<jats:title>Abstract</jats:title><jats:p>β<jats:sub>1</jats:sub>‐Solamargine and three new glycoalkaloids, robustine, <jats:italic>N</jats:italic>‐hydroxyrobustine, and 25‐acetoxyrobustine, have been isolated from the roots of <jats:italic>Solanum robustum</jats:italic>, the structures of which have been elucidated as 3‐<jats:italic>O</jats:italic>‐{<jats:italic>O</jats:italic>‐α‐<jats:sc>L</jats:sc>‐arabinopyranosyl‐(1→3)‐<jats:italic>O</jats:italic>‐[α‐<jats:sc>L</jats:sc>‐rhamnopyranosyl‐(1→2)]‐ <jats:italic>O</jats:italic>‐[α‐<jats:sc>L</jats:sc>‐rhamnopyranosyl‐(1→4)]‐(β‐<jats:sc>D</jats:sc>‐glucopyranosyl}solasodine (<jats:bold>3</jats:bold>)), its <jats:italic>N</jats:italic>‐hydroxy, and its 25‐acetoxy derivative. These compounds have characteristic structures in comparison with the hitherto known <jats:italic>Solanum</jats:italic> glycoalkaloids. <jats:chem-struct-wrap><jats:chem-struct><jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" mimetype="image/gif" position="anchor" specific-use="enlarged-web-image" xlink:href="graphic/must001.gif"><jats:alt-text>magnified image</jats:alt-text></jats:graphic></jats:chem-struct></jats:chem-struct-wrap>