Técnicas modernas em espectrometria de massas aplicadas no isolamento de bioherbicidas produzidos por microrganismos / Modern Techniques on Mass Spectrometry applied to the isolation of bioherbicides produced by microorganisms

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

In this work a quick and efficient methodology was employed for the identification of phytotoxic metabolites produced by microorganisms. The isolation of the bioactive compound was guided by Lemna minor bioassay. Mass spectrometry, especially LC-MS, was used to accelerate the process of identification of the phytotoxin. All bacteria were symbiotic to the phytopatogenic fungi Sclerotium rolfsii.. The bacterium Burkholderia sp was selected among the five bacteria analyzed, due to its greater phytotoxic activity in the bioassay. The phytotoxin was characterized as a 20 member macropentolide. This compound belongs to the polyhidroxybutirates (PHBs) chemical class. Its structure was determined by NMR1H, NMR 13C, HMQC, HMBC, IV, ESI-MS/MS and HRMS. It has never been isolated from natural sources before. Although a synthetic route has been proposed in the literature this is the first time that its phytotoxic activity is reported. This work leads to a new perspective for the application of low molecular weight PHBs and propose a phytotoxic structure that can be used as a model for the synthesis of new herbicide class.

ASSUNTO(S)

bioherbicidas bioherbicides microorganism lc-ms lc-ms bionesaio microrganismos bioassay

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