Abstract
Six new triterpenes, uncarinic acids K—P (1–6), along with 24 known analogues, were isolated as minor constituents of an aqueous decoction of the hook-bearing stems of Uncaria rhynchophylla (Gou-teng). By comprehensive spectroscopic data analysis, their structures were elucidated as derivatives of olean-12-en-28-oic acid and urs-12-en-28-oic acid with different oxidized forms at C-3, C-6, and/or C-23, respectively. Cell-based preliminary bioassay showed that the (E)-/(Z)-coumaroyloxy and (E)-/(Z)-feruloyloxy units at C-27 of olean-12-en-28-oic acid and urs-12-en-28-oic acid played roles in their bioactivities.
Graphical Abstract
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Disclosure statement
No potential conflict of interest was reported by the authors.