Perera Wilmer H, Ghiviriga Ion, Rodenburg Douglas L, Alves Kamilla, Bowling John J, Avula Bharathi, Khan Ikhlas A, McChesney James D
Ironstone Separations, Inc., Etta, Oxford, MS 38627, USA.
Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
Phytochemistry. 2017 Mar;135:106-114. doi: 10.1016/j.phytochem.2016.12.001. Epub 2016 Dec 12.
Two diterpene glycosides were isolated from a commercial Stevia rebaudiana leaf extract. One was found to be 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(2-O-β-d-xylopyranosyl-3-O-β-d-glucopyranosyl- β-d-glucopyranosyl) ester (rebaudioside T), whereas the other was determined to be 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid-(6-O-α-l-arabinopyranosyl-β-d-glucopyranosyl) ester (rebaudioside U). In addition, five C-19 sugar free derivatives were prepared and identified as follows: 13-[(2-O-α-l-rhamnopyranosyl-β-d-glucopyranosyl)]oxy]kaur-16-en-19-oic acid (dulcoside A); 13-[(2-O-β-d-xylopyranosy-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]kaur-16-en-19-oic acid; 13-[(2-O-β-d-xylopyranosyl-β-d-glucopyranosyl-)oxy]kaur-16-en-19-oic acid; 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-xylopyranosyl-)oxy]kaur-16-en-19-oic acid (rebaudioside R) and 13-[(2-O-6-deoxy-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy]kaur-16-en-19-oic acid, respectively. Chemical structures were determined by NMR experiments. HPLC analyses were also useful to differentiate different steviol-C13 sugar substituent patterns by elution position.
从一种市售的甜叶菊叶提取物中分离出两种二萜糖苷。其中一种被鉴定为13-[(2-O-β-D-吡喃葡萄糖基-3-O-β-D-吡喃葡萄糖基-β-D-吡喃葡萄糖基)氧基]对映-贝壳杉-16-烯-19-酸-(2-O-β-D-吡喃木糖基-3-O-β-D-吡喃葡萄糖基-β-D-吡喃葡萄糖基)酯（莱鲍迪甙T），而另一种被确定为13-[(2-O-β-D-吡喃葡萄糖基-3-O-β-D-吡喃葡萄糖基-β-D-吡喃葡萄糖基)氧基]对映-贝壳杉-16-烯-19-酸-(6-O-α-L-阿拉伯吡喃糖基-β-D-吡喃葡萄糖基)酯（莱鲍迪甙U）。此外，制备并鉴定了五种C-19无糖衍生物，具体如下：13-[(2-O-α-L-鼠李吡喃糖基-β-D-吡喃葡萄糖基)]氧基]贝壳杉-16-烯-19-酸（dulcoside A）；13-[(2-O-β-D-吡喃木糖基-3-O-β-D-吡喃葡萄糖基-β-D-吡喃葡萄糖基)氧基]贝壳杉-16-烯-19-酸；13-[(2-O-β-D-吡喃木糖基-β-D-吡喃葡萄糖基-)氧基]贝壳杉-16-烯-19-酸；13-[(2-O-β-D-吡喃葡萄糖基-3-O-β-D-吡喃葡萄糖基-β-D-吡喃木糖基-)氧基]贝壳杉-16-烯-19-酸（莱鲍迪甙R）和13-[(2-O-6-脱氧-β-D-吡喃葡萄糖基-3-O-β-D-吡喃葡萄糖基-β-D-吡喃葡萄糖基)氧基]贝壳杉-16-烯-19-酸。化学结构通过核磁共振实验确定。高效液相色谱分析对于通过洗脱位置区分不同的甜菊醇-C13糖取代模式也很有用。
