Comprehensive review of β-carbolines from microbes and their biosynthesis

β-carbolines were historically known as plant-derived metabolites. They are known to exhibit a broad spectrum of biological activities with clinical and economic significance. In recent years, a growing number of β-carbolines have been isolated from microbial sources. Despite this growing body of work, a comprehensive account of these developments has been lacking. In this work, we review all β-carbolines reported from microbial sources thus far. Although a significant number of β-carboline metabolites are shared by microbes and higher organisms, microbes are found to produce a structurally distinct group of metabolites. This article presents a review of more than 190 β-carbolines isolated from bacterial and fungal species spanning 100 original literature sources. Significant biological activities associated with these metabolites are presented in the report. In addition, the review captures up-to-date developments in the biosynthetic understanding of β-carbolines from microbial sources.