Estudo de marcadores em espécies de Aniba (Lauraceae) bioativas da Amazônia

Abstract

The Amazon region stands out for its immense biodiversity, which is considered as a source for the discovery of new molecules of pharmacological interest. In this field of research, the genus Aniba (Lauraceae) has wide variability and abundance. Aniba species are chemically described with the presence of alkaloids, flavonoids, terpenoids, pyrans and lignans. In this context, it is proposed the isolation and identification of the biomarkers of extracts of the species A. panurensis, A. parviflora, A. ferrea and A. roseadora, aiming to develop a method for the rapid characterization of the extracts of species of Aniba (Lauraceae), besides describing its biological activities. To achieve these objectives, ethanolic extracts (branches and leaves) were prepared by maceration, and these were partitioned. By means of classical chromatographic methods (TLC) and by spectrometric techniques (MS), the chemical characterization of hexane and methanolic fractions was carried out. Thus, the major ions of m/z 300, 328 and 330 were detected, which, by comparing the fragmentation data with the literature, correspond to the alkaloids: N-methylcoclaurine, isoboldine, laurotetanine and reticuline; in addition to these ions, the ions of m/z 283, 311 and 863, which may be associated with flavonoids: izalpinine, 3, 5, 7-tri-O-methylgalangine and procyanidin trimer were detected in the negative mode by ESI ionization. The fractionation to obtain the major components was developed by the use of classical chromatographic techniques, such as CC and TLCP, thus resulting in the obtaining of 6 substances, which were elucidated by the union of spectroscopic and spectrometric techniques such as: MS and NMR (1H and 13C uni and bidimensional). Thus, styrylpyrones were identified: 5,6-dehydrokawaine, 4-methoxy-11,12-methylenedioxy-6-trans-styryl-pyran-2-one and rel- (6R, 7S, 8S, 5'S) -4'- methoxy-8- (11,12-dimethoxyphenyl)-7- [6- (4-methoxy-2-pyranyl) -6- (E) -styryl-1'-oxabicyclo [4,2,0] octa-4'-en -2'-one (A. panurensis), the pyridine alkaloid: anibine (A. roseadora) and the kawalactones: tetrahydroyangonine and dihydrometisticina (A. parviflora). Aiming to analyze the antimicrobial potential of extracts, fractions and isolated substances, the antibacterial and antiparasitic tests were carried out. Good results for extracts and fractions of A. panurensis with MICs of 7.8 and 15.62 μg/mL were compared to three grampositive bacteria (Staphylococcus simulans, S. aureus and methicillin-resistant S. aureus (MRSA)). In the antiplasmódico test against Plasmodium falciparum, good results were obtained for the ethanolic extracts of A. parviflora and A. panurensis, with a better result of IC50 = 29.03 µg/mL for the leaves extract of A. parviflora; and positive results for two isolated substances, with IC 50 = 36.16 μg/mL for 4-methoxy-11,12-methylenedioxy-6-trans-styryrilpyran-2-one and IC50 = 24.10 μg/mL for rel-(6R, 7S, 8S, 5'S)-4'-methoxy-8-(11,12dimethoxyphenyl)-7-[6-(4-methoxy-2-pyranyl]-6- (E) - styryl-1'-oxabicyclo[4,2,0]octa-4'-en2'-one. The results confirm the presence of alkaloids, flavonoids and pyrans in the species of Aniba, in addition to describing a HPTLC method for rapid detection of these isolated standards and reporting the antimicrobial potential of extracts, fractions and isolated substances.