2 articles
The benzophenanthridine alkaloids sanguinarine (SA) and chelerythrine (CHE) exhibit antimicrobial, anti-inflammatory, anticancer, and other properties. While structurally similar, they differ in the strength of their pharmacological effects and in their mechanisms of action, although they are present together in plants. Therefore, the task of their preparative separation is of current practical inportance.
A mixture of SA and CHE bisulfates, obtained from Macleaya microcarpa leaves, was separated into individual alkaloids using the method developed in this work, based on titration with di- and trisubstituted phosphates. The resulting alkaloid pseudo-bases were converted back to bisulfates for further study or additional fractionation. Analysis of the raw materials, intermediates, and final products was performed using high-performance liquid chromatography (HPLC) and ultraviolet spectrophotometry.
By fractionating 2.5 g of the bisulfate mixture containing 39.2% SA and 33.7% CHE by weight, 899 ± 36 mg of the SA fraction with an SA content of 90.6 ± 1.1% by weight or 95.4 ± 1.2% of the total alkaloids and a recovery of 83.1 ± 4.7%, 463 ± 19 mg of the CHE fraction with a CHE content of 93.4 ± 0.2% by weight or 98.1 ± 0.2% of the total alkaloids and a recovery of 51.3 ± 4.2%, and 344 ± 26 mg of the intermediate fraction containing 19.1 ± 2.8% SA and 76.1 ± 2.8% CHE by weight were obtained (N = 5). Repeated fractionation increased the purity of SA and CHE fractions, and processing of the intermediate fraction allowed an additional amount of CHE to be obtained.
. A simple method for separating a mixture of SA and CHE into individual alkaloids, based on their sequential precipitation as pseudo-bases during acid-base titration, was developed. This method provides good separation of the alkaloids without the use of expensive technologies.
The expansion of the range of herbal medicinal products requires the availability of a large number of different reference standards for their analysis. A possible solution is the use of herbal reference standards (HRS), which, in turn, requires the development of simple production methods that meet all the requirements for reference standards.
Using ten plant species containing polyphenolic compounds, a general scheme for preparing HRS was developed and tested, which includes extraction of plant material with low concentrations of a polar organic solvent (usually 20% isopropanol), subsequent salting-out of the organic phase with ammonium sulfate, and drying the organic extract on the surface of anhydrous lactose. The composition of the obtained HRS and intermediates was determined by high-performance liquid chromatography using primary chemical reference standards.
For all studied plant species, satisfactory values of the yield of target components, good solubility of the prepared HRS, and similarity of the chromatographic profiles of HRS and the corresponding plant material were obtained.
A simple and inexpensive method for preparing HRS, based on salting-out solvent extraction of target components, is proposed.