Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.

The persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]...

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Main Authors: Ina Ehlers, Tatiana R Betson, Walter Vetter, Jürgen Schleucher
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4228495?pdf=render
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author Ina Ehlers
Tatiana R Betson
Walter Vetter
Jürgen Schleucher
author_facet Ina Ehlers
Tatiana R Betson
Walter Vetter
Jürgen Schleucher
author_sort Ina Ehlers
collection DOAJ
description The persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene) as by-product, but DDD is also formed by reductive degradation of DDT in the environment. To differentiate between DDD formation pathways, we applied deuterium NMR spectroscopy to measure intramolecular deuterium distributions (2H isotopomer abundances) of DDT and DDD. DDD formed in the technical DDT synthesis was strongly deuterium-enriched at one intramolecular position, which we traced back to 2H/1H fractionation of a chlorination step in the technical synthesis. In contrast, DDD formed by reductive degradation was strongly depleted at the same position, which was due to the incorporation of 2H-depleted hydride equivalents during reductive degradation. Thus, intramolecular isotope distributions give mechanistic information on reaction pathways, and explain a puzzling difference in the whole-molecule 2H/1H ratio between DDT and DDD. In general, our results highlight that intramolecular isotope distributions are essential to interpret whole-molecule isotope ratios. Intramolecular isotope information allows distinguishing pathways of DDD formation, which is important to identify polluters or to assess DDT turnover in the environment. Because intramolecular isotope data directly reflect isotope fractionation of individual chemical reactions, they are broadly applicable to elucidate transformation pathways of small bioactive molecules in chemistry, physiology and environmental science.
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spelling doaj.art-34b326155a7b4c869c9a2aed74c033f62022-12-21T19:38:12ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-01910e11064810.1371/journal.pone.0110648Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.Ina EhlersTatiana R BetsonWalter VetterJürgen SchleucherThe persistent organic pollutant DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) is still indispensable in the fight against malaria, although DDT and related compounds pose toxicological hazards. Technical DDT contains the dichloro congener DDD (1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene) as by-product, but DDD is also formed by reductive degradation of DDT in the environment. To differentiate between DDD formation pathways, we applied deuterium NMR spectroscopy to measure intramolecular deuterium distributions (2H isotopomer abundances) of DDT and DDD. DDD formed in the technical DDT synthesis was strongly deuterium-enriched at one intramolecular position, which we traced back to 2H/1H fractionation of a chlorination step in the technical synthesis. In contrast, DDD formed by reductive degradation was strongly depleted at the same position, which was due to the incorporation of 2H-depleted hydride equivalents during reductive degradation. Thus, intramolecular isotope distributions give mechanistic information on reaction pathways, and explain a puzzling difference in the whole-molecule 2H/1H ratio between DDT and DDD. In general, our results highlight that intramolecular isotope distributions are essential to interpret whole-molecule isotope ratios. Intramolecular isotope information allows distinguishing pathways of DDD formation, which is important to identify polluters or to assess DDT turnover in the environment. Because intramolecular isotope data directly reflect isotope fractionation of individual chemical reactions, they are broadly applicable to elucidate transformation pathways of small bioactive molecules in chemistry, physiology and environmental science.http://europepmc.org/articles/PMC4228495?pdf=render
spellingShingle Ina Ehlers
Tatiana R Betson
Walter Vetter
Jürgen Schleucher
Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.
PLoS ONE
title Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.
title_full Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.
title_fullStr Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.
title_full_unstemmed Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.
title_short Elucidating turnover pathways of bioactive small molecules by isotopomer analysis: the persistent organic pollutant DDT.
title_sort elucidating turnover pathways of bioactive small molecules by isotopomer analysis the persistent organic pollutant ddt
url http://europepmc.org/articles/PMC4228495?pdf=render
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