The Chemistry of High-Oxidation State Securinega Alkaloids

Abstract

Securinega alkaloids have fascinated the chemical community for over six decades. Among these intriguing secondary metabolites, there are members that are biosynthesized via oxidation(s) of the basic tetracyclic core of securinega natural products. These oxidation processes result in a sub-family of natural products with intriguing structural variations. We have grouped them as "high-oxidation state" securinega alkaloids. In this minireview, we, for the first time, categorize high-oxidation state securinega alkaloids into five groups based on their structural phenotype. We then describe all known syntheses of high-oxidation state securinega alkaloids based on our classification. Plausible biosynthetic origins of securinega alkaloids in each group are described. Notable interplays between chemical synthesis and biosynthesis within this family of natural products are depicted. The updated comprehensive investigation of the chemistry of high-oxidation state securinega alkaloids provides us with an outlook on remaining key challenges related to these fascinating natural products.