Tsuji K, Watanuki T, Kondo F, Watanabe M F, Nakazawa H, Suzuki M, Uchida H, Harada K
Kanagawa Prefectural Public Health Laboratories, Yokohama, Japan.
Toxicon. 1997 Jul;35(7):1033-41. doi: 10.1016/s0041-0101(96)00223-1.
Microcystins, the cyclic heptapeptide toxins produced by cyanobacteria such as Microcystis, show tumor-promoting activity through inhibition of protein phosphatases 1 and 2A. They potentially threaten human health, and are increasing the world-wide interest in the health risk associated with cyanobacterial toxins. In this study, the effect of chlorination on the decomposition of microcystins-LR and -RR was examined. The toxins were easily decomposed by chlorination with sodium hypochlorite, and the decomposition depended on the free chlorine dose. In this operation, many reaction products were formed, one of which was determined to be dihydroxymicrocystin formed through the chloronium ion at the conjugated diene of Adda [3-amino-9-methoxy-10-phenyl-2,6,8-trimethyl-deca-4(E), 6(E)-dienoic acid], followed by hydrolysis. Other products may be its stereoisomers and/or regioismers. No noxious products were detected from the chlorination process of microcystin-LR. Although these results suggested that chlorination at an adequate chlorine dose is very effective for the removal of microcystin in raw water, preoxidation of the cell itself with chlorine must be avoided, because it frequently causes toxin release from algae and produce trihalomethanes during water treatment.
微囊藻毒素是由微囊藻等蓝藻产生的环状七肽毒素，通过抑制蛋白磷酸酶1和2A表现出促肿瘤活性。它们对人类健康构成潜在威胁，也日益引起全球对蓝藻毒素相关健康风险的关注。在本研究中，考察了氯化作用对微囊藻毒素-LR和-RR分解的影响。这些毒素很容易被次氯酸钠氯化分解，且分解作用取决于游离氯剂量。在此过程中形成了许多反应产物，其中一种被确定为通过Adda[3-氨基-9-甲氧基-10-苯基-2,6,8-三甲基-癸-4(E),6(E)-二烯酸]共轭二烯处的氯鎓离子形成二羟基微囊藻毒素，随后发生水解。其他产物可能是其立体异构体和/或区域异构体。在微囊藻毒素-LR的氯化过程中未检测到有害产物。尽管这些结果表明以适当的氯剂量进行氯化对于去除原水中的微囊藻毒素非常有效，但必须避免用氯对细胞本身进行预氧化，因为这经常会导致藻类释放毒素并在水处理过程中产生三卤甲烷。
