Simultaneous Quantification of Five Sesquiterpene Components after Ultrasound Extraction in Artemisia annua L. by an Accurate and Rapid UPLC⁻PDA Assay

A Discovery-Based Metabolomic Approach Using UPLC-Q-TOF-MS/MS Reveals Potential Antimalarial Compounds Present in Artemisia annua L

In 1972, Nobel laureate Youyou Tu's research team conducted clinical trials on the dried material of Artemisia annua L. from Beijing extracted by ether and then treated with alkali (called "ether neutral dry"), which showed that artemisinin was not the only antimalarial component contained. The biosynthesis of sesquiterpenoids in A. annua has increased exponentially after unremitting cultivation efforts, and the plant resources are now quite different from those in the 1970s. In consideration of emerging artemisinin resistance, it is of great theoretical and practical value to further study the antimalarial activity of A. annua and explore its causes. The purpose of this study is to clarify scientific questions, such as "What ingredients are synergistic with artemisinin in A. annua?", and "Are there non-artemisinin antimalarial ingredients in A. annua?". In this paper, Beijing wild A. annua was used as a control and two representative cultivation species of A. annua were selected to evaluate the antimalarial activity of the herbal medicine. The antimalarial activity of different extracts on mice was studied using the Peters' four-day suppressive test. UPLC-Q-TOF-MS was used to obtain mass spectrum data for all samples, and a UNIFI platform was used for identification. A multivariate statistical method was used to screen the different compounds with positive correlations. The antimalarial activity of different components from the ether extract and alkali treatments was determined and antimalarial components other than artemisinin were obtained. A total of 24 flavonoids, 68 sesquiterpenoids and 21 other compounds were identified. Compounds associated with differential antimalarial activity were identified. The material basis for the antimalarial activity of A. annua was clarified. The antimalarial components of A. annua include two categories: first, artemisinin and non-artemisinin antimalarial active components, of which the non-artemisinin antimalarial active components may include 5α-hydroperoxy-eudesma-4(15),11-diene; second, several antimalarial synergistic ingredients in A. annua, including arteanniun B, arteanniun B analogues and polymethoxy flavonoids.

Chemical Profiling and Biological Activity of Extracts from Nine Norwegian Medicinal and Aromatic Plants

There is an increased interest in identifying beneficial compounds of plant origin that can be added to animal diets to improve animal performance and have a health-promoting effect. In the present study, nine herb species of the Norwegian wild flora or which can be cultivated in Norway were selected for phytogenic evaluation (hops, maral root, mint, oregano, purslane, rosemary, roseroot, sweet wormwood, yarrow). Dried herbs were sequentially extracted with dichloromethane (DCM), ethanol (EtOH) and finally water (H₂O) by ultrasound-assisted extraction (UAE). The UAE protocol was found to be more rational than conventional Soxhlet with respect to DCM extraction. Total extraction yield was found to be highest for oregano (Origanum vulgare) with 34.4 g 100⁻¹ g dry matter (DM). H₂O-extracts gave the highest yields of the three solvents, with up to 25 g 100⁻¹ g DM for purslane (Portulaca oleracea ssp. sativa) and mint (Mentha piperita). EtOH- and H₂O-extracts were the most efficient extracts with respect to free radical scavenging capacity (ABTS (=2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), and oregano, mint, hops (Humulus lupulus) and maral root-leaves (Leuzea carthamoides) were found to be the most efficient antioxidant sources. Hops (EtOH-extract) contained α- and β-acids, xanthohumols, chlorogenic acid and the hitherto unreported 3-O-glucosides of kaempferol and quercetin. Maral root-leaves contained among other compounds hexosides of the 6-hydroxy- and 6-methoxy-kaempferol and -quercetin, whereas roseroot (Rosea rhodiola) revealed contents of rosavin, rhodiosin and rhodionin. Sweet wormwood (Artemisia annua) contained chlorogenic acid and several derivatives thereof, scopoletin and poly-methylated flavones (eupatin, casticin, chrysoplenetin). Antimicrobial potential of different plant extracts was demonstrated against Gram-positive and Gram-negative bacteria using the indicator organisms Staphylococcus aureus, and Escherichia coli, and the Atlantic salmon bacterial pathogens Moritella viscosa, Tenacibaculum finnmarkense and Aliivibrio wodanis. DCM extracts possessed the highest activities. Data demonstrate the potential ability of herb extracts as natural antimicrobials. However, future safety studies should be performed to elucidate any compromising effect on fish health.

Analytical Methods for the Determination of Major Drugs Used for the Treatment of COVID-19. A Review

At the beginning of the COVID-19 outbreak (end 2019 - 2020), therapeutic treatments based on approved drugs have been the fastest approaches to combat the new coronavirus pandemic. Nowadays several vaccines are available. However, the worldwide vaccination program is going to take a long time and its success will depend on the vaccine public's acceptance. Therefore, outside of vaccination, the repurposing of existing antiviral, anti-inflammatory and other types of drugs, have been considered an alternative medical strategy for the COVI-19 infection. Due to the broad clinical potential of the drugs, but also to their possible side effects, analytical methods are needed to monitor the drug concentrations in biological fluids and pharmaceutical products. This review deals with analytical methods developed in the period 2015 - July 2021 to detect potential drugs that, according to a literature survey, have been taken into consideration for the treatment of COVID-19. The drugs considered here have been selected on the basis of the number of articles published in the period January 2020-July 2021, using the combination of the keywords: COVID-19 and drugs or SARS-CoV-2 and drugs. A section is also devoted to monoclonal antibodies. Over the period considered, the analytical methods have been employed in a variety of real samples, such as body fluids (plasma, blood and urine), pharmaceutical products, environmental matrices and food.

A review on the latest advances in extraction and analysis of artemisinin

INTRODUCTION

Artemisinin (1), a well-known natural antimalarial drug, is a sesquiterpene lactone that contains a unique peroxide bridge. Since its discovery, the amount of research into the analysis of artemisinin has increased considerably, and it has been further intensified since the Noble Prize win by Tu Youyou in the year 2015 for the discovery of artemisinin.

OBJECTIVE

To review literature on the extraction and analysis of artemisinin, published during 2017-present, and to present an appraisal of those methods.

METHODOLOGY

Extensive literature search was carried out which involved, but not limited to, the use of, various databases, like Web of Knowledge, PubMed and Google Scholar, and relevant published materials including published books. The keywords used, in various combinations, with artemisinin being present in all combinations, in the search were artemisinin, Artemisia annua, analysis, extraction, quantitative, qualitative and quality control.

RESULTS

During the period covered in this review, several methods of analysis of artemisinin have been reported, the most of which were liquid chromatography (LC)-based methods. However, the use of new methods like near-infrared analysis, fluorometirc analysis and molecular imprinting, and a significant increase in the use of computational tools have been observed. Mainly several methods involving supercritical fluid extraction and ultrasound-assisted extraction of artemisinin have dominated the extraction area.

CONCLUSIONS

Newer analytical tools, as well as improved protocols for the known analytical tools, for qualitative and quantitative determination of artemisinin (1), have been made available by various researchers during the period covered by this review. Supercritical fluid extraction and ultrasound-assisted extraction are still the methods of choice for extraction of artemisinin.