Complete isolation and characterization of silybins and isosilybins from milk thistle (Silybum marianum)Electronic supplementary information (ESI) available: HPLC chromatograms of isolates and extracts. See http://www.rsc.org/suppdata/ob/b3/b300099k/

Abstract

Complete separation, isolation, and structural characterization of four diastereoisomeric flavonolignans, silybins A (1) and B (2), and isosilybins A (3) and B (4) from the seeds of milk thistle (Silybum marianum) were achieved for the first time using a preparative reversed-phase HPLC method. In addition, three other flavonolignans, silychristin (5) isosilychristin (6) and silydianin (7), and a flavonoid, taxifolin (8) were isolated. Structures, including absolute stereochemistries of 1-4, were confirmed using 2D NMR and CD spectroscopy.

A novel rapid method for simultaneous determination of eight active compounds in silymarin using a reversed-phase UPLC-UV detector

“…The structures were identified by the analysis of the spectroscopic data (IR, NMR, ESI/MS-MS, CD). The data were compared with published spectroscopic data [16,27]. Methanol and formic acid are of HPLC grade and purchased from Dikma Technology Inc. (USA).…”

A sensitive LC–MS/MS assay for the simultaneous analysis of the major active components of silymarin in human plasma

“…Additionally, there is ongoing interest in potential anti-tumor, anti-inflammatory, and anti-fibrotic actions of silymarin extracts that have been documented in the biomedical literature [3]. Silymarin is comprised of a mixture of flavonolignans including diastereomers silybin A and B, isosilybin A and B, silychristin A and B, and silydianin, all of which are thought to confer purported pharmacological activity to milk thistle extracts [5,6].…”

Structure–Activity Relationship for (+)-Taxifolin Isolated from Silymarin as an Inhibitor of Amyloid β Aggregation

“…17) The second fraction was separated in a YMC-Pack ODS-AL column (20 mm i.d. Â 150 mm; YMC) using 40% MeOH/H 2 O to give (þ)-taxifolin (4, 6.7 mg from 310 mg of silymarin, 2.2%), 18) isosilychristin (5, 3.9 mg from 310 mg of silymarin, 1.3%), 19) and silychristin (6, 26 mg from 310 mg of silymarin, 8.4%) 20) (Fig. 1A).…”

“…Briefly, vanillin (0.10 g, 0.63 mmol) dissolved in CH 2 Cl 2 was demethylated by being treated with 1 M boron tribromide in dichloromethane (2.6 mL, 2.6 mmol) at 4 C for 1 h to quantitatively give 3,4-dihydroxybenzaldehyde. The C); 19) …”

“…The structures of these compounds were confirmed by 1 H-NMR (AVANCE III 500, ref. tetramethylsilane, Bruker, Germany), [16][17][18][19][20] EI-MS (JMS-600H, 70 eV, 300 mA, JEOL, Tokyo, Japan), and specific optical rotation (P-2200, Jasco, Tokyo, Japan).…”