Triterpenoid Saponins from the Bark of Nothopanaxdavidii

Two new triterpenoid saponins、 named yiyeliangwanoside Ⅶ[1] and Ⅷ [2] ,along with a known triterpenoid saponin liangwanoside Ⅱ[3] were isolated from the alcoholic extract of the bark of Nothopanax davldii(Franch.) Harms(family Araliaceae). Their structures have been determined on the basis of spectral and chemical data as 3-O-β(2’,4’-O-diacetyl)-D-Xylopyrano-syl-3β-hydroxyolean-12-ene-28,29-dioic acid-28-O-[α-rhamnopyranosyl(1-4)-β-D-glucopyano- syl(1-6)-β-D-glucopyranosyl] ester[1] ;3-O-β-(3’-O-acetyl)-D-xylopyranosyl-3β-hydroxyolean-12-ene-28, 29-dioic acid-28-O-[α-L-rhamnopyranosyl(1-4)-β-D-glucopyranosyl(1-6)-β-D-glu-copyranosyl] ester [2]; 3-O-α-L-arabinopyranosyl-3β-hydroxyolean-12-ene-28, 29-dioic acid-28-O-[α-L-thamnopyranosyl(1-4)-β-D-glucopyranosyl(1-6)-β-D-glucopyranosyl] ester [3].

异叶梁王茶甙Ⅲ和Ⅳ的结构

继前报后,又从异叶梁王茶[Nothopanax davidii(France)Harms]树皮中分离得到两种五环三萜皂甙。经化学和波谱(IR,~1HNMR,^(13)CHMR,~1H-~1HCOSY,^(13)C-~1H COSY,MS)分析,分别鉴定为3-O-α-(2’,4’-O-二乙酰基)-L-吡喃阿拉伯糖-3β-羟基齐墩果-12-烯-28,29-双羧酸-28-O-[α-L-吡喃鼠李糖(1-4)-β-D-吡喃葡萄糖(1—6)-β-D-吡喃葡萄糖]酯甙(Ⅲ),命名为异叶梁王茶甙Ⅲ和3-O-β-(2-O-乙酰基)-D-吡喃木糖-3β-羟齐墩果-12-烯-28,29-双羧酸甙(Ⅳ),命名为异叶梁王茶甙Ⅳ。这两种皂甙均系首次从植物中分出的新化合物。

异叶梁王茶化学成分的研究

从异叶梁王茶[Nothopanax davidii(Franch)Harms]树皮中分离得到两种五环三萜皂甙,经化学和光谱(IR,~1HNMR,^(13)CNMR,~1H-~1H COSY,~1H-^(13)C COSY,NOESY,MS)分析,分别鉴定为3-O-α-(3′,4′-O-二乙酰基)-L-吡喃阿拉伯糖-β-羟齐墩果-12-烯-28,29-双羧酸-28-O-[α-L-吡喃鼠李糖(1→6)-β-D-吡喃葡萄糖(1→4)-β-D-吡喃葡萄糖]酯甙(Ⅱ)和3-O-α-(3′-O-乙酰基)-L-吡喃阿拉伯糖-3β-羟齐墩果-12-烯-28,29-双羧酸甙(Ⅱ),前者命名为异叶梁王茶甙Ⅰ,后者命名为异叶梁王茶甙Ⅱ。这两个皂甙均系新化合物。

神木天坑两种药茶同源植物叶总黄酮提取工艺及抗氧化活性研究

喀斯特天坑地区拥有许多特色的药茶资源。本研究采用超声波提取法对神木天坑五棱苦丁茶总黄酮进行提取,并运用单因素试验和响应面试验相结合的方式对提取条件进行优化。然后以神木天坑的五棱苦丁茶、异叶梁王茶的叶片为材料,以苦丁茶叶片为对照,测定3种药茶的总黄酮含量;同时,为研究3种药茶的抗氧化活性,进行体外羟基自由基(·OH)、超氧阴离子(·O-2)和二苯基苦基苯肼自由基(DPPH·)的清除试验。结果显示:乙醇浓度40%(V∶V)、料液比1∶50(g/mL)、提取温度64.9℃、提取时间35.2 min、超声波功率316.8 W和超声频率35 kHz时,苦丁茶、五棱苦丁茶、异叶梁王茶总黄酮得率分别为10.61%、4.98%和15.73%。当控制黄酮浓度为1 mg/mL时,3种茶叶黄酮均具有较好的总还原力,抗氧化活性较好,其中以异叶梁王茶对·OH、·O-2和DPPH·的清除率最大,分别为53.02%、49.84%和73.96%。试验结果表明异叶梁王茶具有较好的抗氧化能力,为其资源开发奠定一定的科学基础。