title: Preparative isolation and purification of alkannin/shikonin derivatives from natural products by high-speed counter-current chromatography.
abstract: Alkannin and shikonin (A/S) and their derivatives have been found in the roots of several Boraginaceous species and are also produced through plant tissue cultures. The chiral compounds A/S are potent pharmaceutical substances with a wide spectrum of biological and pharmacological activities like wound healing, antimicrobial, anti-inflammatory, anticancer and antioxidant activity. High-speed counter-current chromatography (HSCCC) was applied for the first time to the separation, preparative isolation and purification of A/S and their esters from extracts of Alkanna tinctoria roots, as well as commercial samples. The constituents of HSCCC fractions and their purity were determined by high-performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), since DAD cannot detect oligomeric A/S derivatives that are present in most of the samples containing the respective monomeric derivatives. The purity of HSCCC fractions was compared with the one of fractions isolated by column chromatography (CC) using as stationary phases silica gel and Sephadex LH-20. As shown, the purity of monomeric alkannin/shikonin was greater by HSCCC than CC separation of commercial A/S samples.
authors.affiliation: Organic Chemistry Laboratory, Department of Chemical Engineering, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece. adreana@auth.gr
authors.forename: Andreana N
authors.initials: AN
authors.lastname: Assimopoulou
authors.forename: Sonja
authors.initials: S
authors.lastname: Sturm
authors.forename: Hermann
authors.initials: H
authors.lastname: Stuppner
authors.forename: Vassilios P
authors.initials: VP
authors.lastname: Papageorgiou
mesh_terms: D028082:Boraginaceae / Q000737:chemistry*; D002845:Chromatography / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D009285:Naphthoquinones / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry
chemical_list: D009285:Naphthoquinones; D010936:Plant Extracts; C018204:alkannin; C016101:shikonin