Granadaene: Proposed structure of the group B Streptococcus polyenic pigment

The chemical nature of the red pigment produced by the group B streptococcus (GBS) Streptococcus agalactiae, earlier thought to be a carotene, is investigated. Elemental analysis and mass and nuclear magnetic resonance spectral studies result in a proposal of the structure to be a 676-Da ornithine rhamno-polyene with a linear chain of 12 conjugated double bonds, named granadaene, which may help understand its biosynthetic pathway and the role of cyl-genes in the universal linkage between pigment and hemolytic activity in GBS.