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. 2024 Jun 21;29(13):2949.
doi: 10.3390/molecules29132949.

Determination of Flavonolignan Compositional Ratios in Silybum marianum (Milk Thistle) Extracts Using High-Performance Liquid Chromatography

Wei Chen  1 , Xi Zhao  1 , Zhenghua Huang  1 , Shihui Luo  1 , Xuguang Zhang  2 , Wei Sun  1 , Tao Lan  3 , Ruikun He  1
Affiliations

Determination of Flavonolignan Compositional Ratios in Silybum marianum (Milk Thistle) Extracts Using High-Performance Liquid Chromatography

Wei Chen et al. Molecules. .

Abstract

Milk thistle is one of the most popular ingredients in the liver protection products market. Silymarin is the main component of milk thistle and contains multiple isomers. There have been few studies focusing on the compositional ratios of silymarin isomers. In this study, we developed an HPLC method for the separation and quantification of silymarin isomers, thereby elucidating their compositional ratios. Through the analysis of more than 40 milk thistle extract products on the market, we found that the ratios, specifically Ratio 1 (the silybin B content to the silybin A content, SBNB/SBNA) and Ratio 2 (the sum of the contents of silybin B and isosilybin B to the sum of the contents of silybin A and isosilybin A, (SBNB + IBNB)/(SBNA + IBNA)), are highly consistent across milk thistle extracts, averaging approximately 1.58 and 1.28, respectively. Furthermore, such ratios were verified in milk thistle seed samples. This study introduces significant findings concerning the stable ratios among silymarin isomers in milk thistle extracts and seeds, thereby offering an innovative approach for quality assurance of milk thistle extracts.

Keywords: HPLC; Silybum marianum; compositional ratios; flavonolignan; milk thistle.

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Conflict of interest statement

Wei Chen, Xi Zhao, Zhenghua Huang, Shihui Luo, Ruikun He and Tao Lan are named inventors on a technical patent related to identification of milk thistle extracts (202311558642.9). Wei Chen, Xi Zhao, Zhenghua Huang, Shihui Luo, Wei Sun and Ruikun He are employed by By-health Co Ltd. The remaining authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Chemical structure of silymarin flavonolignan isomers (molecular formula: C25H22O10).
Figure 2
Figure 2
HPLC chromatogram of reference standards (A) and milk thistle extract (B).
Figure 3
Figure 3
The ranges of total silymarin flavonolignans content (A), Ratio 1 (B) and Ratio 2 (C) in the 42 tested milk thistle extracts.
See this image and copyright information in PMC

References

    1. Pendry B.A., Kemp V., Hughes M.J., Freeman J., Nuhu H.K., Sanchez-Medina A., Corcoran O., Galante E. Silymarin content in Silybum marianum extracts as a biomarker for the quality of commercial tinctures. J. Herb. Med. 2017;10:31–36. doi: 10.1016/j.hermed.2017.07.001. - DOI
    1. Fei Y., Liu X., Wang W. Revising tropesis of partial Chinese traditional medicine in edition 2005 Pharmacopoeia of PRC (draft showed in public) China Pharm. 2005;16:5.
    1. Quaglia M.G., Bossu E., Donati E., Mazzanti G., Brandt A. Determination of silymarine in the extract from the dried Silybum marianum fruits by high performance liquid chromatography and capillary electrophoresis. J. Pharm. Biomed. Anal. 1999;19:8. doi: 10.1016/S0731-7085(98)00231-3. - DOI - PubMed
    1. Tajmohammadi A., Razavi B.M., Hosseinzadeh H. Silybum marianum (milk thistle) and its main constituent, silymarin, as a potential therapeutic plant in metabolic syndrome: A review. Phytother. Res. 2018;32:1933–1949. doi: 10.1002/ptr.6153. - DOI - PubMed
    1. Shibano M., Lin A.-S., Itokawa H., Lee K.-H. Separation and characterization of active flavonolignans of Silybum marianum by liquid chromatography connected with hybrid ion-trap and time-of-flight mass spectrometry (LC–MS/IT-TOF) J. Nat. Prod. 2007;70:5. doi: 10.1021/np070136b. - DOI - PubMed

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