title: Structural modifications imparting reduced toxicity in microcystins from Microcystis spp.
abstract: A cyanobacterial (blue-green algal) bloom containing Microcystis aeruginosa (dominant), M. viridis, and M. wesenbergii, was collected from Homer Lake (Illinois, U.S.A.) in the summer of 1988 and microcystins were isolated. One microcystin of substantially reduced toxicity was isolated, together with ten hepatotoxic microcystins. The compound with reduced toxicity was nonlethal at 1 mg/kg (i.p. mouse) and was determined to have a (C3H7O2) mono-ester of the alpha-carboxyl on the Glu unit of microcystin-LR. The other nine microcystins apart from MCLR had approximate LD50S ranging from 97 micrograms/kg to 750 micrograms/kg.
authors.affiliation: Department of Veterinary Biosciences, University of Illinois, Urbana 61801.
authors.forename: R R
authors.initials: RR
authors.lastname: Stotts
authors.forename: M
authors.initials: M
authors.lastname: Namikoshi
authors.forename: W M
authors.initials: WM
authors.lastname: Haschek
authors.forename: K L
authors.initials: KL
authors.lastname: Rinehart
authors.forename: W W
authors.initials: WW
authors.lastname: Carmichael
authors.forename: A M
authors.initials: AM
authors.lastname: Dahlem
authors.forename: V R
authors.initials: VR
authors.lastname: Beasley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry / Q000633:toxicity*; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007928:Lethal Dose 50; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects; D008297:Male; D051379:Mice; D046931:Microcystis / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009929:Organ Size / Q000187:drug effects; D010456:Peptides, Cyclic / Q000633:toxicity*; D013329:Structure-Activity Relationship
chemical_list: D001427:Bacterial Toxins; D010456:Peptides, Cyclic