New prodigiosin-like pigment from Alteromonas rubra

Area of Science:

• Microbiology
• Natural Product Chemistry
• Spectroscopy

Background:

• Prodigiosins are red pigments produced by various bacteria.
• Alteromonas rubra produces a red pigment previously thought to be solely prodigiosin.

Purpose of the Study:

• To characterize the red pigment from Alteromonas rubra.
• To identify and elucidate the structure of any novel compounds present.

Main Methods:

• Isolation and purification of pigments from Alteromonas rubra.
• Structural elucidation using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy.
• Comparative analysis of pigments from other bacterial species.

Main Results:

• The red pigment from Alteromonas rubra is a mixture of prodigiosin (pigment 1) and a new cyclic isomer (pigment 2).
• The structure of the novel cyclic prodigiosin isomer (pigment 2) was determined using advanced spectroscopic techniques.
• Pigment 2 was not detected in prodigiosins from Serratia marcescens, Vibrio psychoerythrus, or bacterium LL-100-6.

Conclusions:

• Alteromonas rubra produces a unique cyclic prodigiosin isomer.
• The discovery of pigment 2 expands the known structural diversity of prodigiosins.
• The absence of pigment 2 in other tested species suggests a specific biosynthetic pathway in Alteromonas rubra.