Artemisinin-(Iso)quinoline Hybrids by C-H Activation and Click Chemistry: Combating Multidrug-Resistant Malaria

Characterization of antimalarial activity of artemisinin-based hybrid drugs

In response to the spread of artemisinin (ART) resistance, ART-based hybrid drugs were developed, and their activity profile was characterized against drug-sensitive and drug-resistant Plasmodium falciparum parasites. Two hybrids were found to display parasite growth reduction, stage-specificity, speed of activity, additivity of activity in drug combinations, and stability in hepatic microsomes of similar levels to those displayed by dihydroartemisinin (DHA). Conversely, the rate of chemical homolysis of the peroxide bonds is slower in hybrids than in DHA. From a mechanistic perspective, heme plays a central role in the chemical homolysis of peroxide, inhibiting heme detoxification and disrupting parasite heme redox homeostasis. The hybrid exhibiting slow homolysis of peroxide bonds was more potent in reducing the viability of ART-resistant parasites in a ring-stage survival assay than the hybrid exhibiting fast homolysis. However, both hybrids showed limited activity against ART-induced quiescent parasites in the quiescent-stage survival assay. Our findings are consistent with previous results showing that slow homolysis of peroxide-containing drugs may retain activity against proliferating ART-resistant parasites. However, our data suggest that this property does not overcome the limited activity of peroxides in killing non-proliferating parasites in a quiescent state.

Design, synthesis and biological evaluation of indoline-maleimide conjugates as potential antitumor agents for the treatment of colorectal cancer

An efficient protocol for direct coupling of maleimides and indolines at the C7-position was achieved under Rh(III) catalysis. Thirty four novel indoline-maleimide conjugates were prepared in good to excellent yields using this method. All compounds were evaluated for their anti-proliferative effect against colorectal cell lines. Among them, compound 3ab showed the most potent anti-proliferative activity against the CRC cells, and displayed low toxicity in the normal cell. Further investigation indicated that 3ab could effectively suppress the proliferation and migration of CRC cells, along with inducing cell cycle arrest and apoptosis. Mechanistic studies revealed that compound 3ab inhibited the proliferation of CRC cells via suppressing the AKT/GSK-3β pathway. In vivo evaluation demonstrated remarkable antitumor effect of 3ab (10 mg/kg) in the HCT116 xenograft model with no obvious toxicity, which is superior to that of 5-Fluorouracil (20 mg/kg). Therefore, conjugate 3ab could be considered as a potential CRC therapy agent for further development.

Access to Artemisinin-Triazole Antimalarials via Organo-Click Reaction: High In Vitro/In Vivo Activity against Multi-Drug-Resistant Malaria Parasites

Malaria is one of the most widespread diseases worldwide. Besides a growing number of people potentially threatened by malaria, the consistent emergence of resistance against established antimalarial pharmaceuticals leads to an urge toward new antimalarial drugs. Hybridization of two chemically diverse compounds into a new bioactive product is a successful concept to improve the properties of a hybrid drug relative to the parent compounds and also to overcome multidrug resistance. 1,2,3-Triazoles are a significant pharmacophore system among nitrogen-containing heterocycles with various applications, such as antiviral, antimalarial, antibacterial, and anticancer agents. Several marketed drugs possess these versatile moieties, which are used in a wide range of medical indications. While the synthesis of hybrid compounds containing a 1,2,3-triazole unit was described using Cu- and Ru-catalyzed azide-alkyne cycloaddition, an alternative metal-free pathway has never been reported for the synthesis of antimalarial hybrids. However, a metal-free pathway is a green method that allows toxic and expensive metals to be replaced with an organocatalyst. Herein, we present the synthesis of new artemisinin-triazole antimalarial hybrids via a facile Ramachary-Bressy-Wang organocatalyzed azide-carbonyl [3 + 2] cycloaddition (organo-click) reaction. The prepared new hybrid compounds are highly potent in vitro against chloroquine (CQ)-resistant and multi-drug-resistant Plasmodium falciparum strains (IC50 (Dd2) down to 2.1 nM; IC50 (K1) down to 1.8 nM) compared to CQ (IC50 (Dd2) = 165.3 nM; IC50 (K1) = 302.8 nM). Moreover, the most potent hybrid drug was more efficacious in suppressing parasitemia and extending animal survival in Plasmodium berghei-infected mice (up to 100% animal survival and up to 40 days of survival time) than the reference drug artemisinin, illustrating the potential of the hybridization concept as an alternative and powerful drug-discovery approach.

Synthesis of Novel Artemisinin, Ciprofloxacin, and Norfloxacin Hybrids with Potent Antiplasmodial Activity

The synthesis and antiplasmodial evaluation of new hybrids combining the pharmacophore structures of artemisinin, ciprofloxacin or norfloxacin, and 7-chloroquinoline are reported in this study. The first step for all of the syntheses is the obtainment of key piperazine esters intermediates bearing the drugs ciprofloxacin and norfloxacin. Using these platforms, 18 final compounds were synthesized through a multistep procedure with overall yields ranging between 8 and 20%. All compounds were screened for their antiplasmodial activity against the chloroquine-resistant Plasmodium falciparum FcB1 strain. Compounds 20, 21, 22, and 28, bearing an artesunate fragment with ciprofloxacin, exhibited IC50 values in the range of 3.5-5.4 nM and excellent selectivity indices. Among the compounds bearing the artesunate moiety on the norfloxacin, two of them, 23 and 24, afforded IC50 values of 1.5 nM and 1.9 nM, respectively. They also showed excellent selectivity indices. The most potent compounds were also evaluated against the CQ-resistant Dd2 strain of Plasmodium falciparum, demonstrating that those compounds incorporating the artesunate fragment were the most potent. Finally, the combination of artesunate with either ciprofloxacin or norfloxacin moieties in a single molecular entity proved to substantially enhance the activity and selectivity when compared to the administration of the unconjugated counterparts artesunate/ciprofloxacin and artesunate/norfloxacin.

Dihydroartemisinin-Ursodeoxycholic Bile Acid Hybrids in the Fight against SARS-CoV-2

Here, we propose the molecular hybridization of dihydroartemisinin (DHA) and ursodeoxycholic bile acid (UDCA), approved drugs, for the preparation of antiviral agents against SARS-CoV-2. DHA and UDCA were selected on the basis of their recently demonstrated in vitro activity against SARS-CoV-2. A selection of DHA-UDCA-based hybrids obtained by varying the nature of the linkage and the bile acid conjugation point as well as unconjugated DHA and UDCA were tested in vitro for cytotoxicity and anti-SARS-CoV-2 activity on Vero E6 and Calu-3 human lung cells. The hybrid DHA-t-UDCMe, obtained by conjugation via click chemistry on a gram scale, was identified as a potential candidate for SARS-CoV-2 infection treatment due to significant reduction of viral replication, possibly involving ACE2 downregulation, no cytotoxicity, and chemical stability.

Autofluorescent antimalarials by hybridization of artemisinin and coumarin: in vitro/in vivo studies and live-cell imaging

Malaria is one of our planet's most widespread and deadliest diseases, and there is an ever-consistent need for new and improved pharmaceuticals. Natural products have been an essential source of hit and lead compounds for drug discovery. Antimalarial drug artemisinin (ART), a highly effective natural product, is an enantiopure sesquiterpene lactone and occurs in Artemisia annua L. The development of improved antimalarial drugs, which are highly potent and at the same time inherently fluorescent is particularly favorable and highly desirable since they can be used for live-cell imaging, avoiding the requirement of the drug's linkage to an external fluorescent label. Herein, we present the first antimalarial autofluorescent artemisinin-coumarin hybrids with high fluorescence quantum yields of up to 0.94 and exhibiting excellent activity in vitro against CQ-resistant and multidrug-resistant P. falciparum strains (IC50 (Dd2) down to 0.5 nM; IC50 (K1) down to 0.3 nM) compared to reference drugs CQ (IC50 (Dd2) 165.3 nM; IC50 (K1) 302.8 nM) and artemisinin (IC50 (Dd2) 11.3 nM; IC50 (K1) 5.4 nM). Furthermore, a clear correlation between in vitro potency and in vivo efficacy of antimalarial autofluorescent hybrids was demonstrated. Moreover, deliberately designed autofluorescent artemisinin-coumarin hybrids, were not only able to overcome drug resistance, they were also of high value in investigating their mode of action via time-dependent imaging resolution in living P. falciparum-infected red blood cells.

Triazole hybrid compounds: A new frontier in malaria treatment

Reviewing the advancements in malaria treatment, the emergence of triazole hybrid compounds stands out as a groundbreaking development. Combining the advantages of triazole and other moieties, these hybrid compounds offer a new frontier in the battle against malaria. Their potential as effective antimalarial agents has captured the attention of researchers and holds promise for overcoming the challenges posed by drug-resistant malaria strains. We focused on their broad spectrum of antimalarial activity of diverse hybridized 1,2,3-triazoles and 1,2,4-triazoles, structure-activity relationship (SAR), drug-likeness, bioavailability and pharmacokinetic properties reported since 2018 targeting multiple stages of the Plasmodium life cycle. This versatility makes them highly effective against both drug-sensitive and drug-resistant strains of P. falciparum, making them invaluable tools in regions where resistance is prevalent. The synergistic effects of combining the triazole moiety with other pharmacophores have resulted in even greater antimalarial potency. This approach has the potential to circumvent existing resistance mechanisms and provide a more sustainable solution to malaria treatment. While triazole hybrid compounds show great promise, further research and clinical trials are warranted to fully evaluate their safety, efficacy and long-term effects. As research progresses, these compounds can potentially revolutionize the field and contribute to global efforts to eradicate malaria, ultimately saving countless lives worldwide.

Recent developments in the synthesis of hybrid antimalarial drug discovery

In this 21st century, Malaria remains a global burden and causes massive economic trouble to disease-endemic nations. The control and eradication of malaria is a major challenge that requires an urgent need to develop novel antimalarial drugs. To overcome the aforementioned situation, several researchers have given significant effort to develop hybrid antimalarial agents in the search for new antimalarial drugs. Hence, we have summarized those developments of hybrid antimalarial agents from 2017 to till date. This review illustrates the current progress in the recent synthesis of hybrid antimalarial agents along with focusing on their antimalarial evaluation to find the most potent hybrids. This present mini-review will also be useful for the scientific community for the development of new antimalarial drugs to eradicate malaria.

Autofluorescent Artemisinin-Benzimidazole Hybrids via Organo-Click Reaction: Study of Antiviral Properties and Mode of Action in Living Cells

Drug modification by a fluorescent label is a common tool for studying its mechanism of action with fluorescence microscopy techniques. However, the attachment of a fluorescent label can significantly alter the polarity, solubility, and biological activity of the investigated drug, and, as a result, the studied mechanism of action can be misrepresented. Therefore, developing efficient drugs, which are inherently fluorescent and can be tracked directly in the cell is highly favorable. Here an easy formation of fluorescent hybrid drugs is presented, generated by a combination of two readily available non-fluorescent pharmacophores via a non-cleavable linker using a Ramachary-Bressy-Wang organocatalyzed azide-carbonyl [3+2] cycloaddition (organo-click) reaction. All newly prepared fluorescent compounds showed strong anti-HCMV activity (EC50 down to 0.07±0.00 μM), thus presenting a very promising drug developmental basis compared to the approved drug ganciclovir (EC50 2.60±0.50 μM). Remarkably, in vitro fluorescent imaging investigation of new compounds revealed induced changes in mitochondrial structures, which is a phenotypical hallmark of antiviral activity. This approach opens up new vistas for the easy formation of potent fluorescent drugs from readily available non-fluorescent parent compounds and might facilitate insight into their mode of action in living cells, avoiding the requirement of linkage to external fluorescent markers.

Is structural hybridization invoking new dimensions for antimalarial drug discovery research?

Despite effective prevention methods, malaria is a devastating, persistent infection caused by protozoal parasites that result in nearly half a million fatalities annually. Any progress made thus far in the eradication of the disease is jeopardized by the expansion of malaria parasites that have evolved to become resistant to a wide range of drugs, including first-line therapy. To surmount this significant obstacle, it is necessary to develop newly synthesized drugs with multiple modes of action that may have a novel target in various stages of Plasmodium parasite development and this is made possible by the hybridization concept. Hybridization is the combination of at least two diverse pharmacophore units with some linkers bringing about a single molecule with a diverse mode of action. It intensifies a drug's physiological and chemical characteristics, such as absorption, cellular target contact, metabolism, excretion, distribution, and toxicity. This review article outlines the currently published most potent hybrid drugs against the Plasmodium species.

Conjugated carbon monoxide-releasing molecules have broad-spectrum antimicrobial activity

Aim: To test the antimicrobial effect of carbon monoxide-releasing molecules (CORMs) conjugated with azoles on different microorganisms. Methods & results: We used broth microdilution, checkerboard and cytotoxicity assays, as well as imaging, fluorescence and bioluminescence experiments to study [Re(CO)3(2,2'-bipyridyl)(Ctz)]+ (also known as ReBpyCtz). ReBpyCtz exhibits a low minimum inhibitory concentration value, increases the intracellular formation of reactive oxygen species and causes significant alterations on Staphylococcus aureus's membrane. ReBpyCtz is active against fungi, having a more prolonged fungicidal effect on Candida glabrata than clotrimazole and is selectively active on blood-stage malaria parasites, at a concentration that is not toxic to kidney epithelial cells. Conclusion: Conjugated CORMs have the potential to be active against different types of pathogens, thus constituting a promising class of broad-spectrum antimicrobials.

Recent developments in antimalarial activities of 4-aminoquinoline derivatives

Malaria is the fifth most lethal parasitic infection in the world. Antimalarial medications have played a crucial role in preventing and eradicating malaria. Numerous heterocyclic moieties have been incorporated into the creation of effective antimalarial drugs. The 4-aminoquinoline moiety is favoured in antimalarial drug discovery due to the diverse biological applications of its derivative. Since the 1960s, 4-aminoquinoline has been an important antimalarial drug due to its low toxicity, high tolerability, and rapid absorption after administration. This review focused on the antimalarial efficacy of the 4-aminoquinoline moiety hybridised with various heterocyclic scaffolds developed by scientists since 2018 against diverse Plasmodium clones. It could aid in the future development of more effective antimalarial agents.

Late-Stage C(sp2 )-H Arylation of Artemisinic Acid and Arteannuin B: Effect of Olefin Migration Towards Synthesis of C-13 Arylated Artemisinin Derivatives

In recent years, C-H bond functionalization has emerged as a pivotal tool for late-stage functionalization of complex natural products for the synthesis of potent biologically active derivatives. Artemisinin and its C-12 functionalized semi-synthetic derivatives are well-known clinically used anti-malarial drugs due to the presence of the essential 1,2,4-trioxane pharmacophore. However, in the wake of parasite developing resistance against artemisinin-based drugs, we conceptualized the synthesis of C-13 functionalized artemisinin derivatives as new antimalarials. In this regard, we envisaged that artemisinic acid could be a suitable precursor for the synthesis of C-13 functionalized artemisinin derivatives. Herein, we report C-13 arylation of artemisinic acid, a sesquiterpene acid and our attempts towards synthesis of C-13 arylated artemisinin derivatives. However, all our efforts resulted in the formation of a novel ring-contracted rearranged product. Additionally, we have extended our developed protocol for C-13 arylation of arteannuin B, a sesquiterpene lactone epoxide considered to be the biogenetic precursor of artemisinic acid. Indeed, the synthesis of C-13 arylated arteannuin B renders our developed protocol to be effective in sesquiterpene lactone as well.

Identification of antimalarial targets of chloroquine by a combined deconvolution strategy of ABPP and MS-CETSA

BACKGROUND

Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine (CQ) has played an indispensable role, however, its mechanism of action (MoA) is not fully understood.

METHODS

We used the principle of photo-affinity labeling and click chemistry-based functionalization in the design of a CQ probe and developed a combined deconvolution strategy of activity-based protein profiling (ABPP) and mass spectrometry-coupled cellular thermal shift assay (MS-CETSA) that identified the protein targets of CQ in an unbiased manner in this study. The interactions between CQ and these identified potential protein hits were confirmed by biophysical and enzymatic assays.

RESULTS

We developed a novel clickable, photo-affinity chloroquine analog probe (CQP) which retains the antimalarial activity in the nanomole range, and identified a total of 40 proteins that specifically interacted and photo-crosslinked with CQP which was inhibited in the presence of excess CQ. Using MS-CETSA, we identified 83 candidate interacting proteins out of a total of 3375 measured parasite proteins. At the same time, we identified 8 proteins as the most potential hits which were commonly identified by both methods.

CONCLUSIONS

We found that CQ could disrupt glycolysis and energy metabolism of malarial parasites through direct binding with some of the key enzymes, a new mechanism that is different from its well-known inhibitory effect of hemozoin formation. This is the first report of identifying CQ antimalarial targets by a parallel usage of labeled (ABPP) and label-free (MS-CETSA) methods.

A Hybrid of Amodiaquine and Primaquine Linked by Gold(I) Is a Multistage Antimalarial Agent Targeting Heme Detoxification and Thiol Redox Homeostasis

Hybrid-based drugs linked through a transition metal constitute an emerging concept for Plasmodium intervention. To advance the drug design concept and enhance the therapeutic potential of this class of drugs, we developed a novel hybrid composed of quinolinic ligands amodiaquine (AQ) and primaquine (PQ) linked by gold(I), named [AuAQPQ]PF₆. This compound demonstrated potent and efficacious antiplasmodial activity against multiple stages of the Plasmodium life cycle. The source of this activity was thoroughly investigated by comparing parasite susceptibility to the hybrid's components, the annotation of structure-activity relationships and studies of the mechanism of action. The activity of [AuAQPQ]PF₆ for the parasite's asexual blood stages was influenced by the presence of AQ, while its activity against gametocytes and pre-erythrocytic parasites was influenced by both quinolinic components. Moreover, the coordination of ligands to gold(I) was found to be essential for the enhancement of potency, as suggested by the observation that a combination of quinolinic ligands does not reproduce the antimalarial potency and efficacy as observed for the metallic hybrid. Our results indicate that this gold(I) hybrid compound presents a dual mechanism of action by inhibiting the beta-hematin formation and enzymatic activity of thioredoxin reductases. Overall, our findings support the potential of transition metals as a dual chemical linker and an antiplasmodial payload for the development of hybrid-based drugs.

The antimalarial activity of 1,2,4-trioxolane/trioxane hybrids and dimers: A review

Malaria, a mosquito-borne parasitic infection caused by protozoan parasites belonging to the genus Plasmodium, is a dangerous disease that contributes to millions of hospital visits and hundreds and thousands of deaths across the world, especially in Sub-Saharan Africa. Antimalarial agents are vital for treating malaria and controlling transmission, and 1,2,4-trioxolane/trioxane-containing agents, especially artemisinin and its derivatives, own antimalarial efficacy and low toxicity with unique mechanisms of action. Moreover, artemisinin-based combination therapies were recommended by the World Health Organization as the first-line treatment for uncomplicated malaria infection and have remained as the mainstay of the treatment of malaria, demonstrating that 1,2,4-trioxolane/trioxane derivatives are useful prototypes for the control and eradication of malaria. However, malaria parasites have already developed resistance to almost all of the currently available antimalarial agents, creating an urgent need for the search of novel pharmaceutical interventions for malaria. The purpose of this review article is to provide an emphasis on the current scenario (January 2012 to January 2022) of 1,2,4-trioxolane/trioxane hybrids and dimers with potential antimalarial activity and the structure-activity relationships are also discussed to facilitate further rational design of more effective candidates.

Biotransformation of artemisinin to a novel derivative via ring rearrangement by Aspergillus niger

Abstract

Artemisinin is a component part of current frontline medicines for the treatment of malaria. The aim of this study is to make analogues of artemisinin using microbial transformation and evaluate their in vitro antimalarial activity. A panel of microorganisms were screened for biotransformation of artemisinin (1). The biotransformation products were extracted, purified and isolated using silica gel column chromatography and semi-preparative HPLC. Spectroscopic methods including LC-HRMS, GC–MS, FT-IR, 1D and 2D NMR were used to elucidate the structure of the artemisinin metabolites.¹H NMR spectroscopy was further used to study the time-course biotransformation. The antiplasmodial activity (IC₅₀) of the biotransformation products of 1 against intraerythrocytic cultures of Plasmodium falciparum were determined using bioluminescence assays. A filamentous fungus Aspergillus niger CICC 2487 was found to possess the best efficiency to convert artemisinin (1) to a novel derivative, 4-methoxy-9,10-dimethyloctahydrofuro-(3,2-i)-isochromen-11(4H)-one (2) via ring rearrangement and further degradation, along with three known derivatives, compound (3), deoxyartemisinin (4) and 3-hydroxy-deoxyartemisinin (5). Kinetic study of the biotransformation of artemisinin indicated the formation of artemisinin G as a key intermediate which could be hydrolyzed and methylated to form the new compound 2. Our study shows that the anti-plasmodial potency of compounds 2, 3, 4 and 5 were ablated compared to 1, which attributed to the loss of the unique peroxide bridge in artemisinin (1). This is the first report of microbial degradation and ring rearrangement of artemisinin with subsequent hydrolysis and methoxylation by A.niger.

Key points

• Aspergillus niger CICC 2487 was found to be efficient for biotransformation of artemisinin

• A novel and unusual artemisinin derivative was isolated and elucidated

• The peroxide bridge in artemisinin is crucial for its high antimalarial potency

• The pathway of biotransformation involves the formation of artemisinin G as a key intermediate

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-11888-0.

Synthesis and In Vitro Study of Artemisinin/Synthetic Peroxide Based Hybrid Compounds against SARS‐CoV‐2 and Cancer

The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) cause life‐threatening diseases in millions of people worldwide, in particular, in patients with cancer, and there is an urgent need for antiviral agents against this infection. While in vitro activities of artemisinins against SARS‐CoV‐2 and cancer have recently been demonstrated, no study of artemisinin and/or synthetic peroxide‐based hybrid compounds active against both cancer and SARS‐CoV‐2 has been reported yet. However, the hybrid drug's properties (e. g., activity and/or selectivity) can be improved compared to its parent compounds and effective new agents can be obtained by modification/hybridization of existing drugs or bioactive natural products. In this study, a series of new artesunic acid and synthetic peroxide based new hybrids were synthesized and analyzed in vitro for the first time for their inhibitory activity against SARS‐CoV‐2 and leukemia cell lines. Several artesunic acid‐derived hybrids exerted a similar or stronger potency against K562 leukemia cells (81–83 % inhibition values) than the reference drug doxorubicin (78 % inhibition value) and they were also more efficient than their parent compounds artesunic acid (49.2 % inhibition value) and quinoline derivative (5.5 % inhibition value). Interestingly, the same artesunic acid‐quinoline hybrids also show inhibitory activity against SARS‐CoV‐2 in vitro (EC₅₀ 13–19 μm) and no cytotoxic effects on Vero E6 cells (CC₅₀ up to 110 μM). These results provide a valuable basis for design of further artemisinin‐derived hybrids to treat both cancer and SARS‐CoV‐2 infections.

PfMDR1 Transport Rates Assessed in Intact Isolated Plasmodium falciparum Digestive Vacuoles Reflect Functional Drug Resistance Relationship with pfmdr1 Mutations

Drug resistance often emerges from mutations in solute transporters. Single amino acid exchanges may alter functionality of transporters with ‘de novo’ ability to transport drugs away from their site of action. The PfMDR1 transporter (or P-glycoprotein 1) is located in the membrane of the digestive vacuole (DV), functions as an ATP-dependent pump, and transports substrates into the DV. In this study, four strains of Plasmodium falciparum, carrying various pfmdr1 gene mutations, were analysed for their transport characteristics of Fluo-4 in isolated DVs of parasites. To obtain quantitative estimates for PfMDR1 DV surface expression, PfMDR1 protein amounts on each strain’s DV membrane were evaluated by quantitative ELISA. Fluo-4, acting as a substrate for PfMDR1, was applied in DV uptake assays (‘reverse Ca²⁺ imaging’). Viable DVs were isolated from trophozoite stages with preserved PfMDR1 activity. This newly developed assay enabled us to measure the number of Fluo-4 molecules actively transported into isolated DVs per PfMDR1 molecule. The drug-resistant strain Dd2 presented the highest transport rates, followed by K1 and the drug-sensitive strain 3D7, compatible with their copy numbers. With this assay, an evaluation of the probability of resistance formation for newly developed drugs can be implemented in early stages of drug development.

The Role of the Iron Protoporphyrins Heme and Hematin in the Antimalarial Activity of Endoperoxide Drugs

Plasmodium has evolved to regulate the levels and oxidative states of iron protoporphyrin IX (Fe-PPIX). Antimalarial endoperoxides such as 1,2,4-trioxane artemisinin and 1,2,4-trioxolane arterolane undergo a bioreductive activation step mediated by heme (FeII-PPIX) but not by hematin (FeIII-PPIX), leading to the generation of a radical species. This can alkylate proteins vital for parasite survival and alkylate heme into hematin–drug adducts. Heme alkylation is abundant and accompanied by interconversion from the ferrous to the ferric state, which may induce an imbalance in the iron redox homeostasis. In addition to this, hematin–artemisinin adducts antagonize the spontaneous biomineralization of hematin into hemozoin crystals, differing strikingly from artemisinins, which do not directly suppress hematin biomineralization. These hematin–drug adducts, despite being devoid of the peroxide bond required for radical-induced alkylation, are powerful antiplasmodial agents. This review addresses our current understanding of Fe-PPIX as a bioreductive activator and molecular target. A compelling pharmacological model is that by alkylating heme, endoperoxide drugs can cause an imbalance in the iron homeostasis and that the hematin–drug adducts formed have strong cytocidal effects by possibly reproducing some of the toxifying effects of free Fe-PPIX. The antiplasmodial phenotype and the mode of action of hematin–drug adducts open new possibilities for reconciliating the mechanism of endoperoxide drugs and for malaria intervention.

Recent contributions of quinolines to antimalarial and anticancer drug discovery research

Quinoline, a privileged scaffold in medicinal chemistry, has always been associated with a multitude of biological activities. Especially in antimalarial and anticancer research, quinoline played (and still plays) a central role, giving rise to the development of an array of quinoline-containing pharmaceuticals in these therapeutic areas. However, both diseases still affect millions of people every year, pointing to the necessity of new therapies. Quinolines have a long-standing history as antimalarial agents, but established quinoline-containing antimalarial drugs are now facing widespread resistance of the Plasmodium parasite. Nevertheless, as evidenced by a massive number of recent literature contributions, they are still of great value for future developments in this field. On the other hand, the number of currently approved anticancer drugs containing a quinoline scaffold are limited, but a strong increase and interest in quinoline compounds as potential anticancer agents can be seen in the last few years. In this review, a literature overview of recent contributions made by quinoline-containing compounds as potent antimalarial or anticancer agents is provided, covering publications between 2018 and 2020.

Artemisinin and Derivatives-Based Hybrid Compounds: Promising Therapeutics for the Treatment of Cancer and Malaria

Cancer and malaria are major health conditions around the world despite many strategies and therapeutics available for their treatment. The most used strategy for the treatment of these diseases is the administration of therapeutic drugs, which suffer from several shortcomings. Some of the pharmacological limitations associated with these drugs are multi-drug resistance, drug toxicity, poor biocompatibility and bioavailability, and poor water solubility. The currently ongoing preclinical studies have demonstrated that combination therapy is a potent approach that can overcome some of the aforementioned limitations. Artemisinin and its derivatives have been reported to exhibit potent efficacy as anticancer and antimalarial agents. This review reports hybrid compounds containing artemisinin scaffolds and their derivatives with promising therapeutic effects for the treatment of cancer and malaria.

Anti-SARS-CoV-2 Inhibitory Profile of New Quinoline Compounds in Cell Culture-Based Infection Models

The presently ongoing pandemic of human SARS‐CoV‐2 infections (COVID‐19) presents an enormous challenge in surveillance, vaccine and antiviral drug development. Here we report the synthesis of new bioactive quinoline‐morpholine hybrid compounds and their virological evaluation, which proves pronounced cell culture‐based inhibitory profile against SARS‐CoV‐2. Thus, selected quinoline compounds may suggest specific hit‐to‐lead development.

Studies of Potency and Efficacy of an Optimized Artemisinin-Quinoline Hybrid against Multiple Stages of the Plasmodium Life Cycle

A recently developed artemisinin-quinoline hybrid, named 163A, has been shown to display potent activity against the asexual blood stage of Plasmodium, the malaria parasite. In this study, we determined its in vitro cytotoxicity to mammalian cells, its potency to suppress P. berghei hepatic infection and to decrease the viability of P. falciparum gametocytes, in addition to determining whether the drug exhibits efficacy of a P. berghei infection in mice. This hybrid compound has a low level of cytotoxicity to mammalian cells and, conversely, a high level of selectivity. It is potent in the prevention of hepatic stage development as well as in killing gametocytes, denoting a potential blockage of malaria transmission. The hybrid presents a potent inhibitory activity for beta-hematin crystal formation, in which subsequent assays revealed that its endoperoxide component undergoes bioactivation by reductive reaction with ferrous heme towards the formation of heme-drug adducts; in parallel, the 7-chloroquinoline component has binding affinity for ferric hemin. Both structural components of the hybrid co-operate to enhance the inhibition of beta-hematin, and this bitopic ligand property is essential for arresting the growth of asexual blood parasites. We demonstrated the in vivo efficacy of the hybrid as an erythrocytic schizonticide agent in comparison to a chloroquine/artemisinin combination therapy. Collectively, the findings suggest that the bitopic property of the hybrid is highly operative on heme detoxification suppression, and this provides compelling evidence for explaining the action of the hybrid on the asexual blood stage. For sporozoite and gametocyte stages, the hybrid conserves the potency typically observed for endoperoxide drugs, and this is possibly achieved due to the redox chemistry of endoperoxide components with ferrous heme.

Stereoselective Access to Antimelanoma Agents by Hybridization and Dimerization of Dihydroartemisinin and Artesunic acid

A library of five hybrids and six dimers of dihydroartemisinin and artesunic acid has been synthetized in a stereo-controlled manner and evaluated for the anticancer activity against metastatic melanoma cell line (RPMI7951). Among novel derivatives, three artesunic acid dimers showed antimelanoma activity and cancer selectivity, being not toxic on normal human fibroblast (C3PV) cell line. Among the three dimers, the one bearing 4-hydroxybenzyl alcohol as a spacer showed no cytotoxic effect (CC50 >300 μM) and high antimelanoma activity (IC50 =0.05 μM), which was two orders of magnitude higher than that of parent artesunic acid, and of the same order of commercial drug paclitaxel. In addition, this dimer showed cancer-type selectivity towards melanoma compared to prostate (PC3) and breast (MDA-MB-231) tumors. The occurrence of a radical mechanism was hypothesized by DFO and EPR analyses. Qualitative structure activity relationships highlighted the role of artesunic acid scaffold in the control of toxicity and antimelanoma activity.

Design, synthesis, crystal structure and anti-plasmodial evaluation of tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine derivatives

Effective chemotherapy is essential for controlling malaria. However, resistance of Plasmodium falciparum to existing antimalarial drugs has undermined attempts to control and eventually eradicate the disease. In this study, a series of 2-((substituted)(4-(5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl)piperazin-1-yl)methyl)-6-substitutedphenol derivatives were prepared using Petasis reaction with a view to evaluate their activities against P. falciparum. The development of synthesized compounds (F1-F16) was justified through the study of H¹ NMR, C¹³ NMR, mass spectra. Compound F1 and F2 were also structurally validated by single crystal X-ray diffraction analysis. All the compounds were evaluated for their in vitro antiplasmodial assessment against the W2 strain (chloroquine-resistant) of P. falciparum IC₅₀ values ranging from 0.74-6.4 μM. Two compounds, F4 and F16 exhibited significant activity against W2 strain of P. falciparum with 0.75 and 0.74 μM. The compounds (F3-F6 and F16) were also evaluated for in vitro cytotoxicity against two cancer cell lines, human lung (A549) and cervical (HeLa) cells, which demonstrated non-cytotoxicity with significant selectivity indices. In addition, in silico ADME profiling and physiochemical properties predicts drug-like properties with a very low toxic effect. Thus, all these results indicate that tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine scaffolds may serve as models for the development of antimalarial agents.

Copper catalyzed five-component domino strategy for the synthesis of nicotinimidamides

A library of medicinally and synthetically important nicotinimidamides was synthesized by a copper-catalyzed multicomponent domino reaction of oxime esters, terminal ynones, sulfonyl azides, aryl aldehydes and acetic ammonium. Its synthetic pathway involves the formation of a highly reactive N-sulfonyl acetylketenimine, characterized by high selectivity, combinations of potential nucleophiles and electrophiles, mild reaction conditions and a wide substrate scope, and is a rare five-component example of a CuAAC/ring-opening reaction.

New Trends On Biological Activities And Clinical Studies Of Quinolinic Analogues: A Review

The quinolinic ring, present in several molecules, has a great diversity of biological activities. Therefore, this ring is in the structure composition of several candidates of drugs in preclinical and clinical studies, thus, it is necessary the grouping of these results to facilitate the design of new drugs. For this reason, some of the activities were selected for this review, such as: antimalarial, antimicrobial, anticancer, anti-inflammatory, antidiabetic, anti-rheumatic and antiviral. All publications of scientific articles chosen are dated between 2000 and 2020. In addition to presenting the structures of some natural and synthetic compounds with their activities, we list the clinical studies of phases III and IV of antimalarial drugs containing the quinoline nucleus and phase III clinical studies of hydroxychloroquine and chloroquine to assess their possible role in COVID-19. Finally, we show some of the mechanisms of action, as well as the side effects of some of the quinolinic derivatives.

Combating multi-drug resistant malaria parasite by inhibiting falcipain-2 and heme-polymerization: Artemisinin-peptidyl vinyl phosphonate hybrid molecules as new antimalarials

Artemisinin-based combination therapies (ACTs) have been able to reduce the clinical and pathological malaria cases in endemic areas around the globe. However, recent reports have shown a progressive decline in malaria parasite clearance in South-east Asia after ACT treatment, thus envisaging a need for new artemisinin (ART) derivatives and combinations. To address the emergence of drug resistance to current antimalarials, here we report the synthesis of artemisinin-peptidyl vinyl phosphonate hybrid molecules that show superior efficacy than artemisinin alone against chloroquine-resistant as well as multidrug-resistant Plasmodium falciparum strains with EC₅₀ in pico-molar ranges. Further, the compounds effectively inhibited the survival of ring-stage parasite for laboratory-adapted artemisinin-resistant parasite lines as compared to artemisinin. These hybrid molecules showed complete parasite clearance in vivo using P. berghei mouse malaria model in comparison to artemisinin alone. Studies on the mode of action of hybrid molecules suggested that these artemisinin-peptidyl vinyl phosphonate hybrid molecules possessed dual activities: inhibited falcipain-2 (FP-2) activity, a P. falciparum cysteine protease involved in hemoglobin degradation, and also blocked the hemozoin formation in the food-vacuole, a step earlier shown to be blocked by artemisinin. Since these hybrid molecules blocked multiple steps of a pathway and showed synergistic efficacies, we believe that these lead compounds can be developed as effective antimalarials to prevent the spread of resistance to current antimalarials.

Advancement of chimeric hybrid drugs to cure malaria infection: An overview with special emphasis on endoperoxide pharmacophores

Emergence and spread of Plasmodium falciparum resistant to artemisinin-based combination therapy has led to a situation of haste in the scientific and pharmaceutical communities. Sincere efforts are redirected towards finding alternative chemotherapeutic agents that are capable of combating multidrug-resistant parasite strains. Extensive research yielded the concept of "Chimeric Bitherapy (CB)" which involves the linking of two molecules with individual pharmacological activity and exhibit dual mode of action into a single hybrid molecule. Current research in this field seems to endorse hybrid molecules as the next-generation antimalarial drugs and are more effective compared to the multi-component drugs because of the lower occurrence of drug-drug adverse effects. This review is an attempt to congregate complete survey on endoperoxide based hybrid antiplasmodial molecules that will give glimpse on the future directions for successful development and discovery of useful antimalarial hybrid drugs.

Bioactive half-sandwich Rh and Ir bipyridyl complexes containing artemisinin

Reaction of dihydroartemisinin (DHA) with 4-methyl-4'-carboxy-2,2'-bipyridine yielded the new ester derivative L1. Six novel organometallic half-sandwich chlorido Rh(III) and Ir(III) complexes (1-6) containing pentamethylcyclopentadienyl, (Cp*), tetramethylphenylcyclopentadienyl (Cp^xph), or tetramethylbiphenylcyclopentadienyl (Cp^xbiph), and N,N-chelated bipyridyl group of L1, have been synthesized and characterized. The complexes were screened for inhibitory activity against the Plasmodium falciparum 3D7 (sensitive), Dd2 (multi-drug resistant) and NF54 late stage gametocytes (LSGNF54), the parasite strain Trichomonas vaginalis G3, as well as A2780 (human ovarian carcinoma), A549 (human alveolar adenocarcinoma), HCT116 (human colorectal carcinoma), MCF7 (human breast cancer) and PC3 (human prostate cancer) cancer cell lines. They show nanomolar antiplasmodial activity, outperforming chloroquine and artemisinin. Their activities were also comparable to dihydroartemisinin. As anticancer agents, several of the complexes showed high inhibitory effects, with Ir(III) complex 3, containing the tetramethylbiphenylcyclopentadienyl ligand, having similar IC₅₀ values (concentration for 50% of maximum inhibition of cell growth) as the clinical drug cisplatin (1.06-9.23 μM versus 0.24-7.2 μM, respectively). Overall, the iridium complexes (1-3) are more potent compared to the rhodium derivatives (4-6), and complex 3 emerges as the most promising candidate for future studies.

Design, synthesis and pharmacological evaluation of novel Artemisinin-Thymol

A molecular hybridization of natural products is a new concept in drug discovery and having critical roles to design new molecules with improved biological properties. Hybrid molecules display higher biological activities when compared to the parent drugs. In the present study, two natural products (thymol and artemisinin (ART)) are used for the synthesis of new hybrid thymol-artemisinin. After characterization, the cytotoxic activity of ART-thymol was tested against different cancer cell lines and non-cancerous human cell line. ART-Thymol show the cytotoxic effect with EC₅₀ values 70,96μM for HepG2, 97,31μM for LnCap, 6,03μM for Caco-2, 77,98μM for HeLa and 62,28μM for HEK293 cells, respectively. Moreover, ART-Thymol was checked for drug-likeness, and the kinase inhibitory activity. ART-Thymol is investigated by using molecular docking. The results of qPCR was indicated CDK2 and P38 were inhibited by ART-Thymol. These results improved that thymol-artemisinin may be new candidates as an anticancer agents.

Medicinal chemistry updates on quinoline- and endoperoxide-based hybrids with potent antimalarial activity

The resistance of conventional antimalarial drugs against the malarial parasite continues to pose a challenge to control the disease. The indiscriminate exploitation of the available antimalarials has resulted in increasing treatment failures, which urges on the search for novel lead molecules. Artemisinin-based combination therapy (ACT) is the current WHO-recommended first-line treatment for the majority of malaria cases. Hybrid molecules offer a newer strategy for the development of next-generation antimalarial drugs. These comprise molecules, each with an individual pharmacological activity, linked together into a single hybrid molecule. This approach has been utilized by several research groups to develop molecules with potent antimalarial activity. In this review, we provide an overview of the pivotal roles of quinoline- and endoperoxide-based hybrids as inhibitors of the life-cycle progression of Plasmodium. Based on the exhaustive literature reports, we have collated the structural and functional analyses of quinoline- and endoperoxide-based hybrid molecules that show potency equal to or greater than those of the individual compounds, offering an effective therapeutics option for clinical use.

Green strategies for transition metal-catalyzed C–H activation in molecular syntheses

Sustainable strategies for the activation of inert C–H bonds towards improved resource-economy.

Multicomponent crystals of an artemisinin derivative and cinchona alkaloids for use as antimalarial drugs

Multicomponent crystals of an artemisinin derivative and cinchona alkaloids were produced, combining two major types of antimalaria drugs with unique hydrogen bond interactions. These salts demonstrate a new category of antimalarial pharmaceuticals.

Antimalarial application of quinones: A recent update

Atovaquone belongs to a naphthoquinone class of drugs and is used in combination with proguanil (Malarone) for the treatment of acute, uncomplicated malaria caused by Plasmodium falciparum (including chloroquine-resistant P. falciparum/P. vivax). Numerous quinone-derived compounds have attracted considerable attention in the last few decades due to their potential in antimalarial drug discovery. Several semi-synthetic derivatives of natural quinones, synthetic quinones (naphtho-/benzo-quinone, anthraquinones, thiazinoquinones), and quinone-based hybrids were explored for their in vitro and in vivo antimalarial activities. A careful literature survey revealed that this topic has not been compiled as a review article so far. Therefore, we herein summarise the recent discovery (the year 2009-2020) of quinone based antimalarial compounds in chronological order. This compilation would be very useful towards the exploration of novel quinone-derived compounds against malarial parasites with promising efficacy and lesser side effects.

A Novel Hybrid of Chloroquine and Primaquine Linked by Gold(I): Multitarget and Multiphase Antiplasmodial Agent

Plasmodium parasites kill 435 000 people around the world every year due to unavailable vaccines, a limited arsenal of antimalarial drugs, delayed treatment, and the reduced clinical effectiveness of current practices caused by drug resistance. Therefore, there is an urgent need to discover and develop new antiplasmodial candidates. In this work, we present a novel strategy to develop a multitarget metallic hybrid antimalarial agent with possible dual efficacy in both sexual and asexual erythrocytic stages. A hybrid of antimalarial drugs (chloroquine and primaquine) linked by gold(I) was synthesized and characterized by spectroscopic and analytical techniques. The CQPQ-gold(I) hybrid molecule affects essential parasite targets, it inhibits β-hematin formation and interacts moderately with the DNA minor groove. Its interaction with PfTrxR was also examined in computational modeling studies. The CQPQ-gold(I) hybrid displayed an excellent in vitro antimalarial activity against the blood-stage of Plasmodium falciparum and liver-stage of Plasmodium berghei and efficacy in vivo against P. berghei, thereby demonstrating its multiple-stage antiplasmodial activity. This metallic hybrid is a promising chemotherapeutic agent that could act in the treatment, prevention, and transmission of malaria.

Exploring the chemical space of 1,2,3-triazolyl triclosan analogs for discovery of new antileishmanial chemotherapeutic agents

Triclosan and isoniazid are known antitubercular compounds that have proven to be also active against Leishmania parasites. On these grounds, a collection of 37 diverse 1,2,3-triazoles based on the antitubercular molecules triclosan and 5-octyl-2-phenoxyphenol (8PP) were designed in search of novel structures with leishmanicidal activity and prepared using different alkynes and azides. The 37 compounds were assayed against Leishmania donovani, the etiological agent of leishmaniasis, yielding some analogs with activity at micromolar concentrations and against M. tuberculosis H37Rv resulting in scarce active compounds with an MIC of 20 μM. To study the mechanism of action of these catechols, we analyzed the inhibition activity of the library on the M. tuberculosis enoyl-ACP reductase (ENR) InhA, obtaining poor inhibition of the enzyme. The cytotoxicity against Vero cells was also tested, resulting in none of the compounds being cytotoxic at concentrations of up to 20 μM. Derivative 5f could be considered a valuable starting point for future antileishmanial drug development. The validation of a putative leishmanial InhA orthologue as a therapeutic target needs to be further investigated.

Synthesis, Structure-Activity Relationship, and Antimalarial Efficacy of 6-Chloro-2-arylvinylquinolines

There is an urgent need to develop new efficacious antimalarials to address the emerging drug-resistant clinical cases. Our previous phenotypic screening identified styrylquinoline UCF501 as a promising antimalarial compound. To optimize UCF501, we herein report a detailed structure-activity relationship study of 2-arylvinylquinolines, leading to the discovery of potent, low nanomolar antiplasmodial compounds against a Plasmodium falciparum CQ-resistant Dd2 strain, with excellent selectivity profiles (resistance index < 1 and selectivity index > 200). Several metabolically stable 2-arylvinylquinolines are identified as fast-acting agents that kill asexual blood-stage parasites at the trophozoite phase, and the most promising compound 24 also demonstrates transmission blocking potential. Additionally, the monophosphate salt of 24 exhibits excellent in vivo antimalarial efficacy in the murine model without noticeable toxicity. Thus, the 2-arylvinylquinolines represent a promising class of antimalarial drug leads.

An insight into the recent development of the clinical candidates for the treatment of malaria and their target proteins

Malaria is an endemic disease, prevalent in tropical and subtropical regions which cost half of million deaths annually. The eradication of malaria is one of the global health priority nevertheless, current therapeutic efforts seem to be insufficient due to the emergence of drug resistance towards most of the available drugs, even first-line treatment ACT, unavailability of the vaccine, and lack of drugs with a new mechanism of action. Intensification of antimalarial research in recent years has resulted into the development of single dose multistage therapeutic agents which has advantage of overcoming the antimalarial drug resistance. The present review explored the current progress in the development of new promising antimalarials against prominent target proteins that have the potential to be a clinical candidate. Here, we also reviewed different aspects of drug resistance and highlighted new drug candidates that are currently in a clinical trial or clinical development, along with a few other molecules with excellent antimalarial activity overs ACTs. The summarized scientific value of previous approaches and structural features of antimalarials related to the activity are highlighted that will be helpful for the development of next-generation antimalarials.

Synthesis and Antiplasmodial Activity of Novel Fosmidomycin Derivatives and Conjugates with Artemisinin and Aminochloroquinoline

Malaria, despite many efforts, remains among the most problematic infectious diseases worldwide, mainly due to the development of drug resistance by Plasmodium falciparum. The antibiotic fosmidomycin (FSM) is also known for its antimalarial activity by targeting the non-mevalonate isoprenoid synthesis pathway, which is essential for the malaria parasites but is absent in mammalians. In this study, we synthesized and evaluated against the chloroquine-resistant P. falciparum FcB1/Colombia strain, a series of FSM analogs, derivatives, and conjugates with other antimalarial agents, such as artemisinin (ART) and aminochloroquinoline (ACQ). The biological evaluation revealed four new compounds with higher antimalarial activity than FSM: two FSM-ACQ derivatives and two FSM-ART conjugates, with 3.5-5.4 and 41.5-23.1 times more potent activities than FSM, respectively.

Artemisinins as Anticancer Drugs: Novel Therapeutic Approaches, Molecular Mechanisms, and Clinical Trials

Artemisinin and its derivatives have shown broad-spectrum antitumor activities in vitro and in vivo. Furthermore, outcomes from a limited number of clinical trials provide encouraging evidence for their excellent antitumor activities. However, some problems such as poor solubility, toxicity and controversial mechanisms of action hamper their use as effective antitumor agents in the clinic. In order to accelerate the use of ARTs in the clinic, researchers have recently developed novel therapeutic approaches including developing novel derivatives, manufacturing novel nano-formulations, and combining ARTs with other drugs for cancer therapy. The related mechanisms of action were explored. This review describes ARTs used to induce non-apoptotic cell death containing oncosis, autophagy, and ferroptosis. Moreover, it highlights the ARTs-caused effects on cancer metabolism, immunosuppression and cancer stem cells and discusses clinical trials of ARTs used to treat cancer. The review provides additional insight into the molecular mechanism of action of ARTs and their considerable clinical potential.

Discovery of fast-acting dual-stage antimalarial agents by profiling pyridylvinylquinoline chemical space via copper catalyzed azide-alkyne cycloadditions

To identity fast-acting, multistage antimalarial agents, a series of pyridylvinylquinoline-triazole analogues have been synthesized via CuAAC. Most of the compounds display significant inhibitory effect on the drug-resistant malarial Dd2 strain at low submicromolar concentrations. Among the tested analogues, compound 60 is the most potent molecule with an EC₅₀ value of 0.04 ± 0.01 μM. Our current study indicates that compound 60 is a fast-acting antimalarial compound and it demonstrates stage specific action at the trophozoite phase in the P. falciparum asexual life cycle. In addition, compound 60 is active against both early and late stage P. falciparum gametocytes. From a mechanistic perspective, compound 60 shows good activity as an inhibitor of β-hematin formation. Collectively, our findings suggest that fast-acting agent 60 targets dual life stages of the malarial parasites and warrant further investigation of pyridylvinylquinoline hybrids as new antimalarials.

The potential of artemisinins as anti-obesity agents via modulating the immune system

Artemisinin and its derivatives are the most effective antimalarial drugs. Besides anti-malarial activity, artemisinin and its derivatives have displayed wide-spectrum bioactivities such as anti-parasite, anti-tumor, and anti-obesity effects. Obesity is an epidemic worldwide which is a big threat to human health, but there are only a few approved anti-obesity drugs in the world. Also, these drugs are efficient to limited patients partly because their safety and efficacy are questioned. Anti-inflammatory therapies may be valuable in obesity treatment since growing evidence shows chronic metabolic inflammation is implicated in metabolic disease pathogenesis. As artemisinin and its derivatives display effective anti-inflammatory and immunoregulatory properties with less toxicity, it provides an insight for novel drug development in obesity therapeutic strategies via immune-regulatory mechanisms. In this review, the potential of artemisinin and its derivatives to treat various metabolic diseases such as obesity and diabetes is discussed.