Chemical characterization of Artemisia annua L. subcritical extract

The aerial parts of Artemisia annua L. from Bulgaria were extracted with 1,1,1,2-tetrafluoroethane. Static two-stage extraction at a pressure of 8 and 12 bar was used at a relatively low temperature. The yield was 2%. The chemical profile of the product was reported for the first time. GC-MS analysis showed that the extract contained the essential oil constituents, but in lower concentrations. In total, 28 components were identified, the main ones being artemisia ketone (26.2%), camphor (10.7%), and eucalyptol (9.1%). Artheanin B (3.7%) and arteannuic acid (3.7%) were found to be cometabolites and precursors of artemisinin. The content of the sesquiterpene lactone artemisinin, determined spectrophotometrically, was found to be 1.28 ± 0.10 %. The results revealed that the extract is of interest with the presence of biologically active substances used as a modern anti-malaria and potential anti-coronavirus agent. © 2022 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria.

Network pharmacology-based predictions of active components and pharmacological mechanisms of Artemisia annua L. for the treatment of the novel Corona virus disease 2019 (COVID-19).

BACKGROUND: Novel Corona Virus Disease 2019 (COVID-19) is closely associated with cytokines storms. The Chinese medicinal herb Artemisia annua L. (A. annua) has been traditionally used to control many inflammatory diseases, such as malaria and rheumatoid arthritis. We performed network analysis and employed molecular docking and network analysis to elucidate active components or targets and the underlying mechanisms of A. annua for the treatment of COVID-19. METHODS: Active components of A. annua were identified through the TCMSP database according to their oral bioavailability (OB) and drug-likeness (DL). Moreover, target genes associated with COVID-19 were mined from GeneCards, OMIM, and TTD. A compound-target (C-T) network was constructed to predict the relationship of active components with the targets. A Compound-disease-target (C-D-T) network has been built to reveal the direct therapeutic target for COVID-19. Molecular docking, molecular dynamics simulation studies (MD), and MM-GBSA binding free energy calculations were used to the closest molecules and targets between A. annua and COVID-19. RESULTS: In our network, GO, and KEGG analysis indicated that A. annua acted in response to COVID-19 by regulating inflammatory response, proliferation, differentiation, and apoptosis. The molecular docking results manifested excellent results to verify the binding capacity between the hub components and hub targets in COVID-19. MD and MM-GBSA data showed quercetin to be the more effective candidate against the virus by target MAPK1, and kaempferol to be the other more effective candidate against the virus by target TP53. We identified A. annua's potentially active compounds and targets associated with them that act against COVID-19. CONCLUSIONS: These findings suggest that A. annua may prevent and inhibit the inflammatory processes related to COVID-19.

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. © 2022 Elsevier GmbH