Aerobic transformation of short-chain alkylphenol polyethoxylates by mixed bacterial cultures

Ahel, Marijan; Hršak, Dubravka; Giger, Walter

doi:10.1007/bf00214159

Cited by 65 publications

(63 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recent studies revealed the occurrence of chemical biodegradation conditions for temperatures and pH levels similar to those reported herein for August 2006 (Ahel et al 1994;Chang et al 2005), and so, because in this month the levels of all compounds found were below the detection limits of both analytical methods (HPLC-DAD and GC-MS), it is hypothesized that biodegradation occurred.…”

Section: Resultsmentioning

confidence: 98%

Distribution of endocrine disruptors in the Mondego River estuary, Portugal

Ribeiro

Pardal

Martinho

et al. 2008

Environ Monit Assess

View full text Add to dashboard Cite

Recent studies in the Mondego River estuary demonstrated signs of pollution in the area, but the nature of the contamination remains unexplored. Because there seems to be any studies in that zone checking for the simultaneous presence of xenoestrogenic endocrine disrupting compounds, either of animal (estradiol and estrone), vegetal (daidzein, genistein and biochanin A), pharmaceutical (17α-ethynylestradiol) or industrial (bisphenol A, 4-octylphenol, 4-nonylphenol) origins, the main objective of this study was to investigate their presence, in every year season and at eight points along the estuarine gradient. For this propose, water samples (2 L) were collected in high and low tides, preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by HPLC-DAD and GC-MS. The current data showed the absence of contamination by animal or pharmaceutical estrogens and by alkylphenols, but demonstrated the presence of high levels of phytoestrogens (up to 1

show abstract

Section: Resultsmentioning

confidence: 98%

Distribution of endocrine disruptors in the Mondego River estuary, Portugal

Ribeiro

Pardal

Martinho

et al. 2008

Environ Monit Assess

View full text Add to dashboard Cite

show abstract

“…10 are more relevant to the biodegradation of alkylphenolic surfactants, such as nonylphenol polyethoxylates (NPnEO, where n ϭ 6 -40). The parent surfactant itself is not active, but during sewage treatment, APnEO are biodegraded via shortening of the ethoxylate chain to short-chain ethoxylates and carboxylic acid derivatives and finally APs (45), which are all estrogenic (24). Fig.…”

Section: Estrogenic Activity Of Different Isomers Of Phenylphenol-mentioning

confidence: 99%

Structural Features of Alkylphenolic Chemicals Associated with Estrogenic Activity

Routledge

Sumpter

1997

Journal of Biological Chemistry

481

281

View full text Add to dashboard Cite

The ability of certain man-made chemicals to mimic the effects of natural steroid hormones and their potential to disrupt the delicate balance of the endocrine system in animals are of increasing concern. The growing list of reported hormone-mimics includes the alkylphenolic (AP) compounds, a small number of which have been reported to be weakly estrogenic. In their most basic form, APs are composed of an alkyl group, which can vary in size, branching, and position, joined to a phenolic ring. The aim of this project was to identify the important structural features responsible for the estrogenic activity of AP chemicals. This was achieved by incubating APs with different structural features in a medium containing a previously described estrogen-inducible strain of yeast (Saccharomyces cerevisiae) expressing the human estrogen receptor and comparing their activity spectrophotometrically by the resulting color change of the medium. The results were compared to the effects of the main natural estrogen 17␤-estradiol. The data indicate that both the position (para > meta > ortho) and branching (tertiary > secondary ‫؍‬ normal) of the alkyl group affect estrogenicity. Optimal estrogenic activity requires a single tertiary branched alkyl group composed of between 6 and 8 carbons located at the para position on an otherwise unhindered phenol ring. The results are discussed in relation to the purity and composition of the chemicals tested.In the early 1930s, scientists began synthesizing compounds based on the phenanthrene nucleus of steroidal estrogens in an attempt to produce substances with similar properties and considerable clinical value. Estrogenic activity was assessed by subcutaneous administration of chemicals (dissolved in sesame oil) to ovariectomized rats that were then observed for the onset of estrus (1). It soon became apparent that the phenanthrene condensed ring structure was not required for estrogenic activity, with the discovery that diphenyl and diphenyl methane derivatives (2) and stilbene derivatives (3-6) containing two hydroxyl groups in the para positions (e.g. 4,4Ј-dihydroxy diphenyl) were also active. The substituted derivative of stilbene (4,4Ј-dihydroxystilbene) was renamed stilbestrol and was used as the parent compound in the production of another series of estrogenic compounds, including 4,4Ј-dihydroxydiethylstilbene

show abstract

“…3) Exotype shortening of the EO chain is thought to be accompanied by oxidation of the EO moiety (oxidative biodegradation), 4,5) because, together with the shortchain APEO n s, their carboxylates, which oxidize at the EO chain terminus, have been detected in many environmental samples. But, no genes or enzymes relevant to the biodegradation of APEO n have been identified, except for PEG dehydrogenases and a diglycolic acid dehydrogenase, which are involved in the oxidative biodegradation of PEG.…”

mentioning

confidence: 99%