Seco[D-Asp3]microcystin-RR and [D-Asp3,D-Glu(OMe)6]microcystin-RR, two new microcystins from a toxic water bloom of the cyanobacterium Planktothrix rubescens

• Published in: Journal of natural products (Washington, D.C.) Vol. 67; no. 3; pp. 337 - 342
• Main Authors: Grach-Pogrebinsky, O, Sedmak, B, Carmeli, S
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 26.03.2004; Amer Chemical Soc; American Society of Pharmacognosy
• Subjects: Bacteriology; Biological and medical sciences; Chemistry, Medicinal; Cyanophyta; Fundamental and applied biological sciences. Psychology; Life Sciences & Biomedicine; Microbiology; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Pharmacology & Pharmacy; Planktothrix rubescens; Plant Sciences; Science & Technology; Slovenia, Bled, Bled L; Slovenia; STRAINS; OSCILLATORIA-AGARDHII; LAKE; LR; Peptides; Enzyme; Cyclic peptides; Phosphoprotein phosphatase; Phosphoric monoester hydrolases; Enzyme inhibitor; Esterases; Heptapeptide; In vitro; Biological activity; Hexapeptide; Toxin; Microbial origin; Bloom; Absolute configuration; Cyanobacteria; Bacteria; Hydrolases; Isolation; Structural analysis
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np034036r

Two novel microcystins, seco[D-Asp(3)]microcystin-RR (1) and [D-Asp(3),D-Glu(OMe)(6)]-microcystin-RR (2), along with the known [D-Asp(3)]microcystin-RR (3), were isolated from a Planktothrix rubescens toxic bloom collected in Lake Bled, Slovenia. The structures were deduced using one- and two-dimensional NMR techniques, ESIMS/CID/MS analysis, and Marfey's method for determining the amino acids' absolute stereochemistry. Compounds I and 3 exhibit weak PP1 inhibitory activity. The NMR data of compound 3 are reported here for the first time.