Assessment of the Reproductive-Endocrine Disrupting Potential of Chlorine Dioxide Oxidation Products of Plant Sterols
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- 作者：Michael R. van den Heuvel ; Frederic D. L. Leusch ; Sean Taylor ; Nicholas Shannon ; and A. Bruce McKague
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：April 15, 2006
- 年：2006
- 卷：40
- 期：8
- 页码：2594 - 2600
- 全文大小：207K
- 年卷期：v.40,no.8(April 15, 2006)
- ISSN：1520-5851
文摘
This study examined the hypothesis that chlorine dioxidebleaching used in pulp and paper production causes theformation of reproductive-endocrine disrupting compoundsfrom plant sterols. This was tested by conducting alaboratory simulation of the chlorine dioxide oxidation oftwo plant sterols, 
-sitosterol and stigmasterol. Oxidationproducts of the plant sterol -sitosterol were purified andidentified and found to be cholestan-24-ethyl-3-one,4-cholestene-24-ethyl-3-one, and 4-cholestene-24-ethyl-3,6-dione. The first two compounds were found in a numberof pulp and paper effluents and biosolids. The sterols andtheir oxidation products were tested in vitro usingbioassays for androgenicity and estrogenicity. A 28 d invivo bioassay was employed to examine masculinization infemale mosquitofish. In vitro bioassays revealed littleestrogenic activity in the parent sterols or in mixtures oftheir oxidation products. Androgenic activity as measuredby the androgen receptor binding bioassay was in theorder of 19-96 
g/g testosterone equivalents but with noincrease or decrease with chlorine dioxide oxidation.The mosquitofish bioassay did not show significantmasculinization for any of the preparations tested. Anumber of androstane steroids were identified in the sterolstested, however, those compounds could only accountfor a small fraction of the androgenic activity in the sterols.It was clear that the parent sterols were not themselvesacting as androgens in the bioassays used. This studyindicated that chlorine dioxide oxidation of sterols producedpredominantly oxidized sterols that were not likely to actthrough androgenic or estrogenic mechanisms.
-sitosterol and stigmasterol. Oxidationproducts of the plant sterol -sitosterol were purified andidentified and found to be cholestan-24-ethyl-3-one,4-cholestene-24-ethyl-3-one, and 4-cholestene-24-ethyl-3,6-dione. The first two compounds were found in a numberof pulp and paper effluents and biosolids. The sterols andtheir oxidation products were tested in vitro usingbioassays for androgenicity and estrogenicity. A 28 d invivo bioassay was employed to examine masculinization infemale mosquitofish. In vitro bioassays revealed littleestrogenic activity in the parent sterols or in mixtures oftheir oxidation products. Androgenic activity as measuredby the androgen receptor binding bioassay was in theorder of 19-96 g/g testosterone equivalents but with noincrease or decrease with chlorine dioxide oxidation.The mosquitofish bioassay did not show significantmasculinization for any of the preparations tested. Anumber of androstane steroids were identified in the sterolstested, however, those compounds could only accountfor a small fraction of the androgenic activity in the sterols.It was clear that the parent sterols were not themselvesacting as androgens in the bioassays used. This studyindicated that chlorine dioxide oxidation of sterols producedpredominantly oxidized sterols that were not likely to actthrough androgenic or estrogenic mechanisms.