Otro
An Unprecedented Neolignan Skeleton from Chimarrhis turbinata
Registro en:
Journal of Natural Products. Washington: Amer Chemical Soc, v. 74, n. 3, p. 487-491, 2011.
0163-3864
10.1021/np1007476
WOS:000288691800029
0000-0001-7616-9652
Autor
Cardoso, Carmen L.
Castro-Gamboa, Ian
Bergamini, Giovana M.
Cavalheiro, Alberto José
Silva, Dulce Helena Siqueira
Lopes, Márcia Nasser
Araújo, Angela Regina
Furlan, Maysa
Verli, Hugo
Bolzani, Vanderlan da Silva
Resumen
A lignan with a new skeleton named chimarrhinin (1) was isolated from an extract of the leaves of Chimarrhis turbinata, a Rubiaceae plant species. (13)C NMR spectrometric techniques including 1D and 2D experiments and HRESIMS provided unequivocal structural confirmation of this new C(6).C(3) skeleton type. The relative configuration of 1 was established by 2D (1)H-H analysis and J couplings, while its conformation was evaluated through molecular modeling using the RM1 semiempirical method, with the aid of coupling constants obtained by NMR analysis. The antioxidant activity of the new derivative 1 and two known and previously isolated phenolic derivatives (2 and 3) was investigated. An IC(50) value of 7.50 +/- 0.5 mu mol L(-1) was obtained for the new derivative 1, while 2 and 3 showed IC(50) values of 18.60 +/- 0.4 and 18.50 +/- 0.6 mu mol, respectively. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)