ABSTRACT
The chemical composition of Gynostemma burmanicum King ex Chakrav. was investigated for the first time in this study. Nine dammarane glycosides (1â9) were isolated from the EtOH extract of the aerial parts of G. burmanicum. Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The new compounds were 3ß,20S-dihydroxydammar-24-ene-3-O-ß-D-glucopyranosyl-20-O-[ß-D-xylopyranosyl-(1â6)-ß-D-glucopyranoside] (1), 3ß,12ß,20S-trihydroxydammar-24-ene-3-O-ß-D-xylopyranosyl-20-O-[ß-D-xylopyranosyl-(1â6)-ß-D-glucopyranoside] (2), and 12-oxo-3ß,20S-dihydroxydammar-24-ene-3-O-[ß-D-glucopyranosyl(1â2)-ß-D-glucopyranosyl]-20-O-[ß-D-xylopyranosyl-(1â6)-ß-D-glucopyranoside] (3).
Subject(s)
Glycosides/isolation & purification , Gynostemma/chemistry , Triterpenes/isolation & purification , Glycosides/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Extracts/chemistry , Saponins/chemistry , Saponins/isolation & purification , Triterpenes/chemistry , DammaranesABSTRACT
Studying the chemical component in flowers of Premna integrifolia L. collected in Nam Ha province in summer 2004 showed that: flower of Premna integrifolia L. contains alkaloids, flavonoids, free sugars and 15 inorganic elements including Al, Si, Mg, Ca, Ba, Fe, Mn, Ti, Ni, Cr, Mo, Cu, P, Na and K. One refined A1 substance was isolated and extracted successfully in light yellow needle crystal form, slight smelling, bitterness, melting temperature F=158.8 -163.9oC. On the basis of m.p.UV, IR, MS, 1H-NMR, 13C-NMR, DEPT, HMQC analyses it was identified as acid p.methoxy cinnamic