<jats:title>Abstract</jats:title><jats:p>New protoberberine alkaloids, namely alangiumkaloids A (<jats:bold>1</jats:bold>) and B (<jats:bold>2</jats:bold>), 27‐<jats:italic>O</jats:italic>‐<jats:italic>trans</jats:italic>‐caffeoylcylicodiscic acid (<jats:bold>3</jats:bold>), and β‐<jats:sc>D</jats:sc>‐glucopyranos‐1‐yl <jats:italic>N</jats:italic>‐methylpyrrole‐2‐carboxylate (<jats:bold>5</jats:bold>) together with myriceric acid B (<jats:bold>4</jats:bold>), isoalangiside (<jats:bold>6</jats:bold>), alangiside (<jats:bold>7</jats:bold>), 3‐<jats:italic>O</jats:italic>‐demethyl‐2‐<jats:italic>O</jats:italic>‐methylalangiside (<jats:bold>8</jats:bold>), and demethylalangiside (<jats:bold>9</jats:bold>) have been isolated from <jats:italic>Alangium salviifolium</jats:italic>. The cancer chemopreventive properties and cytotoxic activities of the isolated compounds were evaluated. Compounds <jats:bold>3</jats:bold>, <jats:bold>4</jats:bold>, and <jats:bold>9</jats:bold> scavenged DPPH free radicals with IC<jats:sub>50</jats:sub> values of 21.4, 21.8, and 24.0 μ<jats:sc>M</jats:sc>, respectively. Alangisides <jats:bold>7</jats:bold> and <jats:bold>9</jats:bold> inhibited superoxide anion radical formation in the xanthine/xanthine oxidase (XXO) assay with IC<jats:sub>50</jats:sub> values of 19.4 and 5.3 μ<jats:sc>M</jats:sc>, respectively. Compounds <jats:bold>6</jats:bold>–<jats:bold>9</jats:bold> showed excellent antioxidant activity in the oxygen radical absorbance capacity (ORAC) assay with 12.8–24.9 ORAC units. Compounds <jats:bold>3</jats:bold> and <jats:bold>4</jats:bold> inhibited aromatase activity with IC<jats:sub>50</jats:sub> values of 4.7 and 6.8 μ<jats:sc>M</jats:sc>, respectively. Although the isolated compounds showed only weak cytotoxicity or were inactive, compounds <jats:bold>3</jats:bold> and <jats:bold>4</jats:bold> exhibited cytotoxic activity towards the MOLT‐3 cell line with IC<jats:sub>50</jats:sub> values of 5.6 and 3.9 μ<jats:sc>M</jats:sc>, respectively, and compound <jats:bold>8</jats:bold> selectively inhibited the growth of the HepG2 cancer cell line with an IC<jats:sub>50</jats:sub> value of 7.1 μ<jats:sc>M</jats:sc>.