Two Cyclic Dipeptides from <I>Pseudomonas fluorescens</I> GcM5-1A Carried by the Pine Wood Nematode and Their Toxicities to Japanese Black Pine Suspension Cells and Seedlings in vitro

  • Qunqun Guo
  • Daosen Guo
  • Boguang Zhao
  • Jie Xu
  • Ronggui Li
Keywords: Bursaphelenchus xylophilus, cyclo(-Pro-Tyr-), cyclo(-Pro-Val-), interaction, Pinus thunbergii, Pseudomonas fluorescens GcM5-1A, toxicity


Pseudomonas fluorescens GcM5-1A, isolated from the pine wood nematode (PWN), Bursaphelenchus xylophilus, was cultured in Luria Broth medium (LB). The clarified culture was extracted with ethyl acetate, and two dipeptides were purified from the extract. The chemical structures of 1 and 2 were identified as cyclo(-Pro-Val-)and cyclo(-Pro-Tyr-), respectively, by MS, 1H NMR, 13C NMR, 1H-1H COSY, 1H -13C COSY spectra. Bioassay results showed that the two compounds were toxic to both suspension cells and seedlings of Pinus thunbergii, which may offer some clues to research the mechanism of pine wilt disease caused by PWN.