Isolation and structure determination of lyngbyastatin 3, a lyngbyastatin 1 homologue from the marine cyanobacterium Lyngbya majuscula. Determination of the configuration of the 4-amino-2,2-dimethyl-3-oxopentanoic acid unit in majusculamide C, dolastatin 12, lyngbyastatin 1, and lyngbyastatin 3 from cyanobacteria.
The structure of lyngbyastatin 3 (1), including the configurations of the two unusual amino acid residues, viz., the 3-amino-2-methylhexanoic acid (Amha) and 4-amino-2,2-dimethyl-3-oxopentanoic acid units (Ibu), has been established by chemical degradation. Analysis of the cyanobacterial samples of lyngbyastatin 3 (1), lyngbyastatin 1 (2), and dolastatin 12 (3) demonstrated that they are mixtures of Ibu epimers [R (major) and S (minor)], whereas the structurally related majusculamide C (4) is a single diastereomer having an S-Ibu unit.
Williams
Philip G
PG
Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA.
Moore
Richard E
RE
Paul
Valerie J
VJ
D000596:Amino Acids; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry*; D047630:Depsipeptides; D008401:Gas Chromatography-Mass Spectrometry; D006141:Guam; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009842:Oligopeptides; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000302:isolation & purification*; D013237:Stereoisomerism
D000596:Amino Acids; D047630:Depsipeptides; D009842:Oligopeptides; D010456:Peptides, Cyclic; C115556:dolastatin 12; C115557:lyngbyastatin 1; C481240:lyngbyastatin 3