Recent advances in the analysis of plant alkaloids by capillary electrophoresis and micellar electrokinetic chromatography

Abstract

Plants produce secondary metabolites as a result of a defense mechanism of plants against biotic and abiotic stresses. Alkaloids represent a diverse group of secondary metabolites that contain a basic nitrogen atom. Capillary electrophoresis has many advantages such as short analysis time, little sample consumption, high separation efficiency, and high sensitivity over conventional separation methods. Therefore, capillary electrophoresis has been extensively used for the analysis of alkaloids in plant extracts. In this review, we discuss advances in analytical capillary electrophoresis used for their identification and quantification in plants.

Preparation of open tubular capillary column covalently coated with polystyrene sulfonate with 4,4′‐Azobis(4‐cyanopentanoyl chloride) as polymerization initiator for electrochromatographic separation of alkaloids, sulfonamides, and peptides

“…Separation of alkaloids: Rhizoma coptidis is a medicinally important herb and is used in traditional Chinese medicine [46]. Analytical methods have been developed using HPLC and CE for the separation of alkaloids (Table S1) [47–50]. In the present work, a nonaqueous method has been developed and optimized for baseline separation within five minutes of five cationic alkaloids present in herbs: coptisine, berberine, epiberberine, palmatine, and jattrorhizine [51, 52].…”

Strategies for capillary electrophoresis: Method development and validation for pharmaceutical and biological applications—Updated and completely revised edition

“…Although not specifically addressed in this section, it is important to note that the addition of surfactants to the BGE can not only affect the separation mechanism but also the EOF [25] and the detection step [26]. In addition, it is worth mentioning that MEKC not only provides a versatile separation mode but also a simple way to work with poorly soluble analytes, as it is the case of Sudan dyes [27], alkaloids [28], some pesticides [29], or natural products [30]. Moreover, and due to its paramount importance to CE, the use of MEKC has been extensively discussed and reviewed in the literature focusing on their use for chiral separations [18], analysis of drug purity, log P value estimation [31], or the separation conditions for several different kinds of pharmaceutical compounds [32].…”

“…Again, depending on the p I of the protein (or compound), the surfactant may need to be changed to improve the separation efficiency and, for example, avoid ion pairing behavior and impair the separation. As discussed in a recent review, it is possible to increase resolution/separation efficiency of proteins by implementing 2D separation [28]. Peptide separation via MEKC and MEEKC was applied to separate six different pharmaceutical insulin drugs from each other.…”

“…Here, the optimum BGE was composed of 50 mM sodium phosphate, pH 9 and 30 mM SDS; allowing the analysis of ethanol, butanol, and pentanol with limit of detections (LODs) of 0.17%, 0.18%, and 0.50%, respectively [51]. Table 2 [28,42,44,45,49,[52][53][54][55][56][57][58][59] provides additional examples of combinations of BGEs optimized for the separation of specific analytes.…”

Separation of enantiomers by open‐tubular capillary electrochromatography using (R)‐1,1′‐bi‐2‐naphthol derivatives as chiral stationary phases

“…Consequently, the number of theoretical plates in CEC is much higher compared with HPLC. The CEC has high selectivity in the separation of compounds [11][12][13][14][15][16] and has been widely applied in areas including environment, medicine, chemistry, biology, and chiral separation [17][18][19]. The columns used for CEC may be divided into the open-tubular column, packed and monolithic.…”