decreases in the order of PHE > BaA > ANT > ACE. On the catalyst of Pt–GaN:ZnO, PHE, BaA, ANT, and ACE can be degraded completely after 1, 3, 6, and 8 h visible light irradiation respectively. The mechanism examination evidences that the degradation of PAHs is induced by the formation of holes and active H species in the present photocatalytic system. The holes interact with PAHs to produce PAHs + , which are active enough to react with O 2 and active H species. The theoretical calculation results display that the active positions of PAHs without sp 3 orbital hybridization can be predicted by the frontier electron density ( f r ).

Anthracene-Bridged Binuclear Ruthenium Complexes: Electrochemical and Spectroscopic Evidence of Electronic Communication Through the π System

Six dinuclear cyclometalated ruthenium complexes, 1-6, based on diphenylanthracene (DPA) and anthracene (AN) as bridging ligands have been synthesized and fully characterized electrochemically and spectroscopically. The anodic electrochemistry of the homobinuclear ruthenium complexes, 1-6, has been examined in three different nonaqueous solvents (ACN, DMF, and CH(2)Cl(2)). The ability of the anthracene derivatives to transmit electronic effects between the two redox units has been demonstrated by the observed splitting of the voltammetric signals ascribed to the metal centers. The electronic communication has also been evidenced by the presence of intervalence charge transfer transition bands in the near-infrared region of the spectrum due to an intramolecular electron transfer process mediated by the bridge when the mixed valence species (Ru(II)/Ru(III)) are electrochemically generated. Cyclic voltammetric measurements have been carried out under different conditions of solvent and supporting electrolyte. Differences in DeltaE degrees', the potential separation of the formal potentials of the metal-based anodic processes, have been observed and found to depend on the medium employed. These differences have been ascribed to different degrees of ion pairing. Such effects can be, in turn, modulated as a function of not only the polarity and donor strength of the solvent but also of the coordinating capacity of the anion employed as a supporting electrolyte.

The relationship between CD44 and the resistance to antineoplastic agents of breast neoplasms

The cell adhesion molecule CD44 antigen correlates with the antineoplastic agents resistance of breast neoplasms closely. Its high expression can enhance the invasion of the breast neoplasms. CD44 mole-cule can affect the expression of the TGF-β of breast neoplasm cells to induce the resistance to tamoxifen. The influence on erbB-2 cell signal pathway result in the resistance to the trastuzumab. CD44 can strengthen the re-sistance to anthracene nucleus by inducing expression of protein MRP2 and inhibiting the topoismerase. The modulation of survivn and multidrug resistance gene intensifies the resistance to paclitaxel. Key words: Antigens,CD44 ; Breast neoplasms ; Drug resistance,neoplasm ;

Oxidation of anthracene by immobilized laccase from Trametes versicolor

The laccase of Trametes versicolor was immobilized on the functionalized nanoparticles SBA-15 with the average diameter less than 10 nm. Laccase mediated oxidations of anthracene (ANT) were investigated in the presence of two mediators, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and 1-hydroxybenzotriazole (HBT). Oxidation of ANT was more efficiently enhanced by adding 1 mM of HBT than that by adding ABTS. After 48 h oxidation HBT group significantly oxidized ANT with residue 58% relative to 88% in the ABTS group. HPLC and GC/MS analyses indicated the main product of ANT oxidation was anthraquinone (ANQ). The fluorescein diacetate (FDA) uptake of two human cell lines was used to assess the cytotoxicity and genotoxicity of ANT and ANQ. Treatments with ANT and ANQ at 5 and 10 μM exhibited significant cytotoxicity to the HaCaT cells and the A3 lymphocytes and no significant genotoxicity was observed. The results illustrated that ANQ is less toxic than ANT as well.

Multiple Modes for Coordination of Phenazine to Molybdenum: Ring Fusion Promotes Access to η4-Coordination, Oxidative Addition of Dihydrogen and Hydrogenation of Aromatic Nitrogen Compounds

Mo(PMe(3))(6) reacts with phenazine (PhzH) to give (eta(6)-C(6)-PhzH)Mo(PMe(3))(3), (mu-eta(6),eta(6)-PhzH)[Mo(PMe(3))(3)](2) and (eta(4)-C(4)-PhzH)(2)Mo(PMe(3))(2), each of which displays previously unknown coordination modes for phenazine. Both mononuclear (eta(6)-C(6)-PhzH)Mo(PMe(3))(3) and dinuclear (mu-eta(6),eta(6)-PhzH)[Mo(PMe(3))(3)](2) react with H(2) at room temperature to give the respective dihydride complexes, (eta(4)-C(4)-PhzH)Mo(PMe(3))(3)H(2) and (mu-eta(6),eta(4)-PhzH)[Mo(PMe(3))(3)][Mo(PMe(3))(3)H(2)]. A comparison of (eta(6)-C(6)-PhzH)Mo(PMe(3))(3) with the anthracene (AnH) and acridine (AcrH) counterparts, (eta(6)-AnH)Mo(PMe(3))(3) and (eta(6)-C(6)-AcrH)Mo(PMe(3))(3), indicates that oxidative addition of H(2) is promoted by incorporation of nitrogen substituents into the central ring. Furthermore, comparison of (eta(6)-C(6)-PhzH)Mo(PMe(3))(3) with the quinoxaline (QoxH) analogue, (eta(6)-C(6)-QoxH)Mo(PMe(3))(3), indicates that ring fusion also promotes oxidative addition of H(2). The mononitrogen quinoline (QH) and acridine compounds, (eta(6)-C(6)-QH)Mo(PMe(3))(3) and (eta(6)-C(6)-AcrH)Mo(PMe(3))(3), which respectively possess two and three fused six-membered rings, exhibit a similar trend, with the former being inert towards H(2), while the latter reacts rapidly to yield (eta(4)-C(4)-AcrH)Mo(PMe(3))(3)H(2). Ring fusion also promotes hydrogenation of the heterocyclic ligand, with (eta(6)-C(6)-AcrH)Mo(PMe(3))(3) releasing 9,10-dihydroacridine upon treatment with H(2) in benzene at 95 degrees C. Furthermore, catalytic hydrogenation of acridine to a mixture of 9,10-dihydroacridine and 1,2,3,4-tetrahydroacridine may be achieved by treatment of (eta(6)-C(6)-AcrH)Mo(PMe(3))(3) with acridine and H(2) at 95 degrees C.

Photochemistry of Anthracene-9,10-endoperoxide

The wavelength dependence of the photochemistry of anthracene-9,10-endoperoxide (APO) in acetonitrile was quantitatively investigated at 5 degrees C, with excitation varied from 240 to 450 nm. Anthracene (AC) and a diepoxide (DE) were identified as the main primary photoproducts. After short exposure times DE was at all wavelengths the dominating photoproduct, while AC was only formed for lambda <or= 320 nm. The maximum AC quantum yield of 29% was reached at 270 nm. Anthraquinone (AQ) and a bicyclic acetal (BA) were identified as the main secondary products. Formation of AQ and BA occurred both from DE and from ground-state APO. Formation of BA from ground-state APO involved excited DE or BA itself, while formation of BA from DE required UV excitation of DE. Room-temperature thermolysis of APO only produced AQ. For lambda <or= 310 nm the total photochemistry quantum yield was, within error margins, constant and close to unity. Between 300 and 450 nm, the tail of the APO absorption spectrum, a more or less monotonic decrease of the total photochemistry quantum yield was observed.

The effect of isothiocyanates on CYP1A1 and CYP1A2 activities induced by polycyclic aromatic hydrocarbons in Mcf7 cells

Polycyclic aromatic hydrocarbons (PAHs) – environmental carcinogens – are metabolized by CYP1A1 and CYP1A2 enzymes to oxy-derivatives, which are able to bind to DNA and initiate carcinogenesis. PAHs induce CYP1A1 and CYP1A2 activity, which increases the risk of development of carcinogenesis. Isothiocyanates (ITCs), naturally occurring in Brassica vegetables, possess chemopreventive properties and are able to reduce the CYP1A enzyme activity. In this paper we report our study of the ability of ITCs: sulforaphane and its analogues: isothiocyanate-2-oxohexyl and alyssin, to inhibit CYP1A1 and CYP1A2 enzyme activity induced by the PAHs, anthracene (ANT) and dibenzo[a,h]anthracene (DBA) in human breast cancer cell line Mcf7. The aim was to determine whether the differences in structure of ITCs change their inhibitory properties, and whether these properties depend on the type of inducer. The results indicate that the properties of ITCs depend on the type of PAH: ITCs are more potent in inhibiting activity induced by the weaker inducer. It was also found that the change in ITCs’ structure influences their activities. ITC 2-oxohexyl was the weakest inhibitor, whereas sulforaphane and alyssin exhibited similar potency. The study revealed that inhibition of CYP1A1 activity is direct whereas inhibition of CYP1A2 activity is not only direct but is also caused by the level of protein disturbance.

9,10‐Anthraquinone hinders β‐aggregation: How does a small molecule interfere with Aβ‐peptide amyloid fibrillation?

Amyloid aggregation is linked to a number of neurodegenerative syndromes, the most prevalent one being Alzheimer's disease. In this pathology, the beta-amyloid peptides (Abeta) aggregate into oligomers, protofibrils, and fibrils and eventually into plaques, which constitute the characteristic hallmark of Alzheimer's disease. Several low-molecular-weight compounds able to impair the Abeta aggregation process have been recently discovered; yet, a detailed description of their interactions with oligomers and fibrils is hitherto missing. Here, molecular dynamics simulations are used to investigate the influence of two relatively similar tricyclic, planar compounds, that is, 9, 10-anthraquinone (AQ) and anthracene (AC), on the early phase of the aggregation of the Abeta heptapeptide segment H(14)QKLVFF(20), the hydrophobic stretch that promotes the Abeta self-assembly. The simulations show that AQ interferes with beta-sheet formation more than AC. In particular, AQ intercalates into the beta-sheet because polar interactions between the compound and the peptide backbone destabilize the interstrand hydrogen bonds, thereby favoring disorder. The thioflavin T-binding assay indicates that AQ, but not AC, sensibly reduces the amount of aggregated Abeta(1-40) peptide. Taken together, the in silico and in vitro results provide evidence that structural perturbations by AQ can remarkably affect ordered oligomerization. Moreover, the simulations shed light at the atomic level on the interactions between AQ and Abeta oligomers, providing useful insights for the design of small-molecule inhibitors of aggregation with therapeutic potential in Alzheimer's disease.

Dimethylated arsenics-promoted skin and lung tumorigenesis through the induction of oxidative stress in mice

Objective To examine the possibility that a candidate causal species of the skin and lung tumor promotion induced by exposure to dimethylarsinic acid(DMAv)and dimethylarsinous acid(DMAⅢ),caused by the induction of oxidative stress in mice.Methods Two stages lung tumotigensis animal model induced by lung tumor initiator(4-nitroquinoline 1-oxide,4NQO)and promoter(DMAv)in ddY mice,was used to examine the effect of(-)epigallocatechin gallate(EGCG)on DMAv promoting lung tumorigenesis.Two stages skin tumorigenesis animal model induced by skin tumor initiator[dimethylbenz(α)anthracene,DMBA]and promoter(DMAⅢ)in hairless mice.was used to examine the effects of DMAⅢ in skin tumorigenesis and histopathology.The goxo-2'-deoxyguanosine (8-oxodG)in lung and epidermis were analyzed by HPLC.Results The incidence of lung tumors and 8-oxodG level of lung tissue decreased significantly in 4NQO+DMAv+EGCG group.compared with 4NQO+DMAv group (0.89±0.30 vs 4.00±0.82,1.21±0.09 vs 1.53±0.32,P＜0.01).The incidence of severe keratosis in DMBA+ DMIⅢ group was more than that in DMBA group(25 vs 10,P＜0.05).An significant elevation of 8-oxodG in epidermis was observed in 0.5 h[(1.67±0.17)/105 dG],1.0 h[(1.62±012)/105 dG],2.0 h[(1.66±023)/105dG], 3.0 h[(1.60±0.15)/105 dG],compared with 0 h[(1.25±0.11)/105 dG],being significant(P＜0.05).Conclusion tumor promotion due to DMAv administration is mediated by DMAⅢ through the induction of oxidative stress. Key words: Cacodylic acid; Oxidative stress; Neoplasms; Dimethylarsinous acid; Epigallocatechin gallate

Determination of anthracene by real-time immuno-polymerase chain reaction assay

A reliable and sensitive competitive real-time immuno-PCR (RT-IPCR) assay for the determination of anthracene (AN) was developed. 9-Anthracenebutanoic acid, γ-oxo-(ANA) was synthesized as the hapten of AN. Mixed anhydride reaction (MAR) was used to couple the ANA to ovalbumin (OVA) to form artificial coating antigen. Active ester method (AEM) was used to couple the ANA to bovine serum albumin (BSA) to form artificial immune antigen. Male New Zealand white rabbits were immunized with immune antigen to obtain polyclonal antibodies (pAbs), with which, a novel RT-IPCR assay for determination of AN was described. Under optimized assay conditions, AN can be determined in the concentration range from 1 fg mL −1 to 100 pg mL −1 with a detection limit of 0.5 fg mL −1. The cross-reactivities of the anti-AN antibody to seven structurally related compounds were below 15%. Environmental water samples were successfully analyzed, showing a good accuracy and suitability to analyze AN in field samples. Recovery was between 93.3% and 120.0% and would be acceptable for use in an on-site field test to provide rapid, semiquantitative, and reliable test results for making environmental decisions.

Intact anthracene inhibits photosynthesis in algal cells: A fluorescence induction study on Chlamydomonas reinhardtii cw92 strain

Short-term (24 h) experiments were performed to examine the effect of anthracene (ANT) on Chlamydomonas reinhardtii cw92 grown in a batch culture system aerated with 2.5% CO 2. At concentrations ranging from 0.7 to 5.6 μM, ANT inhibited the growth of population in a concentration-dependent manner and EC 50 calculated amounted to 1.6 μM. At concentrations from 0.7 to 4.2 μM ANT stimulated respiration and inhibited the intensity of photosynthesis but did not affect chlorophyll content in the cells. ANT influenced chlorophyll a fluorescence parameters, measured by OJIP test (O, J, I and P are the different steps of fluorescence induction curve). ANT diminished the performance index (PI), the yield of primary photochemistry ( φ Po), the yield of electron transport ( φ Εο, the efficiency of moving the electron beyond Qa − ( Ψ 0) and the fraction of active oxygen evolving complexes (OEC). The fraction of active PS II reaction centres in the treated samples dramatically dropped. The most pronounced changes in ANT-treated cells were observed in the stimulation of energy dissipation parameter (DI 0/RC). The only OJIP parameter that was not influenced by ANT was energy absorption by photosynthetic antennae (ABS). The results lead to a conclusion that the inhibition of photosynthesis may be a consequence of unspecific ANT-membrane interaction, resulting from hydrophobic character of this hydrocarbon.

Effect of a heavy atom in the S 1(ππ*) ↝ T 1(ππ*) nonradiative transition. 9,10-Dichloroanthracene

The rate constant K ST for the nonradiative intersystem crossing transition S 1(1 B 1u ) ↝ T 1(3 B 1u ) (I) in 9,10-dichloroanthracene (DClA) is calculated in terms of the model of vibronic-induced spin-orbit (VISO) interactions. The magnitude fluorescence quantum yield ϕfl is estimated. Comparison of K ST(I) and ϕfl for DClA with the corresponding values obtained earlier for anthracene (AC), where K ST is governed by the conversion channels (I) and S 1(1 B 1u ) ↝ T 2(3 B 3g ) (II), shows that the theoretical estimates reflect the anomalous heavyatom effect in these molecules in accordance with the experimental (literature) data. The cause for this effect is revealed. The influence of different factors on the K ST(I) constant and on the ratio of its components K ST (where s denotes the z and y spin-sublevels) is established for DClA. These factors are the magnitude of the spin-orbit coupling parameter in a chlorine atom, the change, as compared to AC (in the same conversion channel (I)) of the distribution of electrons in the carbon core of the DClA molecule, and the change in the form of out-of-plane vibrational modes involved in VISO interactions.

Cell metabolic changes of porphyrins and superoxide anions by anthracene and benzo( a)pyrene

The aim of this work was to evaluate the induction of protoporphyrins IX (PpIX) activity and superoxide anions (SO) in human leukocytes exposed to anthracene (ANT) and benzo( a)pyrene (B( a)P). The leukocyte LC 50s for both hydrocarbons and the PpIX accumulation and SO overproduction were measured. The LC 50s were 0.35 and 3.23 μM for ANT and B( a)P, respectively. A linear relationship ( r = 0.97, p < 0.01) between PpIX and ANT concentration was obtained. The induced accumulation of PpIX was proportional ( r = 0.63, p < 0.01) to B( a)P concentration. SO overproduction showed a linear relationship ( r = 0.83, p < 0.05) with ANT concentrations. The linear regression analysis of the effect of B( a)P on the superoxide anion overproduction showed a good coefficient ( r = 0.97, p < 0.01), showed that ANT and B( a)P exposure induces PpIX accumulation, probably by disruption of the haem biosynthesis. ANT and B( a)P induce SO overproduction, perhaps through a process of redox cycling.

Inhibition by quercetin of the promoting effect of teleocidin on skin papilloma formation in mice initiated with 7,12-dimethylbenz[a]anthracene.

Quercetin markedly suppressed the promoting effect of teleocidin on skin tumor formation in mice initiated with 7,12-dimethylbenz[a]anthracene. This activity of quercetin may have some bearing on the fact that quercetin is not carcinogenic despite showing mutagenicity.

Decomposition of polycyclic aromatic hydrocarbons in atmospheric aqueous droplets through sulfate anion radicals: An experimental and theoretical study

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that have received considerable attention because of their carcinogenic and mutagenic effects. PAHs can be degraded by sulfate anion radicals in atmospheric aqueous droplets. This study was to investigate the mechanism and degradation products of sulfate anion radical reaction with anthracene (ANT) by experimental and quantum chemical approaches. From these observations of the experiments, the sulfate anion radical is capable of oxidizing ANT rapidly and three intermediates anthraquinone (ATQ), 1-hydroxyanthraquinone (1-hATQ), and 1,4-dihydroxyanthraquinone (1,4-dhATQ) were detected as degradation products by GC-MS. The proposed one-electronic transfer mechanism of sulfate anion radical reaction with ANT was modeled using hybrid density function theory (BHandHLYP) methods. Geometry optimization and vibrational frequency analysis calculation were performed for reactants, transition states, intermediates, and products. The potential energy surfaces of these reactions are explored to establish structures and relative energies of reactants, intermediates, transition states, and products. Computational results suggest that initial electron transfer step is predicted to have activation energy of − 3.35 kcal/mol in water, indicating that ANT can be oxidized quickly in atmospheric aqueous droplets. The reaction pathways have been proposed on the basis of these experimental and theoretical findings. The results may provide useful information for a better understanding of the sulfate anion radical-initiated reactions in atmospheric aqueous droplets such as clouds, rains or fogs.

Histo-Pathological Study: Skin Cancer Varieties Due to a Compound of Coal Tar & of Vinegar

Results: It was observed that the repeated application of DMBA alone and repeated application of TPA after single application of DMBA produced both epidermal and dermal tumours like papilloma, dysplasia, keratoacanthoma, squamous cell carcinoma in situ, extensive squamous cell carcinoma, and fibrosarcoma. The malignant varieties of skin tumors were 30 % more with the repeated application of DMBA alone than that by repeated application of TPA after single application of DMBA. The statistical analysis of cellular DNA, RNA and proteins concentrations estimates were found comparatively significant in experimental groups. Conclusion: The contact of DMBA (a compound of coal tar) can act as initiator as well as promoter for skin tumourigenisis. Abbreviations: ¤ DMBA (Dimethyl Benz anthracene) is derived from anthracene i.e. poly-aromatic hydrocarbon found in commonly used coal tar.¤¤ TPA (tetradecanyl phorbol acetate) is derived from acetate that is salt or ester of ethanoic acid manufactured by oxidation of ethanol and commonly used for production of vinegar.

Biocompatible nanoparticles of amphiphilic cyclodextrins entangling porphyrins as suitable vessels for light-induced energy and electron transfer

In this contribution we explore the capability of biocompatible nanoparticles (NPs) of cationic amphiphilic cyclodextrins entangling the anionic hydrophilic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphyrin (TPPS) to facilitate photoinduced energy and electron transfer with suitable donor and acceptor guest molecules, by using a combination of absorption, induced circular dichroism and fluorescence spectroscopy. It is shown that anthracene (AN) and anthraquinone-2-sulfonate (AQS), chosen as appropriate energy donor and electron acceptor, respectively, can be trapped within the NPs network. Fluorescence experiments carried out in the presence and, for comparison, in the absence of NPs provide clear evidence that the amphiphilic NPs strongly encourage singlet–singlet energy transfer from AN to TPPS as well as photoinduced electron transfer from TPPS to AQS. In view of the biocompatibility and drug-carring properties of the NPs used, these results can be of interest from the perspective of designing photo-activated drug delivery systems.