Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, 1 Hwayang-dong Gwangjin-gu, Seoul 143-701, South Korea.
Carbohydr Res. 2011 Jan 3;346(1):133-9. doi: 10.1016/j.carres.2010.10.007. Epub 2010 Nov 18.
α-Cyclosophoro-octadecaoses (α-C18), produced by Rhodobacter sphaeroides, are mostly homogeneous in size with 18 glucose units per ring as the predominant form. α-C18s are linked by β-(1→4)-linkages and one α-(1→6)-linkage and are also known to be highly substituted by acetyl (0-2 per mol) and/or succinoyl groups (1-7 per mol). We isolated and purified α-C18 and successfully used it in capillary electrophoresis (CE) as a chiral additive for the separation of five flavanones and flavanone-7-O-glycosides, including naringenin, hesperetin, eriodictyol, homoeriodictyol, isosakuranetin, and hesperidin. Throughout the CE experiment with unsubstituted α-C18 (uα-C18) obtained after alkaline treatment of the isolated α-C18, we found that successful chiral separation critically depends on the presence of succinate substituents attached to α-C18 in CE, suggesting that succinoylation of α-C18 is decisive for effective stereoisomeric separation.
α-环十八碳寡糖（α-C18）由球形红杆菌产生，其大小基本均一，以 18 个葡萄糖单元为主要环形式。α-C18 通过β-（1→4）-键和一个α-（1→6）-键连接，也已知高度取代乙酰基（每摩尔 0-2 个）和/或琥珀酰基（每摩尔 1-7 个）。我们分离并纯化了 α-C18，并成功地将其用作毛细管电泳（CE）中的手性添加剂，用于分离五种黄烷酮和黄烷酮-7-O-糖苷，包括柚皮素、橙皮素、圣草酚、异圣草酚、异美花椒精和橙皮苷。在整个使用未取代的α-C18（uα-C18）进行的 CE 实验中，我们发现成功的手性分离关键取决于 CE 中附着在α-C18 上的琥珀酸取代基的存在，这表明α-C18 的琥珀酰化对于有效立体异构体分离是决定性的。
