Pyrrole Alkaloids

Pyrrole alkaloids are an important class of heterocyclic compounds with complex structures and powerful biological activities. They are widely found in plants and marine organisms and play an important role in the growth and metabolism of various organisms. Interestingly, marine organisms are the most important class of the sources of pyrrole alkaloids. This is because the structures of the pyrrole alkaloids present in marine organisms are most diverse and novel. In recent years, studies on the isolation and purification, biological activity and synthesis of pyrrole alkaloids have become a hot topic in natural product research. With the gradual understanding of pyrrole alkaloids, people began to extract a variety of pyrrole alkaloids from organisms and studied their biological activities through in vitro and in vivo experiments, and finally achieved fruitful research results.

Figure 1. The basic structure of the pyrrole nucleus in pyrrole alkaloids.

Sources of pyrrole alkaloids

There are two main sources of pyrrole alkaloids, namely plants and marine organisms.

Plants

Plants containing pyrrole alkaloids are so numerous and widespread that they can be expected to be present in most environments. The main sources are the families Asteraceae, Boraginaceae, Rutaceae and Leguminosae. The most common plant-derived pyrrole alkaloids are the derivatives of chlorophyll. These compounds contain four groups of pyrrole joined by methine bridges.

Marine organisms

Pyrrole alkaloids are not only widely found in terrestrial habitats, but are also frequently found as natural products in the marine environment. They are often derived from marine organisms, ranging from microbes over algae and sponges to animals. For example, pyrrole alkaloids are one of the most abundant metabolites derived from marine sponges, and they emerge with different structural features, including fused rings, brominated compounds, and various functional group derivatives with different biological properties. The rich structure and unique biological properties of these marine pyrrole alkaloids have stimulated a great deal of interest among chemists.

Bioactivities of pyrrole alkaloids

Pyrrole alkaloids are one of the most abundant metabolites in marine organisms and occur in diverse structural features that include fused ring, brominated compounds, and various functional-group derivatives with diverse biological properties. These pyrrole alkaloids show a wide range of biological activities and the main activities are shown below.

Anticancer activity

Anticancer activity is one of the most studied activities of pyrrole alkaloids. For example, a pyrrole alkaloid containing the imidazole nucleus, dibromophakellstatin, was isolated by Pettit et al. from the marine sponge Phakellia mauritiana^[1]. The alkaloid showed inhibitory activity against a panel of human cancer cell lines, including ovary (OVCAR-3), brain (SF-295), kidney (A-498), lung (H-460), colon (KM20L2), and melanoma (SK-MEL-5).

Antifungal activity

Pyrrole alkaloids also have a broad range of antifungal activities. For example, Aldisin is a class of pyrrole alkaloids with a novel structure that was identified from the sponge Hymeniacidon aldis de Laubenf els and collected at Guam Island^[2]. As a metabolic intermediate identified from several species of marine sponges, Aldisin and its derivatives possess a wide range of antibacterial activities.

Neuroprotective activity

Some pyrrole alkaloids can act on the nervous system and may be used in the treatment of certain psychiatric disorders. For example, the analysis of A. damicornis allowed people to isolate a bromopyrrole alkaloid, daminin, which was shown to be a potent neuroprotective agent that might represent a new therapeutic tool for the treatment of central nervous system (CNS) diseases such as Parkinson's and Alzheimer's diseases^[3].

Act as serotonergic receptor antagonists

Many pyrrole alkaloids consisting of a pyrrole ring linked to an imidazole group are biologically active and can act as serotonergic receptor antagonists. For example, Kobayashi and coworkers isolated the alkaloid keramadin from the Okinawan sea sponge Agelas sp. in 1984^[4]. Keramadin exhibited the antagonist of serotonergic receptors.

What we offer

As a supplier of alkaloids, Alfa Chemistry has always shown great interest in the latest developments in pyrrole alkaloids. Alfa Chemistry is committed to providing a wide range of pyrrole alkaloids. If you do not find what you need, please contact us. We also offer product customization according to customer's detailed requirements.

References

Pettit, G. R.; et al. Antineoplastic agents. 362. isolation and X-ray crystal structure of dibromophakellstatin from the Indian ocean sponge Phakellia mauritiana. J. Nat. Prod. 1997, 60: 180-183.
Schmitz, F. J.; et al. Marine natural products: pyrrololactams from several sponges. J Nat Prod. 1985, 48: 47-53.
Aiello, A.; et al. Daminin, a bioactive pyrrole alkaloid from the Mediterranean sponge Axinella damicornis. Tetrahedron. 2005, 61: 7266-7270.
Nakamura, H.; et al. Keramadine, a novel antagonist of serotonergic receptors isolated from the Okinawan sea sponge Agelas sp. Tetrahedron Lett. 1984, 25: 2475-2478.