New prodigiosin-like pigment from Alteromonas rubra

Abstract
The red prodigiosin-like pigment from A. rubra was a mixture of prodigiosin (pigment 1) and a new cyclic isomer (pigment 2). The new structure was elucidated by mass and NMR spectra. Careful examinations of the prodigiosins produced by Serratia marcescens, Vibrio psychroerythrus and an unidentified red bacterium (LL-100-6) failed to disclose any of the new pigment, pigment 2.