[Determination of six alkaloids in six types of Coptidis Rhizoma pieces by RP-HPLC and spectrum-effect relationships with anti-diabetes pharmacodynamics data]

Abstract

To establish a method for determining the contents of six alkaloids (jatrorrhizine hydrochloride, columbamine hydrochloride, epiberberine hydrochloride, coptisine hydrochloride, palmatine hydrochloride, berberine hydrochloride) in six types of Coptidis Rhizoma pieces (crude pieces, ginger juice stir-fried pieces, vinegar stir-fried pieces, wine steamed pieces, wine stir-fried pieces, evodiae juice stir-fried pieces) by RP-HPLC, and explore the relationship with the curative effect of traditional Chinese medicine (TCM) and pharmacodynamics results. The chromatographic column was Welch XtimateTM C₁₈ (4.6 mm×250 mm, 5 μm), with 0.1% triethylamine solution (adjust pH at 10 with ammonium bicarbonate and ammonia) as mobile phase A and acetonitrile as mobile phase B for gradient elution (0-15 min, 10%-25%B; 15-25 min, 25%-30%B; 25-40 min, 30%-45%B) at a rate of 1.0 mL•min⁻¹. The column temperature was set at 30 ℃, and the wavelength was set at 270 nm. The six alkaloids showed a good linear relationship within the range of 0.85-16.96 mg•L⁻¹ (r=0.999 7), 1.25-24.96 mg•L⁻¹ (r=0.999 9), 2.05-40.96 mg•L⁻¹ (r=0.999 9), 3.65-72.96 mg•L⁻¹ (r=0.999 9), 2.88-57.60 mg•L⁻¹ (r=0.999 8), and 13.25-264.96 mg•L⁻¹ (r=0.999 6) respectively. The average recoveries (n=9) of the six alkaloids were 102.4% (RSD 1.2%), 101.8% (RSD 1.3%), 100.3% (RSD 1.8%), 100.7%(RSD 1.8%), 101.2% (RSD 1.5%) and 97.90% (RSD 2.0%) respectively, and their average contents were 3.55, 4.49, 9.12, 19.17, 15.69, 62.56 mg•g⁻¹, respectively. This determination method was accurate and repeatable, which could be used for the content determination in six types of Coptidis Rhizoma pieces. Data analysis on contents determination and preliminary pharmacodynamics results was conducted by using principal component analysis (PCA) and hierarchical clustering analysis (HCA). The analysis results showed that three types of Coptidis Rhizoma pieces (wine steamed pieces, wine stir-fried pieces, and evodiae juice stir-fried pieces) had significant differences with crude pieces, and the wine steamed Coptidis Rhizoma pieces showed most difference with crude pieces especially, mainly related to triglyceride (TG) and fasting blood glucose levels (FBG) in serum. In addition, columbamine hydrochloride was most affected among the six alkaloids. Those three types of Coptidis Rhizoma pieces (wine steamed pieces, wine stir-fried pieces, and evodiae juice stir-fried pieces), had more advantages for "anti-diabetes" in TCM clinical application, especially in the treatment of diabetic hyperlipidemia.

Keywords: Coptidis Rhizoma pieces; HPLC; berberine hydrochloride; columbamine hydrochloride; content determination; coptisine hydrochloride; epiberberine hydrochloride; hierarchical clustering analysis (HCA); jatrorrhizine hydrochloride; palmatine hydrochloride; pharmacodynamics data; principal components analysis (PCA).