What is it?

FIG. 1 Prodigiosin (2-methyl-3-pentyl-6-methoxyprodiginine, FIG.1) is a red-pigmented alkaloid of the family of prodigisins (or prodiginines) naturally occurring red pigments characterized by a common pyrrolyldipyrrolylmethene skeleton (FIG.2) produced as secondary metabolite by a restricted group of microorganism* , including some Streptomyces and Serratia strains, and various marine bacteria.1,2
These pigments are emerging as a novel group of compounds having distinct biological activities: antibacterial, antimycotic, immunomodulating, anti-tumor, anti-cancer and antimalarial.3
FIG. 2

Prodigiosin was first isolated from Serratia Marcescens** in pure form in 1929 by Wrede and Rothhass, and was shown to be localized in extracellular and cell-associated vescicles and in intracellular granules.1,3 However, early studies indicated that prodigiosin, a highly hydrophobic molecule, is possibly associated with the cell envelope and, in particular, is present in a complex with a 100-kDa protein in the inner membrane.1
As with many secondary metabolites, the true physiological role in the producer organisms is still debated, it was suggested that the biosynthesis might function as a ‘metabolic sink’, by consuming the overflow of NAD(P)H or proline from primary metabolism. In addition to their proposed antibacterial, antifungal or trypanolytic activities, prodiginines have been associated with surface adherence and enhancing bacterial dispersal. 1