Fluorene and fluoranthene

Boldrin, B., Tiehm, A. Fritzsche, C. (1993). Degradation of phenanthrene, fluorene, and fluoranthene, and pyrene by a Mycobacterium sp. Applied and Environmental Microbiology, 59, 1927-30. 

Weissenfels, W.D., Beyer, M. Klein, J. (1990). Degradation of phenanthrene, fluorene and fluoranthene by pure bacterial cultures. Applied Microbiology and Biotechnology, 32, 479-84. 

EC>16-EC35, using the EPA RfD for pyrene (C16) as a surrogate. Anthracene, fluorene, and fluoranthene are also in this group however, pyrene was selected because it had the lowest RfD. 

EC16-EC35, using an intermediate oral MRL for fluorene and fluoranthene as a surrogate. 

Rathkamp, G. and D. Hoffmann Fluorenes and fluoranthenes in cigarette smoke 24th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 24, Paper No. 28, 1970, p. 20. 

Dias JR (1992a) Studies in Deciphering the Information Content of Chemical Formulas -A Comprehensive Study of Fluorenes and Fluoranthenes. J Chem Inf Compt Sd 32 2... 

Carbazole, A-methylcarbazole, IV-ethylcarbazole, dibenzofuran, dibenzothiophene, fluorene, dibenzo-p-dioxin, phenoxathiin, phenoxazine, phenothiazine, xanthene, biphenyl, naphthalene, phenanthrene, anthracene, and fluoranthene could be transformed by E. coli, [314] which was transformed using a plasmid bearing the carAa, Ac, and Ad genes, and expressing only the carA-encoded proteins. Further work is needed to develop a final biocatalyst and to prove the advantages that this degradative pathway would incorporate in a refining bioprocess. 

Hemoglobin is another heme-containing protein, which has been shown to be active towards PAH, oxidation in presence of peroxide [420], This protein was also modified via PEG and methyl esterification to obtain a more hydrophobic protein with altered activity and substrate specificity. The modified protein had four times the catalytic efficiency than that of the unmodified protein for pyrene oxidation. Several PAHs were also oxidized including acenaphthene, anthracene, azulene, benzo(a)pyrene, fluoranthene, fluorene, and phenanthrene however, no reaction was observed with chrysene and biphenyl. Modification of hemoglobin with p-nitrophenol and p-aminophenol has also been reported [425], The modification was reported to enhance the substrate affinity up to 30 times. Additionally, the solvent concentration at which the enzyme showed maximum activity was also higher. Both the effects were attributed to the increase in hydrophobicity of the active site. 

The numbering and lettering system for several PAHs is also given. Compounds are (1) naphthalene, (2) fluorene, (3) anthracene, (4) phenanthrene, (5) aceanthrylene, (6) benzo[a]-fluorene, (7) benzo[a]fluorene, (8) benzo[a]-fluorene, (9) fluoranthene, (10) naphthacene, (11) pyrene, (12) benzofluoranthene, (13) benzo[g,/r,fluoranthene, (14) perylene, (15) benzo[e]pyrene, (16) benzo[g,/),/]perylene, (17) anthanthrene, and (18) coronene. 

Fig. 3. (a) Benzophenanthrene. (6) Dibenzofluorene. (c) Phenanthrene. (d) Fluorene. (e) Fluoranthene. In these hydrocarbons the interfering protons are shown black and their van der Waals radii are shown dotted (after Reid, 1957). 

The strong interaction found in benzophenanthrene (Fig. 3a) is considerably reduced by the change in angle introduced by the five-membered ring in dibenzofluorene (Fig. 3b). Corresponding reductions in frequency shifts are found in the phenanthrene-fluorene-fluoranthene series (Fig. 3c, d, e). Here the phenanthrene-like interaction is much reduced in fluorene and virtually removed in fluoranthene. 

Alkyltrinaphthenoacenaphthalenes/Fluorenes and/or Alkyldinaphthenophenanthrenes/Anthracenes and/or Alkylpyrenes/Fluoranthenes. 

The effect of tilorone and congeners (Fig. 6) on the DNA-dependent RNA polymerase reaction is shown in Fig. 7). The template activity of native DNA is strongly inhibited by DEAP-fluoranthene, showing an 80% inhibition at a concentration 8 x 10 6 M. Other derivatives, at this concentration do not show any significant inhibition of the template activity of DNA. However, at higher concentrations one observes a dose-dependent inhibition of DNA-template activity by DEAE-fluorenone, DMAA-dibenzothiophene, DEAA-fluorene and DMAA-dibenzofuran. The monosubstituted derivative, MEAA-fluorene does not show any activity, even at higher concentrations. 

In a two-year toxicological study (Culp et al., 2000), the incidences of tumours and DNA adducts in mice fed either coal tar or pure benzo[a] pyrene were examined. Benzo[a]pyrene formed adducts readily with DNA and appeared to be responsible for forestomach tumours, like those induced by ingestion of coal tar, but not for lung tumours. Other mice that were fed coal tar (Koganti et al., 2001) had DNA adducts with benzo[u]pyrene, benzo[c]fluorene and benzo[Z)]fluoranthene in the lungs, but those fed coal tar-contaminated soil had only the adducts with benzo[c]fluorene and benzo[ ]fluoranthene. Although benzo[u]pyrene activation has been studied extensively, little is known about the activation mechanisms of benzofluor-enes and benzofluoranthenes. 

Interactions between selected noncarcinogenic PAHs and carcinogenic benzo[a]pyrene have also been documented to reduce the carcinogenic potential of benzo[a]pyrene in animals. Benzo[a]fluoranthene, benzo[k]fluoranthene, chrysene, perylene, and a mixture of anthracene, phenanthracene, and pyrene significantly inhibited benzo[a]pyrene-induced injection-site sarcomas. However, other PAHs including anthracene, benzo[g,h,i]perylene, fluorene, and indeno[1,2,3-c,d]pyrene had no antagonistic effects (Falk et al. 1964). Coexposure of tracheal explants to benzo[e]pyrene and benzo[a]pyrene resulted in an increased incidence of tracheal epithelial sarcomas over that seen with either PAH alone (Topping et al. 1981). Phenanthrene administration with benzo[a]pyrene decreased the DNA adduct formation in mice (Rice et al. 1984). 

PAHs may also volatilize from soil. Volatilization of acenaphthene, acenaphthylene, anthracene, fluorene, and phenanthrene (low molecular weight PAHs) from soil may be substantial (Coover and Sims 1987 Southworth 1979 Wild and Jones 1993). However, of 14 PAHs studied in two soils, volatilization was found to account for about 20% of the loss of 1 -methyinaphthalene and 30% of the loss of naphthalene volatilization was not an important loss mechanism for anthracene, phenanthrene, fluoranthene, pyrene, chrysene, benz[a]anthracene, benzo[b]fluoranthene, dibenz[a,h]anthracene, benzo[a]pyrene, and indeno[1,2,3-c,d]pyrene (Park et al. 1990). 

PAHs have been found in the tissues of aquatic organisms. In an assessment of STORET data covering the period 1980-1982, Staples et al. (1985) reported median concentrations in biota of <2.0 mg/kg (ppm) wet weight for 8 PAHs (acenaphthene, acenaphthylene, benz[a]anthracene, benzo[a]pyrene, chrysene, fluoranthene, fluorene, and pyrene) and <2.5 mg/kg wet weight for seven PAHs (anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[g,h,i]perylene, indenopyrene, naphthalene, and phenanthrene). The number of samples ranged from 83 (naphthalene) to 140 (acenaphthylene) only benzo[g,h,i]perylene (1 sample, 0.8%) and indenopyrene (1 sample, 0.8%) were found in detectable concentrations. 

The levels, either in concentration or percent weight, in which several PAHs appear in various other substances are given below. A coal tar sample has been found to contain approximately 0.007 mg/kg benz[a]anthracene, 3 mg/kg benzo[b]fluoranthene. 4 g/kg chrysene, and 30 mg/kg benzo[a]pyrene (Perwak et al. 1982). High-temperature coal tar contains 1,000 mg/kg dibenz[a,h]anthracene (lARC 1985). A sample of coal tar pitch was found to contain <10 mg/kg benz[a]anthracene, <10 mg/kg chrysene, and approximately 10 mg/kg benzo[a]pyrene creosote oil contains <3 mg/kg benz[a]anthracene, <1 mg/kg chrysene, and <10 mg/kg benzo[a]pyrene (Perwak et al. 1982). Creosote has been reported to contain 21% phenanthrene. 10% fluorene, 10% fluoranthene. 9% acenaphthene. 8.5% pyrene. 3% chrysene. 3% naphthalene, and 2% anthracene (Lorenz and Gjovik 1972). 

PAHs have generally not been detected in surveys of human tissue, presumably because the compounds are fairly rapidly metabolized. Phenanthrene was the only PAH detected in the 1982 National Human Adipose Tissue Survey it was found in trace concentrations in 13% of the samples (EPA 1986). Acenaphthylene, acenaphthene, fluorene, and chrysene were not found at levels below the detection limit (0.010 pg/g 10 ppt). However, autopsies performed on cancer-free corpses found PAH levels of 11-2,700 ppt (ng/g) in fat samples (Obana et al. 1981). Several PAHs were detected, including anthracene, pyrene, benzo[e]pyrene, benzo[k]fluoranthene, benzo[a]pyrene, and benzo[g,h,i]perylene, with pyrene being detected in the highest concentrations. A similar study done on livers from autopsied cancer-free corpses found levels of 6-500 ppt (ng/g) of all of the same PAHs except benzo[e]pyrene, which was not detected (Obana et al. 1981). As in the fat sample studies, pyrene appeared in the highest concentrations in the liver, but the overall levels were less than in fat. 

The following figures illustrate this phenomenon for fluorene and benzo[b]fluorene (Fig. 48) and fluoranthene and benzo[k]fluoranthene (Fig. 49), respectively. 

On a hot, sunny day evaporation of creosote from the surface of treated wood may release coal tar creosote constituents to the atmosphere. Only the volatile creosote components such as acenaphthene and naphthalene will volatilize the heavier fractions will remain on the wood (E1SDA 1980). Volatilization may also be greater during warmer months when ambient temperatures are higher. Gevao and Jones (1998) observed greater volatilization of acenaphthene, fluorene, phenanthrene, anthracene, and fluoranthene from creosote-treated wood at 30 °C than at 4 °C. 

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