Ulongapeptin, a Cytotoxic Cyclic Depsipeptide from a Palauan Marine Cyanobacterium Lyngbya sp.
journal contributionposted on 06.05.2003, 00:00 by Philip G. Williams, Wesley Y. Yoshida, Michael K. Quon, Richard E. Moore, Valerie J. Paul
Ulongapeptin (1), a cyclic depsipeptide, was isolated from a Palauan marine cyanobacterium Lyngbya sp. The gross structure was elucidated through one-dimensional TOCSY experiments and other spectroscopic techniques. The absolute and relative stereochemistry of the β-amino acid, 3-amino-2-methyl-7-octynoic acid (AMO), in 1 was determined by synthesis of the saturated α-alkyl-β-amino acid and Marfey's analysis of the acid hydrolysate of tetrahydro-1. Ulongapeptin (1) was cytotoxic against KB cells at an IC50 value of 0.63 μM.