Steinberg, C. E.W.. Institute of Freshwater Ecology and Inland Fisheries, Stein@igb-berlin.de
Haitzer, M. E.W.. Institute of Freshwater Ecology and Inland Fisheries, haitzer@zi.biologie.uni-muenchen.de
Perminova, I. V.. Lomonosov Moscow State University, Department of Chemistry, iperm@organic.chem.msu.su
Yashchenko, N. Yu.. Lomonosov Moscow State University, Department of Chemistry, yanat@organic .chem.msu.su
Petrosyan, V. S.. Lomonosov Moscow State University, Department of Chemistry, petros@organic.chem.msu.su

 
TOWARDS A QUANTATIVE STRUCTURE ACTIVITY RELATIONSHIP (QSAR) OF DISSOLVED HUMIC SUBSTANCES AS DETOXIFYING AGENTS IN FRESHWATERS
 
In freshwaters dissolved organic carbon (including humic substances, HS) exceeds all living carbon roughly by an order of magnitude. Despite direct nutrional value, HS may also alter bioconcentration and toxicity of xenobiotics. To obtain insight into the effect of HS on the bioconcentration of hydrophobic organic chemicals, tests with the nematode Caenorhabditis elegans were carried out. By comparing the bioconcentration of PAH in the presence and absence of HS, the "biologically determined" partition coefficients for pyrene and benzo[a]pyrene were calculated. These partition coefficients were positively related to the aromaticity of the HS. To estimate an impact of HS on the acute toxicity of pyrene, fluoranthene and anthracene, alterations of the grazing activity of Daphnia magna were studied. All twenty six HS samples studieddisplayed a detoxifying impact. The best relationship was established between the detoxifying ability of HS and their aromaticity. The documented dependences of a decrease in both bioconcentration and toxicity of the PAHs in the presence of the HS on the content of aromatic structures in the latter could be indicative to a mechanism of chemical interaction between PAHs and HS. Combination of hydrogen bonding and donor-acceptor interaction can be considered as the most probable one.
 
Day: Monday, Feb. 1
Time: 02:45 - 03:00pm
Location: Hilton of Santa Fe
 
Code: SS06MO0245H