A Comprehensive Review on Pyranoindole-containing Agents

A huge number of nitrogen-containing heterocyclic compounds are ubiquitous in natural products, pharmaceuticals, and bioactive molecules. Among these, the pyranoindole represents an important structural motif, as it constitutes the central subunit in both the biologically active natural products and therapeutic agents. Talathermophilins, notoamides, norgeamides, carneamides, and versicamides are examples of naturally occurring pyranoindoles, while the well-known etodolac and pemedolac are a tetrahydropyrano[ 3,4-b]indole deriving from synthetic procedures. Besides the well-known antiinflammatory and fibrinolytic activity, molecules comprising the pyranoindole framework have been demonstrated to exhibit various biological activities, such as antiulcer, antidepressant, analgesic, and antiproliferative. Herein, we report the most common natural and synthetic products bearing a pyranoindole nucleus, their syntheses, and biological activities.