RESUMEN
Two carotenoids, lutein (1) and lutein 3'-methyl ether (2), have been isolated from the EtOAc fraction othe MeOH extract of Peristrophe lanceolaria, growing in Thailand. The structures of these compounds were elucidated from their ID and 2D NMR spectroscopic data and from comparisons made with the literature data. This is the first report of the isolation of lutein-3'-methyl ether as a natural product.
Asunto(s)
Acanthaceae/química , Luteína/aislamiento & purificación , Éteres Metílicos/aislamiento & purificación , Espectroscopía de Resonancia Magnética con Carbono-13 , Luteína/química , Éteres Metílicos/química , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , Espectroscopía de Protones por Resonancia MagnéticaRESUMEN
A new 1,6-benzoxazocine-5-one alkaloid has been isolated as its butyl acetal derivative (1) along with peristrophine from the n-BuOH and EtOAc fractions of the crude MeOH extract of the aerial parts of Peristrophe lanceolaria growing in Thailand. The structures of these compounds were elucidated on the basis of their spectroscopic data. These compounds were isolated for the first time from P. lanceolaria. The EtOAc and n-BuOH fractions also possessed significant antioxidant activity with IC50 values of 57 and 50 µg/mL, respectively (DPPH method), whereas 1 had an IC50 value of 23 µg/mL.
Asunto(s)
Alcaloides/química , Depuradores de Radicales Libres/química , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , Antioxidantes/química , Compuestos de Bifenilo/química , Picratos/química , TailandiaRESUMEN
Three monoterpenoid gluco-indole alkaloids, 3beta-isodihydrocadambine, cadambine, and 3alpha-dihydrocadambine, were isolated from Nauclea cadamba ROXB. growing in Thailand. The stereochemistry at C19 in 3beta-isodihydrocadambine was elucidated to be R by spectroscopic analysis. Treatment of 3alpha-dihydrocadambine with beta-glucosidase in aqueous ammonium acetate solution gave an indolopyridine alkaloid, 16-carbomethoxynaufoline, and an unusually rearranged compound.