Determination of Astragaloside IV in Astragalus

Astragalus, a commonly used qi-tonifying medicine, was first recorded in the “Shen Nong’s Materia Medica” and was listed as a top grade, with a history of more than 2,000 years. Sweet in taste and warm in nature, it has the functions of invigorating qi and raising yang, solidifying the surface and relieving sweat, diuresis and swelling, invigorating body fluid and nourishing blood, supporting toxins and expelling pus, astringing sores and promoting muscles. Modern pharmaceutical research has found that Astragalus has many functions such as protecting nerve cells, protecting cardiomyocytes, enhancing myocardial contractility, scavenging oxygen free radicals, regulating immune function, and inhibiting platelet aggregation.

Astragalus contains a variety of bioactive components, including astragaloside IV, astragalus polysaccharide, astragalus flavonoids, amino acids, linolenic acid, linoleic acid, sitosterol, folic acid and various trace elements. Among them, astragaloside IV has anti-inflammatory, analgesic, antihypertensive, sedative and other pharmacological effects.

In this paper, referring to the method of Chinese Pharmacopoeia 2020 Edition I, Welch Ultisil® XB-C18 was used as a chromatographic column to determine the content of astragaloside IV in Astragalus membranaceus.

Chromatographic Condition

Column: Ultisil®XB-C18(4.6 × 250mm，5 μ m)
Mobile phase: acetonitrile / water =32/68;
Detection wavelength: evaporative light scattering detector;
Drift tube temperature: 110 ℃;
Carrier gas flow rate: 3.0l/min;
Column temperature: 30 ℃;
Flow rate: 1.0ml/min;
Injection volume: 10 μ L.

Configuration of sample solutions

Reference substance solution: take an appropriate amount of astragaloside IV reference substance, dissolve in 80% methanol to make a solution containing 0.5 mg/mL.

Test solution: take about 1 g of this product powder (passed through a No. 4 sieve), accurately weigh it, put it in a conical flask with a stopper, and accurately add 80% methanol solution containing 4% concentrated ammonia test solution (take the concentrated ammonia test solution). 4mL, force 80% methanol to 100mL, shake well) 50mL, close the plug, weigh it, heat under reflux for 1 hour, let it cool, weigh it again, and supplement it with 80% methanol solution containing 4% concentrated ammonia test solution. Lost weight, shake well, filter, precisely measure 25 mL of the continuous filtrate, evaporate to dryness, dissolve the residue with 80% methanol, transfer it to a 5 mL volumetric flask, add 80% methanol to the mark, shake well, filter, and take the continuous filtrate , that is.

Chromatogram and data

1. Reference solution

2. Test solution

Results

Using Welch Ultisil® XB-C18 (4.6×250mm, 5μm), under this chromatographic condition, it can meet the detection requirements.