Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold

• Henry S. T. Smith,
• Ben Giuliani,
• Kanchana Wijesekera,
• Kah Yean Lum,
• Sandra Duffy,
• Aaron Lock,
• Jonathan M. White,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90

• Plasmodium falciparum 3D7 strain. The tertiary alkylamine products 10–14 displayed antimalarial activity with IC50 values ranging from 9.90 to 23.30 µM against P. falciparum 3D7, with compounds 10–12 demonstrating no toxicity at 80 µM against the human embryonic kidney cell line HEK293. Keywords: amine

• -position (tele-substituted; Figure 1), distant from the halogen leaving group at position 5 [10]. A plausible reaction mechanism was proposed by Korsik et al. [10]. The antimalarial activity of series 4 triazolopyrazine scaffolds is generally reduced by substitution of an amine functionality at the 8

• -chlorophenyl)-[1,2,4]triazolo[4,3-a]pyrazine were synthesised, purified (≥95% purity, determined by 1H and 13C NMR and HPLC–MS analysis) and assayed for in vitro antimalarial activity. Results and Discussion Synthesis of aminated triazolopyrazine analogues The amination of 5-chloro-3-(4-chlorophenyl)-[1,2,4

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space

• Carlos Nieto,
• Alejandro Manchado,
• Ángel García-González,
• David Díez and
• Narciso M. Garrido

Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163

• against chloroquine-sensitive and resistant Plasmodium falciparium strains in mice were reported by Jain and co-workers [65]. Initially, these authors developed simple halohistidine derivatives as first generation analogues showing successful in vitro antimalarial activity. Prompted by these findings, a

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• ). Spiro tetraoxanes were tested for their antimalarial activity. From the biological results, it was observed that compounds with an amide moiety were more active compared to those possessing an ester or a carboxylic group. It was observed that tetraoxanes with a primary amide were more active towards

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• and Dd2 strains) and the cytotoxicity against a human embryonic kidney (HEK293) cell line were tested. Some of the compounds demonstrated moderate antimalarial activity with IC50 values ranging from 0.2 to >80 µM; none of the compounds displayed any cytotoxicity against HEK293 cells at 80 µM

• . Antimalarial activity was significantly reduced when C-8 of the triazolopyrazine scaffold was substituted with CF3 and CF2H moieties, whereas incorporation of a CF2Me group at the same position completely abolished antiplasmodial effects. Keywords: antimalarial; characterisation; DiversinateTM; fluorine

• triazolopyrazines were all evaluated in vitro for antimalarial activity and cytotoxicity. Results and Discussion Previous structure–activity relationship (SAR) studies reported that any substitution at the C8 position of Series 4 triazolopyrazines can lower the potency for P. falciparum [14][15][16]. However, a

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• antitumor, antituberculosis and antimalarial activities [2][3][4][5][6]. Among these structurally intriguing natural products, aberrarone (1) shows antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum (IC50 = 10 μg/mL) [7]. Structurally, aberrarone possesses an unusual

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• ][10]. In addition, these 2-oxopyrroles are structural subunits of various bioactive natural compounds and synthetic drugs. For example, codinaeopsin has been isolated from a fungal extract of a tree called Vochysia guatemalensis which shows antimalarial activity [11]. Pyrrocidine A was isolated from

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• , natural and (semi)synthetic endoperoxides with wide structural diversity show antimalarial activity against Plasmodium falciparum malaria. In this case, the reductive activation of the endoperoxide ring with the homolytic cleavage of the O–O bond leads to the generation of carbon-centered free radicals

• that play important roles in antimalarial activity by damaging membranes, inhibiting nucleic acid and protein syntheses, and so on [8][9]. The best studied endoperoxide-containing compound is probably prostaglandin H2 (PGH2), the common precursor of biologically active prostanoids [10][11][12

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

• Viktor A. Zapol’skii,
• Isabell Berneburg,
• Ursula Bilitewski,
• Melissa Dillenberger,
• Katja Becker,
• Stefan Jungwirth,
• Aditya Shekhar,
• Bastian Krueger and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54

• cycle from 3-methyl-2-(2,3,3-trichloro-1-nitroallylidene)oxazolidine (6) is also described. In addition, the antimalarial activity of the synthesized compounds has been evaluated in vitro against the protozoan malaria parasite Plasmodium falciparum. Notably, the 7-chloro-4-(5-(dichloromethyl)-4-nitro-3

• ± 0.04 µM (100 ng/mL, 200 nM), respectively. Two compounds (3b and 10d) have also been tested for anti-SARS-CoV-2, antibacterial, and cytotoxic activity. Keywords: antimalarial activity; anti-SARS-CoV-2 activity; chloroquine; 2-nitroperchlorobutadiene; nucleophilic vinylic substitution; 1H-pyrazoles

• already been described in the literature [15][16][17][18]. The antimalarial activity of chloroquinolinyl-pyrazoles, synthesized from the reaction of 1,1,1-trifluoro-4-methoxy-3-alken-2-ones with 4-hydrazinyl-7-chloroquinoline, has been evaluated in vitro against a chloroquine-resistant Plasmodium

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• have a relatively simple structure and therefore make an attractive target for further medicinal chemistry studies. To enable these new SAR studies, we need to develop an efficient synthetic method to provide sufficient materials firstly. Hoshinoamide A shows a better antimalarial activity and less

• hoshinoamide A and other highly methylated polypeptide analogues. Our strategy was also helpful to further study its antimalarial activity. Structure-and-activity and functional studies with the fluorescent-labeled analogs are currently under investigation in our lab. Experimental General experimental

Synthetic accesses to biguanide compounds

• Oleksandr Grytsai,
• Cyril Ronco and
• Rachid Benhida

Beilstein J. Org. Chem. 2021, 17, 1001–1040, doi:10.3762/bjoc.17.82

Anthelmintic drug discovery: target identification, screening methods and the role of open science

• Frederick A. Partridge,
• Ruth Forman,
• Carole J. R. Bataille,
• Graham M. Wynne,
• Marina Nick,
• Angela J. Russell,
• Kathryn J. Else and
• David B. Sattelle

Beilstein J. Org. Chem. 2020, 16, 1203–1224, doi:10.3762/bjoc.16.105

• to radically open up the drug development process, with the goal of increasing the efficiency, reducing the cost of research duplication, reducing the hoarding of data and creating collaborative communities [174]. This approach has been applied to the discovery of compounds with antimalarial activity

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

• Gerardo M. Ojeda,
• Prabhat Ranjan,
• Pavel Fedoseev,
• Lisandra Amable,
• Upendra K. Sharma,
• Daniel G. Rivera and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

• variety of pharmacological and antimicrobial properties [5][6], including analgesic, antihypertensive, anti-inflammatory, anticancer, antifungal and antimalarial activity (Figure 1). A key feature of the tetrazole ring is its bioisosteric character with the carboxylic acid and amide functional groups

Doebner-type pyrazolopyridine carboxylic acids in an Ugi four-component reaction

• Maryna V. Murlykina,
• Oleksandr V. Kolomiets,
• Maryna M. Kornet,
• Yana I. Sakhno,
• Sergey M. Desenko,
• Victoriya V. Dyakonenko,
• Svetlana V. Shishkina,
• Oleksandr A. Brazhko,
• Vladimir I. Musatov,
• Alexander V. Tsygankov,
• Erik V. Van der Eycken and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2019, 15, 1281–1288, doi:10.3762/bjoc.15.126

• discovery. The target products containing a heterocyclic core bound to a peptide-like chain also showed a broad spectrum of biological activity: β-secretase (BACE1) inhibitory activity [15]; inducing apoptosis in colorectal cancer cells [16]; antimalarial activity against a chloroquine (CQ) non-resistant

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• , that shows antimalarial activity [40] and satavaptan, a selective V2-receptor antagonist that is useful for the treatment of cirrhosis (Figure 5) [41][42]. Additionally, methisazone is a 2-oxindole derivative that has been used as antiviral drug, especially for the prophylactic treatment of small-pox

Synthesis and biological investigation of (+)-3-hydroxymethylartemisinin

• Toni Smeilus,
• Farnoush Mousavizadeh,
• Johannes Krieger,
• Xingzhao Tu,
• Marcel Kaiser and
• Athanassios Giannis

Beilstein J. Org. Chem. 2019, 15, 567–570, doi:10.3762/bjoc.15.51

• -hydroxymethyl-9-epi-artemisinin (18), starting from the known and readily available chiral aldehyde 3 and alkyne 4. Subsequently, the synthesized compounds have been evaluated for their antimalarial activity against the drug-sensitive P. falciparum NF54 strain. All of them were inactive. In addition, they did

• , whereas the desired (+)-3-hydroxymethylartemisinin (2) was produced from 17 in two steps including epimerization and cleavage of the TES group in excellent yield (Scheme 3). Finally, we evaluated the antimalarial activity of (+)-3-hydroxymethylartemisinin (2) as well as of the derivatives 16 and 18

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• . Suckling et al. designed a set of 31 Strathclyde minor groove binders (S-MGBs), derived from distamycin, by varying the head groups (amidine, amide, or alkene), heterocyclic building blocks and their alkyl substituents and the basicity of the C-terminal tail group in order to investigate their antimalarial

• activity against a chloroquine sensitive (3D7) and resistant (Dd2) strain of Plasmodium falciparum [100]. Conjugates with an alkene link between the two N-terminal building blocks and a C-alkylthiazole moiety appeared to the most active among others with IC50 values in the range of 30–500 nM. The same

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• , it was essential to have a phenyl as a substituent in order to get good yields. A radical mechanism was proposed but the role of oxygen was not discussed. Aminoquinoline derivatives are found in naturally occurring and synthetic bioactive compounds, most notable for their antimalarial activity. So

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

Synthesis of the furo[2,3-b]chromene ring system of hyperaspindols A and B

• Danielle L. Paterson and
• David Barker

Beilstein J. Org. Chem. 2015, 11, 265–270, doi:10.3762/bjoc.11.29

• ]chromenes. Compound which contain this motif, such as albanol A and australisine A, display potent bioactive properties including hypotensive, anticancer, antimicrobial and antimalarial activity [10][11][12]. The unique ring system found in the hyperaspidinols combined with the potent biological activities

(2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-Mono(di,tri)fluoromethylcyclopropyl]alanines and their incorporation into hormaomycin analogues

• Armin de Meijere,
• Sergei I. Kozhushkov,
• Dmitrii S. Yufit,
• Christian Grosse,
• Marcel Kaiser and
• Vitaly A. Raev

Beilstein J. Org. Chem. 2014, 10, 2844–2857, doi:10.3762/bjoc.10.302

• production of various streptomycetes including the producing strain itself, and an exceptionally selective inhibitory effect on coryneform bacteria [3][4], an interesting antimalarial activity was discovered [13]. It was this property that led us to consider the synthesis of even more analogues of 1. Bearing

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• considerable role. In medicinal chemistry of peroxides, artemisinin a natural peroxide exhibiting high antimalarial activity, is the most important drug in use for approximately 30 years. Artemisinin was isolated in 1971 from leaves of annual wormwood (Artemesia annua) [49][50][51]; the 1,2,4-trioxane ring V

• pharmacophore was synthesized in two steps by the oxidation of alcohol 156 with H5IO6/RuCl3 followed by amidation of the acid 157 (Scheme 39) [88]. It was shown that compound 158 exhibits antimalarial activity comparable with that of artemisinin [88]. Plakinic acids belong to a large family of natural products

• , neither sodium hydride nor sodium salt 183 cleave the ozonide ring to a substantial degree. The resulting 1,2,4-trioxolanes 188 and 189 exhibit high in vitro antimalarial activity comparable with that of artemisinin and in vivo even higher activity than that of artemisinin [93]. Aminoquinoline-containing

Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues

• Xu-Wen Li,
• Jennifer Herrmann,
• Yi Zang,
• Philippe Grellier,
• Soizic Prado,
• Rolf Müller and
• Bastien Nay

Beilstein J. Org. Chem. 2013, 9, 1551–1558, doi:10.3762/bjoc.9.176

• at an IC50 around 20 ng/mL (i.e., aurachins B, C and E, whereas aurachin D was 100- to 200-fold less active) [6]. This antimalarial activity was comparable to that of endochin (5) [13][14] and 2-methyl-4(1H)-quinolone analogues as determined in the course of important structure–activity optimization

Synthesis of 2-amino-3-arylpropan-1-ols and 1-(2,3-diaminopropyl)-1,2,3-triazoles and evaluation of their antimalarial activity

• Matthias D’hooghe,
• Stéphanie Vandekerckhove,
• Karen Mollet,
• Karel Vervisch,
• Stijn Dekeukeleire,
• Liesbeth Lehoucq,
• Carmen Lategan,
• Peter J. Smith,
• Kelly Chibale and
• Norbert De Kimpe

Beilstein J. Org. Chem. 2011, 7, 1745–1752, doi:10.3762/bjoc.7.205

• antiplasmodial activity against both a chloroquine-sensitive and a chloroquine-resistant strain of Plasmodium falciparum with IC50-values of ≤25 μM. Keywords: aminopropanes; antimalarial activity; aziridines; β-lactams; ring opening; Introduction Malaria remains a major issue in health control, especially in

Synthesis of spiroannulated and 3-arylated 1,2,4-trioxanes from mesitylol and methyl 4-hydroxytiglate by photooxygenation and peroxyacetalization

• Axel G. Griesbeck,
• Lars-Oliver Höinck and
• Jörg M. Neudörfl

Beilstein J. Org. Chem. 2010, 6, No. 61, doi:10.3762/bjoc.6.61

• 1.460 (3 compounds) to 1.482 (4 compounds). All compounds 10a–h investigated by us fall into this range, 10a,g,h showing the longest O1-O2 bond distances. With regards to antimalarial activity, all 4-arylated 1,2,4-trioxanes exhibited low in vitro activities (EC50/plasmodium falciparum > 50 μM) with the