title: [Anti-diatom compounds from marine bacterium Pseudomonas putida].
abstract: OBJECTIVE
  In order to provide more natural antifouling compounds, marine bacterium Pseudomonas putida isolated from the sponge Haliclona sp. was explored to test its anti-diatom compounds.
  
  
  METHODS
  The strain was identified by colonial morphology, scanning electron microscope (SEM) and 16S rDNA sequence analysis. The separation procedure was guided by bioactive (Anti-diatom) and chemical (TLC, DAD-HPLCand 1H NMR) analysis, and their structures were elucidated by spectrographic techniques. The anti-diatom activity of all purified compounds was assayed.
  
  
  RESULTS
  Strain 272 isolated from the sponge Haliclona sp. was identified as Pseudomonas putida. Six diketopiperazine compounds were isolated from the culture of this strain and their structures were determined as cyclo(Leu-Pro) (1), cyclo (Leu-Ala) (2), cyclo(Phe-Ala) (3), cyclo(Val-Tyr) (4), cyclo(Ala-Tyr) (5), cyclo(Ala-Trp) (6); Compounds 3 and 6 displayed significant anti-diatom activity with the inhibitory rate of 50% and 85% at the concentration of 50 microg/mL, respectively.
  
  
  CONCLUSIONS
  The anti-diatom compounds isolated from marine bacterium Pseudomonas putida were cyclo (Phe-Ala) and cyclo (Ala-Trp).
authors.affiliation: Marine Science & Technology Institute, Yangzhou University, Yangzhou 225127, China. jshazjs@126.com
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Marine Science & Technology Institute, Yangzhou University, Yangzhou 225127, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Marine Science & Technology Institute, Yangzhou University, Yangzhou 225127, China.
authors.forename: Li
authors.initials: L
authors.lastname: Miao
authors.affiliation: Marine Science & Technology Institute, Yangzhou University, Yangzhou 225127, China.
authors.forename: Cuili
authors.initials: C
authors.lastname: Jin
authors.affiliation: Marine Science & Technology Institute, Yangzhou University, Yangzhou 225127, China.
authors.forename: Weiyang
authors.initials: W
authors.lastname: Bao
mesh_terms: D000818:Animals; D001685:Biological Factors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D017377:Diatoms / Q000187:drug effects* / Q000254:growth & development; D015394:Molecular Structure; D010802:Phylogeny; D011161:Porifera / Q000382:microbiology*; D016958:Pseudomonas putida / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D012623:Seawater / Q000382:microbiology*
chemical_list: D001685:Biological Factors