Isolation of two toxic heptapeptide microcystins from an axenic strain of Microcystis aeruginosa, K-139.
Two toxic heptapeptides were isolated from an axenic Microcystis aeruginosa strain, K-139. Using mainly a non-destructive NMR method, we determined the structure of the major toxin to be 7-desmethylmicrocystin LR which lacks an N-methyl group of the dehydroalanine moiety of microcystin LR. The minor toxin was deduced to be 3,7-didesmethylmicrocystin LR. The chromatographic and NMR analyses of 7-desmethylmicrocystin LR were compared with those of 3-desmethylmicrocystin LR.
Harada
K
K
Faculty of Pharmacy, Meijo University, Nagoya, Japan.
Ogawa
K
K
Matsuura
K
K
Nagai
H
H
Murata
H
H
Suzuki
M
M
Itezono
Y
Y
Nakayama
N
N
Shirai
M
M
Nakano
M
M
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001427:Bacterial Toxins / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D005856:Germ-Free Life; D046931:Microcystis / Q000032:analysis*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*
D000596:Amino Acids; D001427:Bacterial Toxins; D010456:Peptides, Cyclic; C070123:3,7-didesmethylmicrocystin LR; C070122:7-desmethylmicrocystin LR