title: Alkannin/shikonin mixture from roots of Onosma echioides (L.) L.: extraction method study and quantification.
abstract: This work reports the extraction procedures of alkannin/shikonin mixture from roots of six populations of Onosma echioides, by means of three extraction techniques: Soxhlet extraction, maceration and rapid solid-liquid dynamic extraction (RSLDE). Five solvents with different polarity (hexane, petroleum ether, chloroform, ethyl acetate, methanol) were also studied. Analysis of the extracts was performed by an HPLC-DAD (diode array detector) system. The most efficient extraction technique was Soxhlet procedure using ethyl acetate for 6 h. Studied samples of O. echioides showed an alkannin/shikonin content in the range of 0.02-0.24 mg/kg. Other naphthoquinone derivatives (deoxyalkannin/deoxyshikonin and 5,8-dihydroxy-2-(4-methyl-6-oxo-5,6-dihydro-2H-pyran-2-yl)-[1,4]naphthoquinone and arnebin-6) were found for the first time in O. echioides and characterized in the extracts using HPLC-MS apparatus equipped with an ESI ionization source.
authors.affiliation: Department of Chemical Sciences, Faculty of Pharmacy, University of Camerino, Camerino, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Sagratini
authors.forename: Gloria
authors.initials: G
authors.lastname: Cristalli
authors.forename: Dario
authors.initials: D
authors.lastname: Giardinà
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gioventù
authors.forename: Filippo
authors.initials: F
authors.lastname: Maggi
authors.forename: Massimo
authors.initials: M
authors.lastname: Ricciutelli
authors.forename: Sauro
authors.initials: S
authors.lastname: Vittori
mesh_terms: D028082:Boraginaceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D015394:Molecular Structure; D009285:Naphthoquinones / Q000032:analysis* / Q000737:chemistry / Q000145:classification; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D009285:Naphthoquinones; D010936:Plant Extracts; D012997:Solvents; C018204:alkannin; C016101:shikonin