Isolation of a Novel Menaquinone with a Partly Hydrogenated Side Chain from Propionibacterium arabinosum

Abstract

A novel menaquinone has been isolated from Propionibacterium arabinosum. Its ultraviolet-absorption spectrum is that of a typical manaquinone. The E^1%_1cm value corresponds to that of MK-9, but it does not run with MK-9 on reversed-phase thin layer chromatograms. Mass spectra indicate that four additional hydrogen atoms are present as compared to MK-9, so that two double bonds of the nine isoprene units in the side chain are saturated. Hence the compound is designated MK-9 (4H) and a structure is proposed.