Synthesis and Biological Activity of Derivatives of (C-30)-Substituted Lupane Triterpenoids and Gallic Acid Bound Through a 1,2,3-Triazole Linker

Abstract

New conjugates of lupane triterpenoids bound through a 1,2,3-triazole linker with gallate derivatives were prepared via Cu-catalyzed cycloaddition reactions of [3β,28-diacetoxy-20(29)-lupen-30-yl]azide and 3β-acetoxylup-20(29)-en-30-azido-28-oic acid with gallate derivatives with propargyl substituents in various positions. Conjugate 4 based on betulin with a modified gallate substituent containing a dioxolane moiety possessed potent antioxidant properties and anti-inflammatory activity (suppression of NO hyperexpression).