Abstract: Eight alkaloids have been isolated from the roots of Stephania lincangensis H. S. Lo. et M. Yang which is a novel species growing in Lincang district of Yunnan province. The structures of these compounds were identified as 1-tetrahydropalmatine (Ⅰ), capaurine (Ⅱ) isocorydine (Ⅲ), corydine (Ⅳ), roemerine (Ⅴ) and palmatine (Ⅵ) by means of spectral and chemical methods. Two others, namely lincangenine [4-hydroxy-2,3,9,10-pentamethoxyprotoberberine (Ⅶ)] and l-l,2,3,9,10-pentamethoxytetrahydroprotoberberine (Ⅷ), are new alkaloids, l-tetrahydropalmatine is the main alkaloid with 2.39% yield.

Key words: Stephania lincangensis, Alkaloids, Lincangenine, 1-1,2,3,9,10-pentameth-Oxytetrahydroprotoberberine