Isolation of a naphthaquinone with partly hydrogenated side chain from Corynebacterium diphtheriae.

1. Corynebacterium diphtheriae contains relatively large amounts (6.6mumoles/g. dry wt.) of a naphthaquinone whose ultraviolet-absorption spectrum is that of a typical menaquinone (vitamin K(2)), the E(1%) (1 cm.) value corresponding with that of MK-8, but on reversed-phase paper chromatograms it runs with MK-9. 2. In the presence of Adams catalyst hydrogen uptake is 2 atoms/mol. less than that calculated for MK-8. 3. Hydrogenated samples of the Corynebacterium quinone and the hydrogenation product of authentic MK-8 ran together on reversed-phase chromatograms. 4. Infrared-absorption spectra indicated close relationship with the menaquinone series, and nuclear-magnetic-resonance measurements show that one, non-terminal, double bond of the side chain has been saturated. 5. The compound is thus designated MK-8(2H), indicating a menaquinone with eight isoprene units but only seven double bonds in the side chain.