Structure of a new echinocystic acid bisdesmoside isolated from Codonopsis lanceolata roots and the cytotoxic activity of prosapogenins
Structure of a new echinocystic acid bisdesmoside isolated from Codonopsis lanceolata roots and the cytotoxic activity of prosapogenins
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DOI：
10.1021/jf011647l
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发表时间：
2002-07-17
影响因子：
6.1
通讯作者：
Park, HJ
中科院分区：
文献类型：
--
作者：
Lee, KT;Choi, J;Park, HJ
我们从党参科（Codonopsis lanceolata）的根中分离出一种新的皂苷，命名为党参苷（1），并将其定性为3-O-[β-D-吡喃木糖基（1-3）-β-D-吡喃葡萄糖醛酸基]-3β,16α-二羟基齐墩果酸-28-oic酸28-O-[β-D-吡喃木糖基] (1-3)-α-L-吡喃鼠李糖基(1-2)-α-L-吡喃阿拉伯糖基]酯通过化学、物理化学和2DNMR技术测定。 1 完全水解产生皂苷元 (1a)，部分水解并进一步分离得到两种皂苷元 (1b、1c)。根据以下公式，发现1a、1b和1c的结构分别为3β,16α-二羟基齐墩果酸-28-oic酸（棘囊酸，1a）、1a的3-O-β-D-吡喃葡萄糖醛酸苷和1a的3-O-β-D-吡喃木糖基（1-3）-β-D-吡喃葡萄糖醛酸苷。光谱数据。在MTT测定中，1a表现出边缘细胞毒性活性，而1b表现出比1a更强的细胞毒性。然而，双锁链皂苷 1 没有表现出细胞毒性（针对测试细胞系的 IC50 > 0.3 mM）。该结果表明，C-3 处葡萄糖醛酸的糖苷键增强了皂苷元 (1a) 的细胞毒性，而木糖与 1b 的附加糖基化则强烈增强了 3-O-单糖 (1b) 的细胞毒性。因此，具有细胞毒性的党诺苷元的真实形式必须是皂苷元或前皂苷元。
We isolated a new saponin named codonoposide (1) from the roots of Codonopsis lanceolata (Campanulaceae) and characterized it as 3-O-[beta-D-xylopyranosyl(1-3)-beta-D-glucuronopyranosyl]-3beta,16alpha-dihydroxyolean-28-oic acid 28-O-[beta-D-xylopyranosyl (1-3)-alpha-L-rhamnopyranosyl (1-2)-alpha-L-arabinopyranosyl] ester by chemical, physicochemical, and 2DNMR techniques. Complete hydrolysis of 1 produced a sapogenin (1a), and the partial hydrolysis and further isolation afforded two prosapogenins (1b, 1c). The structures of 1a, 1b, and 1c were found to be 3beta,16alpha-dihydroxyolean-28-oic acid (echinocystic acid, 1a), 3-O-beta-D-glucuronopyranoside of la, and 3-O-beta-D-xylopyranosyl (1-3)-beta-D-glucuronopyranoside of 1a, respectively, on the basis of spectroscopic data. On MTT assay, 1a showed marginal cytotoxic activity whereas 1b exhibited more cytotoxicity than 1a. However, the bisdesmosylsaponin 1 exhibited no cytotoxicity (IC50>0.3 mM against tested cell lines). This result indicated that glycoside linkage of glucuronic acid at C-3 enhances the cytotoxicity of sapogenin (1a), and additive glycosylation of xylose to 1b strongly enhances the cytotoxicity of 3-O-monosaccharides (1b). Therefore, true forms of codonoposide for the cytotoxicity must be sapogenins or prosapogenins.