title: Feedback regulation of beta-thujaplicin production and formation of its methyl ether in a suspension culture of Cupressus lusitanica.
abstract: Suspension cell cultures of Cupressus lusitanica produce beta-thujaplicin, a tropolone found mostly in Cupressaceae heartwood. The factors controlling beta-thujaplicin accumulation in this cell culture system were investigated. Initial cell density of the cultures did not affect beta-thujaplicin levels, though initial addition of beta-thujaplicin suppressed its de novo production. When beta-thujaplicin accumulation reached a certain level (ca. 40 mg/l) in the medium, the cultures seemed to cease beta-thujaplicin production. However, beta-thujaplicin productivity was restored when the beta-thujaplicin-containing medium was exchanged for fresh medium; the formation of 2-methoxy-6-(methylethyl)cyclohepta-2,4,6-trien-1-one, an isomer of methylated beta-thujaplicin, in medium was also observed. These results suggest that beta-thujaplicin synthesis was regulated by product feedback mechanism in this cell line, and that excess accumulation of beta-thujaplicin is relieved by conversion of beta-thujaplicin to its methyl ether.
authors.affiliation: Faculty of Agriculture, Kyushu University, 812-8581, Fukuoka, Japan
authors.forename: Junko
authors.initials: J
authors.lastname: Yamada
authors.forename: Koki
authors.initials: K
authors.lastname: Fujita
authors.forename: Kokki
authors.initials: K
authors.lastname: Sakai
mesh_terms: D002452:Cell Count; D002478:Cells, Cultured; D003470:Culture Media; D029781:Cupressus / Q000166:cytology* / Q000378:metabolism*; D025461:Feedback, Physiological; D015394:Molecular Structure; D039821:Monoterpenes / Q000737:chemistry* / Q000378:metabolism*; D013997:Time Factors; D014334:Tropolone / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D003470:Culture Media; D039821:Monoterpenes; D014334:Tropolone; C009479:beta-thujaplicin