论文部分内容阅读
The cyanobacterial neurotoxin,β-N-methylamino-L-alanine (BMAA),has been suggested as an important environmental factor for neurodegenerative disease such as amyotrophic lateral sclerosis Parkinsonism dementia complex (ALS/PDC) in Guam.BMAA was reportedly produced by the majority of cyanobacterial isolates surveyed,both free and symbiotic living,in freshwater as well as marine environments.In this study,we report two methods using liquid chromatography-electrespray ionization-mass spectrometry (LC-ESI-MS/MS) each coupled with a different type of hydrophilic interaction liquid chromatography (HILIC) column to detect BMAA.The detection limit,repeatability and recovery of BMAA in both methods,which were based on tandem quadrupole mass spectrometry and multiple reaction monitoring (MRM) scan mode at m/z 119 to102were very good.A third method using AQC-derivatized BMAA was also used for comparison.Axenic cultures of Microcystis aeruginosa and Nostoc sp.isolated from Chinese freshwater were collected and analyzed for both free and protein-bound BMAA.Cultures of two strains of M.aeruginosa collected in four stages were analyzed in order to compare the presence of BMAA in different stages.BMAA was detected at very low levels only in the AQC derivatized method.No free or protein-bound BMAA toxin were found in the axenic cultures of cyanobacteria using non-derivatized BMAA.We suggest that cyanobacteria grown under specific culture conditions may be relatively free of BMAA and potentially useful for commercial development.