Abstract:
Two new nortriterpenoid saponins, named yemuoside YM
10 (Ⅰ) and YM
12 (Ⅱ) , were isolated from Stauntonia chinensis Decne. A new prosaponin (Ⅵ) was isolated from the cleavage of ester-glycoside linkage. Their chemicaI structures were elucidated by means of chemical and spectrometric analysis.Yemuoside YM
10 (Ⅰ): C
58H
92O
25, a white powder, mp 215~8219℃ (dec), α
D20-4.41° ( c 0.272, CH
3OH). Its structure was found to be 28-O-α-L-rhamnopyanosyl- (1→-4) -β-D-glucopyranosyl- (1→-6) -β D-glucopyranosyl ester of 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-30-norolean -12, 20 (29) -dien-28-oic acid.Yemuoside YM
12 (Ⅱ)- C
52H
82O
21, a white powder, rap 200~204℃ ( dec. ), α
D20+10.12° ( c 0.346, CH
3OH). Its structure was found to be 28-O-β-D-glucopyranosyl- (1→6) -β-D-glucopyranosyl ester of 3-O-α-L-rhamnopyranosyl- (1→-2) -α-L-arabinopyranosyl-30-norolean - 12, 20 (29) -dien - 28 - oic acid.Prosaponin (Ⅳ) :C
40H
62O
11, a white powder, mp 243~246℃ (dec.), α_D
22 +12.13° ( c 0.128, CH
3OH). Its strvcture was found to be 3-O-α-L-rhamnopyranosyl- (1→2) -α-L-arabinopyranosyl-30-norolcan 12, 20 (29)-dien-28-oic acid.