title: Novel tryptophan metabolites, chromoazepinone A, B and C, produced by a blocked mutant of Chromobacterium violaceum, the biosynthetic implications and the biological activity of chromoazepinone A and B.
abstract: Chromobacterium violaceum produces tryptophan metabolites, purple pigments of violacein and deoxyviolacein. A blocked mutant was prepared with N-methyl-N'-nitrosoguanidine to gain insights into the biosynthetic mechanisms of the pigments. Five tryptophan metabolites were isolated: three novel compounds, named chromoazepinone A, B and C and two known compounds, chromopyrrolic acid and arcyriarubin A. The structure determinations of the three novel compounds are described. The biosynthetic pathways of these metabolites are proposed on the basis of the findings about violacein biosynthesis. Chromoazepinone A and B were found to have an interesting effect of inhibition of Wnt signal transcriptional activity, which is implicated in the formation of numerous tumors when aberrantly activated.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School of Science and Technology, Niigata University, Nishi-ku, Ikarashi 2-8050, Niigata 950-2181, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Mizuoka
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Toume
authors.forename: Masami
authors.initials: M
authors.lastname: Ishibashi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hoshino
mesh_terms: D001381:Azepines / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D002460:Cell Line; D002861:Chromobacterium / Q000235:genetics* / Q000378:metabolism*; D004952:Esters; D009154:Mutation; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects; D014364:Tryptophan / Q000378:metabolism*; D051153:Wnt Proteins / Q000378:metabolism
chemical_list: D001381:Azepines; D004952:Esters; D051153:Wnt Proteins; D014364:Tryptophan