Planta Med 2013; 79 - PO9
DOI: 10.1055/s-0033-1348789

Qualitative and Quantitative Evaluation of Silymarin Constituents by qNMR: HiFSA and Chemometrics Applied to the Quality Control of Milk Thistle Products

M da 1, S Santos 1, 2, JG Napolitano 2, SN Chen 2, GF Pauli 2
  • 1Institute of Chemistry of Sao Carlos, University of Sao Paulo, Sao Carlos, SP 13560 – 970, Brazil
  • 2Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA

The seeds of milk thistle (Silybum marianum) have been used for centuries as a phytomedicine for the treatment of liver ailments. Nowadays, milk thistle is one of the top-selling botanical supplements in the U.S. market. Considering the high chemical complexity of milk thistle extracts, and even of the derivative product, silymarin, the development of new analytical methods is essential to establish botanical integrity in biological studies and guarantee the quality and consistency of commercial products. This report presents a reliable NMR-based approach for the qualitative and quantitative assessment of milk thistle products. It utilizes high-resolution 1D 1H NMR spectra and subsequent data evaluation by 1H iterative full spin analysis (HiFSA) and multivariate statistical analysis. While HiFSA enables a detailed analysis of complex NMR signal patterns and the quantification of known chemical markers, including several silymarin constituents, the chemometric analysis establishes compositional differences between milk thistle samples. A total of thirteen commercial products were evaluated and compared to an inclusivity panel of milk thistle extracts, generated from authenticated S. marianum seeds using an automated solvent extraction (ASE) system.