Dioscoreae Rhizoma has been widely used as food and traditional medicine in the world. It contains purine derivatives, saponins, starch and mucilage as main constituents. Among these components, allantoin is one of the biologically active compounds in Dioscoreae Rhizoma [1, 2]. There are a number of methods to determine allantoin in this medicinal plant. However, these methods are somewhat complex because of time-consuming sample preparation and adjusting of buffer conditions. In this study, we developed an easy and reliable HPLC method using CN columns, and applied it to analyze the allantoin content of four Dioscoreae Rhizoma samples. It is possible to separate and quantify allantoin from other polar constituents using CN columns such as YMC-Pack CN, Zorbax SB-CN, and DiscoveryP® Cyano columns. The intraday precision was 0.58–3.33% for YMC-Pack CN, 0.41–2.20% for Zorbax SB-CN and 0.45–1.93% for DiscoveryP® Cyano columns, whereas interday variations were 0.09–1.84%, 0.04–2.59% and 0.87–5.18% for YMC-Pack CN, Zorbax SB-CN and DiscoveryP® Cyano columns, respectively. The recoveries of allantoin were in the range of 98.8–102.6% (RSD 1.1–1.6%) for YMC-Pack CN, 99.7–110.5% (RSD 1.3–4.9%) for Zorbax SB-CN, and 97.2–110.1% (RSD 1.8–5.7%) for DiscoveryP® Cyano columns. The content of allantoin in four Dioscoreae Rhizoma samples was in the range of 4.1–7.1mg/g dry weight. This study showed that analysis of allantoin using CN column is a simple and reliable method, which could be adopted to verify allantoin content in various Dioscorea preparations.
Acknowledgements: This study was financially supported by a grant (No. PF06102–00) from Plant Diversity Research Center of the 21C Frontier R&D Programs.
References: [1] Fu, Y.C. et al. (2006) Food Chem. 94: 541–549. [2] Fu, Y.C. et al. (2005) LWT-Food Sci. Technol. 38: 735–744.
