Palau amide

Bioactivity-guided fractionation of the extract of a species of Lyngbya from Palau yielded Palau amide 126, which had an IC50 value of 13 nM against KB cells. Total synthesis of a cyclic depsipeptide with the proposed structure of 126 was achieved, which showed different rotation and NMR data compared to those reported for palau amide. It implied that... 

Another common class of lipopeptide from cyanobacteria includes a starter PKS lipid section, almost always found as an eight-carbon chain (exceptions being jamaicamide, carmabin, and palau amide ), in which oxidation of the Ci -terminus occurs to typically produce a terminal alkyne functionality. Such terminally oxidized PKS motifs can be further dissected into those with an overall linear structure, such as the jamaica-mides, ° apramides, dragonamides, carmabins, " and dragamabin, and those possessing a 3-hydroxy or... 

Several other cyclic depsipeptides, all cytotoxic, were isolated in 2003 by V.J. Paul s group in Palau from sometimes imspecified species of Lyngbya and Symploca. Some of the structures presented below are strongly cytotoxic in vitro towards KB cells, with IC50 values lower than 1 jiM the most active is palau amide, with an IC50 equal to 13 nM (0.013 jiM). 

Williams, P.G., Yoshida, W.Y., Quon, M.K., Moore, R.E., and Paul, V.J. (2003c) The structure of palau amide, a potent cytotoxin from a species of the marine cyanobacterium Lyngbya. J. Nat. Prod., 66, 1545-1549. 

Palau amide, Palau amine, and Related Compounds... 

Zou, B., Long, K., and Ma, D.W. (2005) Total synlhesis and cytotoxicity studies of a cyclic depsipeptide with proposed structure of palau amide. Org. Lett., 7, 4237-4240. 

Mohapatra, D.K and Nayak, S. (2008) Stereoselective synthesis of the C33-C44 fragment of palau amide. Tetrahedron Lett., 49, 786-789. 

Sugiyama, H., Watanabe, A., Tenya, T., and Suenaga, K. (2009) Synthesis of palau amide and its diastereoisomers Confirmation of its stereostructure. Tetrahedron Lett., 50, 7343—7345. 

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