title: cis-trans Isomerization of silybins A and B.
abstract: Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF3∙OEt2) isomerization of silybins A (1a) and B (1b) (trans-isomers). The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis-trans-isomerization of silybin are proposed and supported by quantum mechanical calculations.
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.
authors.forename: Michaela
authors.initials: M
authors.lastname: Novotná
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.|Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, CZ-12840 Prague 2, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Gažák
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Biedermann
authors.affiliation: Inserm UMR-S850, Faculté de Pharmacie, Université de Limoges, 2 Rue du Docteur Marcland, F-87025 Limoges, France.|Present address: Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183, Linköping, Sweden.
authors.forename: Florent
authors.initials: F
authors.lastname: Di Meo
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Marhol
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.
authors.forename: Marek
authors.initials: M
authors.lastname: Kuzma
authors.affiliation: Institute of Organic Chemistry and Biochemistry, v.v.i. AS CR, Flemingovo náměstí 2, Prague 6, CZ-16610, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Bednárová
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.
authors.forename: Kateřina
authors.initials: K
authors.lastname: Fuksová
authors.affiliation: Inserm UMR-S850, Faculté de Pharmacie, Université de Limoges, 2 Rue du Docteur Marcland, F-87025 Limoges, France.|Department of Physical Chemistry, University of Olomouc, tř. 17. listopadu 12, CZ-77146 Olomouc, Czech Republic.|Laboratoire de Chimie des Matériaux Nouveaux, Université de Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Trouillas
authors.affiliation: Institute of Microbiology, v.v.i. AS CR, Vídeňská 1083, Prague 4, CZ-14220, Czech Republic.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Křen
keywords: 10,11-cis-silybin; 2,3-cis-silybin; isomerization; silibinin; silybin; silymarin