Evaluation of chalcone derivatives for their role as antiparasitic and neuroprotectant in experimentally induced cerebral malaria mouse model.

Unlabelled: Cerebral malaria is a severe complication of infection with a complex pathophysiology. The current course of treatment is ineffective in lowering mortality or post-treatment side effects such as neurological and cognitive abnormalities. Chalcones are enormously distributed in spices, fruits, vegetables, tea, and soy-based foodstuffs that are well known for their antimalarial activity, and in recent years they have been widely explored for brain diseases like Alzheimer's disease.

Antimalarial and immunomodulatory potential of chalcone derivatives in experimental model of malaria.

Background: Malaria is a complex issue due to the availability of few therapies and chemical families against Plasmodium and mosquitoes. There is increasing resistance to various drugs and insecticides in Plasmodium and in the vector. Additionally, human behaviors are responsible for promoting resistance as well as increasing the risk of exposure to infections.

Binding Expedient of 2-carbamido-1,3-indandione to Nucleic Acids: Potential Fluorescent Probe.

Fluorescent and computational methods were used to elucidate the binding expedient of 2-carbamido-1,3-indandione (CAID) tautomers to nucleotides. The dependence of the fluorescence emission of CAID loaded nucleic acids sequences to compound concentration, temperature and time variation was investigated. It was found that the subject compound binds to nucleic acids but does not intercalate.

Chemical evolution: from formamide to nucleobases and amino acids without the presence of catalyst.

Abiotic synthesis of nucleobases and amino acids is of critical importance as it sheds light on potential prebiotic chemical reactions. During thermal decomposition of formamide in vacuum conditions, purine, cytosine, adenine, hypoxanthine, uracil, pterin, urea, urocanic acid, glycine, alanine and norvaline were detected. The compounds were obtained without catalyst by heating at 100-180 °C or microwave heating of formamide.

Ultrastructural alterations in Plasmodium falciparum induced by chalcone derivatives.

Objective: Chalcones (1, 3-diaryl-2-propen-1-ones) and their derivatives are widely explored from the past decade for its antimalarial activity. To elucidate their mechanism of action on the malaria parasite, the ultrastructural changes with the action of these derivatives in different organelles of the parasite were studied in vitro. Infected RBCs [CQ sensitive (MRC-2) and CQ resistant (RKL-9) Plasmodium strain] were treated with three chalcone derivatives 1, 2 and 3 and standard drugs, i.

In vitro anti-malarial efficacy of chalcones: cytotoxicity profile, mechanism of action and their effect on erythrocytes.

Background: Malaria extensively leads to mortality and morbidity in endemic regions, and the emergence of drug resistant parasites is alarming. Plant derived synthetic pharmaceutical compounds are found to be a foremost research to obtain diverse range of potent leads. Amongst them, the chalcone scaffold is a functional template for drug discovery.

Synthesis, Characterization, Quantum-Chemical Calculations and Cytotoxic Activity of 1,8-Naphthalimide Derivatives with Non-Protein Amino Acids.

Background: The 1,8-Naphthalimides constitute an important class of biologically active, DNAbinding compounds. There are no available data on the synthesis of 1,8-naphthalimide derivatives with nonprotein amino acids and their biological activity. The aim of this paper was to determine the synthesis, structural characterization and cytotoxic activity of new 1-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)cycloalkane-1- carboxylic acids with 5-, 6-, 7-, 8- and 12-membered rings as well as 2-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)- yl)adamantane-2-carboxylic acid and 1-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)-1,2,3,4-tetrahydronaphthalene- 1-carboxylic acid.

Tautomerism of Inosine in Water: Is It Possible?

Syn- and anti-conformers of four tautomer structures of inosine were studied in the gas phase and in solvent water to investigate the possibility of hydrogen bonding and tautomeric conversion. It was found that in the gas phase and in water solution the most stable is the syn-conformer of the 6-keto tautomer followed by its anti-conformer and syn-conformer of the 6-enol form. In the gas phase, the percent content of syn- and anti-conformers is 83.

Hybrid MC/QC simulations of water-assisted proton transfer in nucleosides. Guanosine and its analog acyclovir.

To provide an in-depth insight into the molecular basis of spontaneous tautomerism in DNA and RNA base pairs, a hybrid Monte Carlo (MC)-quantum chemical (QC) methodology is implemented to map two-dimensional potential energy surfaces along the reaction coordinates of solvent-assisted proton transfer processes in guanosine and its analog acyclovir in aqueous solution. The solvent effects were simulated by explicit inclusion of water molecules that model the relevant part of the first hydration shell around the solute. The position of these water molecules was estimated by carrying out a classical Metropolis Monte Carlo simulation of dilute water solutions of the guanosine (Gs) and acyclovir (ACV) and subsequently analyzing solute-solvent intermolecular interactions in the statistically-independent MC-generated configurations.

Anti-conjunctivitis effect of fresh juice of xGraptoveria (Crassulaceae): A phytochemical and ethnobotanical study.

Aim: The parent of xGraptoveria, Graptopetalum paraguayense, is used in Chinese folk medicine for alleviating hepatic disorders, detumescence and detoxication, lowering of blood pressure, inhibition of cancer cells, exerting diuretic effects, relieving pain and infections. No data are available regarding its anti-conjunctivitis effect. The aim of this preliminary study is to test the anti-conjunctivitis properties of xGraptoveria (Crassulaceae) and to identify its bioactive constituents.

2-Carbamido-1,3-indandione - a Fluorescent Molecular Probe and Sunscreen Candidate.

The present work reports theoretical and experimental studies on the photophysical properties of two tautomeric forms of 2-carbamido-1,3-indandione (CAID). By means of UV-vis, steady-state and time-dependent fluorescence spectroscopy it is shown that both enol forms, 2-(hydroxylaminomethylidene)-indan-1,3-dione and 2-carboamide-1-hydroxy-3-oxo-indan, coexist in solution. On the base of spectroscopic studies of CAID interaction with human serum albumin and DNA sequences, it was shown that the compound has potential and it is suitable for use as fluorescent molecular probe for investigation of different biomolecules.

Synthesis of 3',4'-dihydro-2H,2'H,5H-spiro [imidazolidine-4,1'-naphthalene]-2,5-dione and its derivatives.

The synthesis of two novel compounds, 1-amino-3',4'-dihydro-2H,2'H,5H-spiro[imidazolidine-4,1'-naphthalene]-2,5-dione and 1,3-bis(hydroxymethyl)-3',4'-dihydro-2H,2'H,5H-spiro[imidazolidine-4,1'-naphthalene]-2,5-dione, was reported. The structures of the compounds were verified by (1)H, (13)C NMR and IR spectroscopy and quantum-chemical calculations at DFT level.

Tautomeric equilibria of 5-fluorouracil anionic species in water.

It has long been postulated that rare tautomeric or ionized forms of nucleic acid bases may play a role in mispair formation. Therefore, ab initio quantum chemical investigations on the tautomeric equilibrium in 5-fluorouracil (5FU) and its anions (deprotonated from N1, AN1, and from N3, AN3) and their tautomeric forms in water were performed. The effect of the water as solvent was introduced using solute-solvent clusters (four water molecules).

Physicochemical characterization and in vitro behavior of daunorubicin-loaded poly(butylcyanoacrylate) nanoparticles.

The design, preparation and characterization of poly(butylcyanoacrylate) nanoparticles as a drug-delivery system for daunorubicin is reported. A range of light scattering [photon correlation spectroscopy (PCS)], spectroscopic [(1)H nuclear magnetic resonance ((1)H NMR), Fourier transform infrared (FTIR), chromatographic [gel permeation chromatography (GPC)] and quantum chemical techniques have been employed for the physicochemical characterization of drug-loaded nanoparticles and to clarify the mechanisms of drug immobilization in the polymer matrix. The presence of daunorubicin in the polymerization medium was found to affect both the degree of polymerization and the compactness of the resulting nanoparticles.

Ab initio study of 2,4-substituted azolidines. II. Amino-imino tautomerism of 2-aminothiazolidine-4-one and 4-aminothiazolidine-2-one in water solution.

The relative stabilities of the tautomers of 2-aminothiazolidine-4-one and 4-aminothiazolidine-2-one were calculated at the MP2/6-31+G(d,p) level by considering their mono- and trihydrated complexes. Single-point calculations at the MP4/6-31+G(d,p)//MP2/6-31+G(d,p) level of theory were performed to obtain more accurate energies. The values of proton transfer barriers in the isolated, mono- and trihydrated tautomers of 2-aminothiazolidine-4-one (2AT) and 4-aminothiazolidine-2-one (4AT) were calculated for two different mechanisms of tautomerisation.

Oxo-hydroxy tautomerism of 5-fluorouracil: water-assisted proton transfer.

Post-Hartree-Fock ab initio quantum chemical calculations were performed for 5-fluorouracil in the gas phase and in a three-water cluster. Full geometry optimizations of the 5-fluorouracil-water complexes were carried out at the MP2/6-31+G(d,p) level of theory. MP4/6-31+G(d,p)//MP2/6-31+G(d,p) and MP4/6-31++G(d,p)//MP2/6-31+G(d,p) single-point calculations were performed to obtain more accurate energies.