Chemical constituents of the leaves of Uncaria rhynchophylla (Miq.) Jacks.

Aim To study the chemical constituents from the ethanol extract of the leaves of Uncaria rhynchophylla.Methods Several chromatographic methods,including preparative TLC,silica gel column chromatography and preparative-HPLC,and recrystallization were used for the isolation and purification.The structural elucidation was based on the physico-chemical properties,spectral data and chromatographic analysis.(Results) Five compounds were obtained and they were identified as vincoside lactam(Ⅰ),isocorynoxeine(Ⅱ),isorhynchophylline(Ⅲ),corynoxeine(Ⅵ),rhynchophylline(Ⅴ).Conclusion Compound Ⅲ were isolated from the leaves of U.rhynchophylla for the first time.The comprehensive NMR data of the compound are given more clearly on the basis of 2D-NMR technology.