Department of Environmental Science and Engineering, School of Life Science, Jinggangshan University, Ji'an, 343009, China.
Department of Environmental Science and Engineering, School of Life Science, Jinggangshan University, Ji'an, 343009, China.
Chemosphere. 2020 Jun;249:126113. doi: 10.1016/j.chemosphere.2020.126113. Epub 2020 Feb 9.
The widespread occurrence and distribution of organotin compounds (OTCs) in both marine and freshwater ecosystems has aroused considerable concerns in most countries worldwide. In this work, individual kinetics of the elimination of three butyltins and three phenyltins from C. demersum L. were systematically studied for over 240 h in clean water after a 48h period of accumulation. All OTCs were rapidly metabolized to nontoxic inorganic tin by C. demersum L. through stepwise debutylation or dephenylation. In addition to inorganic tin, monobutyltin (MBT) and monophenyltin (MPT) were the primary degradation products of tributyltin (TBT) and triphenyltin (TPT), with small amounts of dibutyltin (DBT) and diphenyltin (DPT), respectively, also being present. The estimated half-life of TPT (240 h) in C. demersum L. was longer than that of TBT (100 h), although the TPT was less hydrophobic. The corresponding degradation mechanisms may be attributed to a cascade of enzymatic reactions of CYP450 enzymes in C. demersum L. The pH played an important role in both plant growth and TBT degradation. Although pH 8.9 was more suitable for C. demersum L. growth, it uptook and metabolized more TBT at pH 5.0, which may be because the cationic species TBT (at pH 5.0) was metabolized more easily than the neutral hydroxide species TBTOH (at pH 8.9). C. demersum L. may thus be the plant with the most potential for the remediation of OTC-contaminated freshwater environments.
有机锡化合物（OTCs）在海洋和淡水生态系统中的广泛存在和分布引起了世界上大多数国家的极大关注。在这项工作中，在积累 48 小时后，在清洁水中对菹草（C. demersum L.）中三种丁基锡和三种苯基锡的消除个体动力学进行了超过 240 小时的系统研究。所有 OTCs 都通过菹草（C. demersum L.）通过逐步丁基或苯基去甲酰化被快速代谢为无毒的无机锡。除了无机锡之外，一丁基锡（MBT）和一苯基锡（MPT）是三丁基锡（TBT）和三苯基锡（TPT）的主要降解产物，分别存在少量的二丁基锡（DBT）和二苯基锡（DPT）。TBT 在菹草（C. demersum L.）中的半衰期（240 小时）长于 TPT（100 小时），尽管 TPT 的疏水性较低。相应的降解机制可能归因于菹草（C. demersum L.）中 CYP450 酶的级联酶反应。pH 在植物生长和 TBT 降解中都起着重要作用。尽管 pH 8.9 更适合菹草（C. demersum L.）生长，但在 pH 5.0 时吸收和代谢更多的 TBT，这可能是因为阳离子物种 TBT（在 pH 5.0 时）比中性氢氧化物物种 TBTOH（在 pH 8.9 时）更容易代谢。因此，菹草（C. demersum L.）可能是修复 OTC 污染淡水环境最有潜力的植物。
