title: Neuraminidase inhibitors from marine-derived actinomycete Streptomyces seoulensis.
abstract: OBJECTIVE
  This work was performed to characterize new secondary metabolites with neuraminidase (NA) inhibitory activity from marine actinomycete strains.
  
  
  RESULTS
  An actinomycete strain IFB-A01, capable of producing new NA inhibitors, was isolated from the gut of shrimp Penasus orientalis and identified as Streptomyces seoulensis according to its 16S rRNA sequence (over 99% homology with that of the standard strain). Repeated chromatography of the methanol extract of the solid-substrate culture of S. seoulensis IFB-A01 led to the isolation of streptoseolactone (1), and limazepines G (2) and H (3). The structures of 1-3 were determined by a combination of IR, ESI-MS, 1D ((1) H and (13) C NMR, and DEPT) and 2D NMR experiments (HMQC, HMBC, (1) H-(1) H COSY and NOESY). Compounds 1-3 showed significant inhibition on NA in a dose-dependent manner with IC50 values of 3.92, 7.50 and 7.37 μmol l(-1), respectively.
  
  
  CONCLUSIONS
  This is the first report of two new (1 and 2) and known (3, recovered as a natural product for the first time in the work) NA inhibitors from the marine-derived actinomycete S. seoulensis IFB-A01.
  
  
  CONCLUSIONS
  The three natural NA inhibitors maybe of value for the development of drug(s) necessitated for the treatment of viral infections.
authors: Institute of Functional Biomolecules, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China.
authors: R H
authors: RH
authors: Jiao
authors: H
authors: H
authors: Xu
authors: J T
authors: JT
authors: Cui
authors: H M
authors: HM
authors: Ge
authors: R X
authors: RX
authors: Tan
mesh_terms: D000818:Animals; D001569:Benzodiazepines / Q000737:chemistry / Q000302:isolation & purification*; D003016:Clostridium perfringens / Q000201:enzymology; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009439:Neuraminidase / Q000037:antagonists & inhibitors*; D033561:Penaeidae / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013302:Streptomyces / Q000737:chemistry* / Q000235:genetics
chemical_list: D007783:Lactones; D012336:RNA, Ribosomal, 16S; C586307:limazepine G; C586309:limazepine h; C586308:streptoseolactone; D001569:Benzodiazepines; D009439:Neuraminidase