J Nat Prod. 2003 Feb; 66(2): 320-3.

Two new nor-triterpene glycosides from peruvian "UÃ±a de Gato" (Uncaria tomentosa).

Kitajima M, Hashimoto K, Yokoya M, Takayama H, Sandoval M, Aimi N.

Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.

Two new 27-nor-triterpene glycosides, tomentosides A (1) and B (2), were isolated from Peruvian "UÃ±a de Gato" (cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis and chemical interconversions. This is the first report of naturally occurring pyroquinovic acid glycosides.