Protoberberine Alkaloids and Cancer Chemopreventive Properties of Compounds from <i>Alangium salviifolium</i>

Abstract

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