Isolation and identification of microcystin variants from a south Florida estuary

CHED 1103

Carlos A Miranda, cmira003@fiu.edu1, Weihua Song, wsong003@fiu.edu2, and Kevin O'Shea, osheak@fiu.edu2. (1) Department of Chemistry, Florida International University, 11200 SW 8th street, Miami, FL 33199, (2) Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th st, Miami, FL 33199
Blue-green algae (BGA) produce microcystin (MC), which are toxic cyclic heptapeptides. Relatively high levels of MC are released into the surface water during a bloom of BGA creating a threat to public safety. We collected the biomass during a large bloom of BGA in South Florida. The biomass was sonicated, filtered, and pigment removed through a solid phase extraction (SPE) using C18 cartridge. The resulting solution was refined using preparative HPLC by monitoring at 238 nm, typical absorption maximum of MC variants. The HPLC chromatograph had several peaks, which are indicative of different MC variants. The major peak was isolated and identified as MC-LR by MS and proton NMR. MC-LR accounts for ~ 80 % of the MC content. An additional 2-3 peaks were observed in the chromatogram. Studies are underway to characterize the remaining MC variants. A number of studies on the remediation and therapeutic technologies are planned.
 

Undergraduate Research Poster Session: Environmental Chemistry
2:00 PM-4:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008