Molecular mechanisms of silybin and 2,3-dehydrosilybin antiradical activity-role of individual hydroxyl groups

作者：Gazak Radek; Sedmera Petr; Vrbacky Marek; Vostalova Jitka; Drahota Zdenek; Marhol Petr; Walterova Daniela; Kren Vladimir^*

来源：Free Radical Biology and Medicine, 2009, 46(6): 745-758.

DOI：10.1016/j.freeradbiomed.2008.11.016

• Silybin
• Silymarin
• Dehydrosilybin
• Dimer formation
• Antiradical mechanism
• Laccase (Trametes pubescens)
• Reactive oxygen species
• Free radicals

The flavonolignans silybin (1) and 2,3-dehydrosilybin (2) are important natural compounds with Multiple biological activities operating at various cell levels. Many of these effects ire connected with their radical-scavenging activities. The molecular mechanisms of the antioxidant activity of these compounds and even the functional groups responsible for this activity are not yet well known. Their mechanism can be inferred from the structures of the dimeric products obtained from radical-mediated reactions of selectively methylated derivatives of 1 and 2. The radical oxidation of 1 methylated at 7-OH and 2 methylated at both 3-OH and 7-OH yields C-C and C-O dimers that enable the molecular mechanism of their E-ring interaction with radicals to lie elucidated and shows the importance of the 20-OH group in this respect. The pivotal role of the 3-OH group in the radical-scavenging activity of 2 was confirmed through the formation of another type of dimer from its selectively methylated derivative.

• 出版日期2009-3-15
• 单位河北医科大学