RESUMO
Hoshinoamide C (1), an antiparasitic lipopeptide, was isolated from the marine cyanobacterium Caldora penicillata. Its planar structure was elucidated by spectral analyses, mainly 2D NMR, and the absolute configurations of the α-amino acid moieties were determined by degradation reactions followed by chiral-phase HPLC analyses. To clarify the absolute configuration of an unusual amino acid moiety, we synthesized two possible diastereomers of hoshinoamide C and determined its absolute configuration based on a comparison of their spectroscopic data with those of the natural compound. Hoshinoamide C (1) did not exhibit any cytotoxicity against HeLa or HL60 cells at 10 µM, but inhibited the growth of the parasites responsible for malaria (IC50 0.96 µM) and African sleeping sickness (IC50 2.9 µM).
Assuntos
Anti-Infecciosos/farmacologia , Cianobactérias/química , Lipopeptídeos/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Antiparasitários , Cromatografia Líquida de Alta Pressão , Células HL-60 , Células HeLa , Humanos , Concentração Inibidora 50 , Lipopeptídeos/química , Lipopeptídeos/isolamento & purificação , Estrutura MolecularRESUMO
Hoshinoamides A (1) and B (2), new acyclic lipopeptides, were isolated from the marine cyanobacterium Caldora penicillata. Their structures were elucidated by spectroscopic analyses and degradation reactions. Hoshinoamides A (1) and B (2) did not exhibit any cytotoxicity against HeLa cells at 10 µM, but inhibited the in vitro growth of the malarial parasite Plasmodium falciparum (IC50 = 0.52 and 1.0 µM, respectively).
Assuntos
Cianobactérias/química , Lipopeptídeos/isolamento & purificação , Lipopeptídeos/farmacologia , Água do Mar/microbiologia , Células HeLa , Humanos , Microbiologia da ÁguaRESUMO
Kohamamides A, B, and C (1-3), new cyclic depsipeptides that belong to the kulolide superfamily, were isolated from an Okeania sp. marine cyanobacterium. Their structures were elucidated by spectroscopic analyses and degradation reactions. Kohamamide B (2) exhibited moderate cytotoxicity against HL60 cells. Although many natural products in the kulolide superfamily have been isolated from cyanobacteria collected in various parts of the world, kohamamides 1-3 are the first members to be isolated from the East Asian marine environment. In addition, unlike other members of this superfamily, kohamamides 1-3 contain a Leu residue adjacent to the Pro residue, rather than another lipophilic amino acid.