title: Novel vitamin E forms in leaves of Kalanchoe daigremontiana and Phaseolus coccineus.
abstract: In the present study, we isolated novel tocochromanols from green leaves of Kalanchoe daigremontiana and primary leaves of etiolated seedlings of Phaseolus coccineus that were identified as β-, γ-, and δ-tocomonoenols with unsaturation at the terminal isoprene unit of the side chain. The content of γ-tocomonoenol in leaves of etiolated bean increased gradually with the age of seedlings, reaching 50% of the γ-tocopherol level in 40-day-old plants. The content of this compound in leaves was increased by short illumination of etiolated plants and by addition of homogentisic acid, a biosynthetic precursor of tocopherols. These data indicated that γ-tocomonoenol is synthesized de novo from homogentisic acid and tetrahydro-geranylgeraniol diphosphate, a phytol precursor. Based on these results, a biosynthetic pathway of tocomonoenols is proposed.
authors.affiliation: Department of Plant Physiology and Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland. jerzy.kruk@uj.edu.pl
authors.forename: Jerzy
authors.initials: J
authors.lastname: Kruk
authors.forename: Adam
authors.initials: A
authors.lastname: Pisarski
authors.forename: Renata
authors.initials: R
authors.lastname: Szymańska
mesh_terms: D053898:Biosynthetic Pathways; D002851:Chromatography, High Pressure Liquid; D006713:Homogentisic Acid / Q000378:metabolism; D031962:Kalanchoe / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D013058:Mass Spectrometry; D027805:Phaseolus / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D036226:Seedlings / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors; D014810:Vitamin E / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D014810:Vitamin E; D006713:Homogentisic Acid