New highly saturated members of the vitamin K2 series from Thermomonospora

Summary Menaquinones (vitamin K 2 ) were the only isoprenoid quinones found in the Actinomycetes tested. Thermomonospora strains belonging to the species T. alba, T. curvata and T. fusca contained very complex mixtures of menaquinones with nine, ten and eleven isoprene units. Hexa- and octahydrogenated menaquinones with ten isoprene units constituted the major components in T. alba , whereas, octahydrogenated menaquinones with ten isoprene units predominated in T. curvata and T. fusca . Substantial amounts of hitherto undescribed hexa-, octa-, and decahydrogenated menaquinones with eleven isoprene units were also present in the three species. The representative of the taxon Thermomonospora (Actinobifida) chromogena examined differed in possessing major amounts of tetrahydrogenated menaquinones with only nine isoprene units; a pattern also found in Saccharomonospora viridis, Actinomadura flexuosa and Micromonospora halophytica subsp. halophytica . The chemotaxonomic data and supporting results of numerical taxonomic studies suggest that Actinobifida chromogena may have been wrongly classified in the genus Thermomonospora .