Structural diversity and biological relevance of benzenoid and atypical ansamycins and their congeners

Covering: 2011 to 2021 The structural division of ansamycins, including those of atypical cores and different lengths of the ansa chains, is presented. Recently discovered benzenoid and atypical ansamycin scaffolds are presented in relation to their natural source and biosynthetic routes realized in bacteria as well as their muta and semisynthetic modifications influencing biological properties. To better understand the structure-activity relationships among benzenoid ansamycins structural aspects together with mechanisms of action regarding different targets in cells, are discussed. The most promising directions for structural optimizations of benzenoid ansamycins, characterized by predominant anticancer properties, were discussed in view of their potential medical and pharmaceutical applications. The bibliography of the review covers mainly years from 2011 to 2021. Origin, division, and key structural aspects for biological functionality of ansamycins are discussed. Semisynthetic, mutasynthetic and hybrid approaches, yielding new macrolactams, along their mechanism of action and biological potency are compared.