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A novel ursane triterpene, named swinhoeic acid, was isolated from the roots of Rubus swinhoei. Its structure was elucidated as 18, 19-seco, 2a , 3b - dihydroxy- 19 -oxo- urs- 11, 13(18)- dien- 28- oic acid by means of MS, 1DNMR and 2DNMR.