title: Structure and Metabolic-Flow Analysis of Molecular Complexity in a (13) C-Labeled Tree by 2D and 3D NMR.
abstract: Improved signal identification for biological small molecules (BSMs) in a mixture was demonstrated by using multidimensional NMR on samples from (13) C-enriched Rhododendron japonicum (59.5 atom%) cultivated in air containing (13) C-labeled carbon dioxide for 14 weeks. The resonance assignment of 386 carbon atoms and 380 hydrogen atoms in the mixture was achieved. 42 BSMs, including eight that were unlisted in the spectral databases, were identified. Comparisons between the experimental values and the (13) C chemical shift values calculated by density functional theory supported the identifications of unlisted BSMs. Tracing the (13) C/(12) C ratio by multidimensional NMR spectra revealed faster and slower turnover ratios of BSMs involved in central metabolism and those categorized as secondary metabolites, respectively. The identification of BSMs and subsequent flow analysis provided insight into the metabolic systems of the plant.
authors.affiliation: RIKEN Center for Sustainable Resource Science, Graduate School of Medical Life Science, Yokohama City University and, Graduate School of Bioagricultural Sciences, Nagoya University, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 235-0045, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Komatsu
authors.affiliation: RIKEN Center for Sustainable Resource Science, Graduate School of Medical Life Science, Yokohama City University and, Graduate School of Bioagricultural Sciences, Nagoya University, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 235-0045, Japan.
authors.forename: Risa
authors.initials: R
authors.lastname: Ohishi
authors.affiliation: RIKEN Center for Sustainable Resource Science, Graduate School of Medical Life Science, Yokohama City University and, Graduate School of Bioagricultural Sciences, Nagoya University, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 235-0045, Japan.
authors.forename: Amiu
authors.initials: A
authors.lastname: Shino
authors.affiliation: RIKEN Center for Sustainable Resource Science, Graduate School of Medical Life Science, Yokohama City University and, Graduate School of Bioagricultural Sciences, Nagoya University, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 235-0045, Japan. jun.kikuchi@riken.jp.
authors.forename: Jun
authors.identifier: 0000-0002-6809-394X
authors.initials: J
authors.lastname: Kikuchi
keywords: NMR spectroscopy; density functional theory; isotopic labeling; metabolism; structure elucidation