Biosynthesis, asymmetric synthesis, and pharmacology, including cellular targets, of the pyrrole-2-aminoimidazole marine alkaloids

Abstract

The pyrrole-2-aminoimidazole (P-2-AI) alkaloids are a growing family of marine alkaloids, now numbering well over 150 members, with high topographical and biological information content. Their intriguing structural complexity, rich and compact stereochemical content, high N to C ratio (~1:2), and increasingly studied biological activities are attracting a growing number of researchers from numerous disciplines world-wide. This review surveys advances in this area with a focus on the structural diversity, biosynthetic hypotheses with increasing but still rare verifying experimental studies, asymmetric syntheses, and biological studies including cellular target receptor isolation studies of this stimulating and exciting alkaloid family.

Bromopyrrole Alkaloids from Okinawan Marine Sponges <i>Agelas</i> spp.

“…15) As part of that research project, bromopyrrole alkaloids in sponges Agelas spp. (SS-162, SS-307) were investigated, resulting in the isolation of 18 unique alkaloids including five dimeric bromopyrrole alkaloids (1-5), ten monomeric bromopyrrole alkaloids (6)(7)(8)(9)(10)(11)(12)(13)(14)(15), and three conjugates of monomeric bromopyrrole alkaloid and hydroxykynurenine (16)(17)(18). In this mini-review, we describe the isolation, structure elucidation, and antimicrobial activities of these alkaloids.…”

“…12,13) Though a number of bromopyrrole alkaloids have been isolated from marine sponges to date, stylissadines A and B 14) from Stylissa flabellata, are the only known examples of tetrameric bromopyrrole alkaloids. In our continuing search for structurally and biogenetically unique natural products from marine organisms, we have reported the isolation of some bromopyrrole alkaloids from Okinawan marine sponges.…”

C-N bond forming reactions in the synthesis of substituted 2-aminoimidazole derivatives

“…For example, Leucetta and Clathrina-derived alkaloids, which have been isolated from marine sponges during the last three decades, were reported to exhibit antibacterial, anti-inflammatory, anticancer, and antiviral activity. [1][2][3] Different types of substituted 2-aminoimidazoles, including the pyrrole-2-aminomidazoles of the oroidin family and their synthetic analogs 4,5 possess anti-biofilm activities, 6,7 while 2-arylamino or iminoimidazolidines (e.g. clonidine), known hypertensive agents, 8 have also been evaluated as α 2 -adrenoceptor antagonists for the treatment of depression ( Figure 1).…”

Bromopyrrole Alkaloids from a Marine Sponge <i>Agelas</i> sp.

“…1 : 2). [2][3][4] Bromopyrrole alkaloids have been reported to show various bioactivities such as immunosuppressive, anticancer, and antimicrobial activities. [2][3][4] In our continuing search for metabolites from Okinawan marine sponges, we have previously reported the isolation of a series of bromopyrrole alkaloids from Agelas spp.…”

“…[2][3][4] Bromopyrrole alkaloids have been reported to show various bioactivities such as immunosuppressive, anticancer, and antimicrobial activities. [2][3][4] In our continuing search for metabolites from Okinawan marine sponges, we have previously reported the isolation of a series of bromopyrrole alkaloids from Agelas spp. [5][6][7][8][9][10][11] Recently, we have also reported monomeric bromopyrrole alkaloids, nagelamides U-W, 12) and dimeric bromopyrrole alkaloids, nagelamides X-Z, 13) from the extracts of a sponge Agelas sp.…”