Search results for "Plasmodium"

In vitro and in silico studies of polycondensed diazine systems as anti-parasitic agents

2012

Abstract Parasitic diseases caused by protozoarian agents are still relevant today more than ever. Recently, we synthesized several polycondensed diazine derivatives by means 1,3-dipolar cycloaddition reactions. A broad selection of these compounds were submitted to in vitro biological screening against Plasmodium falciparum , Leishmania infantum , Trypanosoma brucei , and Trypanosoma cruzi , resulting active at micromolar level. Induced Fit Docking/MM-GBSA studies were performed giving interesting indications about the probable mechanism of action of the most active compounds

Pentamethylcyclopentadienyl-rhodium and iridium complexes containing (N^N and N^O) bound chloroquine analogue ligands: synthesis, characterization an…

2016

The synthesis and characterization of twenty new pentamethylcyclopentadienyl-rhodium and iridium complexes containing N^N and N^O-chelating chloroquine analogue ligands are described. The in vitro antimalarial activity of the new ligands as well as the complexes was evaluated against the chloroquine sensitive (CQS) NF54 and the chloroquine resistant (CQR) Dd2 strains of Plasmodium falciparum. The antimalarial activity was found to be good to moderate; although all complexes are less active than artesunate, some of the ligands and complexes showed better activity than chloroquine (CQ). In particular, rhodium complexes were found to be considerably more active than iridium complexes against t…

Inhibition of Eimeria tenella CDK-related kinase 2: From target identification to lead compounds.

2010

Apicomplexan parasites encompass several human- and animal-pathogenic protozoans such as Plasmodium falciparum, Toxoplasma gondii, and Eimeria tenella. E. tenella causes coccidiosis, a disease that afflicts chickens, leading to tremendous economic losses to the global poultry industry. The considerable increase in drug resistance makes it necessary to develop new therapeutic strategies against this parasite. Cyclin-dependent kinases (CDKs) are key molecules in cell-cycle regulation and are therefore prominent target proteins in parasitic diseases. Bioinformatics analysis revealed four potential CDK-like proteins, of which one—E. tenella CDK-related kinase 2 (EtCRK2)—has already been charact…

The IFN-γ-Inducible GTPase, Irga6, Protects Mice against Toxoplasma gondii but Not against Plasmodium berghei and Some Other Intracellular Pathogens

2011

Clearance of infection with intracellular pathogens in mice involves interferon-regulated GTPases of the IRG protein family. Experiments with mice genetically deficient in members of this family such as Irgm1(LRG-47), Irgm3(IGTP), and Irgd(IRG-47) has revealed a critical role in microbial clearance, especially for Toxoplasma gondii. The in vivo role of another member of this family, Irga6 (IIGP, IIGP1) has been studied in less detail. We investigated the susceptibility of two independently generated mouse strains deficient in Irga6 to in vivo infection with T. gondii, Mycobacterium tuberculosis, Leishmania mexicana, L. major, Listeria monocytogenes, Anaplasma phagocytophilum and Plasmodium …

Transfusion‐transmitted malaria of plasmodium malariae in palermo, sicily

2021

Transfusion-transmitted malaria (TTM) is a rare occurrence with serious consequences for the recipient. In non-endemic areas, the incidence of transmission of malaria by transfusion is very low. We report a clinical case of transfusion-transmitted malaria due to Plasmodium malariae, which happened in a patient with acute hemorrhagic gastropathy. Case presentation: In April 2019, a 70-year-old Italian man with recurrent spiking fever for four days was diagnosed with a P. malariae infection, as confirmed using microscopy and real-time PCR. The patient had never been abroad, but about two months before, he had received a red blood cell transfusion for anemia. Regarding the donor, we revealed t…

2019

Phytochemical investigations of ethanol root bark and stem bark extracts of Cleistochlamys kirkii (Benth.) Oliv. (Annonaceae) yielded a new benzopyranyl cadinane-type sesquiterpene (cleistonol, 1) alongside 12 known compounds (2–13). The structures of the isolated compounds were established from NMR spectroscopic and mass spectrometric analyses. Structures of compounds 5 and 10 were further confirmed by single crystal X-ray crystallographic analyses, which also established their absolute stereochemical configuration. The ethanolic crude extract of C. kirkii root bark gave 72% inhibition against the chloroquine-sensitive 3D7-strain malaria parasite Plasmodium falciparum at 0.01 μg/mL. The is…

Discovery of new antimalarial compounds by use of molecular connectivity techniques.

1999

Abstract Molecular connectivity has been applied to the search for new compounds with antimalarial activity. Linear discriminant analysis and connectivity functions were used to select several potentially suitable drugs which were tested for antimalarial properties by use of an in-vitro micro test which estimates parasite growth by measurement of incorporation of [3H]hypoxanthine. Hexetidine stands out among the compounds selected. Activity assays were performed with Plasmodium falciparum passou and 3CD7 strains, for which the IC50 values (doses resulting in 50% inhibition) were 320 and 400 ng mL−1 respectively. These results are comparable with those obtained for quinine chlorhydrate (IC50…

Dioncophyllines C2, D2, and F and related naphthylisoquinoline alkaloids from the Congolese liana Ancistrocladus ileboensis with potent activities ag…

2017

Dioncophylline F (1), the first 5,8'-coupled dioncophyllaceous alkaloid (i.e., lacking an oxygen function at C-6 and possessing an R-configuration at C-3), was isolated from the recently described Congolese liana Ancistrocladus ileboensis. Two further, likewise Dioncophyllaceae-type, alkaloids, the dioncophyllines C2 (2) and D2 (3), were identified, along with the Ancistrocladaceae-type compound ancistrocladisine B (4), which is oxygenated at C-6 and S-configured at C-3. The structures of the new compounds were determined by spectroscopic, chemical, and chiroptical methods. The stereostructure of 1 was further confirmed by total synthesis. As a consequence of the lack of a methyl group orth…

Prenylated Flavonoids from the Roots of Tephrosia rhodesica

2020

Five new compounds—rhodimer (1), rhodiflavan A (2), rhodiflavan B (3), rhodiflavan C (4), and rhodacarpin (5)—along with 16 known secondary metabolites, were isolated from the CH2Cl2–CH3OH (1:1) extract of the roots of Tephrosia rhodesica. They were identified by NMR spectroscopic, mass spectrometric, X-ray crystallographic, and ECD spectroscopic analyses. The crude extract and the isolated compounds 2–5, 9, 15, and 21 showed activity (100% at 10 μg and IC50 = 5–15 μM) against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum. peerReviewed

Clinical recrudescence of chronic untreated P. malariae infection after BNT162b2 CoVID-19 vaccine

2022

We described a case of clinical reactivation of chronic P. malariae infection following CoVID-19 vaccination with BNT162b2 (Pifzer-Biontech CoVID-19 vaccine) in a 48-year old Italian man.The patient came to our attention for fever of unknown origin show a quartan pattern (every third day) associated to splenomegaly, the onset of the fever occurred one month after CoVID-19 vaccination with BNT162b2. P. malariae was diagnosed using CarestartTM malaria rapid test and Polymerase-Chain Reaction. Post-vaccine transient reduction of immune reactivity is described in literature, although the mechanism is unknown.(c) 2022 Published by Elsevier Ltd.CC_BY_NC_ND_4.0