Copaifera langsdorffii: estudo fitoquímico, validação de métodos cromatográficos e análise sazonal / Copaifera langsdorffii: phytochemical study, chromatographic method validation and seasonality role.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2011

RESUMO

Copaiba refers to large trees that grow mainly in the states of Amazonas, Pará, Ceará and northern Brazil. Copaifera langsdorffii can be found in almost all regions of Brazil. Samples of its oilrresin, especially one obtained from C. langsdorffii have been used in folk medicine as anti-inflammatory, antiseptic, urinary antiseptic and wound healing. In addition, the hydroalcoholic leaves extract of this tree has drawn the attention of our research group because of its antilitiasic properties. Therefore, the goals of this work were: to investigate the chemical profile of samples of C. langsdorffii; to develop and validate chromatographic methods capable of quantifying the main components present in the samples of C. langsdorffii; to evaluate the influence of seasonality in the chemical profile of the ethanolic extracts of this species. For preparation of the extracts maceration and percolation were used. Crude extracts and fractions were analyzed and fractionated by thin layer chromatography and silica gel column chromatography. Promising compounds were purified by HPLC and preparative TLC. The chemical structures of the isolated compounds were elucidated by 1H NMR and 13C. The method for the analysis of the hydroalcoholic extract was developed by HPLC/UV-DAD. Also, a protocol for sample preparation was also developed, including shaking, temperature and ethanol 70% as solvent extractor. For the seasonal analysis, aliquots from the leaves of trees were collected monthly for 14 months. GC/MS and GC-FID was used to identify and develop the method, considering the main volatile compounds present in the oil and leaves. For both, Clevenger type apparatus was used to obtain these volatiles. The phytochemical study led to the isolation and identification of 13 compounds. Also, 12 sesquiterpenes were identified, including -copaene, -caryophyllene, -humulene and caryophyllene oxide. Kaurenoic acid was isolated from oilrresin and from the extracts of leaves, flowers and fruits of C. langsdorffii. Copalic acid and its derivatives were obtained by fractionation of the oilrresin. Fractionation of extracts from leaves, flowers and fruits also resulted in the isolation of ent-labda-7,13-dien-15-oic acid and 2-hydroxy-ent-labda-7,13-dien-15-oic acid. Two flavonols, 3-O--rhamnopyranosyl-quercetin and 3-O--rhamnopyranosyl-kaempferol were isolated from the hydroalcoholic extracts of the leaves of this species. The 2-hidroxyphenylvinyl ethyl ether was isolated from the extract of the fruits. The some fraction was derivatized furnishing methyl kaurenoate, methyl 2-hydroxy-ent-labda-7,13-dien-15-oate and the 4-methoxy-ethyl cinamoate. The developed HPLC method allowed the quantification of five flavonols: rutin, 3-O--rhamnopyranosyl-quercetin, 3-O--rhamnopyranosyl-kaempferol, quercetin and kaempferol. This method showed average recovery of 97%. The qualitative analysis of seasonal variation in the hydroalcoholic extracts of leaves indicated the presence of 3-O--rhamnopyranosyl-quercetin and 3-O--rhamnopyranosyl-kaempferol throughout the studied period. Regarding the quantitative analysis, these two flavonols showed average levels of 1.8 and 1% respectively. The method developed by GC-FID detected and quantified -copaene, -caryophyllene, -humulene in copaiba oil and leaves essential. For both validated methods, the parameters of selectivity, LOD, LOQ, accuracy, precision and robustness showed satisfactory results. In general, the chemical compositions of the studied samples are similar. The developed validated methods can be used as analytical tools for the quality control of copaiba oil, its extracts and products.

ASSUNTO(S)

cg clae copaifera langsdorffii copifera langsdorffii fitoquímica gc hplc oilrresin óleorresina phytochemistry

ACESSO AO ARTIGO

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