Metacycloprodigiosin, a tripyrrole pigment from Streptomyces longisporus ruber

Abstract

We have recently reported the structure and synthesis of undecylprodigiosin (II), a C-25 prodigiosin analog isolated from a strain of Streptomyces.1 At that time it was noted that another more complex C-25 prodigiosin-like pigment was formed concurrently with II. In this communication we describe the isolation and structure determination of this product. Formulated as I,1 2 this new tripyrrole pigment incorporates the unusual structural feature of a meta-bridged pyrrole, the first such system to be observed in a natural product. We propose the trivial name metacycloprodigiosin for this new pigment (I),3 the synthesis of which is described in the accompanying report.4 _ OMe ?-^¡^ " \ II (1) .

Inhibition of erythromycin synthesis by disruption of malonyl-coenzyme A decarboxylase gene eryM in Saccharopolyspora erythraea

“…Although various pigments from Streptomyces spp. have been identified (17,38,42,43,46), it is not possible to assign any specific function for the decarboxylase in pigment biosynthesis. In view of the observation that the pigment deficiency phenotype of mutants can be complemented by pleiotropic regulatory effects (21,44), it is also possible that the decarboxylase gene disruption inhibited the synthesis of the pigment indirectly.…”

Regio- and stereodivergent antibiotic oxidative carbocyclizations catalysed by Rieske oxygenase-like enzymes

“…Metacycloprodigiosin 7 and undecylprodigiosin 8 belong to a large family of structurally-related metabolites called the prodiginines, which also includes streptorubin B 9 , prodigiosin R1 10 and roseophilin 11 (Figure 2A) 19–23 . The prodiginines have attracted considerable recent interest as a result of their potent biological activities.…”

Potent In Vitro Antimalarial Activity of Metacycloprodigiosin Isolated fromStreptomycesspectabilisBCC 4785

“…The strain was incubated in a fermentor containing 75 liters of a liquid medium (10.0 g of soluble starch, 1.0 g of K 2 HPO 4 , 1.0 g of MgSO 4 ⅐ 7H 2 O, 1.0 g of NaCl, 2.0 g of (NH 4 ) 2 SO 4 , and 3.0 g of CaCO 3 per liter). Chromatographic separation and purification of the methanolic extract from mycelia led to the isolation of three known compounds, metacycloprodigiosin (free-base form, orange powder, 490 mg; further purified as a hydrochloride, magenta powder) (18,19), bafilomycin A 1 (colorless crystals, 14 mg) (1,20), and spectinabilin (orange powder, 41 mg) (11). The structures of these compounds ( Fig.…”