A New Triterpenoid from the Aerial Parts of Agrimonia pilosa.

(1S,3R,17R,18R,19R,20R,22R)-1,3,19,22-tetrahydroxy-28-norurs-12-en-2-one (1), along with 5 known triterpenoids (2-6), were isolated from the aerial parts of Agrimonia pilosa Ledeb. Their structures were established based on extensive spectroscopic and MS analysis. The absolute configuration of compound 1 was deduced by circular dichroism (CD). Compound 1 was the first example of a 28-norursene backbone isolated from the genus Agrimonia. Compounds 2-6 were tested for anti-inflammatory activities against RAW 264.7 macrophages. A plausible biosynthetic pathway for compound 1 in A. pilosa was also proposed.