Isolamento e seleção de fungos endofíticos produtores de compostos bioativos associados à Annona crassiflora

Abstract

The endophytic fungi deserve a special mention because of its diversity, and consequently the increased probability of discovery metabolites. This study aimed to isolate endophytic fungi from the leaves of Annona crassiflora, select the best activity and test them for their ability to produce bioactive metabolites with antimicrobial activity, antioxidant and antiproliferative. Were isolated 192 fungi in different periods of the year, being the largest single amount from adult leaves. After isolation extract was prepared in ethyl acetate, and evaluated the activity of the extracts. For the analysis of the antimicrobial activity of micro-organisms Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231 were used, and the activity of 73.22% against at least one of the micro-organisms was obtained. Against S. aureus activity of the extracts was 45.54% C. albicans was inhibited by 31.25%, and 54.46% of the extract the extracts were able to inhibit E. coli. From these results we selected the fungal extracts: A1F2F1, A4F14F1 and A5F18F7. The minimum inhibitory concentration against S. aureus was 250-500 mg / mL for the extract A5F18F7, 500-1000 mg / mL for A4F14F1 and A1F2F1 extract was inactive at the tested concentrations. The A5F18F7 extract showed bactericidal activity at 1000 mg / mL. In the analyzes of antioxidant activity extract A4F14F1 emphasized compared to other all the tests and still got a larger amount of phenolic compounds. The results of the antiproliferative activity shown promising results for A4F14F1 sample, this being evaluated as potential against tumor cells and a low activity against non-cancer cell lines. By analyzing the chemical composition of these extracts was not possible to identify compounds that could be responsible for the activities tested, but it was possible to determine the presence of butanedioic acid consisting of a compound widely used in various fields. Therefore the results suggest the potential of the extracts, and highlight the importance of the study of endophytic fungi, since they can be a source for several new substances with pharmacological activity of interest.