Electrodeposited hydroxyapatite coating on titanium after ultrashort-pulsed laser processing for a novel surface of endosseous implants.

Background: Ceramic endosseous implant coatings have gained esteem due to their favorable osteoinductive and osteoconductive properties. However, such a layer may be prone to failure under in vivo conditions, which necessitates its modification.

Objectives: The aim of the present study was to modify an electrodeposited hydroxyapatite (HA) coating on titanium (Ti) with ultrashort-pulsed lasers for the incorporation of the ceramic into the sample surface and the texturing of the metal surface.

Synthesis of methotrexate-betulonic acid hybrids and evaluation of their effect on artificial and Caco-2 cell membranes.

An efficient protocol for the synthesis of novel methotrexate-betulonic acid hybrids with a (tert-butoxycarbonylamino)-3,6-dioxa-8-octanamine (Boc-DOOA) linkage has been developed. Reaction of N-(2-(2-(2-aminoethoxy)ethoxy)ethyl)-betulonamide with methotrexate resulted in a mixture of isomeric conjugates which were separated by column chromatography. Their structures and composition have been fully established by H NMR, C spectra, FAB mass spectrometry and elemental analysis.

New terbium complex as a luminescent probe for determination of chlorogenic acid in green coffee and roasted coffee infusions.

Green coffee is coming into vogue as a food that contains remarkable contents of antioxidants like chlorogenic acid (ChA) and induces mild stimulation to the consumer. While most methods for determination of ChA require chromatographic separation prior its quantitation, we present the first probe and a simple, sensitive and validated luminescence method for the determination of chlorogenic acid in green and roasted coffee infusion samples that does not require a chromatographic separation. ChA can remarkably quench the luminescence intensity of the Tb complex with 1-(furan-2-ylmethyl)-4-hydroxy-N-(4-methylpyridin-2-yl)-2-oxo-1,2,5,6,7,8-hexahydroquinoline-3-carboxamide (R) in aqueous solution containing urotropine buffer at a near neutral pH 7.

Activity of 1-aryl-4-(naphthalimidoalkyl) piperazine derivatives against Leishmania major and Leishmania mexicana.

A series of 1-aryl-4-(phthalimidoalkyl) piperazines and 1-aryl-4-(naphthalimidoalkyl) piperazines were retrieved from a proprietary library based on their high structural similarity to haloperidol, an antipsychotic with antiparasitic activity, and assessed as potential antileishmanial scaffolds. Selected compounds were tested for antileishmanial activity against promastigotes of Leishmania major and Leishmania mexicana in dose-response assays. Two of the 1-aryl-4-(naphthalimidoalkyl) piperazines (compounds 10 and 11) were active against promastigotes of both Leishmania species without being toxic to human fibroblasts.

New Luminescent Lanthanide Tetrakis-Complexes NEt [LnL ] Based on Dimethyl-N-Benzoylamidophosphate.

New lanthanide dimethyl-N-benzoylamidophosphate (HL) based tetrakis-complexes NEt [LnL ] (Ln =La, Nd, Sm, Eu, Gd, Tb, Dy) are reported. The complexes are characterized by means of NMR, IR, absorption, and luminescent spectroscopy as well as by elemental, X-Ray, and thermal gravimetric analyses. The phenyl groups of the four ligands of the complex anion are directed towards one side, while the methoxy groups are directed in the opposite side, which makes the complexes under consideration structurally similar to calixarenes.

Terpenoid Hydrazones as Biomembrane Penetration Enhancers: FT-IR Spectroscopy and Fluorescence Probe Studies.

Hydrazones based on mono- and bicyclic terpenoids (verbenone, menthone and carvone) have been investigated in vitro as potential biomembrane penetration enhancers. In this regard, liposomes composed of lecithin or cardiolipin as phospholipid phase components with incorporated fluorescence probes have been prepared using the thin-film ultrasonic dispersion method. The mean particle size of the obtained liposomes, established using laser diffraction, was found to be 583 ± 0.

Fluorenonophane chloro-benzene solvate: mol-ecular and crystal structures.

The title compound, 1 ,7 -3,5,9,11-tetra-oxa-1,7(2,7)-difluorena-4,10(1,3)-dibenzena-cyclo-dodeca-phane-1,7-dione (fluorenonophane), exists as a solvate with chloro-benzene, CHO·CHCl. The fluorenonophane contains two fluorenone fragments linked by two -substituted benzene fragments. Some decrease in its macrocyclic cavity leads to a stacking inter-action between the tricyclic fluorenone fragments.

Novel c-Jun N-Terminal Kinase (JNK) Inhibitors with an 11-Indeno[1,2-]quinoxalin-11-one Scaffold.

c-Jun N-terminal kinase (JNK) plays a central role in stress signaling pathways implicated in important pathological processes, including rheumatoid arthritis and ischemia-reperfusion injury. Therefore, inhibition of JNK is of interest for molecular targeted therapy to treat various diseases. We synthesized 13 derivatives of our reported JNK inhibitor 11-indeno[1,2-]quinoxalin-11-one oxime and evaluated their binding to the three JNK isoforms and their biological effects.

Synthesis, Biological Evaluation, and Molecular Modeling of Aza-Crown Ethers.

Synthetic and natural ionophores have been developed to catalyze ion transport and have been shown to exhibit a variety of biological effects. We synthesized 24 aza- and diaza-crown ethers containing adamantyl, adamantylalkyl, aminomethylbenzoyl, and ε-aminocaproyl substituents and analyzed their biological effects in vitro. Ten of the compounds (, -, and ) increased intracellular calcium ([Ca]) in human neutrophils, with the most potent being compound (,'-[2-(1-adamantyl)acetyl]-4,10-diaza-15-crown-5), suggesting that these compounds could alter normal neutrophil [Ca] flux.

GABAA receptor agonist cinazepam and its active metabolite 3-hydroxyphenazepam act differently at the presynaptic site.

Cinazepam CHBrClNO, ("Levana ІC") a partial GABA receptor agonist, and its active metabolite 3-hydroxyphenazepam CHBrClNO were comparatively assessed in vitro using nerve terminals isolated from rat cortex (synaptosomes). At the presynaptic site, cinazepam (100 and 200 µM) facilitated synaptosomal transporter-mediated [H]GABA uptake by enhancing both the initial rate and accumulation, and decreased the ambient level and transporter-mediated release of [H]GABA. Whereas, 3-hydroxyphenazepam decreased the uptake and did not change the ambient synaptosomal level and transporter-mediated release of [H]GABA.

Synthesis, anticancer activity, and molecular modeling of 1,4-naphthoquinones that inhibit MKK7 and Cdc25.

Cell division cycle 25 (Cdc25) and mitogen-activated protein kinase kinase 7 (MKK7) are enzymes involved in intracellular signaling but can also contribute to tumorigenesis. We synthesized and characterized the biological activity of 1,4-naphthoquinones structurally similar to reported Cdc25 and(or) MKK7 inhibitors with anticancer activity. Compound 7 (3-[(1,4-dioxonaphthalen-2-yl)sulfanyl]propanoic acid) exhibited high binding affinity for MKK7 (K = 230 nM), which was greater than the affinity of NSC 95397 (K = 1.

Absorption- and Excitation-Modulated Luminescence of Pr, Nd, and Lu Compounds with Dianions of Tetrafluoroterephthalic and Camphoric Acids.

The luminescence of coordination polymers of Pr, Nd, and Lu with tetrafluoroterephthalate and camphorate, [Ln(Fbdc)(DMF)(HO)] (Ln = Pr, Nd, Lu) and [Ln(Camph)(NO)(MeOH)] (Ln = Pr, Nd, Lu), was studied. Ligand-centered and/or metal-centered emissions appear, which depend on the excitation wavelength, ultimately allowing the emitted light color to be adjusted. Low-efficiency ligand-to-metal energy transfer leads to a difference between the excitation spectra of the tetrafluoroterephthalate- and camphorate-Pr compounds, arising from a primary filtering effect on the ligand-centered excitation, by Pr absorption.

Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds.

The unexpectedly uncatalyzed reaction between 2-amino-4-arylimidazoles, aromatic aldehydes and Meldrum's acid has selectively led to the corresponding Knoevenagel-Michael adducts containing a free amino group in the imidazole fragment. The adducts derived from Meldrum's acid have been smoothly converted into 1,7-diaryl-3-amino-6,7-dihydro-5-pyrrolo[1,2-]imidazol-5-ones and 3-(2-amino-4-aryl-1-imidazol-5-yl)-3-arylpropanoic acids. The interaction of 2-amino-4-arylimidazoles with aromatic aldehydes or isatins and acyclic methylene active compounds has led to the formation of pyrrolo[1,2-]imidazole-6-carbonitriles, pyrrolo[1,2-]imidazole-6-carboxylates and spiro[indoline-3,7'-pyrrolo[1,2-]imidazoles], which can be considered as the analogues of both 3,3'-spirooxindole and 2-aminoimidazole marine sponge alkaloids.

Effect of esters based on terpenoids and GABA on fluidity of phospholipid membranes.

The influence of esters based on gamma-aminobutyric acid (GABA) and mono-/bicyclic terpenoids on membrane structure was investigated. The mechanism of action for terpenoid esters on phospholipids of artificial membranes and lipids isolated from the rat stratum corneum was studied by fluorescence and FT-IR spectroscopy. We report here, that inclusion of monocyclic terpenoid esters in phospholipid liposomes leads to growth of excimer to monomer ratio (/) indicating a decrease of membrane microviscosity.

Synthesis, biological evaluation, and molecular modeling of 11H-indeno[1,2-b]quinoxalin-11-one derivatives and tryptanthrin-6-oxime as c-Jun N-terminal kinase inhibitors.

c-Jun N-terminal kinases (JNKs) play a central role in many physiologic and pathologic processes. We synthesized novel 11H-indeno[1,2-b]quinoxalin-11-one oxime analogs and tryptanthrin-6-oxime (indolo[2,1-b]quinazoline-6,12-dion-6-oxime) and evaluated their effects on JNK activity. Several compounds exhibited sub-micromolar JNK binding affinity and were selective for JNK1/JNK3 versus JNK2.

R-based Tool for a Pairwise Structure-activity Relationship Analysis.

The Structure-Activity Relationship analysis is a complex process that can be enhanced by computational techniques. This article describes a simple tool for SAR analysis that has a graphic user interface and a flexible approach towards the input of molecular data. The application allows calculating molecular similarity represented by Tanimoto index & Euclid distance, as well as, determining activity cliffs by means of Structure-Activity Landscape Index.

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives.

The complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives has been studied both in solution and in the solid state. In this paper we studied the influence of the crown ether ring size and the nature of the substituents at the nitrogen atoms of the paraquat derivatives on the composition and stability of these complexes.

Structure-reactivity modeling using mixture-based representation of chemical reactions.

We describe a novel approach of reaction representation as a combination of two mixtures: a mixture of reactants and a mixture of products. In turn, each mixture can be encoded using an earlier reported approach involving simplex descriptors (SiRMS). The feature vector representing these two mixtures results from either concatenated product and reactant descriptors or the difference between descriptors of products and reactants.

Virtual screening, synthesis and biological evaluation of DNA intercalating antiviral agents.

This paper describes computer-aided design of new anti-viral agents against Vaccinia virus (VACV) potentially acting as nucleic acid intercalators. Earlier obtained experimental data for DNA intercalation affinities and activities against Vesicular stomatitis virus (VSV) have been used to build, respectively, pharmacophore and QSAR models. These models were used for virtual screening of a database of 245 molecules generated around typical scaffolds of known DNA intercalators.

Synthesis, Characterization, and Luminescent Properties of Polymer Complexes of Nd(III) with β-Dicarbonyl Ligands.

The neodymium(III) complexes with 2-methyl-5-phenylpenten-1-3,5-dione and allyl-3-oxo-butanoate were synthesized. The polycomplexes on their basis and copolymers with styrene and N-vinylcarbazole in ratio 5:95 were obtained by free-radical polymerization. The results of above studies have shown that the configuration of the chelate unit is unchanged during the polymerization.

Study on the interaction of 6-(2-morpholin-4-yl-ethyl)-6H-indolo [2,3-b]quinoxaline hydrochloride with human serum albumin by fluorescence spectroscopy.

Under physiological conditions, in vitro interaction between the bio-active substance 6-(2-morpholin-4-yl-ethyl)-6H-indolo[2,3-b]quinoxaline hydrochloride (MIQ) and human serum albumin (HSA) was investigated at an excitation wavelength 260 nm and at different temperatures (298 K, 308 K and 313 K) by fluorescence emission spectroscopy. From spectral analysis, MIQ showed a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The binding constant is estimated asK   =  2.

Luminescence study of nanosized AlO:Tb obtained by gas-dispersed synthesis.

Terbium-doped AlO samples were obtained by gas-dispersed synthesis. It was shown that the resulting powders, with particle sizes of 10-70 nm, consist of a mixture of transition aluminas, among which the δ -polymorph is dominant. The luminescence properties of AlO:Tb have been studied upon excitation in the UV-visible range of the spectrum.

Crystal structures and intense luminescence of tris(3-(2'-pyridyl)-pyrazolyl)borate Tb and Eu complexes with carboxylate co-ligands.

A series of brightly luminescent new mononuclear TpLn(An)(HO) (where An = carboxylate anion, Ln = Eu or Tb and Tp = tris(3-(2'-pyridyl)pyrazolyl)borate) and dinuclear (TpLn)pma(MeOH) (Ln = Eu, Tb, pma = tetraanion of pyromellitic acid) complexes were prepared and characterized by X-ray crystallography. Within each series the compounds possess similar molecular structures, which differ only by the nature of the carboxylate anions. The quantum efficiencies for metal-centered emission of the complexes were up to 29(3)% for Eu and 53(5)% for the Tb compounds and significantly depend on the electronic structure of the additional ligand (i.

Structural and Physico-Chemical Interpretation (SPCI) of QSAR Models and Its Comparison with Matched Molecular Pair Analysis.

This paper describes the Structural and Physico-Chemical Interpretation (SPCI) approach, which is an extension of a recently reported method for interpretation of quantitative structure-activity relationship (QSAR) models. This approach can efficiently be used to reveal structural motifs and the major physicochemical factors affecting the investigated properties. Its efficacy was demonstrated both on the classical Free-Wilson data set and on several data sets with different end points (permeability of the blood-brain barrier, fibrinogen receptor antagonists, acute oral toxicity).