0435567 - MBÚ 2015 RIV NL eng J - Journal Article
Charrier, C. - Azerad, R. - Marhol, Petr - Purchartová, K. - Kuzma, Marek - Křen, Vladimír
Preparation of silybin phase II metabolites: Streptomyces catalyzed glucuronidation.
Journal of Molecular Catalysis B-Enzymatic. Roč. 102, APR 2014 (2014), s. 167-173. ISSN 1381-1177
R&D Projects: GA MŠMT(CZ) LD13041; GA ČR(CZ) GAP301/11/0662
Institutional support: RVO:61388971
Keywords : Silybin diastereomers * Silibinin * Silymarin
Subject RIV: CE - Biochemistry
Impact factor: 2.128, year: 2014

Flavonolignan silybin is a major component of the silymarin complex isolated from seeds of the milk thistle (Silybum marianum) having strong antioxidant and hepatoprotective effects, and also anticancer, chemoprotective, dermatoprotective and hypocholesterolemic activities. Natural silybin (silibinin in pharmacological literature) is a mixture of two diastereomers: silybin A and silybin B. Their metabolism is strongly linked to Phase II biotransformations and respective conjugates are rapidly excreted in bile and urine. Conjugation reactions of both silybins are strictly stereoselective. Therefore, optically pure compounds must be used for metabolic studies. The aim of this study was to obtain the glucuronidated metabolites of both silybin A and B. Streptomyces sp. strain M52104 was found to be a highly effective tool for the preparation of silybin A-20-O-beta-glucuronide, silybin B-20-O-beta-glucuronide, silybin glucuronide and silybin B-7-O-beta-glucuronide and minor amounts of silybin A and B-5-O-beta-glucuronide. The glucuronides, which were thoroughly characterized by MS and NMR spectroscopy, can be used as invaluable authentic standards in metabolic studies of both silybin diastereomers.
Permanent Link: http://hdl.handle.net/11104/0239466