title: Nonequivalent labeling of the phytyl side chain of chlorophyll a in callus of the hornwort Anthoceros punctatus.
abstract: Callus cultures of the hornwort Anthoceros punctatus were induced from the apical portions of the gametophytes. Calli can accumulate rosmarinic acid, which is suggested as an intermediate for anthocerotonic acid, a rare phenylpropanoid dimer with a cyclobutane ring, indicating that calli possess the ability to produce secondary metabolites found primarily in intact plants. Biosynthesis of chloroplastidic terpenoids of liverworts showed preferential labeling of the farnesyl diphosphate (FPP)-derived portion in the phytyl side chain of chlorophyll a (1) when calli of A. punctatus are incubated with (2)H- and (13)C-labeled mevalonate. This finding suggests either that cytoplasmic FPP (or isopentenyl diphosphate, IPP) is taken into chloroplasts and condensed with endogenous IPP derived from a nonmevalonate pathway, or that FPP is synthesized within chloroplasts from extraplastidically formed IPP (or mevalonate) and then condensed with endogenous IPP in a different subplastidic fraction.
authors.affiliation: Department of Bio-organic Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, 080-8555, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Itoh
authors.forename: R P
authors.initials: RP
authors.lastname: Karunagoda
authors.forename: T
authors.initials: T
authors.lastname: Fushie
authors.forename: K
authors.initials: K
authors.lastname: Katoh
authors.forename: K
authors.initials: K
authors.lastname: Nabeta
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002734:Chlorophyll / Q000737:chemistry*; D000077194:Chlorophyll A; D002847:Chromatography, Agarose; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D002934:Cinnamates / Q000737:chemistry*; D053630:Depsides; D045782:Hemiterpenes; D007553:Isotope Labeling; D009682:Magnetic Resonance Spectroscopy; D008798:Mevalonic Acid / Q000737:chemistry; D009904:Optical Rotation; D009943:Organophosphorus Compounds / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D011106:Polyisoprenyl Phosphates / Q000737:chemistry; D012717:Sesquiterpenes; D000097123:Rosmarinic Acid
chemical_list: D000975:Antioxidants; D002734:Chlorophyll; D000077194:Chlorophyll A; D002934:Cinnamates; D053630:Depsides; D045782:Hemiterpenes; D008798:Mevalonic Acid; D009943:Organophosphorus Compounds; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes; D000097123:Rosmarinic Acid; C004809:isopentenyl pyrophosphate; C004808:farnesyl pyrophosphate