Frias Humberto Vieira, Mendes Maria Anita, Cardozo Karina Helena Morais, Carvalho Valdemir Melechco, Tomazela Daniela, Colepicolo Pio, Pinto Ernani
Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, CEP 05508-900, Universidade de São Paulo, SP, Brazil.
Biochem Biophys Res Commun. 2006 Jun 9;344(3):741-6. doi: 10.1016/j.bbrc.2006.03.199. Epub 2006 Apr 17.
Drastic environmental conditions such as elevated temperature, abrupt pH variation, low turbulence, and high nutrient inputs can enhance the development of toxic cyanobacterial blooms in lakes and reservoirs. This study describes the occurrence of four microcystin variants (MC) in a bloom in the eutrophic reservoir Billings, in São Paulo City. The bloom sample was collected in October 2003, and Microcystis were the main genus found. The MC were separated and purified by reverse phase high performance liquid chromatography (RP-HPLC). Their structures were elucidated by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and four MC variants were determined: MC-RR, MC-LR, MC-YR, and MC-hRhR. MC-hRhR is described for the first time as a new variant of MC with two homoarginines at positions 2 and 4 in its structure. ESI-MS/MS analysis thus provides a powerful and convenient tool for the determination of variants of MC. These results represent an important contribution to the knowledge of the biochemistry of toxic cyanobacteria and their toxins, specifically in São Paulo State.
诸如高温、pH值突变、低湍流和高养分输入等极端环境条件会促使湖泊和水库中有毒蓝藻水华的形成。本研究描述了富营养化的比林斯水库（位于圣保罗市）水华中四种微囊藻毒素变体（MC）的出现情况。水华样本于2003年10月采集，主要发现的藻属为微囊藻属。通过反相高效液相色谱法（RP-HPLC）分离并纯化了微囊藻毒素。通过电喷雾电离串联质谱法（ESI-MS/MS）阐明了它们的结构，并确定了四种微囊藻毒素变体：MC-RR、MC-LR、MC-YR和MC-hRhR。MC-hRhR首次被描述为一种新的微囊藻毒素变体，其结构中第2位和第4位含有两个高精氨酸。因此，ESI-MS/MS分析为微囊藻毒素的测定提供了一种强大且便捷的工具。这些结果对有毒蓝藻及其毒素的生物化学知识，特别是在圣保罗州，做出了重要贡献。
