title: Metabolic fate of nicotinamide in higher plants.
abstract: Metabolism of [carbonyl-14C]nicotinamide was surveyed in various plant materials including the model plants, Arabidopsis thaliana, Oryza sativa and Lotus japonicus. In all plants studied, nicotinamide was used for the pyridine (nicotinamide adenine) nucleotide synthesis, probably after conversion to nicotinic acid. Radioactivity from [carbonyl-14C]nicotinamide was incorporated into trigonelline (1-N-methylnicotinic acid) and/or into nicotinic acid 1N-glucoside (Na-Glc). Trigonelline is formed mainly in leaves and cell cultures of O. sativa and L. japonicus and in seedlings of Trifolium incarnatum, Medicago sativa and Raphanus sativus. Trigonelline synthesis from nicotinamide is generally greater in leaves than in roots. Na-Glc was formed as the major nicotinic acid conjugate in A. thaliana and in tobacco Bright Yellow-2 cells. In seedlings of Chrysanthemum coronarium and Theobroma cacao, both trigonelline and Na-Glc were synthesized from [carbonyl-14C]nicotinamide. Trigonelline is accumulated in some seeds, mainly Leguminosae species. The pattern of formation of the nicotinic acid conjugates differs between species and organs.
authors.affiliation: Department of Biological Sciences, Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan.
authors.forename: Ayu
authors.initials: A
authors.lastname: Matsui
authors.forename: Yuling
authors.initials: Y
authors.lastname: Yin
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamanaka
authors.forename: Midori
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ashihara
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000378:metabolism; D017360:Arabidopsis / Q000378:metabolism; D002250:Carbon Radioisotopes; D000070116:Lotus / Q000378:metabolism; D015394:Molecular Structure; D009525:Niacin / Q000737:chemistry / Q000378:metabolism; D009536:Niacinamide / Q000737:chemistry / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D011725:Pyridines / Q000737:chemistry / Q000378:metabolism; D012639:Seeds / Q000378:metabolism
chemical_list: D000470:Alkaloids; D002250:Carbon Radioisotopes; D011725:Pyridines; D009536:Niacinamide; D009525:Niacin; C009560:trigonelline; C023666:pyridine