The Biosynthetic Origin of the 3-Amino-2578-tetrahydroxy-10-methylundecanoic Acid Moiety and Absolute Configuration of Pahayokolides A and B

摘要

Pahayokolides A (>1) and B (>2) are cyclic undecapeptides that were isolated from the cyanobacterium Lyngbya sp. They contain the unusual α-hydroxy-β-amino acid, 3-amino-2,5,7,8-tetrahydroxy-10-methylundecanoic acid (Athmu). The absolute configurations of the amino acids of the pahayokolides, except for the four oxygen bearing stereocenters of Athmu, have been determined by Marphy’s method. Incorporation of labeled leucine and acetate precursors into the pahayokolides have established that Athmu is derived from a leucine or α-keto isocaproic acid starter unit which is further extended with three acetate units.