Synthesis, Characterization And Antioxidant Activity Of Silybin Esterified Derivatives

Silybum marianum (L.) Gaertn. has been used for more than 2000 years to treat liver and gallbladder disorders. Silymarin is a mixture of several flavonolignans isolated from fruits and/or seeds of Silybum marianum. Silybin, as the main bioactive constituents in silymarin, has hepatoprotective, anti-inflammatory and anticancer effects. Recently, silybin received attention due to its alternative beneficial activities that are not directly bound to its hepatoprotective and/or antioxidant effects, these include mostly anticancer and chemopreventive actions. However, the bioavailability and therapeutic efficiency of silybin is rather limited by its very low solubility. Given that the relationship between its functions and structures, silybin was modified via chemical methods in order to improve the solubility and the biological activity in this paper.Chapter 1 The biological activity and chemical modification of silybin and its analogues in recent years was reviewed, then elucidates the reasons why to select this subject, the researching aims, meanings and content.Chapter 2 The experiment was designed to synthesis the ester derivatives from silybin and N-benzoxycarbonylaminoacid as raw materials to improve the solubility and bioavailability. The structural of the target compound was characterized by UV, IR, ESI-MS, and 1H NMR methods.Chapter 3 According to combination principles, a novel silybin acetylferulic acid ester was synthesized from silybin and ferulic acid which has stronger pharmacodynamic effects as starting materials via several steps such as acetylation, chlorination. It was aimed to improve the selectivity and the pharmacological effects of the parent compound. The structural of the target compound was characterized by UV, IR, ESI-MS, and 1H NMR methods.Chapter 4 The solubility of the silybin and its ester derivatives was researched by dynamic method in this section. The synthetic products were found to possess good antioxidant activity compared with the parent compound, as determined using DPPH radical scavenging, reducing power, osphomolybdenum method and determination of lipid peroxidation.