Estudo químico e avaliação do potencial biológico de extratos e substâncias isoladas de espécies dos gêneros cordia e tournefortia (Boraginaceae) / Chemical and biological study of extracts and isolated compounds from plants of Cordia and Tournefortia genera (Boraginaceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

This work describes the isolation and structural identification some chemical constituents, as well as evaluation of the antioxidant, anticholinesterasic, antimalarial, antibacterial and larvicidal potential of extracts and isolated compounds of Cordia multispicata Cham., Cordia nodosa Cham. and Tournefortia bicolor S.W. (Boraginaceae), collected in the Alagoas state. The chemical study of species C. multispicata yielded three flavonoids (Quercetin, 3,7,4-Trimethoxyflavone and 5,3-Dihydroxy-3,7,4-trimethoxyflavone), two phytosteroids (Sitosterol and Stigmasterol), a triterpene (Taraxerol), a diterpene (trans-Fitol) and an ester n-alkylated derivative of ferulic acid. From T. bicolor were isolated two phytosteroids (Sitosterol and Stigmasterol), three flavonoids (Rutin, Quercetin and Tiliroside), a triterpene (β-Amyrin), and five substances whose spectral data hadnt been yet obtained. On the other hand, the chemical study of the species C. nodosa resulted in the isolation of two substances whose spectral data had been also not yet obtained. The isolated substances were identified on the basis of the analysis of spectral data (IR, MS and NMR, including APT, DEPT, COSY, NOESY, HMQC and HMBC). In the assays for detection of potential anti-radicalar (DPPH), amongst extracts only tested one of them was inactive. Some isolated substances [Rutin (IC50 35,78 μmol), Quercetin (IC50 25,31 μmol), Tiliroside (IC50 85 μmol) and 3,7,4-Trimethoxyflavone (IC50 124 μmol)], in relation to the used standards [BHT (IC50 259 μmol) and ascorbic acid (IC50 101 μmol)] showed promising results. In relation to the qualitative anticholinesterasic assays a total of thirty extracts, as well as three isolated substances (Quercetin, Tiliroside, 3,7,4-Trimethoxyflavone) inhibited the action of the acetylcholinesterase enzyme. In the in vivo assays against NK-65 strain of the Plasmodium berghei (250 and 500 mg/Kg) the hexane extract from leaves of C. multispicata was only partially active (p<0,05); while against Staphylococcus aureus and Pseudomonas aeruginosa strains, isolated from patients of the Hospital de Doenças Tropicais de Maceió, with different levels of resistance to comments used antibiotics, all the tested extracts were inactive. In the assays against 4th larval instars of the Aedes aegypti, the results most promising (mortality upper to 50%, IC50 164,16 ppm or IC50 193,61 ppm) were obtained with some extracts of C. nodosa and T. bicolor.

ASSUNTO(S)

cordia flavonóides tournefortia boraginaceae tournefortia flavonoids boraginaceae quimica dos produtos naturais cordia atividade biológica biological activity

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