RESUMO
Cystomanamides A-D were isolated as novel natural product scaffolds from Cystobacter fuscus MCy9118, and their structures were established by spectroscopic techniques including 2D NMR, LC-SPE-NMR/-MS, and HR-MS. The cystomanamides contain ß-hydroxy amino acids along with 3-amino-9-methyldecanoic acid that is N-glycosylated in cystomanamide C and D. The gene cluster for cystomanamide biosynthesis was identified by gene disruption as PKS/NRPS hybrid incorporating an iso-fatty acid as starter unit and including a reductive amination step at the interface of the PKS and NRPS modules.
Assuntos
Aminoácidos Básicos/química , Produtos Biológicos/química , Ácidos Decanoicos/química , Lipopeptídeos/biossíntese , Myxococcales/química , Sequência de Aminoácidos , Produtos Biológicos/metabolismo , Vias Biossintéticas/genética , Glicosilação , Lipopeptídeos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Família MultigênicaRESUMO
Molluscicides can play an important role in the control of schistosomiasis because snails of the genus Biomphalaria act as intermediate hosts for the parasite. Schistosomiasis is one of 13 neglected tropical diseases with high morbidity and mortality that collectively affect one billion of the world's poorest population, mainly in developing countries. Thiopalmyrone (1) and palmyrrolinone (2), metabolites isolated from extracts of a Palmyra Atoll environmental assemblage of two cyanobacteria, cf. Oscillatoria and Hormoscilla spp., represent new and potent molluscicidal chemotypes against Biomphalaria glabrata (LC50=8.3 and 6.0 µM, respectively). A slight enhancement in molluscicidal effect (LC50=5.0 µM) was observed when these two natural products were utilized as an equimolar binary mixture.
