RESUMO
From the MeOH extract of Ptychopetalum olacoides, which is used in Brazilian folk medicine for the treatment of chronic degenerative conditions of the nervous system, four novel clerodane-type diterpenoids named 6alpha,7alpha-dihydroxyannonene (1), 7alpha,20-dihydroxyannonene (2), 7alpha-hydroxysolidagolactone I (3), and ptycho-6alpha,7alpha-diol (4) were isolated by bioassay-directed fractionation using NGF-differentiated PC12 cells. The structures of 1-4 were established by extensive NMR spectroscopic analyses and chemical conversion. Compounds 1 and 2 significantly enhanced NGF-mediated neurite outgrowth in PC12 cells at concentrations ranging from 0.1 to 50.0 microM for 1 and 0.1 to 30.0 microM for 2, whereas 3 and 4 had no morphological effect on NGF-mediated PC12 cells in the same concentration range. The structure-activity relationship of these compounds is also discussed.
Assuntos
Diterpenos/química , Fator de Crescimento Neural/metabolismo , Olacaceae/metabolismo , Plantas Medicinais/metabolismo , Animais , Bioensaio , Diferenciação Celular , Diterpenos Clerodânicos/química , Sinergismo Farmacológico , Espectroscopia de Ressonância Magnética , Conformação Molecular , Neuritos/metabolismo , Células PC12 , Plantas Medicinais/química , Ratos , Espectrofotometria Infravermelho/métodosRESUMO
Four new clerodane-type diterpenoids, ptychonolide (1), 20-O-methylptychonal acetal (2), and an equilibrium mixture of ptychonal hemiacetal (3) and ptychonal (4), were isolated from the MeOH extract of the bark of a Brazilian plant, Ptychopetalum olacoides. The structure of 1 was elucidated as a clerodane-type diterpenoid on the basis of spectroscopic data, whereas 2 was assigned to an acetal derivative of 1. Compounds 3 and 4 existed as an equilibrium mixture. A mixture of compounds 3 and 4 was found to exhibit neurite outgrowth-promoting activities on NGF-mediated PC12 cells at concentrations ranging from 0.1 to 10.0 microM.
Assuntos
Diterpenos Clerodânicos , Fator de Crescimento Neural/agonistas , Neuritos/efeitos dos fármacos , Olacaceae/química , Plantas Medicinais/química , Animais , Brasil , Diterpenos Clerodânicos/química , Diterpenos Clerodânicos/isolamento & purificação , Diterpenos Clerodânicos/farmacologia , Relação Dose-Resposta a Droga , Estrutura Molecular , Células PC12 , RatosRESUMO
Two new phenylpropanoid-substituted epicatechins, namely, catiguanin A ( 1) and catiguanin B ( 2), were isolated from the bark of Trichilia catigua along with four known compounds, cinchonain Ia ( 3), cinchonain Ib ( 4), cinchonain Ic ( 5), and cinchonain Id ( 6). The structures of 1 and 2 were elucidated by analysis of spectroscopic data and by comparison of their NMR data with those of previously reported cinchonains. The isolated compounds exhibited potent antioxidant activity in the alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical scavenging test, with IC 50 values in the 2.3-9.4 microM range.