A5064150460- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Chemical Reaction Mechanisms
- Crystallography and molecular interactions
- Synthesis and Biological Evaluation
- Advanced Chemical Physics Studies
- Synthesis and biological activity
- Molecular Sensors and Ion Detection
- Click Chemistry and Applications
- Metal complexes synthesis and properties
- Synthesis and Characterization of Heterocyclic Compounds
- Cyclopropane Reaction Mechanisms
- DNA and Nucleic Acid Chemistry
- Free Radicals and Antioxidants
- Enzyme Catalysis and Immobilization
- Amino Acid Enzymes and Metabolism
- Inorganic and Organometallic Chemistry
- Luminescence and Fluorescent Materials
- Magnetism in coordination complexes
- Organic Chemistry Cycloaddition Reactions
- Receptor Mechanisms and Signaling
- Analytical Chemistry and Sensors
- Synthesis and Properties of Aromatic Compounds
- Photochemistry and Electron Transfer Studies
- Organic and Inorganic Chemical Reactions
Rudjer Boskovic Institute
2016-2025
University of Zagreb
2001-2021
University of Bijeljina
2018
Greek Rescue Team
2015-2018
National Institute of Chemistry
2010-2012
University of Sussex
2009
University of Tartu
2009
University of Bath
2009
The basicities of simple organic bases – aliphatic and aromatic amines, amidines, phosphazenes, as well saturated unsaturated nitrogen heterocycles are examined in acetonitrile, dimethyl sulfoxide, tetrahydrofuran, water the gas phase. (p K aH values) conjugate acids a large variety these media presented discussed. Equations employing easily usable structural descriptors have been derived for approximately converting from acetonitrile to other solvents. Recommendations given on their...
In this work we explored the relationship between structure and solvent effects on basicity of a large selection conjugated N‐heterocyclic nitrogen bases in different media: polar aprotic acetonitrile, protic water gas phase. Altogether, 58 previously unpublished values media for 39 compounds are presented, including 30 experimentally determined p K acetonitrile. We present gas‐phase quino[7,8‐ h ]quinoline, which is one most basic heterocyclic without basicity‐enhancing substituents. The...
Abstract Monoamine oxidases (MAOs) are flavoenzymes important in regulating amine neurotransmitter levels and the central pharmacological targets treating depression Parkinson's disease. On basis of quantum chemical calculations, we have proposed a new two‐step hydride mechanism for MAO‐catalysed oxidative deamination amines. In rate‐limiting first step, through its N5 atom, flavin abstracts anion from substrate α‐carbon atom forms strong covalent adduct with thus created cation. This is...
The enzyme-catalyzed degradation of the biogenic amine serotonin is an essential regulatory mechanism its level in human organism. In particular, monoamine oxidase A (MAO A) important flavoenzyme involved metabolism neurotransmitters. Despite extensive research efforts, neither catalytic nor inhibition mechanisms MAO enzymes are currently fully understood. this article, we present quantum mechanics/molecular mechanics simulation rate-limiting step for decomposition, which consists hydride...
The bis-guanidino compound H2C{hpp}2 (I; hppH = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) has been converted to the monocation [I-H]+ and isolated as chloride tetraphenylborate salts. Solution-state spectroscopic data do not differentiate protonated guanidinium from neutral guanidino group but suggest intramolecular "—N—H···N═" hydrogen bonding form an eight-membered C3N4H heterocycle. Solid-state CPMAS 15N NMR spectroscopy confirms protonation at one of imine nitrogens, although...
Monoamine oxidase (MAO), which exists in two isozymic forms, MAO A and B, is an important flavoenzyme responsible for the metabolism of amine neurotransmitters such as dopamine, serotonin, norepinephrine. Despite extensive research effort, neither catalytic nor inhibition mechanisms have been completely understood. There has also dispute with regard to protonation state substrate upon entering active site, well identity residues that are initial deprotonation irreversible acetylenic...
Monoamine oxidases (MAO) A and B are important flavoenzymes involved in the metabolism of amine neurotransmitters. Orru et al. ( J. Neural Transm. 2013 , 120 847 - 851 ) recently presented experimental results that have challenged prevailing assumption MAO employ an identical catalytic mechanism. We compared spatial configuration ionizable groups both isozymes estimated time-averaged electrostatic potential by calculating pKa values five active site residues. Superimposition structures shows...
Monoamine oxidases (MAOs) A and B are flavoenzymes responsible for the metabolism of biogenic amines, such as dopamine, serotonin, noradrenaline (NA), which is why they have been extensively implicated in etiology course various neurodegenerative disorders and, accordingly, used primary pharmacological targets to treat these debilitating cognitive diseases. The precise chemical mechanism through MAOs regulate amine concentration, vital development novel inhibitors, still not unambiguously...
ABSTRACT Monoamine oxidases (MAOs) A and B are flavoenzymes responsible for the metabolism of biogenic amines such as dopamine, serotonin noradrenaline. In this work, we present a comprehensive study rate‐limiting step dopamine degradation by MAO B, which consists in hydride transfer from methylene group substrate to flavin moiety FAD prosthetic group. This article builds on our previous quantum chemical same reaction using cluster model (Vianello et al ., Eur J Org Chem 2012; 7057), but now...
Monoamine oxidases (MAOs) are flavin adenine dinucleotide containing flavoenzymes that catalyze the degradation of a range brain neurotransmitters, whose imbalance is extensively linked with pathology various neurological disorders. This why MAOs have been central pharmacological targets in treating neurodegeneration for more than 60 years. Still, despite this practical importance, precise chemical mechanisms underlying irreversible inhibition MAO B isoform clinical drugs rasagiline (RAS)...
An efficient but reasonably accurate B3LYP/6-311+G(d,p)//B3LYP/6-31G(d) computational procedure showed that pentasubstituted cyclopentadienes such as (CN)5C5H, (NO2)5C5H, and (NC)5C5H containing strongly electron-withdrawing groups are neutral organic superacids of unprecedented strength. The boldface denotes the atom attached to cyclopentadiene framework. All them exhibit prototropic tautomerism by forming somewhat more stable structures with C=NH, NO2H, N=CH exocyclic fragments,...
Hydration of histamine was examined by infrared spectroscopy and Car–Parrinello molecular dynamics simulation. Histamine is a neurotransmitter inflammation mediator, which at physiological pH conditions present mainly in monocationic form. Our focus on the part vibrational spectra that corresponds to N–H stretching, since these degrees freedom are essential for its interactions with either water molecules or transporters receptors. Assignment experimental revealed broad feature between 3350...
In this article we report a combined experimental and computational study concerning the effects of deuteration on binding histamine two other histaminergic agonists to 3H-tiotidine-labeled H2 receptor in neonatal rat astrocytes. Binding affinities were measured by displacing radiolabeled tiotidine from sites present cultured Quantum-chemical calculations performed employing empirical quantization nuclear motion within cluster model site extracted homology entire receptor. Structure built...
Complexation of alkaline earth metal cations with fluorescent tertiary-amide lower-rim calix[4]arene derivative bearing two phenanthridine moieties was studied experimentally (UV spectrophotometry, fluorimetry, isothermal microcalorimetry, NMR spectroscopy) and computationally (classical molecular dynamics DFT calculations) at 25 °C. The complexation reactions were in acetonitrile, methanol, ethanol, whereby the solvent effect on cation-binding processes particularly addressed. complex...
Complexation of alkaline earth metal cations with fluorescent tertiary-amide lower-rim calix[4]arene derivative bearing two phenanthridine moieties was studied experimentally (UV spectrophotometry, fluorimetry, isothermal microcalorimetry, NMR spectroscopy) and computationally (classical molecular dynamics DFT calculations) at 25 °C. The complexation reactions were in acetonitrile, methanol, ethanol, whereby the solvent effect on cation-binding processes particularly addressed. complex...