01796naa a2200301 a 450000100080000000500110000800800410001910000140006024501310007426000090020552009130021465000160112765000180114365000240116165000140118565000140119965000120121365300130122565300200123865300100125865300440126865300240131265300140133670000180135070000190136870000210138777300860140819676732013-10-02       2013    bl uuuu     u00u1 u    #d1 aPETTA, T.  aBioassay-guided isolation of a low molecular weight PHB from Burkholderia sp. with phytotoxic activity.h[electronic resource]  c2013  aThis work reports on the bioassay-guided isolation and identification of themacrocyclic pentolide 1, a cyclic polyhydroxybutyrate (PHB) with low molecularweight. This metabolite is produced by Burkholderia sp. and it exhibited phytotoxicactivity in a Lemna minor bioassay. Its structure was determined by 1H and 13CNMR, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, IR, and electrospray ionization tandem mass spectrometry analyses. The period for maximum production of the pentolide was optimized and determined on the basis of multiple reaction monitoring experiments at 15 days. The potential of Burkholderia sp. as a producer of higher biopolymers of PHB was also investigated. The methodology employed here accelerated the isolation and characterization of a phytotoxicmetabolite whose structure can serve as a model for the synthesis of new classes of herbicides.  aLemna minor  aphytotoxicity  apolyhydroxybutyrate  aBactéria  aHerbicida  aToxidez  aBioassay  aBurkholderia sp  aLC-MS  aLiquid chromatography-mass spectrometry  aPolihidroxibutirato  aPolímero1 aRAICHARDT, L.1 aMELO, I. S. de1 aMORAES, L. A. B.  tApplied Biochemistry and Biotechnology, Totowagv. 170, n. 7, p. 1689-1701, 2013.