%0 Journal Article %A Carlone, George M. %A Anet, Frank A. L. %T Detection of Menaquinone-6 and a Novel Methyl-substituted Menaquinone-6 in Campylobacter jejuni and Campylobacter fetus subsp. fetus %D 1983 %J Microbiology, %V 129 %N 11 %P 3385-3393 %@ 1465-2080 %R https://doi.org/10.1099/00221287-129-11-3385 %I Microbiology Society, %X Menaquinone-6 (2-methyl-3-farnesyl-farnesyl-1,4-naphthoquinone) and a methyl-substituted menaquinone-6 (2,[5 or 8]-dimethyl-3-farnesyl-faniesyl-1,4-naphthoquinone) were the major isoprenoid quinones found in membrane preparations of Campylobacter jejuni and Campylobacter fetus subsp. fetus. By reverse-phase high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) the faster-eluting menaquinone-6 co-chromatographed with a menaquinone-6 standard. The identity of menaquinone-6 was confirmed by UV spectrophotometry, mass spectrometry and nuclear magnetic resonance (NMR) analysis. The slower-eluting methyl-substituted menaquinone-6 co-chromatographed with a menaquinone-7 standard by reverse-phase TLC but eluted between menaquinone-6 and menaquinone-7 standards by HPLC. The UV spectrum of the rnethyl-substituted menaquinone-6 did not correlate with either authentic menaquinone or demethylmenaquinone. Mass spectra showed an increase of 14 mass units when compared to menaquinone-6, and indicated that a methyl substituent was on the naphthoquinone nucleus. NMR spectra confirmed the presence of a methyl substituent at a peri position (carbon-5 or -8) on the benzenoid ring. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-129-11-3385