Avaliação química e biológica do extrato bruto do fungo endofítico Phomopsis sp

Abstract

Endophytic fungi are microorganisms that live in interne tissues of plants, without causing them immediate damage. They are considered an important source to the production of secondary metabolites with antimicrobial, antitumor activities, among others. The present work describes the chemical and biological study of the secondary metabolites produced by the endophytic fungus Phomopsis sp. isolated from the plant Passovia stelis. For that, the fungus at hand was cultivated in large scale using the liquid medium of dextrose potato. The ethylacetat crude extract was obtained through extraction from the broth and then submitted to larvicide assay against larvae of the mosquito Aedes aegypti and antimicrobial against the pathogenic bacteria Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa. It was also performed assays against the enzyme anticholinesterase, antioxidants and antifungal against Cladosporium cladosporioides e Cladosporium sphaerospermum. In the selective larvicide, 3 fractions showed bioactivity (100 ppm) in 24h. In the dosing assay larvicide, the extract of the fungus Phomopsis sp. showed bioactivity with LD50 of 84.7, 81.6 and 79.5 ppm and LD90 de 147.8, 140.2 and 137.7 ppm after 24, 48 e 72 h, respectively. The crude extract was analyzed using TLC, HPLC and NMR and then purified through column chromatography and HLPC-DAD. From F4, the 3-nitropropionic acid was isolated, which is used in neurological research. Succinic acid, which is considered one of the construction blocks in chemical synthesis industry, was isolated from the fraction F7. Other 3 esterified substances, derivatives of tyrosol, were isolated of the fraction F1, and one of them unpublished. In the antioxidant assay, two fractions (F5, F6) showed positive results and in the assay against the enzyme anticholinesterase four fraction (F2, F5, F6, F7) presented bioactivity. These results demonstrate the expressive biopotency of the fungus Phomopsis sp. and open a new perspective for further studies.