Estudo químico de microorganismo associados a Khaya ivorensis (MELIACEAE)

Abstract

This work shows the isolation, identification of microorganisms from the species Khaya ivorensis and the identification of the pathogen that is attacking this plant on Bahia state (Brazil). In total seven strains of microorganisms from K. Ivorensis were isolated, but only six were identified. Two of them, Penicillium spp., Rhizopus spp., were identified according to their characteristics macro and micro morphological structures vegetative and reproductive. Four fungi were identified by the regions ITS 1 and/or ITS 2 of DNAr, by its morphological and microscopic characteristics. In addition, the Blast of the sequences of these regions confirmed the presence of the Pestalotiopsis crassiuscula 96%, Phomopsis sojae 95%, Lasiodiplodia theobromae, and its telemorfo Botryosphaeria rhodina 98%. Literature shows that Botryosphaeria rhodina is common in disease Canker in plant, similar occur in K. ivorensis, suggesting that this fungi is the pathogen in specie studded. After the identification of Khaya pathogen it was studded, yielding to isolation and identification of sixteen compounds from different classes: Des-methyl lasiodiplodin, lasiodiplodin, isocoumarin, two derivatives γ-butirolactones (4-propil-3-carbonyl-2- methyl-4-butanolideo and 4-propil-2-carbonyl-3-methyl-4-butenolideo), 11- hidroxijasmônic acid, 5-hidroximethylfurfural, tirosol, ergosterol, peroxido de ergosterol, steroids (stigmastenon, sitostenon and campestenon), nucleosídeos (5 - inosil, uridine e uracila), manitol and one triglycerides. Both derivatives γ- butirolactonas appear to be new in literature. The isolated compounds were identified by Nuclear Magnetic Ressonance 1D and 2D and Mass Spectrometry. The limonoids methyl angolenasate isolated in large amount from K. ivorensis symptomatic and 7- deacetoxy-7-oxogedunin isolated from Carapa guianensis, were bioassayed against the microorganisms Penicillium ssp., Phomopsis sojae and Botryosphaeria rhodina, in order to analyze if these fungi modify the structure of compounds. However, in some experiments were not observe any difference and in others, only hypothesis can be done by MS analyze. In a complementary study, compounds lasiodiplodin, ergosterol, 5 -inosil and mannitol were assayed as inhibitor of ATP synthesis, and only lasiodiplodin presented good results.