Optimized separation of pharmacologically active anthraquinones in Rhubarb by capillary electrochromatography

Area of Science:

• Analytical Chemistry
• Pharmacognosy
• Chromatography

Background:

• Anthraquinones are therapeutically significant compounds found in Rhubarb and traditional Chinese medicines.
• Accurate separation and analysis of these compounds are crucial for quality control and therapeutic efficacy.

Purpose of the Study:

• To develop and optimize a capillary electrochromatography (CEC) method for separating major anthraquinones.
• To validate the CEC method for analyzing anthraquinones in Rhubarb extract and traditional Chinese drugs.

Main Methods:

• Capillary electrochromatography (CEC) with diode-array detection was employed.
• Optimization of separation parameters including buffer pH, acetonitrile concentration, applied voltage, and column temperature.
• Analysis of aloe-emodin, emodin, chrysophanol, and physcion.

Main Results:

• Baseline separation of the four major anthraquinones was achieved in under 12 minutes.
• An optimized background electrolyte comprised 5 mM acetic acid (pH 4.5) with 80% acetonitrile.
• The method demonstrated effectiveness for analyzing complex traditional Chinese medicine matrices.

Conclusions:

• The developed CEC method provides a rapid and efficient approach for anthraquinone separation.
• CEC is a viable technique for the quality control and analysis of traditional Chinese medicines containing Rhubarb.
• This method supports the standardization and safety of herbal medicinal products.