74(P2-4) Fritillaria ussuriensisの新奇ステロイダルアルカロイド(ポスター発表の部)  [in Japanese] 74(P2-4) Novel Steroidal Alkaloids in Fritillaria ussuriensis  [in Japanese]

In the course of our studies on dried bulbs of Fritillaria genus (Chinese medicine "Bei-mu"), novel steroidal alkaloids having new skeletons were isolated from Fritillaria ussuriensis Maxim. along with known alkaoids. Ussuriedine (5) and ussuriedinone (6) have a seven ring skeleton formed by C-C bond between C-18 and C-27 of 5a-cevanine skeletone. Ussurienine (3) and ussurienone (4), which were isolated from the HCl-MeOH hydrolyzed alkaloid fraction, were shown to be artifacts derived from 5 and 6, respectively. Additional new alkaloid, pingbeinone (7) has a novel skeleton lacking C-18 carbon of 5α-cevanine skeleton. This is the first example of C_<26> steroidal alkaloid from Fritillaria genus. It is notable that F. ussuriensis contains new alkaloids which were assumed to be drived from the modification at C-18 (and C-27 for 5 and 6) of 5α-cevanine skeleton. As the HPLC analysis of 19 kinds of Fritillaria species cultivated in China showed that 3 was detected only in F. ussuriensis, it is important to clarify the biosynthetic pathway of these alkaloids and the relation between F. ussuriensis and other Fritillaria species.