Marine samples biotransformation

Included here are novel arsenic compounds reported in environmental samples over the last five years. Dimethylarsinoylacetate was identified as a naturally occurring arsenical in marine reference materials of mussel, oyster, and lobster hepatopancreas (36). This compound had been proposed as a possible intermediate in the formation of arsenobetaine (31). More recently, however, arsenobetaine was found to degrade to dimethylarsinoylacetate under aerobic microbial conditions (37), and such a biotransformation suggests an alternative hypothesis for the presence of dimethylarsinoylacetate in marine samples. 

Koppen et al. [131] determined HBCD enantiomers in fish samples obtained from fish farms in Etnefjorden, Norway. Levels of HBCDs were detectable in the fish, and the enantiomeric ratios were observed to differ among different fish species. Several recent reports describe the measurement of HBCD enantiomers in marine mammals [122], fish [130,131], human serum[132], and, marine sediment [133]. In certain cases where non-racemic enantiomeric fractions were observed, biotransformations have been attributed to cytochrome P450 metabolism. 

Fish bioaccmnulation and biomarkers in environmental risk assessment have been reviewed by Oost et al. [360]. Fish bioaccmnulation markers may be applied in order to elucidate the aquatic behavior of enviromnental contaminants and to assess exposme of aquatic organisms. The feasibility of PAH tissue concentrations in marine species as a monitoring parameter for PAH exposme depends on their uptake, biotransformation and excretion rates. Since it remains hard to accmately predict bioaccumulation in marine species, even with highly sophisticated models, analyses of tissue levels are required. The main problem is that PAHs do not tend to accumulate in fish tissues in quantities that reflect the exposme. The analysis of PAH metabolite levels in fish bile can be used to assess the actual PAH uptake, rather than the analysis of the non-hydroxylated PAHs content [328,361]. A number of sentinel fish species have been proposed to asses pollution by PAHs [325,326], as well as several mussels [322,323,326,352]. Several studies have also correlated the high levels of 1-OHPy and B(a)Py metabolites found in the bile of cat-shark with contamination sources such as boat traffic and combustion-based industries present in the sampling area [362]. 

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