New constituents of the seeds of Sesamum indicum L.

The seeds of Sesamum indicum L. are a well-known source of lignan-derivatives. The aim of the performed study was to isolated reference compounds for the development of an analytical method. The isolation of polar constituents (n-butanol soluble) of an extract of unpeeled sesame seeds (defatted with n-hexane, extracted with methanol) resulted in the isolation of five known lignan-derivatives: (+)-pinoresinol-4,4'-O-β-D-diglucopyranoside; (+)-pinoresinol-4-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside; sesaminol-2-O-β-D-glucopyranosyl-(1→2)-O-[-β-D-glucopyranosyl(1→6)]-β-D-glucopyranoside; sesamolinol-4-(O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside; sesaminol-2-O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranoside.

Beside these known compounds, the performed isolation reveled two new lignan-derivatives: (+)-episesaminon-9'-O-β-D-glucopyranosyl-(1→2)-O-[-β-D-glucopyranosyl-(1→6)]-β-D-glucopyranosid and (-)-sesaminon-9'-O-β-D-glucopyranosyl-(1→2)-O-[-β-D-glucopyranosyl(1→6)]-β-D-glucopyranoside and a novel alkaloid with an unusual tricyclic skeleton which was named (-)-sesam-indol-N-oxide. Structures were elucidated by 1- and 2-D-NMR spectroscopy and LC-MSⁿ experiments.

Fig. 1