title: Structural determination of dihydro- and tetrahydrogeranylgeranyl groups at the 17-propionate of bacteriochlorophylls-a.
abstract: In the final stage of bacteriochlorophyll (BChl) biosynthesis, the presence of BChl-a molecules possessing dihydrogeranylgeranyl and tetrahydrogeranylgeranyl groups at the 17-propionate has been reported. However, the molecular structures of such BChls-a have not yet been determined in terms of the positions of CC double bonds in the 17(2)-ester. In this study, we isolated significant amounts of such pure BChls-a from Rhodopseudomonas palustris and determined their structures by both mass spectrometry and (1)H and (13)C NMR spectroscopy. The determined structures enable us to discuss a stepwise reduction from a geranylgeranyl to phytyl substituent.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Mizoguchi
authors.forename: Jiro
authors.initials: J
authors.lastname: Harada
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tamiaki
mesh_terms: D025541:Bacteriochlorophyll A / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004224:Diterpenes / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D011422:Propionates / Q000737:chemistry*; D012241:Rhodopseudomonas / Q000737:chemistry* / Q000166:cytology
chemical_list: D025541:Bacteriochlorophyll A; D004224:Diterpenes; D004952:Esters; D011422:Propionates