Purification Of Artemisinin Research Articles

Determination, solvent extraction, and purification of artemisinin from Artemisia annua L.

Artemisinin, the main active compound in Artemisia annua L., has been used for antimalarial properties for centuries and currently attracting increasing interest for its antiviral activities. In addition, several recent publications indicated that this valuable compound can be effective on Sars-CoV-2 virus. In the study, a high-performance liquid chromatography (HPLC) method was optimized in terms of mobile phase compositions, column temperature and flow rate using response surface methodology for the determination of artemisinin from A. annua samples. The method was also validated for some parameters according to the Eurachem guideline. Validated method was applied on A. annua plant samples, cultivated in a controlled condition, and content of artemisinin was found in the range from 5825 to 7972 mg/kg (n = 20). Extraction conditions of artemisinin from the plant samples were also optimized. In the first step of the extraction, solvents with different polarities were applied to the samples for the evaluation of artemisinin solubility. Then, ethanol was chosen for extraction solvent due the high extraction yield and classification in safer chemical ingredients list by EPA. After the extraction, a purification step using various adsorbents was studied to remove remnant impurities such as chlorophyl. The results showed that powdered charcoal was found to be the most effective adsorbent. Amount of the adsorbent was also studied to evaluate for the reduction of chlorophyl without reducing the artemisinin concentration. Finally, purified solvent was dewaxed, evaporated, and dried under nitrogen to concentrate the artemisinin content. In conclusion, the optimized conditions could be regarded as a new alternative technique in pharmaceutical industry for the extraction of artemisinin from A. annua samples.

Purification of Artemisinin from the Product Solution of a Semisynthetic Reaction within a Single Crystallization Step

Artemisinin, a natural compound isolated from the Artemisia annua L. plant, represents an indispensable ingredient in artemsisinin-based combination therapies (ACT) against malaria. Starting from d...

Systematic and Model-Assisted Process Design for the Extraction and Purification of Artemisinin from Artemisia annua L.—Part IV: Crystallization

In this study, process integration for crystallization of a priori purified Artemisia annua L. is investigated. For this total process, the integration operation boundaries and behavior of the crystals are studied. This is performed focusing on a conceptual process design study for artemisinin, aiming towards the development of a crystallization step under given parameters by process integration. At first, different crystallization systems consisting of ethanol-water or acetone-water mixtures are compared. In subsequent steps, the metastable zone width and the behavior of the crystals regarding agglomeration and breakage are checked. Furthermore, the sensitivities of process variables based on several process parameters are investigated. Additionally, the final process integration of crystallization as a combined purification and isolation step is studied.

Systematic and Model-Assisted Process Design for the Extraction and Purification of Artemisinin from Artemisia annua L.—Part III: Chromatographic Purification

In this study, the purification of an extract from Artemisia annua L. using chromatographic methods is studied. In a first step, a screening of different phases and solvents using thin-layer chromatography (TLC) was performed. Then, a laboratory-scale high performance liquid chromatography (HPLC) method was developed and transferred to a pilot scale. A reproducibility study based on 120 injections was carried out. The batch process that was developed and the results from a designed continuous simulated moving bed (SMB) chromatography were compared based on characteristic process numbers and economy.

Systematic and Model-Assisted Process Design for the Extraction and Purification of Artemisinin from Artemisia annua L.—Part II: Model-Based Design of Agitated and Packed Columns for Multistage Extraction and Scrubbing

Liquid-liquid extraction (LLE) is an established unit operation in the manufacturing process of many products. However, development and integration of multistage LLE for new products and separation routes is often hindered and is probably more cost intensive due to a lack of robust development strategies and reliable process models. Even today, extraction columns are designed based on pilot plant experiments. For dimensioning, knowledge of phase equilibrium, hydrodynamics and mass transport kinetics are necessary. Usually, those must be determined experimentally for scale-up, at least in scales of DN50-150 (nominal diameter). This experiment-based methodology is time consuming and it requires large amounts of feedstock, especially in the early phase of the project. In this study the development for the integration of LLE in a new manufacturing process for artemisinin as an anti-malaria drug is presented. For this, a combination of miniaturized laboratory and mini-plant experiments supported by mathematical modelling is used. System data on extraction and washing distributions were determined by means of shaking tests and implemented as a multi-stage extraction in a process model. After the determination of model parameters for mass transfer and plant hydrodynamics in a droplet measurement apparatus, a distributed plug-flow model is used for scale-up studies. Operating points are validated in a mini-plant system. The mini-plant runs are executed in a Kühni-column (DN26) for extraction and a packed extraction column (DN26) for the separation of side components with a throughput of up to 3.6 L/h, yield of up to 100%, and purity of 41% in the feed mixture to 91% after washing.

Systematic and Model-Assisted Process Design for the Extraction and Purification of Artemisinin from Artemisia annua L.—Part I: Conceptual Process Design and Cost Estimation

The article summarizes a systematic process design for the extraction and purification of artemisinin from annual mugwort (Artemisia annua L.). Artemisinin serves as an anti-malaria drug, therefore, resource-efficient and economic processes for its production are needed. The process design was based on lab-scale experiments and afterwards piloted on miniplant-scale at the institute. In this part of the article, a detailed economic feasibility studies including a reference process as a benchmark the lab-scale process and the pilot-scale process is given. Relevant differences between the different scales are discussed. The details of the respective unit operations (solid-liquid extraction, liquid-liquid extraction, chromatography and crystallization) are presented in dedicated articles. The study showed that even miniaturized lab-scale experiments are able to deliver data detailed enough for scale-up calculations on a theoretical basis. To our knowledge, a comparable systematic process design and piloting was never performed by academia before.

Role of impurities in purification of artemisinin from Artemisia annua extracts

Role of impurities in purification of artemisinin from Artemisia annua extracts

Crystallization of Artemisinin from Chromatography Fractions of Artemisia annua Extract

Crystallization is an inevitable step in the purification of artemisinin either from the plant Artemisia annua or from reaction mixtures of semisynthetically produced artemisinin. Rational design of crystallization process requires knowledge about the solid–liquid equilibrium in a given solvent system and effect of impurities on it. In the present work, a crystallization process was designed to purify artemisinin from fractions of a flash chromatography column effluent collected after injecting extracts of Artemisia annua leaves. The fractions from chromatography containing artemisinin were combined together into one fraction, and the impurities present in this fraction were identified. The solubility of artemisinin in the mobile phase used for chromatography, i.e., n-hexane–ethyl acetate mixture of varying compositions, was measured at 25, 15, and 5 °C, respectively. The collective effect of impurities present in the combined fraction on the solid–liquid equilibrium of artemisinin was evaluated by measur...

Chemometrics for Analytical Data Mining in Separation Process Design for Recovery of Artemisinin from Artemisia annua

The separation process for recovery of natural products from plants very often employs multiple separation techniques, and key to the success of such processes is to find the synergy between different separation techniques. Molecular level understanding of process streams is highly required in order to determine the synergy between unit operations, which can be attained through analysis of process streams using advanced process analyzers such as high performance liquid chromatography (HPLC), liquid chromatography–mass spectrometry (LC-MS), etc. Very often use of such process analyzers generates an enormous amount of data making it difficult to extract useful information. Therefore, application of chemometrics for extracting process information from analytical data of process streams is demonstrated in this work. The multivariate data analysis technique PARAFAC is used to extract chemical information such as number of impurities, their relative concentrations, and finally their identification from rather complex analytical chromatograms of flash column chromatography (flash CC) fractions during purification of artemisinin from the crude extract of Artemisia annua. Crude extract of A. annua leaves obtained from dichloromethane is used in this work. Prior to the application of PARAFAC, the data set is preprocessed to remove baseline drift and peak misalignment caused by retention time shifts due to matrix effects. The process information extracted from analytical chromatograms by using the PARAFAC technique indicated the presence of impurities ranging from coumarins, polyacetylenes, and flavonoids to artemisinin related compounds in the flash CC fractions.

The effect of O-methylated flavonoids and other co-metabolites on the crystallization and purification of artemisinin

Methoxylated flavonoids casticin, artemetin and retusin were identified as putative causative factors for low crystallization yields of artemisinin from extracts. Comparative profiling of biomass grown in different countries found elevated levels (∼60% higher) of artemetin in the East African biomass, which also demonstrates poor crystallization yields. The single compound and the combined doping experiments at 0, 25 and 50μgmL−1 doping levels showed that artemetin (at 50μgmL−1) caused a reduction in the amount of artemisinin crystallized by ca. 60%. A combination of the three flavonoids at 50μgmL−1 almost completely inhibited crystallization, reducing the yield by 98%. Treatment of extracts by adsorbents efficiently resolves the problem of low crystallization yield.

Purification of artemisinin from quercetin by anti-solvent crystallization

In the present work, anti-solvent crystallization of artemisinin from four different organic solvents (methanol, ethanol, acetonitrile, and acetone) was studied. Water was used as anti-solvent. The effect of an impurity (quercetin) on the performance of anti-solvent crystallization of artemisinin was investigated. The fundamental process data such as solubility of artemisinin in pure organic solvents and their binary mixtures with varying composition water were measured at room temperature. The solubility of quercetin was measured only in pure organic solvents at room temperature. Anti-solvent crystallization experiments were designed based on the fundamental process data determined. Firstly, the anti-solvent crystallization of artemisinin without impurity was performed from all four organic solvents and then the experiments were repeated with addition of an impurity (quercetin) while keeping all other process parameters constant. Two different concentrations of impurity, i.e., 10% and 50% of its solubility, in the respective organic solvents at room temperature were used. The effect of impurity on performance of anti-solvent crystallization was evaluated by comparing the yield and purity of the artemisinin obtained with those in the absence of impurity. Results of the present work demonstrated that the presence of quercetin in the solution does not affect the final yield of artemisinin from the solution of each of four organic solvents used. However, the purity of artemisinin crystals were reduced when quercetin concentration was 50% of its solubility in all solvents studied.

Purification of Artemisinin from Artemisia annua Extract by Sorption on Different Ligand Loaded Polymeric Adsorbents Designed by Molecular Simulation

A reactive sorption method has been devised for the purification of artemisinin from Artemisia annua extract using a polymeric adsorbent loaded with specific ligands. These ligands were designed by molecular simulation to selectively adsorb artemisinin. The specific interactions of artemisinin with different polymeric adsorbents in organic solvents of varying polarity were further quantified in terms of interaction energy, atomic charges, and vibrational spectral analysis. Solvation studies indicate use of methanol for adsorption while ethyl acetate for desorption of artemisinin. Batch equilibrium and dynamic adsorption-desorption studies were conducted to establish optimum parameters for the purification process. A weakly basic polymeric adsorbent with tertiary amino groups was chosen for artemisinic acid. After adsorption the final purity of artemisinin increases up to 90%.

Chromatography‐Crystallization Hybrid Process for Artemisinin Purification from Artemisia annua

AbstractThe feasibility of using a chromatography‐crystallization hybrid separation process for isolation and purification of artemisinin from the herbal plant Artemisia annua was studied. After separating the crude extracts of Artemisia annua by flash column chromatography, a two‐step antisolvent crystallization process was used for further isolation and purification. The two‐step antisolvent crystallization process was designed based on the solubility of artemisinin in different solvents and solvent mixtures. The first step crystallization process was to remove impurities from the solution and the second step to isolate artemisinin. The crystallization behavior of the two polymorphs of artemisinin during the antisolvent crystallization process was also studied by performing crystallization in solutions of artemisinin in acetonitrile and acetone, respectively. It was observed that the formation of the two polymorphs of artemisinin in acetone solution follows the Ostwald's rule of stages. Fast feeding of the antisolvent (water) resulted in crystallization of the metastable triclinic form which then transformed to the stable orthorhombic form through a solvent‐mediated transformation mechanism. The stable orthorhombic form crystallized out when water was fed slowly. Crystallization from acetonitrile always yielded the stable orthorhombic form regardless of the feeding rate of the antisolvent. Finally, a chromatography‐crystallization hybrid separation process was proposed and tested. The results of the present work demonstrated the feasibility of combining the advantages of column chromatography and crystallization to improve efficiency of the isolation of artemisinin from Artemisia annua.

Cultivation and genetics ofArtemisia annuaL. for increased production of the antimalarial artemisinin

Malaria has been treated for over 350 years with quinine and quinine-derived drugs. However, in several areas of the world, some strains of the malarial parasitePlasmodium falciparumhave developed resistance against these drugs. Recently, the World Health Organization (WHO) recommended the use of artemisinin-combination treatments (ACT) as the first-line treatment for multidrug-resistant falciparum malaria. The WHO estimates that current supplies of artemisinin are sufficient for only 30 million ACT, and is foreseeing the need for 130–220 million ACT in 2005 (WHO, 2004). Current research on the production of synthetic artemisinin-like compounds by the Roll Back Malaria project, pharmaceutical companies and academia resulted in a promising synthetic artemisinin-like compound (OZ277) which is currently undergoing phase I clinical trials. In about 5 years this drug is expected to be approved and made available to the public, however, meeting current global demands for ACT depends on the immediate availability of affordable artemisinin-derived drugs. This will involve expansion of the area under cultivation ofArtemisia annuaand improved methods of cultivation and processing of raw material, associated with more efficient methods for extraction and purification of artemisinin from plant material. This review addresses the agricultural, environmental and genetic aspects that may be useful in the successful large-scale cultivation ofA. annuaand for producing the antimalarial artemisinin in areas where it is urgently needed today. It also includes geographic aspects (latitude and altitude), which will help make decisions about crop establishment in tropical countries, and includes a list of Good Agricultural and Collection Practices forA. annua.

Immunosuppressive activity of a molecule isolated from Artemisia annua on DTH responses compared with cyclosporin A

Artemisia belongs to the family of Compositea; there are different Artemisias in Iran, of which Artemisia annua L. is grown in the north of Iran. In this study, Artemisinin was extracted and purified from the whole plants. The purification of Artemisinin was performed using column chromatography in different polarities of solvents and the results were evaluated by Thin Layer Chromatography (TLC). 1H-NMR (NMR-500) spectroscopy was used to characterize the purified Artemisinin. The immunosuppressive activity of Artemisinin was investigated on Balb/c mice by DTH response in comparison to cyclosporin A (CsA). The data indicated that Artemisinin could suppress the delayed type hypersensitivity (DTH) against sheep blood capsule in Balb/c mice. Also its inhibitory effect on calmodulin (CaM) structure was determined by fluorescence spectroscopy. The data indicated an inhibitory effect of that on the activity of calmodulin by increasing the fluorescence emission of calmodulin. Both in vivo (DTH response) and in vitro (spectrofluorometry) studies indicated the activity of Artemisinin as an immunosuppressive agent and that the fluorescence emission of calmodulin is more than cyclosporin A.