Tryptophan-Derived Microbial Alkaloids

Abstract

Alkaloid natural products comprise a large family of biologically active compounds and many of them exhibit great potential use for biotechnological, agricultural and pharmaceutical industry. Alkaloids are commonly classified according to the amino acid building blocks that provide both the nitrogen atom and the fundamental portion of the skeleton. The first alkaloid was identified in plants, later then, more alkaloids with promising scaffolds for drug discovery and development are of microbial origin, and in particular from filamentous fungi and actinobacteria. We therefore consider alkaloids from microorganisms to be an appropriate starting point to discuss the natural product biosyntheses from the structure-function aspects. This article highlights the microbial alkaloid natural products, including bioactivities, structural diversities, and biosynthesis. The emphasis is on diverse biosynthetic precursors, pathways and novel enzymatic mechanisms. The perspective of strategies for developing structural diversities and creating new structural derivatives will be also discussed.