Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2001-2-2
pubmed:abstractText
Chemoenzymatic glucuronidation of the optically pure silybin A (1) using ovine liver glucuronyl transferase afforded three beta-glucuronides of silybin, substituted at phenolic OH groups at the positions C-20 (2), C-7 (3), and C-5 (4) formed in the yields 27, 62.5, and 2.5%, respectively. Using these standards, it was shown that the main silybin conjugate in humans is its 20-beta-D-glucuronate (2), while the C-7 regioisomer (3) was formed in lower proportion. The rate of conjugation of (natural) silybin diastereomers 10S, 11S and 10R, 11R, and therefore also their metabolism in humans is rather different. The radical scavenging activity of 2 is considerably lower than that of its aglycone (1); however, the activity of 3 is higher than in the silybin. These findings corroborate the hypothesis that, at physiological pH, the exclusive target for one-electron oxidation of the silybin molecule is the o-methoxy-phenolic structure at C-19, C-20. This is first pharmacological study using optically pure silybin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0090-9556
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1513-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Chemoenzymatic preparation of silybin beta-glucuronides and their biological evaluation.
pubmed:affiliation
Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation, Prague, Czech Republic. kren@biomed.cas.cz
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, Non-U.S. Gov't