Modificação estrutural de constituintes isolados de óleos essenciais para potencialização das atividades inseticidas

Abstract

This work consists of the synthesis, characterization and biological activities of new 2,3-unsaturated O-glycosides derived from two monoterpene alcohols derived from the secondary metabolism of plants, geraniol and citronellol. In the literature, numerous articles with descriptions of the various biological properties of these phytocomposites are found, and they act as a basis for structural manipulations to obtain synthetic compounds with increased biological activity or different from those that their precursors present. The 2,3-unsaturated O-glycosides from the monoterpenes were synthesized from an allylic rearrangement of 3,4,6-tri-O-acetyl-D-glycale in the presence of an acid catalyst, K-10 montmorillonite, the geranyl 4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside in 89% yield. The structures of the compounds were elucidated by the usual methods of IV-FT, 13C NMR and 1H NMR. The compounds were tested for their inhibition potential in filamentous and yeast fungi and gram-positive and gram-negative bacteria, where the compounds were able to inhibit the development of microorganisms, with the lowest MIC being 156,2 μg/mL. The acaricidal activity of the compounds was also tested, where 3,4,6-tri-O-acetyl-D-glycale and geranyl 4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside at concentrations of 5000 and 70000 ppm prevented approximately 8% to 98% of the acaricide population compared to commercially available positive standards in the control of the mite.