Determination of isoquinoline alkaloids inThalictrum herbal drugs by non-aqueous capillary electrophoresis

Selective and sensitive determination of protoberberines by capillary electrophoresis coupled with molecularly imprinted microextraction

In this work, we developed a novel molecularly imprinted solid-phase microextraction with capillary electrophoresis method for the selective extraction and determination of protoberberines in complicated samples. The imprinted monolith was prepared in a micropipette tip-based device by using acrylamide as the functional monomer, ethyleneglyoldimethacrylate as the cross-linker and dimethylsulfoxide as the porogen, and exhibited an imprinting factor of 2.41 to berberine, 2.36 to palmatine and 2.38 to jatrorrhizine. Good capillary electrophoresis separation was achieved by using 20 mM phosphate buffer at pH 7 as running buffer with the addition of organic modifier of 10% methanol. Parameters such as sample pH value, sample flow rate and sample volume were investigated for imprinted monolith-based solid-phase microextraction. An imprinted solid-phase microextraction with capillary electrophoresis method was developed, the method showed a wide linear range (0.3-50 μg/mL), good linearity (R² ≥ 0.9947) and good reproducibility (relative standard deviations ≤ 0.73%), the limit of detection was as low as 0.1 μg/mL, which was lower than some reported methods based on capillary electrophoresis for protoberberines. The method has been applied for determination of three common protoberberines in Cortex Phellodendri Chinensis, by using a molecularly imprinted monolith as the selective sorbent, most of the matrices in the Cortex Phellodendri Chinensis sample were removed and three protoberberines were selectively enriched and well determined.

Nonaqueous capillary electrophoresis coupled with laser-induced native fluorescence detection for the analysis of berberine, palmatine, and jatrorrhizine in Chinese herbal medicines

LIF detection is one of the most sensitive detection methods for CE. However, its application is limited because the analyte is usually required to be derivatized with a fluorescent label. As a result, LIF is seldom used to analyze active ingredients in plants. In this work, we introduce a rapid, simple, and sensitive method of nonaqueous CE (NACE) coupled with laser-induced native fluorescence detection for the simultaneous analysis of berberine, palmatine, and jatrorrhizine. This method skillfully utilizes the native fluorescence of these alkaloids and requires no troublesome fluorescent derivatization. As these alkaloids can fluoresce to some degree, they were simply detected by a commercially available 488 nm Ar+ laser. The native fluorescence of the analytes was greatly enhanced by nonaqueous media. Compared with the reported UV detection method, much lower LOD was achieved (6.0 ng/mL for berberine, 7.5 ng/mL for palmatine, and 380 ng/mL for jatrorrhizine). This method was successfully applied to analyze berberine, palmatine, and jatrorrhizine in two Chinese herbal medicines, Rhizoma coptidis and Caulis mahoniae.

Nonaqueous capillary electrophoresis in pharmaceutical analysis

This review presents different solvents and electrolytes commonly used as BGEs in NACE for the analysis of pharmaceutical compounds. Most NACE applications carried out since 1998 for the analysis of compounds of pharmaceutical interest are presented in four tables: (i) analysis of drugs and related substances, (ii) analysis of chiral substances, (iii) analysis of phytochemical extracts and (iv) analysis of drugs in biological fluids. These selected examples are used to illustrate the interest in NACE versus conventional aqueous CE.

Capillary zone electrophoresis as a tool for the quality control of goldenseal extracts

The root extracts of goldenseal (Hydrastis canadensis L.) are popular phytomedicines for the treatment of gastrointestinal disorders and upper respiratory tract infections. Here we describe a simple and fast capillary zone electrophoresis (CZE) method with ultraviolet detection at 225 nm for the quantification of the major goldenseal constituents, berberine and hydrastine, in herbal remedies containing goldenseal root extracts. Tritoqualine, an antihistaminic drug with a hydrastine-like phthalidisoquinoline structure, was applied as an internal standard. The running buffer was a 1:5 mixture of 500 mM ammonium acetate (adjusted to pH 3.4 with acetic acid) and methanol. Our newly developed CZE method was validated regarding limit of detection (LOD), limit of quantification, linearity, accuracy and precision. For both berberine and hydrastine, the LOD was 1.0 microg/mL and the linearity was obtained between 2.5 and 500 microg/mL. Using our newly developed method, both the alkaloids could be analysed in herbal remedies containing goldenseal root extracts within 8 min.

Analysis of protoberberine alkaloids in several herbal drugs and related medicinal preparations by non-aqueous capillary electrophoresis

A simple, rapid, reproducible, and universal non-aqueous capillary electrophoresis method has been developed for the separation and determination of three major active protoberberine alkaloids including berberine, palmatine, and jatrorrhizine within 7 min. The effects of the concentrations of acetic acid and electrolyte, the ratio of organic solvent, and the applied voltage on the separation were investigated. The optimum running buffer was composed of 50 mM ammonium acetate, 0.5% (v/v) acetic acid, and 10% (v/v) acetonitrile in methanol. The applied voltage was 18 kV. The analytes were detected by UV at 214 nm. The linearities between peak areas and the concentrations of the analytes were also investigated, and they exhibit excellent linear behavior over the concentration ranges (correlation coefficients: 0.9975-0.9986). The method was successfully applied to determine the three alkaloids in several families of herbal drugs (Rhizoma Coptidis, Cortex Berberidis, Cortex Phellodendri, Herba Chelidonii, Caulis Mahoniae) and their relevant medicinal preparations for the first time, and the recoveries of the three constituents ranged between 95.6-103.2% for berberine, 97.5-103.3% for palmatine, and 96.1 -103.6% for jatrorrhizine.