Abstract
A menaquinone homologue was isolated from Streptomyces albus IFO 13014. The isolated compound had ultraviolet and infrared absorption spectra very similar to those of menaquinone. The mass spectrum of the compound showed the molecular ion peak at m/z 792, weak fragment ion peaks at m/z 777 (M-15), 583, 515, and 447, and two intense fragment ion peaks at m/z 225 and 187. Fragment ion peaks were not found at m/z 723 (M-69) and 655 (M-69-68) because of the successive loss of isoprene units. The 1H-NMR spectrum exhibited the signals of the following groups: 4×φ-H, δ8.03-7.62; 5×-CH=C-, δ5.04; Q-CH2-, δ3.30 (doublet, J=6.9Hz); Q-CH3, δ2.15; 9×=C-CH2-, δ1.97; =C-CH3 (trans, 1st unit from quinone ring), δ1.76; 4×=C-CH3 (trans, internal units), δ1.57; 3×-CH2-CH2-CH-CH2 and -CH2-CH2-CH-, δ1.25; 5× -C-CH3, δ0.86 (doublet, J=6.3Hz) (φ, benzene ring; Q, quinone ring). The chromenyl acetate was synthesized from the menaquinone and then ozonolyzed. The ozonolysis product represented the mass spectrum of an aldehyde showing ion peaks at m/z 464 (M+), 449 (M-15), 442 (M-42), 407 (M-15-42), 267, and 225. The results indicate that the isolated menaquinone is formulated as 2-methyl-3-II, III, VIII, IX-octahydromultiprenyl9-1, 4-naphthoquinone.
