Enzymatic oxidative dimerization of silymarin flavonolignans

0435748 - MBÚ 2015 RIV NL eng J - Journal Article
Gavezzotti, P. - Vavříková, Eva - Valentová, Kateřina - Fronza, G. - Kudanga, T. - Kuzma, Marek - Riva, S. - Biedermann, David - Křen, Vladimír
Enzymatic oxidative dimerization of silymarin flavonolignans.
Journal of Molecular Catalysis B-Enzymatic. Roč. 109, NOV 2014 (2014), s. 24-30. ISSN 1381-1177
R&D Projects: GA MŠMT(CZ) LD13041; GA ČR(CZ) GP14-14373P
Institutional support: RVO:61388971
Keywords : Silybin dimers * Silydianin dimer * Silymarin
Subject RIV: CE - Biochemistry
Impact factor: 2.128, year: 2014

Dimerization of phenolic compounds can potentially enhance their biological (antioxidant) activity. We present here the selective oxidative dimerization of several flavonolignans from Silybum marianum seed extract, namely, silybin A (1a), silybin B (1b), silychristin (3), and silydianin (4) catalyzed by a laccase from Trametes versicolor. Selective benzylation of C-7 OH group of both silybins ensured the priority of the dimerization reaction, avoiding thus polymerization. C-C homodimers connected via E-rings of silybin A and B and silydianin dimers were successfully isolated after respective debenzylation. On the contrary, dimerization of 7-O-benzyl silychristin afforded a complex, inseparable mixture of the products. All isolated flavonolignan dimers exhibited significantly improved 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared to their monomers and, therefore, seem to be promising for further biological studies
Permanent Link: http://hdl.handle.net/11104/0239644