Merck
  • Home
  • Search Results
  • Why Small Differences Matter: Elucidation of the Mechanisms Underlying the Transformation of 2OH- and 3OH-Carbamazepine in Contact with Sand Filter Material.

Why Small Differences Matter: Elucidation of the Mechanisms Underlying the Transformation of 2OH- and 3OH-Carbamazepine in Contact with Sand Filter Material.

Environmental science & technology (2015-08-25)
Elena Brezina, Carsten Prasse, Manfred Wagner, Thomas A Ternes
ABSTRACT

Carbamazepine (CBZ) is a worldwide used antiepileptic drug, which is metabolized to a large extent in the human body to several metabolites, including 10,11-dihydroxy-10,11-dihydrocarbamazepine (DiOHCBZ), 2-hydroxycarbamazepine (2OHCBZ), and 3-hydroxycarbamazepine (3OHCBZ). 2OHCBZ and 3OHCBZ were previously detected in raw and treated wastewater revealing their widespread emission into the aquatic environment, eventually leading to the contamination of drinking water resources. Sand filtration is frequently applied in drinking water treatment for the removal of inorganic species and suspended particles but has been shown to be capable of removing trace organic contaminants. This study focuses on the elucidation of the (bio)transformation mechanisms of 2OHCBZ and 3OHCBZ in contact with material taken from a rapid sand filter of a German waterworks. Despite their similar structure, which differs only in the position of the phenolic OH moiety, both compounds underwent distinct transformation reactions leading to the formation of a variety of transformation products (TPs). The main biochemical reactions thereby included enzymatic transformation of 2OHCBZ resulting in the formation of a reactive iminoquinone intermediate (2OHCBZ) and nitration via peroxynitrite (2OHCBZ and 3OHCBZ) as well as formation of radicals leading to dimerization (3OHCBZ). Further transformation reactions included hydroxylation, ring cleavage, loss of carbamoyl group, and decarboxylation, as well as O-methylation.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Uric acid, ≥99%, crystalline
Sigma-Aldrich
Uric acid, BioXtra, ≥99% (HPLC)
Sigma-Aldrich
N-Acetyl-L-cysteine, Sigma Grade, ≥99% (TLC), powder
Sigma-Aldrich
N-Acetyl-L-cysteine, BioReagent, suitable for cell culture
Sigma-Aldrich
N-Acetyl-L-cysteine, BioXtra, ≥99% (TLC)
Sigma-Aldrich
Potassium, cubes (in mineral oil), 99.5% trace metals basis
Sigma-Aldrich
Formic acid, ≥95%, FCC, FG
Sigma-Aldrich
Potassium, chunks (in mineral oil), 98% trace metals basis
Sigma-Aldrich
Potassium, ingot, 99.95% trace metals basis
Sigma-Aldrich
Potassium hydride, in paraffin
Sigma-Aldrich
Potassium hydride, 30 wt % dispersion in mineral oil
Sigma-Aldrich
7-Nitroindazole, ≥98%
Sigma-Aldrich
Ammonium acetate, for molecular biology, ≥98%
Sigma-Aldrich
Sodium azide, ReagentPlus®, ≥99.5%
Sigma-Aldrich
Ammonium acetate, BioXtra, ≥98%
Sigma-Aldrich
Sodium azide, BioXtra
Sigma-Aldrich
Ammonium acetate solution, for molecular biology, 7.5 M
Sigma-Aldrich
Ammonium acetate, reagent grade, ≥98%
Sigma-Aldrich
N-Allylthiourea, 98%
Sigma-Aldrich
Ammonium acetate, 99.999% trace metals basis
Sigma-Aldrich
L-Tyrosine, reagent grade, ≥98% (HPLC)
Sigma-Aldrich
Sodium azide, BioUltra, ≥99.5% (T)
Sigma-Aldrich
Sodium azide, purum p.a., ≥99.0% (T)
Sigma-Aldrich
L-Tyrosine, from non-animal source, meets EP, USP testing specifications, suitable for cell culture, 99.0-101.0%
Sigma-Aldrich
L-Tyrosine, BioUltra, ≥99.0% (NT)
Sigma-Aldrich
L-Tyrosine, FG
SAFC
L-Tyrosine