Total syntheses of surugamides and thioamycolamides toward understanding their biosynthesis

Peptidic natural products have received much attention as potential drug leads, and biosynthetic studies of peptidic natural products have contributed to the field of natural product chemistry over the past several decades. However, the key biosynthetic intermediates are generally not isolated from natural sources, and this can hamper a detailed analysis of biosynthesis. Furthermore, reported unusual structures, which are targets for biosynthetic studies, are sometimes the results of structural misassignments. Chemical synthesis techniques are imperative in solving these problems. This review focuses on the chemical syntheses of surugamides and thioamycolamides toward understanding their biosynthesis. These studies can provide the key biosynthetic intermediates that can reveal the biosynthetic pathways and/or true structures of these natural products.