RESUMEN
Four new oleanane type saponins, monepalosides G-J (1-4), were isolated from the water-soluble part of the whole plant of Morina nepalensis var. alba Hand-Mazz. On the basis of chemical and spectroscopic evidence, their structures were determined as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside G, 1), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-beta-D-xylopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside H, 2), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[beta-D-glucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside I, 3), 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 3)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside J, 4), respectively. Two-dimensional NMR spectra, including H-H COSY, HMQC, 2D HMQC-TOCSY, HMBC and ROESY were utilized in the structure elucidation and complete assignments of 1H and 13C NMR spectra.
Asunto(s)
Magnoliopsida/química , Saponinas/aislamiento & purificación , Triterpenos/aislamiento & purificación , China , Medicamentos Herbarios Chinos/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Extractos Vegetales , Saponinas/química , Espectrometría de Masa Bombardeada por Átomos Veloces , Triterpenos/químicaRESUMEN
A novel acylated flavonol glycoside, quercetin 3-O-[2' "-O-(E)-caffeoyl]-alpha-L-arabinopyranosyl-(1-->6)-beta-D-galactopyranoside (1), was isolated from whole plant of Morina nepalensis var. alba. Its structure was determined on the basis of chemical and spectroscopic methods.