Siccanin-related drimane meroterpenoids: biological activities and synthesis

Covering: 1962 to 2023Drimane (hydro)quinones biosynthetically arise from the combination of drimane-type terpenoids with phenols or equivalents. Since the isolation of siccanin in 1962 (structure identified in 1967), over 200 natural drimane (hydro)quinones have been reported. They are widespread with remarkably diverse architectures and biological functions, which are achieved by varying either the drimane subunit, hydroquinone segment, or the fusion types of drimane and hydroquinone segment both of them. This type of natural products has drawn increasing attention in the discovery of novel pharmaceutical leads. Enormous efforts have been devoted to developing efficient and divergent synthesis approaches to facilitate the SAR study of drimane (hydro)quinones, aiming for more promising functional leads. This review is arranged mainly in terms of scaffold types of drimane (hydro)quinones and further categorized on the basis of biological functions. The mechanisms of action are also briefly discussed. Synthetic methods are categorized according to the strategies forging the Csp²-Csp³ linker between drimane segments and (hydro)quinone subunits.