ABSTRACT
Dammarane-type triterpenoid saponins are regarded as the main active constituents of Gynostemma longipes C.Y.Wu. By using MCI and silica gel column chromatography, as well as preparative HPLC, we isolated four new dammarane-type triterpenoid saponins from the polar saponin fraction of G. longipes C.Y.Wu. Their structures were determined by comprehensive analyses of NMR and MS data and identified as (20S)-3β,20,21-trihydroxydammar-19-oxo-24-ene-3-O-{[α-L-rhamnopyranosyl(1→2)]-[β-D-xylopyranosyl(1→3)]-α-L-arabinopyranosyl}-21-O-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside (1), (20S)-3β,20,21-trihydroxydammar-24-ene-19-oxo-3-O-[α-L-rhamnopyranosyl(1→2)]-[β-D-xylopyranosyl(1→3)]-α-L-arabinopyranosyl-21-O-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside (2), (20S)-3β,19,20,21-terahydroxydammar-24-ene-3-O-{[α-L-rhamnopyranosyl(1→2)]-[β-D-xylopyranosyl(1→3)]-α-L-arabinopyranosyl}-21-O-[β-D-glucopyranosyl(1→6)]-β-D-glucopyranoside (3), (20S)-3β,20,21-trihydroxydammar-24-ene-3-O-{[α-L-rhamnopyranosyl(1→2)]-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl}-21-O-[β-D-glucopyranosyl(1→6)]-β-D-glucopyranoside (4). Compounds 1-4 are new dammarane-type triterpenoid saponins which contain five glycosyl residues.
ABSTRACT
The Qinling-Daba Mountains area is the main producing areas of Gynostemma longipes for medicinal usage, and samples of wild whole plants in Pingli, Shaanxi Province and Qingchuan, Sichuan Province were collected. The ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UHPLC-Q-TOF-MS~E) was used to profile the chemical compositions and analyze the similarities and differences of G. longipes samples in these areas. Based on the accurate molecular weight and fragment information obtained from Q-TOF-MS~E, the structures of the main components were identified by combining with the mass spectra, chromatographic behaviors of reference standards and related literatures. The results showed that the components of wild G. longipes from different places among Qinling-Daba Mountains area were similar. Forty-five chemical components were identified in the whole plant of G. longipes from Pingli, Shaanxi Province, including 43 triterpenoid saponins and 2 flavonoids which contain all main peaks in its fingerprint. The main components are dammarane-type triterpenoid saponins, such asgypenoside ⅩLⅨ, gypenoside A and its malonylated product of glycosyl.