Silymarin | CAS 65666-07-1 | Flavonolignan Extract (Research Use Only) | Knowlux

Product Description

Silymarin, CAS 65666-07-1, is a flavonolignan complex extracted from the seeds of milk thistle (Silybum marianum) and supplied by Knowlux for laboratory research use. It is not a single chemical entity but a defined mixture of closely related flavonolignans, principally silybin A and silybin B (together often referred to as silibinin), silychristin, silydianin, and isosilybin A and B. The molecular formula and weight are conventionally expressed on the basis of the silybin component, C25H22O10 and 482.44 g/mol, respectively. Each lot is released with a lot-specific COA, MSDS and full analytical traceability.

Mixture and specification clarification: Because silymarin is a mixture, the CAS number alone does not define the composition of a given lot. Commercial material is traded under different assay bases: "80% by UV" refers to total flavonolignan content measured spectrophotometrically, while "45% by HPLC" refers to a chromatographic assay that resolves individual components. The USP monograph for Powdered Milk Thistle Extract specifies a defined ratio: 20.0-45.0% for the sum of silydianin and silychristin, 40.0-65.0% for the sum of silybin A and silybin B, and 10.0-20.0% for the sum of isosilybin A and isosilybin B, calculated as silybin. Knowlux declares the assay basis (UV or HPLC) and the individual flavonolignan profile on each COA. Buyers should confirm which specification their research requires, as UV-based and HPLC-based grades are not interchangeable for analytical work.

Product Parameters

Product Details

1. Overview

Silymarin is the standardized flavonolignan fraction of milk thistle seed extract, used in research on liver biology and polyphenol pharmacology. The complex is not a single molecule: the seeds contain a family of flavonolignans formed by oxidative coupling of a flavonoid (taxifolin) with coniferyl alcohol, yielding silybin, silychristin, silydianin, and their isomers. The relative abundance of these components varies with the extraction method and the plant source, which is why specification by individual component profile, rather than by CAS number alone, is essential for reproducible research. Knowlux supplies silymarin as a research-grade extract for laboratory and analytical use; this supply is not intended for human consumption and does not constitute a finished supplement or drug product.

2. Research Context (Not a Therapeutic Claim)

Published literature describes silymarin as a flavonolignan mixture studied in in vitro and in vivo research models. Its reported activities include antioxidant effects (free radical scavenging and inhibition of lipid peroxidation), anti-inflammatory actions, and membrane-stabilizing properties. In a rat model of metabolic syndrome, an ethyl acetate extract of S. marianum rich in silydianin and silychristin (51.2%) was reported to lower triglycerides, reduce body weight, and improve blood glucose tolerance, while silybin was present at less than 10% in that particular extract. This finding illustrates that the biological profile depends on which flavonolignans predominate, not simply on total silymarin content. These descriptions are derived from published research and are provided for scientific reference only. Knowlux makes no claims regarding the efficacy, safety, or suitability of this product for any human application. Promotion of silymarin for liver protection, detoxification, hepatitis treatment, or any health benefit is not supported by Knowlux and is inconsistent with research-use-only supply.

3. Quality Control

The specification failures that matter most in silymarin supply are related to the distinction between UV-based and HPLC-based assays, the individual flavonolignan ratio, and residual solvent carryover from extraction. A lot that passes "80% by UV" may have a very different silybin content and silychristin/silydianin ratio than another lot with the same nominal figure. Buyers should require a specific HPLC profile with each component reported, not a single UV absorbance value. Full COA, MSDS, and lot-specific chromatograms are issued with each shipment.

4. Applications

• Reference standard for flavonolignan analytical method development

• In vitro antioxidant capacity and lipid peroxidation assays

• Liver cell biology and hepatoprotection research models

• Comparative studies of silymarin extracts with defined flavonolignan profiles

• LC-MS and biochemical assay calibrators

5. Packaging, Storage & Shipping

Powder: amber glass vial or high-barrier foil bag under nitrogen headspace, sealed with tamper-evident closure. Secondary packaging: light-protected carton with desiccant. Cold-chain shipping with validated gel packs and temperature logger where required. COA, MSDS, packing list and certificate of origin issued with each shipment.

6. Documentation Support

Per lot: COA, MSDS, certificate of origin, residual solvent statement, heavy metal statement, individual flavonolignan profile report. Specification summaries and audit support available on a project basis.

About Knowlux

Knowlux Biotechnology is a GMP-oriented manufacturer and supplier of peptides, APIs and fine-chemical research compounds, operating from Hubei, China. We serve research groups, CDMOs and distributors in more than 40 countries, and support contract synthesis, custom packaging and technical documentation requests.

Compliance Statement

This product is supplied for laboratory research use only. It is not for human or animal administration, not for diagnostic or therapeutic use, not for retail sale, and not for personal use. Silymarin is sold as a dietary supplement ingredient and is used in some jurisdictions as a botanical drug substance; those regulatory positions attach to compliant supplement- and pharmaceutical-grade supply chains and do not apply to, and are not represented by, this research-grade lot. Silymarin carries a German water hazard class of WGK 3; appropriate disposal precautions should be observed. Research context statements are for scientific reference only and do not constitute medical advice, promotional claims, or dosing guidance.