Estudo fitoquímico biomonitorado da entrecasca de maytenus rigida mart. (celastraceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The chosen plant belongs to the family Celastracea which comprehends about 85 genders and from 800 to 900 species with wide distribution in the tropical and subtropical regions of the world. In this family the gender Maytenus highlights due to a great variety of bioactive metabolites. From this gender, the specie Maytenus rigida Mart was collected in the village of Capim-Grosso, State of Alagoas. The main objective of this work was to accomplish a biomonitored phytochemical study of this specie. The in vitro antimalarial test showed that all tested extracts at 16,6 and 50 g/mL were actives against Plasmodium. When the test was realized in vivo, the alcoholic extracts of the leaves and of the entrecasca, as well the etyl acetate extracts of Maytenus rigida Mart were active against Plasmodium. In the antiinflammatory test, the alcoholic extract caused a significant reduction of the paw edema due to carrageenan, at 200 and 400 mg/kg. In the antinociception model, the alcoholic extract caused a significant increase in the latency time in relation to the control group: an increase of 39,0% (p<0,005), at 100 mg/kg. At 200 mg/Kg occurred a significant reduction of 26,5% of the increase (p<0,05). The fractions obtained by the partition of the alcoholic extract of entrecasca were tested at 400 mg/Kg and they increased the latency time significantly in 41,4% to the hexanic fraction, 37,1 % to the chloroformic fraction, 37,2% to the etyl acetate and 78% and 27,9% to the hydroalcoholic fraction. The substance MRCA2 isolated of the etyl acetate fraction produced a significant inhibition in the number of abdominal contortions (69% of inhibition, 100 mg/Kg, v.o) when compared with dipyrone (65% of inhibition, 33 mg/Kg, i.p). In the antiulcerogenic test, the bast ethanolic extract at 100 mg/kg stimulated the protective activity of the gastric mucous. The bast aqueous extract was tested at 100 mg/kg and it reduced significantly (p<0,001) the ulcers induced by indometacin. Hexanic, chloroformic and hydroalcoholic fractions of the bast ethanolic extract were orally at 100 mg/kg. These fractions reduced significantly the ulcers induced by indometacin. The aqueous, chloroformic and hydroalcoholic extracts showed antimicrobial activity. Phenolic compounds were detected and antioxidant activity was observed in the chloroformic, etyl acetate and hydroalcoholic extracts. It was also evaluated the redox behavior in aprotic medium with the isolated substances 4-methylepigallocatechin, epicatechin and naringenin. The quantitative analysis of the chemical composition of the hexanic fraction, by gas chromatography - mass spectrometry, allowed detecting the presence of seven compounds (ethyl dodecanoate, methyl dodecanoate, methyl tetradecanoate, methyl pentadecanoate, methyl hexadecanoate, methyl heptadecanoate, methyl octadecanoate, methyl 6- octadecanoate). The chemical study guided by the bioassays gave the following compounds: 4-methyl-epigallocatechin, epicatechin, 3,4,5-trihydroxybenzoic acid, 3- methoxy-5,7,3,4-tetrahydroxyflavone, b-sitosterol, stigmasterol, lupeol, friedooleanan- 3-ona, 3-b−hydroxy-friedelin, 3-28-dihydroxy-lup-20(29)-ene, 3-hydroxy-lup- 20-en-30-diol and two structures that were characterized by X ray.

ASSUNTO(S)

extratos lc-rmn lc-rmn lc-ms hplc hplc lc-ms quimica organica extracts

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