State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.
Environ Toxicol Chem. 2013 Nov;32(11):2565-70. doi: 10.1002/etc.2337. Epub 2013 Sep 6.
The laboratory trophic transfer of hexabromocyclododecanes (HBCDs) was studied using predatory (oscar) fish and a prey species (tiger barb) exposed to a technical HBCD. Gut absorption, dynamic changes of diastereomer pattern and enantiomer fractions, and potential metabolism of HBCDs were examined. Compared with β- or γ-HBCD, α-HBCD showed lower absorption efficiency in the gut of oscar fish. A predominance of γ-HBCD was observed in the tiger barb after 5 d HBCD-exposed and oscar feeding on the tiger barb for 16 d. After 20 d of depuration, 41.1% γ-HBCD and 42.7% β-HBCD disappeared, and α-HBCD exceeded the initial amount. The transformation from γ-HBCD predominance in the food to α-HBCD predominance in the oscar was attributed mainly to the isomerization of γ-HBCD (at least 3% and up to 22.7%) to α-HBCD. Selective enrichment of the (+) α- and (-) β-enantiomers and no enantioselective enrichment of γ-HBCD were observed in the tiger barbs. No enantioselective uptake of the 3 diasteromers was found in the oscar gut. The enantiomer fractions of α- and γ-diastereomers were significantly higher, but that of β-diastereomer were significantly lower in the oscars than in the tiger barbs, indicating enantioselective metabolism of the 3 diastereomers. Two HBCD monohydroxylated metabolites were detected in the 2 fish species, but their composition patterns differed, indicating a species-specific metabolism of HBCD in the studied fish species.
研究了用肉食性（大眼狮鲈）鱼和被捕食物种（虎皮鱼）进行的六溴环十二烷（HBCDs）的实验室营养传递。检查了肠道吸收、非对映异构体模式和对映体分数的动态变化以及 HBCDs 的潜在代谢。与 β-或 γ-HBCD 相比，α-HBCD 在大眼狮鲈的肠道中表现出较低的吸收效率。在 5 天 HBCD 暴露和大眼狮鲈捕食虎皮鱼 16 天后，虎皮鱼中观察到 γ-HBCD 占优势。在净化 20 天后，41.1%的γ-HBCD 和 42.7%的β-HBCD 消失，而α-HBCD 超过了初始量。从食物中γ-HBCD 占优势到大眼狮鲈中α-HBCD 占优势的转变主要归因于 γ-HBCD 的异构化（至少 3%，高达 22.7%）到α-HBCD。在虎皮鱼中观察到（+）α-和（-）β-对映体的选择性富集，而γ-HBCD 没有对映体选择性富集。在大眼狮鲈的肠道中没有发现 3 种非对映异构体的对映体选择性摄取。α-和 γ-非对映异构体的对映体分数在大眼狮鲈中显著高于在虎皮鱼中，但β-非对映异构体的对映体分数在大眼狮鲈中显著低于虎皮鱼，表明 3 种非对映异构体的对映体选择性代谢。在这两种鱼类中都检测到了两种 HBCD 单羟基代谢物，但它们的组成模式不同，表明研究的鱼类中 HBCD 具有物种特异性的代谢。
