scholarly journals Theoretical and Laboratory Studies on the Interaction of Cosmic‐Ray Particles with Interstellar Ices. I. Synthesis of Polycyclic Aromatic Hydrocarbons by a Cosmic‐Ray–induced Multicenter Mechanism

1997 ◽  
Vol 475 (1) ◽  
pp. 144-154 ◽  
Author(s):  
R. I. Kaiser ◽  
K. Roessler
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Cosmic Ray ◽  
Laboratory Studies ◽  
Polycyclic Aromatic ◽  
Interstellar Ices

Humic Acids Reduce Bioaccumulation of Some Polycyclic Aromatic Hydrocarbons

1983 ◽  
Vol 40 (S2) ◽  
pp. s63-s69 ◽  
Author(s):  
G. J. Leversee ◽  
P. F. Landrum ◽  
J. P. Giesy ◽  
T. Fannin
Keyword(s):  
South Carolina ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Daphnia Magna ◽  
Aromatic Hydrocarbons ◽  
Water Solubility ◽  
Laboratory Studies ◽  
Environmental Transport ◽  
Polycyclic Aromatic ◽  
Water Accumulation ◽  
Refractory Organics

In laboratory studies, Daphnia magna were exposed for 6 h to five polycyclic aromatic hydrocarbons (PAH) (0.1–2.0 μg/L) in water with and without Aldrich® humics (2 mg DOC/L). Compared to results in nonhumic water, accumulation of PAH by Daphnia in water with humics was significantly reduced for benzo[a]pyrene (−25%) while it was increased for methylcholanthrene (+210%). Humics did not significantly alter Daphnia accumulation of anthracene, dibenzanthracene or dimethylbenzanthracene. In additional studies, humics reduced Daphnia accumulation of benzo[a]pyrene (B[a]P) over a range of B[a|P concentrations (1.1–5.4 μg/L) exceeding the reported limit for water solubility (1.1–1.2 μg/L). Humics consistently increased Daphnia accumulation of methylcholanthrene (MC) over a range of humic concentrations from 0.2 to 10.0 μg DOC/L. Particulates and DOC (10–12 mg TOC/L) occurring naturally in two South Carolina streams reduced Daphnia accumulation of B[a]P by 38–66%, with about 40% of the overall reduction attributable to DOC. We conclude that dissolved refractory organics may significantly affect bioavailability and environmental transport of some PAH in fresh waters.

scholarly journals Mechanistic Insights Gained from an Analysis of Carcinogenic Polycyclic Aromatic Hydrocarbons with the Computer Automated Structure Evaluation System

1989 ◽  
Vol 8 (6) ◽  
pp. 1091-1101 ◽  
Author(s):  
Herbert S. Rosenkranz ◽  
Gilles Klopman
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Evaluation System ◽  
Structural Features ◽  
Adduct Formation ◽  
Dna Adduct ◽  
Structural Components ◽  
Laboratory Studies ◽  
Polycyclic Aromatic ◽  
Structure Evaluation

The Computer Automated Structure Evaluation System (CASE) was used to identify the structural components responsible for either the mutagenicity or the carcinogenicity of polycyclic aromatic hydrocarbons (PAHs). These were found not to overlap and some of the structural components were endowed with much more biological activity than others. A study was then undertaken to determine whether these structural features could explain the mutagenicity and carcinogenicity of 7,12-dimethylbenz(a)anthracene (DMBA). It was found that the structures identified by CASE could explain the mutagenicity and carcinogenicity qualitatively as well as quantitatively. Moreover, the identified structures were entirely consistent with recent findings on the metabolism and DNA adduct formation of DMBA. These results are taken to indicate that CASE can be used to identify the structures in a molecule (e.g., PAH) that are sites of metabolism. Laboratory studies can then focus on that portion of the molecule.

The Assessment of Contamination and Source of Polycyclic Aromatic Hydrocarbons from the Sediments of the Someş River

2019 ◽  
Vol 64 (1) ◽  
pp. 55-67
Author(s):  
Vlad Pӑnescu ◽  
◽  
Mihaela Cӑtӑlina Herghelegiu ◽  
Sorin Pop ◽  
Mircea Anton ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Polycyclic Aromatic

1,1’-Biaceanthrylene and 2,2'-Biaceanthrylene: Models for Linking Larger Polycyclic Aromatic Hydrocarbons via Five-Membered Rings

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Electronic Properties ◽  
Aromatic Hydrocarbons ◽  
Model Systems ◽  
Redox Potentials ◽  
Dimer Model ◽  
Optical And Electronic Properties ◽  
Polycyclic Aromatic

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>

1,1’-Biaceanthrylene and 2,2'-Biaceanthrylene: Models for Linking Larger Polycyclic Aromatic Hydrocarbons via Five-Membered Rings

2019 ◽  
Author(s):  
Yachu Du ◽  
Kyle Plunkett
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Electronic Properties ◽  
Aromatic Hydrocarbons ◽  
Model Systems ◽  
Redox Potentials ◽  
Dimer Model ◽  
Optical And Electronic Properties ◽  
Polycyclic Aromatic

We show that polycyclic aromatic hydrocarbon (PAH) chromophores that are linked between two five-membered rings can access planarized structures with reduced optical gaps and redox potentials. Two aceanthrylene chromophores were connected into dimer model systems with the chromophores either projected outward (2,2’-biaceanthrylene) or inward (1,1’-biaceanthrylene) and the optical and electronic properties were compared. Only the planar 2,2’-biaceanthrylene system showed significant reductions of the optical gaps (1 eV) and redox potentials in relation to the aceanthrylene monomer.<br>

Sign in / Sign up

Export Citation Format

Share Document