title: Tigloylshikonin, a new minor Shikonin derivative, from the roots and the commercial root extract of lithospermum erythrorhizon.
abstract: Tigloylshikonin, a new shikonin derivative esterified with tiglic acid ((E)-2-methylbut-2-enoic acid), was isolated as a minor pigment from a food colorant "Shikon color," a commercial root extract from Lithospermum erythrorhizon SIEBOLD et ZUCCARINI. The structure of tigloylshikonin was elucidated using (1)H, (13)C, the difference nuclear Overhauser effect (NOE), and 2D NMR techniques. Its stereochemistry was determined by chiral-phase HPLC analysis. Tigloylshikonin was also found in the roots of L. erythrorhizon, which indicated that this new shikonin derivative is a typical component of naphthoquinone pigments in the roots of L. erythrorhizon.
authors.affiliation: Division of Food Additives, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan. yuito@nihs.go.jp
authors.forename: Yusai
authors.initials: Y
authors.lastname: Ito
authors.forename: Kenichi
authors.initials: K
authors.lastname: Onobori
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kawamura
mesh_terms: D002853:Chromatography, Liquid; D029684:Lithospermum / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009285:Naphthoquinones / Q000737:chemistry* / Q000302:isolation & purification; D018517:Plant Roots / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D009285:Naphthoquinones; C557660:tigloylshikonin; C016101:shikonin