Um novo derivado de antraquinona, denominado guepinone (1), juntamente com as conhecidas substâncias isossulocrina (2) e cloroissosulocrina (3) foram isolados de uma cultura em arroz de Pestalotiopsis guepinii, um fungo endofitico de Virola michelii. Os compostos foram identificados pela análise de seus dados espectrométricos de RMN 1D e 2D e EM. A atividade antimicrobiana dos compostos isolados foi avaliada e a cloroisossulcrina (3) foi a mais ativa.A new anthraquinone derivative, named guepinone (1), along with the known substances isosulochrin (2) and chloroisosulochrin (3), were isolated from a rice culture of Pestalotiopsis guepinii, an endophytic fungus of Virola michelii. The compounds were identified by analysis of 1D and 2D NMR and MS spectral data. The antimicrobial activity of these compounds was evaluated and chloroisosulchrin (3) was the most active.
Keywords: Virola michelii, Pestalotiopsis guepinii, anthraquinone derivatives, endophytic fungus
IntroductionEndophytic fungi have been collected from nearly all plants studied. They colonize the plants without causing visible disease symptoms. The function of the host plant is not yet clear and is supposed to depend on the organ-fungus interaction of each plant indicating that there are no neutral interactions but a balanced antagonism between the plant and the endophytic fungi. Endophytic fungi are very useful in agriculture and industry. They can be used as a tool for introduction of genes of interest into the plants, 2,3 like plague and pathogen inhibitors. 4,5 They are also a source of primary and secondary metabolites of interest.In spite of the several reports concerning the production of substances by endophytic fungi that show biological activities, such as fungicide, herbicide and algicide, among others, 6 there are not many studies concerning the chemical composition of endophytic microorganisms, especially when we analize the wide fungic biodiversity and the specificity in the colonization of plants by fungi. This paper deals with the study of the metabolites produced by the fungus Pestalotiopsis guepinii isolated from Virola michelii.V. michelii belongs to the family Myristicaceae and it is used in folk medicine in the treatement of diseases caused by fungi and in the treatment of infections of the skin.7 Phytochemical study, anti-inflammatory and allelopathic activities of the leaves of the V. michelii were reported. [8][9][10][11] There have been described 205 species of Pestalotiopsis, 12 some of these produce secondary metabolites with important activities, like phytotoxic, antifungic, antioxidant and anticancer activities.13 Studies with P. guepinii lead Novel Anthraquinone Derivatives Produced by Pestalotiopsis guepinii J. Braz. Chem. Soc. 994 to the isolation of the diterpenoid taxol, an important anticancer drug.14 Pestalotiopsis also produce sesquiterpenes, other diterpenes, phenolic derivatives and anthraquinone derivatives. [14][15][16] This paper reports the isolation and structural elucidation of three anthraquinone derivat...