The Carcinogenicity of Cyclopenta[a]phenanthrene and Chrysene Derivatives in the Sencar mouse

Bhatt, Tarlochan S.; Coombs, Maurice M.

doi:10.1080/10406639008034748

Cited by 10 publications

(6 citation statements)

References 11 publications

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“…In cyclopenta[ a ]phenanthrene C p [ a ]P, activity enhancement is induced when Me or OMe group is introduced into the bay-region at C-11 ( 6 and 9 ). ,, For 6 , the principle diol-epoxides are 7 and 8 , whereas for the unusually reactive 9 the 15-ol 10 , 17-ol 11 , and 16,17-diol 12 are produced and 11 is believed to be the proximate carcinogen . Additional increase in steric crowding at C-11 (Et, iP r , n-Bu) reduces carcinogenicity because the approach of target DNA nucleotide is now prevented .…”

Section: Introductionmentioning

confidence: 99%

Substituent Effects and Charge Delocalization Mode in Chrysenium, Benzo[c]phenanthrenium, and Benzo[g]chrysenium Cations: A Stable Ion and Electrophilic Substitution Study

et al. 2001

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The first series of persistent carbocations derived from mono- and disubstituted chrysenes Ch (5- methyl- 3, 2-methoxy- 19, 2-methoxy-11-methyl- 20, 2-methoxy-5-methyl- 21, and 9-methyl-4H-cyclopenta[def]chrysene 22), monosubstituted benzo[c]phenanthrenes BcPh (3-methoxy- 23, 3-hydroxy- 24), and monosubstituted benzo[g]chrysenes BgCh (12-methoxy- 25; 12-hydroxy- 26) were generated in FSO3H/SO2ClF or FSO3H-SbF5 (4:1)/SO2ClF and studied by low-temperature NMR at 500 MHz. The methoxy and methyl substituents direct the protonation to their respective ortho positions. Whereas parent Ch 1 is protonated at C-6/C-12, 3 is protonated at C-6 (3aH+) and at C-12 (3bH+) with the latter being the thermodynamic cation. The 2-methoxy-Ch 19 is protonated at C-1 to give two conformationally distinct carboxonium ions (19aH+/19bH+). In the disubstituted Ch derivatives 20 and 21, the 2-methoxy overrides the 5-methyl and the predominant carbocations formed are via attack ortho to methoxy. For the methano derivative 22 (Me at C-9), a 3:1 mixture of 22aH+/22bH+ is formed. For parent BcPh 13, nitration and benzoylation are directed to C-5. With 3-methoxy-BcPh 23, the site of attack moves to C-4, thus producing two conformationally distinct carboxonium ions (23aH+/23bH+), whereas conventional nitration gave a 2:1 mixture of 23aNO2 and 23bNO2. In 3-hydroxy-BcPh 24, the carboxonium ion 24H+ is exclusively formed. For parent BgCh 16, protonation, nitration, and benzoylation are all directed to C-10 (16H+, 16NO2, 16COPh), but presence of OMe or OH substituent at C-12 changes the site of attack to C-11. Charge delocalization mode is probed based on magnitude of delta delta 13Cs and conformational aspects via NOED experiments. Complete NMR data are also reported for several benzoylation/nitration products. Using ab initio/GIAO (and NICS), the NMR chemical shifts (and aromaticity) in model carbocations A-D were evaluated. This work represents the first direct study of the carbocations derived from the methyl-, methoxy-/hydroxy-derivatives of three important classes of bay-region and fjord-region PAHs whose diol-epoxides extensively bind to DNA. It also extends the available data on electrophilic chemistry of BcPh and BgCh.

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Section: Introductionmentioning

confidence: 99%

Substituent Effects and Charge Delocalization Mode in Chrysenium, Benzo[c]phenanthrenium, and Benzo[g]chrysenium Cations: A Stable Ion and Electrophilic Substitution Study

et al. 2001

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“…108:207 (1995). PAH are ha2ardous in their own right; these pollutants exhibit mutagenic and carcinogenic properties (Blakeslee, 1983, Bhatt and Coombs, 1990). In light of the biotoxicity of this class of compoimds (see Zaia and Biemann, 1994) , PAH are listed as Hazardous Air Pollutants (HAP) under Title in of the 1990 Clean Air Act Amendments (CAAA).…”

Section: Resultsmentioning

confidence: 99%

Annual conference on fire research:

Beall¹

1996

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Due to its ozone-depleting potential, halon 1301 (CFjBr) has been banned from production under the Montreal Protocol. The research for halon replacement(s) has led to the reconsideration of using water in certain applications. However, under cold storage conditions (below 0 °C) water will freeze, thus posing a limitation in low temperature operations. Certain additives, if selected properly, not only can suppress the freezing point of water but also can improve its fire suppression effectiveness. Some water-based agents have recently been proven to be more effective than pure water when used in the form of mist to suppress a small JP-8 pool fire (Finnerty et al., 1996). Among the thirteen agents they tested, potassium lactate (60% w/w) and potassium acetate (60% w/w) were found to be far superior than pure water and other candidate solutions.

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“…Chrysene produced carcinomas and malignant lymphoma in mice after intraperitoneal injection and skin carcinomas in mice following dermal exposure (3). In later studies, the carcinogenicity of chrysene was assessed in three studies on newborn mice (208)(209)(210), in three initiation-promotion studies on mice (126,208,211) and after pulmonary implantation into rats (212). Chrysene gave a positive response in two of three assays in newborn mice, in one of three initiation-promotion studies and the pulmonary implantation study.…”

Section: Toxic Effectsmentioning

confidence: 99%

Polycyclic Aromatic Hydrocarbons and Azaaromatic Compounds

Baxter¹,

Warshawsky²

2012

Patty's Toxicology

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Polycyclic aromatic hydrocarbons (PAHs) are moderately reactive, but undergo photochemical degradation in the atmosphere, and are widely used as chemical raw materials. Aromatic hydrocarbons cause local irritation and changes in endothelial cell permeability and are absorbed rapidly. Accumulation of aromatic hydrocarbons in marine animals occurs to a greater extent and retention is longer compared to alkanes. Toxicity of polynuclear aromatics has been reported comprehensively. It has been reported that exposure to a variety of complex mixtures containing these chemicals, such as soot, coal tar and pitch, mineral oils, coal gasification residues, and cigarette smoke has historically been associated with induction of cancer. Naphthalene causes cataracts in the eyes of experimental animals. Its vapors may cause severe systemic injury. Alkylbenzenes are readily aspirated and produce instant death via cardiac arrest and respiratory paralysis. In general, the acute toxicity of alkylbenzenes is higher for toluene than that for benzene and decreases further with increasing chain length of the substituent, except for highly branched C 8 to C 18 derivatives. Polycyclic aromatic hydrocarbons are metabolized through epoxides and hydroxides and are excreted as conjugates.

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The Carcinogenicity of Cyclopenta[a]phenanthrene and Chrysene Derivatives in the Sencar mouse

Cited by 10 publications

References 11 publications

Substituent Effects and Charge Delocalization Mode in Chrysenium, Benzo[c]phenanthrenium, and Benzo[g]chrysenium Cations: A Stable Ion and Electrophilic Substitution Study

Substituent Effects and Charge Delocalization Mode in Chrysenium, Benzo[c]phenanthrenium, and Benzo[g]chrysenium Cations: A Stable Ion and Electrophilic Substitution Study

Annual conference on fire research:

Polycyclic Aromatic Hydrocarbons and Azaaromatic Compounds

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