Silymarin from Silybum marianum – new approaches to separation and derivatization

Milk thistle (Silybum marianum) has been used medicinally from the 14th century [1]. Today it is a source of silymarin – extract of its fruits – which is used as nutraceutical and in the treatment of the liver problems. Despite high commercial value and large amount produced, until recently preparative separation of the silymarin component has not been achieved. Consequently, extensive research of its biological activity was not possible.

Silymarin was separated by the combination of Sephadex LH-20 chromatography, kinetic resolution and crystallization [2,3]. Silymarin flavonolignans were all obtained in gram quantities and high purity. The derivatization was mainly carried out on silychristin.[4] The toxicity was assayed against several cell lines of different histological origin, the cytotoxicity is mostly negligible. Radical scavenging activity and lipoperoxidation inhibition is very high (eg. anhydrosilychristin lipoperoxidation inhibition IC₅₀= 4.12µM). This is in agreement with observed low redox potentials (dehydrosilychristin 0.39 V) [4].

Supported by the CSF (project No. 15 – 03037S), MSMT CZ (project LD 15080, LD15081).

Keywords: Milk thistle, silymarin, silybin, silychristin, cytotoxicity, lipoperoxidation inhibition.

References:

[1] Biedermann D, Vavrikova E, Cvak L, Kren V. Chemistry of silybin. Nat Prod Rep 2014; 31: 1138 – 1157.

[2] Gazak R, Marhol P, Purchartova K, Monti D, Biedermann D, Riva S, Cvak L, Kren V. Large-scale separation of silybin diastereoisomers using lipases. Process Biochem 2010; 45: 1657 – 1663.

[3] Krenek K, Marhol P, Peikerova Z, Kren V, Biedermann D. Preparatory separation of the silymarin flavonolignans by Sephadex LH-20 gel. Food Res Intl 2014; 65: 115 – 120.

[4] Pyszkova M, Biler M, Biedermann D, Valentova K, Kuzma M, Vrba J, Ulrichova J, Sokolova R, Mojovic M, Popovic-Bijelic A, Kubala M, Trouillas P, Kren V, Vacek J. Flavonolignan 2,3-dehydroderivatives: Preparation, antiradical and cytoprotective activity. Free Radic Biol Med 2016; 90: 114 – 125.

No conflict of interest has been declared by the author(s).