Pyrrole-Derived Alkaloids of Marine Sponges and Their Biological Properties

Abstract Marine sponges remain an unambiguously significant source of secondary metabolites from marine invertebrates. It is estimated that more than 15,000 compounds have been discovered from marine sources, and new compounds are being added steadily. Over the last few decades, numerous reviews have detailed the chemical structure and biological properties of natural marine products. Sponges produce a wide variety of alkaloids and related metabolites containing indole, pyridoacridines, quinoline, pyridine, bromotyrosine, and pyrrole moieties. Among these substances, pyrrole alkaloids are one of the most abundant metabolites in marine sponges and occur in diverse structural features that include fused ring, brominated compounds, and various functional-group derivatives with diverse biological properties. The unique and decorative structures of these pyrrole alkaloids, coupled with the wide-ranging activities that they display, have made them eye-catching lead compounds for structural activities studies as well. This chapter describes the chemical and biological activities of pyrrole-derived alkaloids isolated from various marine sponges reported up to 2016.