RESUMEN
A new bromoindolesulfonic acid derivative, echinosulfonic acid D (1) was isolated from the New-Caledonian sponge Psammoclemma sp. in a minute quantity. The structure of the alkaloid was established by spectroscopic methods and, in particular, by ESI MSn experiments. Echinosulfonic acid D was cytotoxic to KB cells (IC50 2 microg/mL).
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Alcaloides Indólicos/farmacología , Fitoterapia , Poríferos , Ácidos Sulfónicos/farmacología , Alcaloides/química , Alcaloides/farmacología , Animales , Antineoplásicos Fitogénicos/química , Humanos , Alcaloides Indólicos/química , Concentración 50 Inhibidora , Células KB/efectos de los fármacos , Ácidos Sulfónicos/químicaRESUMEN
Extracts of fruits and leaves of Connarus paniculatus afford six quinolizidine alkaloids which were identified as piptanthine, 18-epipiptanthine, ormosanine, homoormosanine, podopetaline (monohydrochloride) and homopodopetaline on the basis of high-field NMR studies. 1D and 2D NMR experiments provide complete assignments of the (1)H and (13)C spectra. In conjunction with detection of nuclear Overhauser effects (NOESY), these results allow detailed structure characterization including determination of relative configurations for the chiral sites and conformational analysis. Exchange phenomena involving nitrogen inversion were detected.
Asunto(s)
Alcaloides/química , Espectroscopía de Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/normas , Quinolizinas/química , Isótopos de Carbono , Deuterio , Conformación Molecular , Extractos Vegetales/química , Protones , Estándares de ReferenciaRESUMEN
An extract of the fruits of Trichosanthes tricuspidata collected in North Vietnam was found cytotoxic in KB cells. A bioassay-guided fractionation led to the isolation of a series of cucurbitacins of which two are new: tricuspidatin and 2-O-glucocucurbitacin J. Their isolation and structure determination are described.