Establishment of a method for analyzing sesamin and asarinin (episesamin) with HPLC-chiral column, and analytical proof that sesamin from Asiasari Radix exists as a d, l-mixture

Abstract

Asiasari Radix [roots and rhizomes of Asiasarum sieboldii F. Maekawa and Asiasarum heterotropoides F. Maekawa var. mandshuricum F. Maekawa (Aristolochiaceae)] is a traditional medicine. Sesamin and asarinin are important components of Asiasari Radix, and it is reported that their stereochemistry is l-form. On the contrary, the stereochemistry of sesamin and episesamin from sesame are reported as d-form. Therefore, we established a method for analyzing lignans with HPLC-chiral column to invesitigate precise stereochemistry of them from Asiasari Radix and sesame. As a result, we clarified that asarinin from Asiasari Radix existed as only l-form, and sesamin and episesamin from sesame existed as only d-form. In addition, we found that sesamin from Asiasari Radix was a mixture of 96〜95% l-form and 4〜5% d-form.