Studies on Coumarins of a Chinese Drug "Qian-Hu"; VI1, Coumarins of Angelica edulis.

Coumarins, edulisin I (Ae-I) ( 1) and edulisin II (Ae-VI) ( 6), were isolated from ether extracts of the roots and rhizomes of ANGELICA EDULIS Miyabe (Umbelliferae), together with five known coumarins. The structures of edulisin I ( 1) and edulisin II ( 6) were established to be 2' ( S), 3' ( R)-3'-senesioyloxy- O-trans-p-coumaroyl-2', 3'-dihydrooroselol and 2' ( S), 3' ( R)-senecioyloxy- O- senecioyl-2', 3'-dihydro-oroselol by chemical studies and spectral analysis. Ae-III ( 3) was identified with isopeucenidin and the configuration at C-2' and C-3' of Ae-III ( 3) was assigned as R and R, respectively by chemical studies and an X-ray crystallographic analysis. Accordingly, the optical rotation of isopeucenidin reported by Steck and Wetter has been corrected.