vitamin-k-semiquinone-radical and isoprene

Vitamin K(2) has been demonstrated to induce gene expression related to bone formation through a nuclear steroid and xenobiotic receptor (SXR). We synthesized new vitamin K analogues with the same isoprene side chains symmetrically introduced at the 2 and 3 positions of 1,4-naphthoquinone and evaluated the transcriptional activity of the target gene. The transcriptional activity was related to the length of the side chain which allowed optimal interaction with ligand-binding domain of SXR.

Topics: Binding Sites; Butadienes; Genes, Reporter; Hemiterpenes; Hep G2 Cells; Humans; Ligands; Luciferases; Pentanes; Pregnane X Receptor; Receptors, Steroid; Structure-Activity Relationship; Transcription, Genetic; Vitamin K

Whole cell acid methanolysates from corynebacteria of the D2 group were found to contain meso-diaminopimelic acid, arabinose and galactose. Among lipids of taxonomic value, saturated and unsaturated straight chain fatty acids (14 to 18 carbon atoms), tuberculostearic acid (10-methyl octadecanoic acid) and mycolic acids were present. The last compounds ranged from 26 to 36 carbon atoms, the predominant types being 28.2, 28.1, 30.3, 30.2, 32.3 and 32.2. By reverse phase thin-layer chromatography the major menaquinone was identified as MK-9(H2)-containing nine isoprene units with two additional hydrogens. Moreover, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides were detected among the phospholipids of these bacteria. Thus, on these bases, the D2 group appears to be closely related to the true corynebacteria.

Topics: Butadienes; Carbohydrates; Chromatography, Thin Layer; Corynebacterium; Diaminopimelic Acid; Fatty Acids; Hemiterpenes; Mycolic Acids; Pentanes; Phospholipids; Vitamin K