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Determination of β-artemether and its main metabolite dihydroartemisinin in plasma employing liquid-phase microextraction prior to liquid chromatographic–tandem mass spectrometric analysis. Talanta 2010; 81:941-7. [DOI: 10.1016/j.talanta.2010.01.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 01/15/2010] [Accepted: 01/18/2010] [Indexed: 11/22/2022]
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52
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Biological actions of artemisinin: insights from medicinal chemistry studies. Molecules 2010; 15:1378-97. [PMID: 20335987 PMCID: PMC6257283 DOI: 10.3390/molecules15031378] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 02/23/2010] [Accepted: 03/02/2010] [Indexed: 11/17/2022] Open
Abstract
Artemisinins have become essential antimalarial drugs for increasingly widespread drug-resistant malaria strains. Although tremendous efforts have been devoted to decipher how this class of molecules works, their exact antimalarial mechanism is still an enigma. Several hypotheses have been proposed to explain their actions, including alkylation of heme by carbon-centered free radicals, interference with proteins such as the sarcoplasmic/endoplasmic calcium ATPase (SERCA), as well as damaging of normal mitochondrial functions. Besides artemisinins, other endoperoxides with various backbones have also been synthesized, some of which showed comparable or even higher antimalarial effects. It is noteworthy that among these artemisinin derivatives, some enantiomers displayed similar in vitro malaria killing efficacy. In this article, the proposed mechanisms of action of artemisinins are reviewed in light of medicinal chemistry findings characterized by efficacy-structure studies, with the hope of gaining more insight into how these potent drugs work.
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53
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Azarifar D, Khosravi K, Soleimanei F. Mild and efficient strontium chloride hexahydrate-catalyzed conversion of ketones and aldehydes into corresponding gem-dihydroperoxides by aqueous H2O2. Molecules 2010; 15:1433-41. [PMID: 20335991 PMCID: PMC6257293 DOI: 10.3390/molecules15031433] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 02/11/2010] [Accepted: 03/01/2010] [Indexed: 11/16/2022] Open
Abstract
SrCl2·6H2O has been shown to act as an efficient catalyst for the conversion of aldehydes or ketones into the corresponding gem-dihydroperoxides (DHPs) by treatment with aqueous H2O2 (30%) in acetonitrile. The reactions proceed under mild and neutral conditions at room temperature to afford good to excellent yields of product.
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Affiliation(s)
- Davood Azarifar
- Faculty of Chemistry, Bu-Ali Sina University, 65178 Hamadan, Iran.
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54
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Tada N, Cui L, Okubo H, Miura T, Itoh A. A facile catalyst-free synthesis of gem-dihydroperoxides with aqueous hydrogen peroxide. Chem Commun (Camb) 2010; 46:1772-4. [PMID: 20177645 DOI: 10.1039/b917056a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
gem-Dihydroperoxides were easily obtained from the corresponding carbonyl compounds in high yields through a catalyst-free method with aqueous H(2)O(2) (35%) in 1,2-dimethoxyethane at room temperature.
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Affiliation(s)
- Norihiro Tada
- Gifu Pharmaceutical University, 5-6-1 Mitahora-higashi, Gifu 502-8585, Japan
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55
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Bernat V, Saffon N, Maynadier M, Vial H, André-Barrès C. α-Spiro endoperoxides: synthesis and evaluation of their antimalarial activities. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.07.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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56
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Electron microscopical study to assess the in vitro effects of the synthetic trioxolane OZ78 against the liver fluke, Fasciola hepatica. Parasitology 2009; 136:1325-37. [PMID: 19660154 DOI: 10.1017/s0031182009990643] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Adult Fasciola hepatica were incubated for 48 h in vitro in the synthetic peroxide, OZ78 at a concentration of 100 microg/ml and then prepared for scanning and transmission electron microscopy. There was limited disruption to the external fluke surface, with only slight swelling and blebbing of the interspinal tegument in the midbody and ventral tail regions. By contrast, significant disruption was observed to the ultrastructure of the tegument and subtegumental tissues. There was severe swelling of the basal infolds in the tegumental syncytium and the flooding spread internally to affect the subtegumental tissues. In the tegumental system, there was swelling of the cisternae of granular endoplasmic reticulum and of the mitochondria, with the latter showing signs of breaking down. Autophagic vacuoles and lipid droplets were present and the synthesis of tegumental secretory bodies was much reduced. The gastrodermal cells were severely affected, with swelling and degeneration of the mitochondria and the presence of autophagic vacuoles and lipid droplets. The granular endoplasmic reticulum was swollen and vesiculated and the cells contained few secretory bodies. Both the vitelline and testis follicles showed evidence of extensive cellular disruption and degeneration. This study confirms previous data indicating the potential flukicidal activity of OZ78.
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57
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Abstract
AbstractTriclabendazole (TCBZ) remains the drug of choice for treating infections of the liver fluke,Fasciola hepaticain livestock and has become the main drug used to treat human cases of the disease as well. Cases of resistance in livestock continue to be reported, suggesting that the problem is increasing. In order to address the problem, there is a need for better understanding of drug action. A ‘state-of-play’ review on different aspects of TCBZ activity was published by the present author in 2005. The main purpose of the current review is to assess what progress has been made in the past four years towards understanding the main aspects of drug activity, including drug pharmacokinetics and pharmacodynamics and an understanding of the mechanism(s) of resistance. Also, what advances have been made in identifying alternative compounds and using drug combinations to enhance TCBZ activity. Stemming from a number ofin vivostudies, it has become evident that fluke isolates of differing sensitivity to TCBZ differ in some of their biological parameters, and information on this interesting phenomenon will be presented. An update on the use of TCBZ for human fascioliasis is also given. The review will indicate what progress has been made, but will also highlight areas that remain inadequately understood and require greater research focus.
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58
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Tsubusaki T, Nishino H. Formation of 1,2-dioxolanes using Mn(III)-based reaction of various arylacetylenes with 2,4-pentanedione and related reaction. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.02.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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59
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An evaluation of the efficacy of compound alpha and triclabendazole against two isolates of Fasciola hepatica. Vet Parasitol 2009; 162:75-88. [DOI: 10.1016/j.vetpar.2009.02.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 01/28/2009] [Accepted: 02/04/2009] [Indexed: 11/21/2022]
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60
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Terent’ev AO, Borisov DA, Chernyshev VV, Nikishin GI. Facile and Selective Procedure for the Synthesis of Bridged 1,2,4,5-Tetraoxanes; Strong Acids As Cosolvents and Catalysts for Addition of Hydrogen Peroxide to β-Diketones. J Org Chem 2009; 74:3335-40. [DOI: 10.1021/jo900226b] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander O. Terent’ev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation, Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation, and A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, 31 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Dmitry A. Borisov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation, Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation, and A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, 31 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Vladimir V. Chernyshev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation, Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation, and A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, 31 Leninsky prosp., 119991 Moscow, Russian Federation
| | - Gennady I. Nikishin
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation, Department of Chemistry, Moscow State University, 119992 Moscow, Russian Federation, and A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, 31 Leninsky prosp., 119991 Moscow, Russian Federation
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61
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Terent’ev AO, Platonov MM, Tursina AI, Chernyshev VV, Nikishin GI. Ring Contraction of 1,2,4,5,7,8-Hexaoxa-3-silonanes by Selective Reduction of COOSi Fragments. Synthesis of New Silicon-Containing Rings, 1,3,5,6-Tetraoxa-2-silepanes. J Org Chem 2009; 74:1917-22. [DOI: 10.1021/jo8023957] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander O. Terent’ev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991, Moscow, Russia
| | - Maxim M. Platonov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991, Moscow, Russia
| | - Anna I. Tursina
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991, Moscow, Russia
| | - Vladimir V. Chernyshev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991, Moscow, Russia
| | - Gennady I. Nikishin
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, 119991, Moscow, Russia
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Abstract
The problem of endemic malaria continues unabated globally. Malaria affects 40 % of the global population, causing an estimated annual mortality of 1.5-2.7 million people. The World Health Organization (WHO) estimates that 90 % of these deaths occur in sub-Saharan Africa among infants under the age of five. While a vaccine against malaria continues to be elusive, chemotherapy remains the most viable alternative towards treatment of the disease. During last years, the situation has become urgent in many ways, but mainly because of the development of chloroquine-resistant (CQR) strains of Plasmodium falciparum (Pf). The discovery that artemisinin (ART, 1), an active principle of Artemisia annua L., expresses a significant antimalarial activity, especially against CQR strains, opened new approaches for combating malaria. Since the early 1980s, hundreds of semi-synthetic and synthetic peroxides have been developed and tested for their antimalarial activity, the results of which were extensively reviewed. In addition, in therapeutic practice, there is no reported case of drug resistance to these antimalarial peroxides. This review summarizes recent achievements in the area of peroxide drug development for malaria chemotherapy.
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63
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Singh C, Verma VP, Naikade NK, Singh AS, Hassam M, Puri SK. Novel Bis- and Tris-1,2,4-trioxanes: Synthesis and Antimalarial Activity against Multidrug-Resistant Plasmodium yoelii in Swiss Mice. J Med Chem 2008; 51:7581-92. [DOI: 10.1021/jm801006v] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chandan Singh
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Ved Prakash Verma
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Niraj Krishna Naikade
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Ajit Shankar Singh
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Mohammad Hassam
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Sunil K. Puri
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
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64
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Singh AS, Verma VP, Hassam M, Krishna NN, Puri SK, Singh C. Amino- and Hydroxy-Functionalized 11-Azaartemisinins and Their Derivatives. Org Lett 2008; 10:5461-4. [DOI: 10.1021/ol802238d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ajit Shankar Singh
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Ved Prakash Verma
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Mohammad Hassam
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Naikade Niraj Krishna
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Sunil K. Puri
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
| | - Chandan Singh
- Division of Medicinal and Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India
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65
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Singh C, Pandey S, Kushwaha AK, Puri SK. New functionalized 1,2,4-trioxepanes: Synthesis and antimalarial activity against multi-drug resistant P. yoelii in mice. Bioorg Med Chem Lett 2008; 18:5190-3. [DOI: 10.1016/j.bmcl.2008.08.096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 08/07/2008] [Accepted: 08/26/2008] [Indexed: 10/21/2022]
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66
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Abstract
Higher plants are a source of thousands of natural products, with an almost infinite variety of different structural variations. These molecules often have specific functions and many of them have biological activities which can be of use to humans. They may provide lead compounds for the development of new drugs or they may be indispensable tools in biomedical research.
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Affiliation(s)
- Kurt Hostettmann
- Laboratory of Pharmacognosy and Phytochemistry, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
| | - Andrew Marston
- Laboratory of Pharmacognosy and Phytochemistry, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
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67
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Chen T, Li M, Zhang R, Wang H. Dihydroartemisinin induces apoptosis and sensitizes human ovarian cancer cells to carboplatin therapy. J Cell Mol Med 2008; 13:1358-70. [PMID: 18466355 PMCID: PMC4496149 DOI: 10.1111/j.1582-4934.2008.00360.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The present study was designed to determine the effects of artemisinin (ARS) and its derivatives on human ovarian cancer cells, to evaluate their potential as novel chemotherapeutic agents used alone or in combination with a conventional cancer chemotherapeutic agent, and to investigate their underlying mechanisms of action. Human ovarian cancer cells (A2780 and OVCAR-3), and immortalized non-tumourigenic human ovarian surface epithelial cells (IOSE144), were exposed to four ARS compounds for cytotoxicity testing. The in vitro and in vivo antitumour effects and possible underlying mechanisms of action of dihydroartemisinin (DHA), the most effective compound, were further determined in ovarian cancer cells. ARS compounds exerted potent cytotoxicity to human ovarian carcinoma cells, with minimal effects on non-tumourigenic ovarian surface epithelial (OSE) cells. DHA inhibited ovarian cancer cell growth when administered alone or in combination with carboplatin, presumably through the death receptor- and, mitochondrion-mediated caspase-dependent apoptotic pathway. These effects were also observed in in vivo ovarian A2780 and OVCAR-3 xenograft tumour models. In conclusion, ARS derivatives, particularly DHA, exhibit significant anticancer activity against ovarian cancer cells in vitro and in vivo, with minimal toxicity to non-tumourigenic human OSE cells, indicating that they may be promising therapeutic agents for ovarian cancer, either used alone or in combination with conventional chemotherapy.
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Affiliation(s)
- Tao Chen
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, PR China
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68
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Caner A, Döşkaya M, Değirmenci A, Can H, Baykan S, Uner A, Başdemir G, Zeybek U, Gürüz Y. Comparison of the effects of Artemisia vulgaris and Artemisia absinthium growing in western Anatolia against trichinellosis (Trichinella spiralis) in rats. Exp Parasitol 2008; 119:173-9. [PMID: 18325496 DOI: 10.1016/j.exppara.2008.01.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 01/21/2008] [Accepted: 01/23/2008] [Indexed: 11/26/2022]
Abstract
Trichinellosis often causing diarrhea and more rarely fever, periorbital edema and myositis in human, is commonly treated with benzimidazole derivatives. The Artemisia genus has been found to be effective against a variety of parasites. In the present study, the efficacy against trichinellosis (Trichinella spiralis) of Artemisia vulgaris and Artemisia absinthium was examined for the first time in rats. The results of trichinoscopy and artificial digestion, during the enteral (adult) phase of the illness show that 300 mg/kg doses of methanol extracts of the aerial parts of A. vulgaris and A. absinthium reduced the larval rate by 75.6% and 63.5% in tongue, 53.4% and 37.7% in diaphragm, 67.8% and 46.2% in quadriceps, and 66.7% and 60.5% in biceps-triceps muscles of rats, respectively. Furthermore, during the parenteral (encapsulated larvae) phase, 600 mg/kg doses of A. vulgaris and A. absinthium extracts decreased the larval rate by 66.4% and 59.9% in tongue, 57.4% and 50.0% in diaphragm, 47.6% and 43.7% in quadriceps, 60.2% and 46.4% in biceps-triceps muscles of rats, respectively. Analysis of antibody also showed that A. vulgaris significantly reduced the antibody response (P<0.05) during the enteral and parenteral phases. Thus, the results of the present study revealed that A. vulgaris could be an alternative drug against trichinellosis.
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Affiliation(s)
- Ayşe Caner
- Department of Parasitology, Ege University Medical School, Bornova, Izmir 35100, Turkey
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69
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Singh C, Chaudhary S, Puri SK. Orally active esters of dihydroartemisinin: Synthesis and antimalarial activity against multidrug-resistant Plasmodium yoelii in mice. Bioorg Med Chem Lett 2008; 18:1436-41. [DOI: 10.1016/j.bmcl.2007.12.074] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Revised: 12/25/2007] [Accepted: 12/29/2007] [Indexed: 10/22/2022]
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70
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Terent'ev AO, Platonov MM, Krylov IB, Chernyshev VV, Nikishin GI. Synthesis of 1-hydroperoxy-1′-alkoxyperoxides by the iodine-catalyzed reactions of geminal bishydroperoxides with acetals or enol ethers. Org Biomol Chem 2008; 6:4435-41. [DOI: 10.1039/b809661a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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71
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De novo identification and stability of the artemisinin pharmacophore: Studies of the reductive decomposition of deoxyartemisinins and deoxyarteethers and the implications for the mode of antimalarial action. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.theochem.2007.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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72
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Artemisinin and a series of novel endoperoxide antimalarials exert early effects on digestive vacuole morphology. Antimicrob Agents Chemother 2007; 52:98-109. [PMID: 17938190 DOI: 10.1128/aac.00609-07] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Artermisinin and its derivatives are now the mainstays of antimalarial treatment; however, their mechanism of action is only poorly understood. We report on the synthesis of a novel series of epoxy-endoperoxides that can be prepared in high yields from simple starting materials. Endoperoxides that are disubstituted with alkyl or benzyl side chains show efficient inhibition of the growth of both chloroquine-sensitive and -resistant strains of Plasmodium falciparum. A trans-epoxide with respect to the peroxide linkage increases the activity compared to that of its cis-epoxy counterpart or the parent endoperoxide. The novel endoperoxides do not show a strong interaction with artemisinin. We have compared the mechanism of action of the novel endoperoxides with that of artemisinin. Electron microscopy reveals that the novel endoperoxides cause the early accumulation of endocytic vesicles, while artemisinin causes the disruption of the digestive vacuole membrane. At longer incubation times artemisinin causes extensive loss of organellar structures, while the novel endoperoxides cause myelin body formation as well as the accumulation of endocytic vesicles. An early event following endoperoxide treatment is the redistribution of the pH-sensitive probe LysoSensor Blue from the digestive vacuole to punctate structures. By contrast, neither artemisinin nor the novel endoperoxides caused alterations in the morphology of the endoplasmic reticulum nor showed antagonistic antimalarial activity when they were used with thapsigargin. Analysis of rhodamine 123 uptake by P. falciparum suggests that disruption of the mitochondrial membrane potential occurs as a downstream effect rather than as an initiator of parasite killing. The data suggest that the digestive vacuole is an important initial site of endoperoxide antimalarial activity.
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73
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Singh C, Chaudhary S, Kanchan R, Puri SK. Conversion of antimalarial drug artemisinin to a new series of tricyclic 1,2,4-trioxanes1. Org Lett 2007; 9:4327-9. [PMID: 17877363 DOI: 10.1021/ol701887x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A highly efficient route for the conversion of the antimalarial drug artemisinin to a novel hydroxy-functionalized tricyclic 1,2,4-trioxane 6 is reported. Neither the trioxane 6 nor its derivatives 14-16, all of which lack the hydrolytically unstable acetal-lactone linkage, show antimalarial activity comparable with that of artemisinin.
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Affiliation(s)
- Chandan Singh
- Division of Medicinal & Process Chemistry and Division of Parasitology, Central Drug Research Institute, Lucknow-226001, India.
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74
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Abstract
Widespread parasitic resistance has led to an urgent need for the development and implementation of new drugs for the treatment of Plasmodium falciparum malaria. Artemisinin and its derivatives are becoming increasingly important, used preferably in combination with a second antimalarial agent to increase the efficacy and slow the development of resistance. However, cost, production and pharmacological issues associated with artemisinin derivatives and potential partner drugs are hindering the implementation of combination therapies. This article reviews the molecular basis of the action of, and resistance to, different antimalarials and examines the prospects for the next generation of drugs to combat this potentially lethal human pathogen.
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Affiliation(s)
- Leann Tilley
- Department of Biochemistry, La Trobe University, Melbourne, Victoria, Australia.
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75
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Gale GA, Kirtikara K, Pittayakhajonwut P, Sivichai S, Thebtaranonth Y, Thongpanchang C, Vichai V. In search of cyclooxygenase inhibitors, anti-Mycobacterium tuberculosis and anti-malarial drugs from Thai flora and microbes. Pharmacol Ther 2007; 115:307-51. [PMID: 17692387 DOI: 10.1016/j.pharmthera.2007.03.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2006] [Accepted: 03/12/2007] [Indexed: 02/02/2023]
Abstract
Malaria continues to be a major infectious disease of the developing world and the problem is compounded not only by the emergence of drug resistant strains but also from a lack of a vaccine. The situation for tuberculosis (TB) infection is equally problematic. Once considered a "treatable" disease for which eradication was predicted, TB has re-emerged as highly lethal, multi-drug resistant strains after the outbreak of AIDS. Worldwide, the disease causes millions of deaths annually. Similarly, treatments for chronic inflammatory diseases such as arthritis have been impeded due to the potentially lethal side effects of the new and widely prescribed non-steroidal anti-inflammatory compounds. Thais have utilized bioresources from plants and some microorganisms for medicine for thousands of years. Because of the need for new drugs to fight malaria and TB, with radically different chemical structures and mode of actions other than existing drugs, efforts have been directed towards searching for new drugs from bioresources. This is also true for anti-inflammatories. Although Thailand is considered species-rich, only a small number of potential bioresources has been investigated. This article briefly describes the pathogenesis of 2 infectious diseases, malaria and TB, and modern medicines employed in chemotherapy. Diversities of Thai flora and fungi and their chemical constituents with antagonistic properties against these 2 diseases are described in detail. Similarly, anti-inflammatory compounds, mostly cyclooxygenase (COX) inhibitors, are also described herein to demonstrate the potential of Thai bioresources to provide a wide array of compounds for treatment of diseases of a different nature.
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Affiliation(s)
- George A Gale
- King Mongkut's University of Technology Thonburi, School of Bioresources and Technology, Conservation Ecology Program, 83 Moo 8, Thakham, Bangkhuntien, Bangkok, Thailand
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76
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Singh C, Sharma U, Saxena G, Puri SK. Orally active antimalarials: Synthesis and bioevaluation of a new series of steroid-based 1,2,4-trioxanes against multi-drug resistant malaria in mice. Bioorg Med Chem Lett 2007; 17:4097-101. [PMID: 17548195 DOI: 10.1016/j.bmcl.2007.05.055] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 05/09/2007] [Accepted: 05/18/2007] [Indexed: 10/23/2022]
Abstract
A new series of steroid-based 1,2,4-trioxanes 7a-f, 8a-f and 9b-e have been synthesized and evaluated for their antimalarial activity against multi-drug resistant Plasmodium yoelii in Swiss mice by oral route. The biological activity shows a strong dependence on the size and the nature of the steroidal side chain. Pregnane-based trioxanes 8a-f show better activity profile than trioxanes 7a-f and 9b-e, derived from cholesterol and tigogenine, respectively.
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Affiliation(s)
- Chandan Singh
- Division of Medicinal and Process Chemistry, Central Drug Research Institute, Lucknow 226001, India.
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77
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Zmitek K, Zupan M, Stavber S, Iskra J. The Effect of Iodine on the Peroxidation of Carbonyl Compounds. J Org Chem 2007; 72:6534-40. [PMID: 17661522 DOI: 10.1021/jo0708745] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peroxidation of ketones and aldehydes with iodine as a catalyst was studied. Ketones reacted with 30% aq hydrogen peroxide in the presence of 10 mol % of iodine to yield gem-dihydroperoxides in acetonitrile and hydroperoxyketals in methanol. The yield of hydroperoxidation of various cyclic ketones was 60-98%, including androstane-3,17-dione, while acyclic ketones were converted with a similar efficiency. Aromatic aldehydes were also converted to gem-dihydroperoxides with hydrogen peroxide and iodine as catalyst in acetonitrile and to hydroperoxyacetal in methanol, while the reactivity of aliphatic ones remained the same as in noncatalyzed reactions. tert-Butylhydroperoxide reacted in a similar manner, giving the corresponding perether derivatives. A study was also made of the relative kinetics of dihydroperoxidation from which the Hammet equation gave a reaction constant (rho) of -2.76, indicating the strong positive charge development in the transition state and the important role of rehybridization in the conversion of hydroperoxyhemiketal to gem-dihydroperoxide. In acetonitrile, the iodine catalyst is apparently able to discriminate between the elimination of a hydroxy, methoxy, and hydroperoxy group and addition of water, methanol, and H2O2 to a carbonyl group.
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Affiliation(s)
- Katja Zmitek
- Laboratory of Organic and Bioorganic Chemistry, JoZef Stefan Institute, Jamova 39, Ljubljana, Slovenia
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78
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Schlitzer M. Malaria Chemotherapeutics Part I: History of Antimalarial Drug Development, Currently Used Therapeutics, and Drugs in Clinical Development. ChemMedChem 2007; 2:944-86. [PMID: 17530725 DOI: 10.1002/cmdc.200600240] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Since ancient times, humankind has had to struggle against the persistent onslaught of pathogenic microorganisms. Nowadays, malaria is still the most important infectious disease worldwide. Considerable success in gaining control over malaria was achieved in the 1950s and 60s through landscaping measures, vector control with the insecticide DDT, and the widespread administration of chloroquine, the most important antimalarial agent ever. In the late 1960s, the final victory over malaria was believed to be within reach. However, the parasites could not be eradicated because they developed resistance against the most widely used and affordable drugs of that time. Today, cases of malaria infections are on the rise and have reached record numbers. This review gives a short description of the malaria disease, briefly addresses the history of antimalarial drug development, and focuses on drugs currently available for malaria therapy. The present knowledge regarding their mode of action and the mechanisms of resistance are explained, as are the attempts made by numerous research groups to overcome the resistance problem within classes of existing drugs and in some novel classes. Finally, this review covers all classes of antimalarials for which at least one drug candidate is in clinical development. Antimalarial agents that are solely in early development stages will be addressed in a separate review.
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Affiliation(s)
- Martin Schlitzer
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marbacher Weg 6, 35032 Marburg, Germany.
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79
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Žmitek K, Zupan M, Iskra J. α-Substituted organic peroxides: synthetic strategies for a biologically important class of gem-dihydroperoxide and perketal derivatives. Org Biomol Chem 2007; 5:3895-908. [DOI: 10.1039/b711647k] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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80
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Zmitek K, Stavber S, Zupan M, Bonnet-Delpon D, Charneau S, Grellier P, Iskra J. Synthesis and antimalarial activities of novel 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes. Bioorg Med Chem 2006; 14:7790-5. [PMID: 16919459 DOI: 10.1016/j.bmc.2006.07.069] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 07/27/2006] [Accepted: 07/31/2006] [Indexed: 11/18/2022]
Abstract
The oxidative system H2O2/fluorinated alcohol (TFE, HFIP) was used for direct acid- and MeReO3-catalyzed synthesis of 1,2,4,5-tetraoxanes from cyclic (C6, C7, and C12) and acyclic ketones. The influence of ring size and alkyl chain length were studied and antimalarial activities of synthetic 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes were determined. Variations in their antimalarial activities were significant, although they share similar electrochemical properties of the peroxide bond.
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Affiliation(s)
- Katja Zmitek
- Laboratory of Organic and Bioorganic Chemistry, Jozef Stefan Institute and Faculty of Chemistry and Chemical Technology of University of Ljubljana, Jamova 39, 1000 Ljubljana, Slovenia
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81
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Singlet oxygen addition to chiral allylic alcohols and subsequent peroxyacetalization with β-naphthaldehyde: synthesis of diastereomerically pure 3-β-naphthyl-substituted 1,2,4-trioxanes. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.05.093] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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82
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O'Neill PM. The therapeutic potential of semi-synthetic artemisinin and synthetic endoperoxide antimalarial agents. Expert Opin Investig Drugs 2006; 14:1117-28. [PMID: 16144496 DOI: 10.1517/13543784.14.9.1117] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Artemisinin derivatives such as artesunate, dihydroartemisinin and artemether are playing an increasing role in the treatment of drug-resistant malaria. They are the most potent antimalarials available, rapidly killing all asexual stages of the parasite Plasmodium falciparum. This review highlights the recent developments in the area of improved second-generation semi-synthetic artemisinin derivatives and fully synthetic antimalarial endoperoxide drugs. In pursuit of synthetic analogues of the artemisinins, one of the major challenges for chemists in this area has been the non-trivial development of techniques for the introduction of the peroxide bridge into candidate drugs. Although chemical research has enabled chemists to incorporate the endoperoxide 'warhead' into synthetic analogues of artemisinin, significant drawbacks with many candidates have included comparatively poor antimalarial activity, non-stereoselective syntheses and chemical approaches that are not readily amenable to scale up. However, very recent progress with synthetic 1,2,4-trioxolanes provides a new benchmark for future medicinal chemistry efforts in this area.
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Affiliation(s)
- Paul M O'Neill
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK.
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83
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Žmitek K, Stavber S, Zupan M, Bonnet-Delpon D, Iskra J. Fluorinated alcohol directed formation of dispiro-1,2,4,5-tetraoxanes by hydrogen peroxide under acid conditions. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.11.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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84
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Singh C, Kanchan R, Srivastava D, Puri SK. 8-(1-Naphthalen-2-yl-vinyl)-6,7,10-trioxaspiro (4.5) decane, a new 1,2,4-trioxane effective against rodent and simian malaria. Bioorg Med Chem Lett 2006; 16:584-6. [PMID: 16275088 DOI: 10.1016/j.bmcl.2005.10.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 09/28/2005] [Accepted: 10/15/2005] [Indexed: 10/25/2022]
Abstract
A new series of 8-(1-aryl-vinyl)-6,7,10-trioxaspiro [4.5] decanes 7a-e and 3-(1-aryl-vinyl)-l,2,5-trioxaspiro [5.5] undecanes 8a-e have been prepared and screened against multi-drug resistant Plasmodium yoelii in mice. 8-(1-Naphthalen-2-yl-vinyl)-6,7,10-trioxaspiro [4.5] decane 7b, the most active trioxane of the series, has also shown promising activity against Plasmodium cynomolgi in rhesus monkeys.
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Affiliation(s)
- Chandan Singh
- Division of Medicinal and Process Chemistry, Central Drug Research Institute, Lucknow 226001, India.
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85
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Parshikov IA, Miriyala B, Muraleedharan KM, Avery MA, Williamson JS. Microbial transformation of artemisinin to 5-hydroxyartemisinin by Eurotium amstelodami and Aspergillus niger. J Ind Microbiol Biotechnol 2005; 33:349-52. [PMID: 16389544 DOI: 10.1007/s10295-005-0071-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Accepted: 12/13/2005] [Indexed: 10/25/2022]
Abstract
Transformation of the anti-malarial drug artemisinin by the fungi Eurotium amstelodami and Aspergillus niger were investigated. Cultures were grown in sucrose/malt broth with artemisinin for 14 days and extracted with ethyl acetate. Extracts were characterized by liquid chromatography. Two metabolites from each fungal extract were isolated and identified using mass spectrometry and nuclear magnetic resonance. 5Beta-hydroxyartemisinin and 7beta-hydroxyartemisinin were isolated in 63 and 32% yields, respectively, from the extract of E. amstelodami, and 80 and 19%, respectively, from the extract of A. niger.
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Affiliation(s)
- Igor A Parshikov
- Department of Medicinal Chemistry, University of Mississippi, University, MS 38677, USA
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86
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Bray PG, Ward SA, O'Neill PM. Quinolines and artemisinin: chemistry, biology and history. Curr Top Microbiol Immunol 2005; 295:3-38. [PMID: 16265885 DOI: 10.1007/3-540-29088-5_1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Plasmodium falciparum is the most important parasitic pathogen in humans, causing hundreds of millions of malaria infections and millions of deaths each year. At present there is no effective malaria vaccine and malaria therapy is totally reliant on the use of drugs. New drugs are urgently needed because of the rapid evolution and spread of parasite resistance to the current therapies. Drug resistance is one of the major factors contributing to the resurgence of malaria, especially resistance to the most affordable drugs such as chloroquine. We need to fully understand the antimalarial mode of action of the existing drugs and the way that the parasite becomes resistant to them in order to design and develop the new therapies that are so urgently needed. In respect of the quinolines and artemisinins, great progress has been made recently in studying the mechanisms of drug action and drug resistance in malaria parasites. Here we summarize from a historical, biological and chemical, perspective the exciting new advances that have been made in the study of these important antimalarial drugs.
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Affiliation(s)
- P G Bray
- Division of Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
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87
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Arav-Boger R, Shapiro TA. MOLECULAR MECHANISMS OF RESISTANCE IN ANTIMALARIAL CHEMOTHERAPY: The Unmet Challenge. Annu Rev Pharmacol Toxicol 2005; 45:565-85. [PMID: 15822189 DOI: 10.1146/annurev.pharmtox.45.120403.095946] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
▪ Abstract The enormous public health problem posed by malaria has been substantially worsened in recent years by the emergence and worldwide spread of drug-resistant parasites. The utility of two major therapies, chloroquine and the synergistic combination of pyrimethamine/sulfadoxine, is now seriously compromised. Although several genetic mechanisms have been described, the major source of drug resistance appears to be point mutations in protein target genes. Clinically significant resistance to these agents requires the accumulation of multiple mutations, which genetic studies of parasite populations suggest arise focally and sweep through the population. Efforts to circumvent resistance range from the use of combination therapy with existing agents to laboratory studies directed toward discovering novel targets and therapies. The prevention and management of drug resistance are among the most important practical problems of tropical medicine and public health. Leonard J. Bruce-Chwatt, 1972
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Affiliation(s)
- Ravit Arav-Boger
- Division of Infectious Diseases, Department of Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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88
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Chemistry of 1,2,4-trioxanes relevant to their mechanism of action. Part 1: Reaction with Fe(II) salts. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.05.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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89
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Waters NC, Dow GS, Kozar MP. Antimalarial compound identification and design: advances in the patent literature, 2000 – 2003. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.14.8.1125] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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90
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Photooxygenation of 3-aryl-2-cyclohexenols: synthesis of a new series of antimalarial 1,2,4-trioxanes. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2004.11.078] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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91
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Structure-activity relationship study of steroidal 1,2,4,5-tetraoxane animalarials using computational procedures. JOURNAL OF THE SERBIAN CHEMICAL SOCIETY 2005. [DOI: 10.2298/jsc0503329b] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A three-dimensional QSAR pharmacophore model for antimalarial activity of steroidal 1,2,4,5-tetraoxanes was developed from a set of 17 substituted antimalarial derivatives out of 27 analogues that exhibited remarkable in vitro activity (below 100 ng/mL) against sensitive and multidrug-resistant Plasmodium falciparum malaria. The pharmacophore, which contains two hydrogen bond acceptors (lipid) and one hydrophobic (aliphatic) feature, was found to map well onto the potent analogues and many other well-known antimalarial trioxane drugs including artemisinin, arteether, artesunic acid, and tetraoxanes. The presence of at least one hydrogen bond acceptor in the trioxane or the tetraoxane moiety appears to be necessary for potent activity of this class of compounds. Docking calculations of some of these compounds with heme are consistent with the above observation as the proximity of the heme iron to the oxygen atom of the trioxane or the tetraoxane moiety favors potent activity of the compounds. Electron transfer from the oxygen of trioxane or the tetraoxane appears to be crucial for mechanism of action of the compounds. This information together with the pharmacophore should enable search for new peroxide containing antimalarial candidates from databases and custom designed synthesis of more efficacious and safer analogues.
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92
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Tokuyasu T, Kunikawa S, McCullough KJ, Masuyama A, Nojima M. Synthesis of Cyclic Peroxides by Chemo- and Regioselective Peroxidation of Dienes with Co(II)/O2/Et3SiH. J Org Chem 2004; 70:251-60. [PMID: 15624930 DOI: 10.1021/jo048359j] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the competitive peroxidation of mixtures of two alkenes with Co(II)/O(2)/Et(3)SiH, it was found that the relative reactivities of the alkene substrates are influenced by three major factors:. (1) relative stability of the intermediate carbon-centered radical formed by the reaction of the alkene with HCo(III) complex, (2) steric effects around the C=C double bond, and (3) electronic factors associated with the C=C double bond. Consistent with results from simple alkenes, the chemo- and regioselective peroxidation of dienes was also realized. Depending on the diene structure, the product included not only the expected acyclic unsaturated triethylsilyl peroxides but also 1,2-dioxolane and 1,2-dioxane derivatives via intramolecular cyclization of the unsaturated peroxy radical intermediates.
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Affiliation(s)
- Takahiro Tokuyasu
- Department of Materials Chemistry & Frontier Research Center, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
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93
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94
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Singh C, Gupta N, Puri SK. Synthesis of new 6-alkylvinyl/arylalkylvinyl substituted 1,2,4-trioxanes active against multidrug-resistant malaria in mice. Bioorg Med Chem 2004; 12:5553-62. [PMID: 15465332 DOI: 10.1016/j.bmc.2004.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Revised: 08/05/2004] [Accepted: 08/06/2004] [Indexed: 11/20/2022]
Abstract
3-Alkyl/arylalkyl substituted 2-butenols 9, 10, 23a-d undergo regiospecific photooxygenation to furnish beta-hydroxyhydroperoxides 11, 12, 24a-d, respectively, in reasonable yields. Acid catalyzed condensation of 11, 12, 24a-d with various ketones furnish new 1,2,4-trioxanes 13-18, 25a-d, 26a-d, 27a-d in good yields. Several of these trioxanes show promising antimalarial activity against multidrug-resistant Plasmodium yoelii in mice by oral and intramuscular routes.
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Affiliation(s)
- Chandan Singh
- Division of Medicinal & Process Chemistry, Central Drug Research Institute, Lucknow 226001, India.
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95
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96
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Efferth T, Oesch F. Oxidative stress response of tumor cells: microarray-based comparison between artemisinins and anthracyclines. Biochem Pharmacol 2004; 68:3-10. [PMID: 15183112 DOI: 10.1016/j.bcp.2004.03.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Accepted: 03/04/2004] [Indexed: 10/26/2022]
Abstract
The antimalarial artemisinins also reveal profound cytotoxic activity against tumor cells. Artemisinins harbor an endoperoxide bridge whose cleavage results in the generation of reactive oxygen species (ROS) and/or artemisinin carbon-centered free radicals. Established cancer drugs such as anthracyclines also form ROS and free radicals that are responsible for the cardiotoxicity of anthracyclines. In contrast, artemisinins do not reveal cardiotoxicity. In the present investigation, we compared the cytotoxic activities of different artemisinins (artemisinin, artesunate, arteether, artemether, artemisitene, dihydroartemisinylester stereoisomers) in 60 cell lines of the National Cancer Institute (NCI), USA, with those of anthracyclines (doxorubicin, daunorubicin, 4'-epirubicin, idarubicin, deoxydoxorubicin, trifluoroacetyl-doxorubicin-14-valerate). The inhibition concentration 50% (IC(50)) values of artemisinins and anthracyclines were correlated with the mRNA expression of 170 genes involved in oxygen stress response and metabolism as recently determined by microarray analysis and deposited in the NCI database (http://dtp.nci.nih.gov). The genes whose expression was significantly linked to cellular drug response in Kendall's tau tests were subjected to hierarchical cluster analysis and cluster image mapping. Mathematical correction for false-positive correlations was done by a false discovery rate algorithm. One cluster contained predominantly genes with a relationship to artemisinins and another one genes with a relationship to anthracyclines. In a third cluster, genes correlating to both drug classes were assembled. This indicates that different sets of genes involved in oxidative stress response and metabolism may contribute to the cytotoxic and differing toxic side effects of these drug classes.
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Affiliation(s)
- Thomas Efferth
- Center for Molecular Biology, University of Heidelberg, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
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97
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O'Neill PM, Posner GH. A Medicinal Chemistry Perspective on Artemisinin and Related Endoperoxides. J Med Chem 2004; 47:2945-64. [PMID: 15163175 DOI: 10.1021/jm030571c] [Citation(s) in RCA: 413] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul M O'Neill
- Department of Chemistry, The Robert Robinson Laboratories, University of Liverpool, Liverpool L69 7ZD, U.K.
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98
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Posner GH, O'Neill PM. Knowledge of the proposed chemical mechanism of action and cytochrome p450 metabolism of antimalarial trioxanes like artemisinin allows rational design of new antimalarial peroxides. Acc Chem Res 2004; 37:397-404. [PMID: 15196049 DOI: 10.1021/ar020227u] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Evidence is reviewed elucidating the mechanism of iron-induced triggering of antimalarial trioxanes. As prodrugs, trioxanes undergo homolytic, inner-sphere, reductive cleavage by ferrous iron to form sequentially oxy radicals, carbon radicals, high-valent iron-oxo species, epoxides, aldehydes, and dicarbonyl compounds. One or more of these reactive intermediates and neutral alkylating agents likely kill the malaria parasites. Several new, orally active antimalarial peroxides have been designed rationally based on this fundamental mechanistic paradigm. Incorporating metabolism-blocking substituents also provides some new, potent, semi-synthetic artemisinin derivatives.
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Affiliation(s)
- Gary H Posner
- Department of Chemistry, The Johns Hopkins University, Baltimore, MD 21218, USA.
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99
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Cos P, Maes L, Vanden Berghe D, Hermans N, Pieters L, Vlietinck A. Plant substances as anti-HIV agents selected according to their putative mechanism of action. JOURNAL OF NATURAL PRODUCTS 2004; 67:284-293. [PMID: 14987070 DOI: 10.1021/np034016p] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Despite the continuous advances made in antiretroviral combination therapy, AIDS has become the leading cause of death in Africa and the fourth worldwide. Today, many research groups are exploring the biodiversity of the plant kingdom to find new and better anti-HIV drugs with novel mechanisms of action. In this review, plant substances showing a promising anti-HIV activity are discussed according to the viral targets with which they interact. Most of these compounds, however, interfere with early steps in the HIV replication, such as the virus entry steps and the viral enzymes reverse transcriptase and integrase, whereas until now almost no plant compounds have been found to interact with the many other viral targets. Since some plant substances are known to modulate several cellular factors, such as NF-kappa B and TNF-alpha, which are also involved in the replication of HIV, their role as potential anti-HIV products is also discussed. In conclusion, several plant-derived antiviral agents are good candidates to be further studied for their potential in the systemic therapy and/or prophylaxis of HIV infections, most probably in combination with other anti-HIV drugs.
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Affiliation(s)
- Paul Cos
- Laboratory of Pharmaceutical Microbiology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
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100
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Becker K, Tilley L, Vennerstrom JL, Roberts D, Rogerson S, Ginsburg H. Oxidative stress in malaria parasite-infected erythrocytes: host–parasite interactions. Int J Parasitol 2004; 34:163-89. [PMID: 15037104 DOI: 10.1016/j.ijpara.2003.09.011] [Citation(s) in RCA: 420] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Revised: 09/18/2003] [Accepted: 09/18/2003] [Indexed: 01/09/2023]
Abstract
Experimenta naturae, like the glucose-6-phosphate dehydrogenase deficiency, indicate that malaria parasites are highly susceptible to alterations in the redox equilibrium. This offers a great potential for the development of urgently required novel chemotherapeutic strategies. However, the relationship between the redox status of malarial parasites and that of their host is complex. In this review article we summarise the presently available knowledge on sources and detoxification pathways of reactive oxygen species in malaria parasite-infected red cells, on clinical aspects of redox metabolism and redox-related mechanisms of drug action as well as future prospects for drug development. As delineated below, alterations in redox status contribute to disease manifestation including sequestration, cerebral pathology, anaemia, respiratory distress, and placental malaria. Studying haemoglobinopathies, like thalassemias and sickle cell disease, and other red cell defects that provide protection against malaria allows insights into this fine balance of redox interactions. The host immune response to malaria involves phagocytosis as well as the production of nitric oxide and oxygen radicals that form part of the host defence system and also contribute to the pathology of the disease. Haemoglobin degradation by the malarial parasite produces the redox active by-products, free haem and H(2)O(2), conferring oxidative insult on the host cell. However, the parasite also supplies antioxidant moieties to the host and possesses an efficient enzymatic antioxidant defence system including glutathione- and thioredoxin-dependent proteins. Mechanistic and structural work on these enzymes might provide a basis for targeting the parasite. Indeed, a number of currently used drugs, especially the endoperoxide antimalarials, appear to act by increasing oxidant stress, and novel drugs such as peroxidic compounds and anthroquinones are being developed.
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Affiliation(s)
- Katja Becker
- Interdisciplinary Research Center, Heinrich-Buff-Ring 26-32, Justus-Liebig University, D-35392 Giessen, Germany.
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