Robert Vianello

Robert Vianello
Rudjer Boskovic Institute | RBI · Division of Organic Chemistry and Biochemistry

Dr.

About

172
Publications
30,740
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Introduction
Robert Vianello currently works as a Senior Scientist with Tenure and Group Leader at the Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute.
Additional affiliations
April 2010 - April 2012
National Institute of Chemistry
Position
  • Fellow
January 2005 - April 2005
Heidelberg University
Position
  • Fellow
December 2000 - present
Rudjer Boskovic Institute
Position
  • Researcher
Education
January 2001 - November 2003
Faculty of Science, Department of Chemistry, University of Zagreb
Field of study
  • Computational Chemistry
October 1996 - November 2000
Faculty of Science, Department of Chemistry, University of Zagreb
Field of study
  • Chemistry

Publications

Publications (172)
Article
Full-text available
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 and DFT calculations) at 25 °C. The comple...
Article
Building on previous research indicating the robust biological effects of coumarins, we focused on exploring imino-coumarin 2-benzazole conjugates. Compounds were tested for antiproliferative activity in vitro, with the most active ones further examined to determine the mechanism of biological action. Five derivatives exhibited significant antipro...
Article
Full-text available
The continuous tightening of pharmaceutical regulations forces drug manufacturers to unambiguously characterize the substances related to the active pharmaceutical ingredients (API). Here, we report the synthesis, complete spectroscopic, chromatographic, thermal and computational characterization, as well as in silico prediction of bacterial mutage...
Article
Full-text available
The sorption and photocatalytic activity of pharmaceutical torasemide using an immobilized TiO2 photocatalyst were investigate. The experimental design included optimization of reaction conditions such as pH and initial pharmaceutical concentration in aqueous solution using the response surface modeling approach, scavenger tests to gain insight int...
Article
Full-text available
Background: Monoamine oxidases (MAO) are flavoenzymes that metabolize a range of brain neurotransmitters, whose dysregulation is closely associated with the development of various neurological disorders. This is why MAOs have been the central target in pharmacological interventions for neurodegeneration for more than 60 years. Still, existing drugs...
Article
Full-text available
Three new phenanthridine peptide derivatives (19, 22, and 23) were synthesized to explore their potential as spectrophotometric probes for DNA and RNA. UV/Vis and circular dichroism (CD) spectra, mass spectroscopy, and computational analysis confirmed the presence of intramolecular interactions in all three compounds. Computational analysis reveale...
Article
We present the design, synthesis, computational analysis, and biological assessment of several acrylonitrile derived imidazo[4,5-b]pyridines, which were evaluated for their anticancer and antioxidant properties. Our aim was to explore how the number of hydroxy groups and the nature of nitrogen substituents influence their biological activity. The p...
Article
Continuing our research into the anticancer properties of acrylonitriles, we present a study involving the design, synthesis, computational analysis, and biological assessment of novel acrylonitriles derived from methoxy, hydroxy, and N-substituted benzazole. Our aim was to examine how varying the number of methoxy and hydroxy groups, as well as th...
Article
Full-text available
Bis(2‐picolyl)amine (bpa), iminodiacetamide (imda), and bis‐1,2,3‐triazole (bta) ferrocene ligands (L) with and without an aliphatic linker were prepared by multi‐step synthesis. The cis‐fac, trans‐fac, or mer stereochemistry of their ML2 complexes with Ni(II), Cu(II), Cd(II), and Zn(II) was studied in the solid state (infrared [IR] and single‐crys...
Article
We used a range of computational techniques to assess the effect of selective C-H deuteration on the antagonist istradefylline affinity for the adenosine A2A receptor, which was discussed relative to its structural analogue caffeine, a well-known and likely the most widely used stimulant. The obtained results revealed that smaller caffeine shows hi...
Article
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The discovery of cephalosporin and demonstration of its improved stability in aqueous solution, as well as enhanced in vitro activity against penicillin-resistant organisms, were major breakthroughs in the development of β-lactam antibiotics. Although cephalosporins are more stable with respect to hydrolytic degradation than penicillins, they still...
Article
Full-text available
Two novel conjugate molecules were designed: pyrene and phenanthridine-amino acid units with a different linker length between the aromatic fragments. Molecular modelling combined with spectrophotometric experiments revealed that in neutral and acidic buffered water solutions conjugates predominantly exist in intramolecularly stacked conformations...
Article
Herein we present the design and the synthesis of novel substituted coumarin–benzimidazole/benzothiazole hybrids bearing a cyclic amidino group on the benzazole core as biologically active agents. All prepared compounds were evaluated for their in vitro antiviral and antioxidative activity as well as for their in vitro antiproliferative activity ag...
Article
Full-text available
Proučavanje procesa stereoizomerizacije od iznimne je važnosti u farmaceutskoj kemiji i biomedicini. Različiti izomeri mogu pokazivati značajne razlike u interakciji s biološkim makromolekulama, što može dovesti do razlika i u njihovim farmakokinetičkim i farmakodinamičkim svojstvima te, u konačnici, u terapijskim i neželjenim učincima. Iako postoj...
Preprint
Full-text available
Two novel hybrid molecules were designed: pyrene and phenanthridine-amino acid units with a different linker length between aromatic fragments. Molecular modelling combined with spectrophotometric experiments revealed that in neutral and acidic buffered water solutions conjugates predominantly exist in intramolecularly stacked conformations as a re...
Article
Full-text available
As anionic surfactants are used as cleaning agents, they pose an environmental and health threat. A novel potentiometric sensor for anionic surfactants based on the 1,3-dioctadecyl-1H-imidazol-3-ium tetraphenylborate (DODI–TPB) ionophore is presented. The newly developed approach for DODI–TPB synthesis is faster and simpler than the currently used...
Article
Full-text available
A piperidine-catalyzed reaction between 3-formylchromone, 1,3-dimethyl barbituric acid, and ylidenemalononitriles is developed that offers chromonyl diene products in good yields. This cascade reaction proceeds via the insertion of ylidenemalononitriles between the Knoevenagel adduct obtained from 3-formylchromone and 1,3-dimethylbarbituric acid, w...
Article
Full-text available
Seven bis(2-picolyl)amine (bpa) and five iminodiacetamide (imda) ligands were prepared with different modifications in their side chain structure. The coordination properties of the ligands (L) were influenced by changes in the aliphatic linker length (C1, C2, or C3), amide group isomers and type of chiral terminal group. Complexation with Cu(II) a...
Article
Nicotinamide adenine dinucleotide (NAD) coenzyme is a vital part of numerous enzymatic reactions that are involved in all major biological processes from energy metabolism to cell survival. Accordingly, it is used in a great number of biocatalytic reactions, as analytical biosensors, and in test kits for diagnostic and analytical purposes. This coe...
Article
Seven complexes, [Ni(NCS)2(isn)2(H2O)2]⋅2H2O (1), [Ni(NCS)2(isn)2(H2O)2] (2), [Ni(NCS)2(isn)3(H2O)]·2.5H2O (3), [Ni(NCS)2(isn)3(H2O)]·3[Ni(NCS)2(isn)4]·9H2O (4), [Ni(NCS)2(isn)4]·3H2O (5), [Ni(NCS)2(isn)4]·2(isn) (6) and [Ni(NCS)2(isn)4]·1.25H2O (7), of Ni(II) thiocyanate with isonicotinamide (isn = pyridine-4-carboxamide) and water as ligands of b...
Cover Page
Full-text available
The front cover picture was designed by Emina Mehić and Lucija Hok, and illustrated by Josipa Zeba. (© Josipa Zeba. Reproduced with permission.) It depicts the halohydrin dehalogenase‐catalysed conversion of epoxides. Extensive screening of enzymes from group B revealed several highly enantioselective transformations, with HheB showing higher enant...
Article
Imidazo[4,5-b]pyridine derived acrylonitriles were synthesized and explored for their in vitro antiproliferative effect on a diverse human cancer cell line panel. Three compounds, 20, 21 and 33, showed strong activity in the submicromolar range (IC50 0.2–0.6 μM), and were chosen for further biological experiments. Immunofluorescence staining and tu...
Article
Halohydrin dehalogenases (HHDHs) possess an unnatural activity of introducing functionalities such as N 3 , CN, NO 2 etc., into a molecule through the ring‐opening reaction of epoxides. The enantioselectivity of HHDHs is substrate‐dependent and not always high enough for synthetic applications. B‐group of HHDHs has been neglected in the past, due t...
Article
Malaria remains one of the major health problems worldwide. The lack of an effective vaccine and the increasing resistance of Plasmodium to the approved antimalarial drugs demands the development of novel antiplasmodial agents that can effectively prevent and/or treat this disease. Harmiquins represent hybrids that combine two moieties with differe...
Article
We describe the synthesis, spectroscopic characterization and computational analysis of the protonation equilibria of several newly designed imidazo[4,5-b]pyridine derived iminocoumarins to confirm their potential as pH sensing molecules in different solvents. The photophysical characterization and acid/base properties of these chromophores have be...
Article
A regioselective [3+2] cycloaddition (32CA) reaction to synthesize unsymmetric spiro-barbituric pyrazolines containing a chromone or phenolic pyrazole moiety was achieved, providing good to excellent yields. These rigid spiro-barbiturates exhibited good functional group tolerance, and they remained stable in the presence of an excessive amount of h...
Article
Full-text available
Although COVID-19 has been primarily associated with pneumonia, recent data show that its causative agent, the SARS-CoV-2 coronavirus, can infect many vital organs beyond the lungs, including the heart, kidneys and the brain. The literature agrees that COVID-19 is likely to have long-term mental health effects on infected individuals, which signifi...
Article
Full-text available
Histamine levels in the human brain are controlled by rather peculiar metabolic pathways. In the first step, histamine is enzymatically methylated at its imidazole Nτ atom, and the produced N-methylhistamine undergoes an oxidative deamination catalyzed by monoamine oxidase B (MAO-B), as is common with other monoaminergic neurotransmitters and neuro...
Article
Calculated proton affinities (PAs) and gas phase basicities (GPBs) are reported for diamantane (C14H20), triamantane (C18H24), 'globular and planar' isomers of tetramantane (C22H28) and pentamantane (C26H32), and for one 'globular' isomer of each of the larger diamondoid molecules: C51H58, C78H72, C102H90, and C131H116. Assuming CxHy as the parent...
Article
Full-text available
We present the synthesis and analytical, spectroscopic and computational characterization of three amino-substituted benzo[b]thieno[2,3-b]pyrido[1,2-a]benzimidazoles as novel pH probes with a potential application in pH-sensing materials. The designed systems differ in the number and position of the introduced isobutylamine groups on the pentacycli...
Article
Full-text available
Spontaneous S-alkylation of methimazole (1) with 1,2-dichloroethane (DCE) into 1,2-bis[(1-methyl-1H-imidazole-2-yl)thio]ethane (2), that we have described recently, opened the question about its formation pathway(s). Results of the synthetic, NMR spectroscopic, crystallographic and computational studies suggest that, under given conditions, 2 is ob...
Article
Full-text available
We used classical linear and microwave-assisted synthesis methods to prepare novel N-substituted, benzimidazole-derived acrylonitriles with antiproliferative activity against several cancer cells in vitro. The most potent systems showed pronounced activity against all tested hematological cancer cell lines, with favorable selectivity towards normal...
Poster
Recently, in the course stability study of thyrostatic drug methimazole (1-methyl-1,3-dihydro-1H-imidazole-2-thione, 2) in DCE we reported synthesis and characterisation of 7-methyl-2H,3H,7H-imidazo[2,1-b]thiazol-4-ium chloride (1) as a novel and stable thiiranium ion isomer [1]. To gain more insight into its reactivity we performed reaction of 1 w...
Article
We describe the synthesis of novel unsubstituted and N-substituted imidazo[4,5-b]pyridine derived acrylonitriles, which were prepared by classical and microwave assisted organic synthesis. Their antioxidative potential was studied using spectroscopic DPPH and ABTS assays, FRAP method and electrochemical oxidation potential measurements. Targeted ac...
Preprint
Full-text available
Although COVID-19 has been primarily associated with pneumonia, recent data show that its causative agent, the SARS-CoV-2 coronavirus, can infect many vital organs beyond the lungs, including the heart, kidneys and the brain. The literature agrees that COVID-19 is likely to have long-term mental health effects on infected individuals, which signifi...
Article
The rise of the resistance of the malaria parasite to the currently approved therapy urges the discovery and development of new efficient agents. Previously we have demonstrated that harmicines, hybrid compounds composed from β-carboline alkaloid harmine and cinnamic acid derivatives, linked via either triazole or amide bond, exert significant anti...
Article
Full-text available
A 1,3-dihexadecyl-1H-benzo[d]imidazol-3-ium-tetraphenylborate (DHBI-TPB) ion-pair implemented in DHBI-TPB surfactant sensor was used for the potentiometric quantification of anionic surfactants in detergents and commercial household care products. The DHBI-TPB ion-pair was characterized by FTIR spectroscopy and computational analysis which revealed...
Article
Full-text available
Novel symmetrical bis-pyrrolo[2,3-d]pyrimidines and bis-purines and their monomers were synthesized and evaluated for their antiproliferative activity in human lung adenocarcinoma (A549), cervical carcinoma (HeLa), ductal pancreatic adenocarcinoma (CFPAC-1) and metastatic colorectal adenocarcinoma (SW620) cells. The use of ultrasound irradiation as...
Article
Full-text available
Two structurally different 1D cobalt(II) coordination polymers with 4,4’‐bipyridine (4,4’‐bpy) and 2‐chloronicotinate (2‐Cl‐nic) or 5‐bromonicotinate (5‐Br‐nic), namely {[Co(2‐Cl‐nic)2(4,4’‐bpy)(H2O)2] ⋅ 4H2O}n (1) and {[Co(4,4’‐bpy)(H2O)4] [Co(5‐Br‐nic)4(H2O)2] ⋅ 4,4’‐bpy ⋅ 2H2O}n (2), were prepared under the same experimental conditions. The coba...
Article
Full-text available
Density functional theory calculations elucidated the precise reaction mechanism for the conversion of diphenylacetylenes into benzonitriles involving the cleavage of the triple C≡C bond, with N-iodosuccinimide (NIS) as an oxidant and trimethylsilyl azide (TMSN3) as a nitrogen donor. The reaction requires six steps with the activation barrier ΔG‡ =...
Article
The synthesis of novel 6-chloro/morpholino/amino/-9-sulfonylpurine derivatives was accomplished in two ways, either (i) involving the condensation reaction of 6-chloropurine with commercially available arylsulfonyl chlorides in acetone and the presence of aqueous KOH at 0 °C, followed by the substitution of C6-chlorine with morpholine, or (ii) empl...
Article
Unlike the closely related and widely investigated amidino-substituted benzimidazoles and benzothiazoles with a range of demonstrated biological activities, the matching benzoxazole analogues still remain a largely understudied and not systematically evaluated class of compounds. To address this challenge, we utilized the Pinner reaction to convert...
Article
We present the design, synthesis and biological activity of novel N-substituted benzimidazole based acrylonitriles as potential tubulin polymerization inhibitors. Their synthesis was achieved using classical linear organic and microwave assisted techniques, starting from aromatic aldehydes and N-substituted-2-cyanomethylbenzimidazoles. All newly pr...
Article
Full-text available
We used a range of computational techniques to reveal an increased histamine affinity for its H2 receptor upon deuteration, which was interpreted through altered hydrogen bonding interactions within the receptor and the aqueous environment preceding the binding. Molecular docking identified the area between third and fifth transmembrane α-helices a...
Article
Six novel 1:2 complexes of silver(I) nitrate with 2,5-, 2,6- and 3,5-dihalopyridines (halo stands for chlorine and bromine) were prepared by the reaction of an aqueous solution of AgNO3 and the corresponding pyridine derivative in water-alcohol solution. In spite of having analogous empirical formulae, they reveal intriguing structural differences,...
Article
Full-text available
The enzyme-catalyzed degradation of the biogenic amine serotonin is an essential regulatory mechanism of its level in the human organism. In particular, monoamine oxidase A (MAO A) is an important flavoenzyme involved in the metabolism of monoamine neurotransmitters. Despite extensive research efforts, neither the catalytic nor the inhibition mecha...
Article
Full-text available
Harmicines represent hybrid compounds composed of β-carboline alkaloid harmine and cinnamic acid derivatives (CADs). In this paper we report the synthesis of amide-type harmicines and the evaluation of their biological activity. N-harmicines 5a-f and O-harmicines 6a-h were prepared by a straightforward synthetic procedure, from harmine-based amines...
Article
Full-text available
Monoamine oxidases (MAOs) catalyze the degradation of a very broad range of biogenic and dietary amines including many neurotransmitters in the brain, whose imbalance is extensively linked with the biochemical pathology of various neurological disorders, and are, accordingly, used as primary pharmacological targets to treat these debilitating cogni...
Article
Full-text available
Human serum albumin (HSA) is the most abundant carrier protein in the human body. Competition for the same binding site between different ligands can lead to an increased active concentration or a faster elimination of one or both ligands. Indomethacin and quercetin both bind to the binding site located in the IIA subdomain. To determine the nature...
Article
Quinolino[7,8-h]quinoline is a superbasic compound, with a pKaH in acetonitrile greater than that of DMAN, although its synthesis and the synthesis of its derivatives can be problematic. The use of halogen derivatives 4,9-dichloroquinolino[7,8-h]quinoline (16) and 4,9-dibromoquinolino[7,8-h]quinoline (17) as precursors has granted the formation of...
Article
Chelating 1,4-disubstituted mono- (8a−8d) and bis-1,2,3-triazole-based (9a−11a) ligands were prepared by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of L-phenylalanine methyl ester to 11a. Cu(II) and Zn(II) complexes were prepared...
Article
Full-text available
The pyridinium oximes are known esterolytic agents, usually classified in the literature as catalysts, which mimic the catalytic mode of hydrolases. Herein, we combined kinetic and computational studies of the pyridinium-4-oxime-mediated acetylthiocholine (AcSCh+) hydrolysis to provide novel insights into their potential catalytic activity. The N-m...
Article
Full-text available
Substituted tetrahedranes offer exceptional carbon bases with the gas‐phase proton affinities (PAs) up to 356 kcal mol⁻¹, due to the strain‐induced ring opening upon protonation. Additional tetrahedrane moieties exert a dramatic basicity amplification to PAs reaching 600 kcal mol⁻¹, being the strongest organic superbases reported, clearly surpassin...
Preprint
Chelating 1,4-disubstituted mono- (8a−8d) and bis-1,2,3-triazole-based (9a−11a) ligands were prepared by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of L-phenylalanine methyl ester to 11a. Cu(II) and Zn(II) complexes were prepared...
Preprint
Chelating 1,4-disubstituted mono- (8a−8d) and bis-1,2,3-triazole-based (9a−11a) ligands were prepared by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of L-phenylalanine methyl ester to 11a. Cu(II) and Zn(II) complexes were prepared...
Article
Full-text available
We studied dopamine levels in three compartments of the dopaminergic synapse, including the presynaptic neuron cytosol, dopamine storage vesicles, and the synaptic gap. By considering three transport pathways (dopamine transporter (DAT), vesicular transporter (VT), and exocytosis), four simulated scenarios were investigated: homeostasis, applicatio...
Article
A variety of structurally different complexes of the isopropyl-bis(2-picolyl)amine (iPr-bpa) ligand were prepared with ZnA2 and CuA2 salts (A = Br─, Br─/PF6─, BF4─/F─, ClO4─). The choice of different counterion affected the stoichiometry, coordination number, geometry and formation of geometrical isomers. Crystal structures of four Zn(II) complexes...
Article
Full-text available
We used a combination of density functional theory (DFT) calculations and the implicit quantization of the acidic N-H and O-H bonds to assess the effect of deuteration on the binding of agonists (2-methylhistamine and 4-methylhistamine) and antagonists (cimetidine and famotidine) to the histamine H2 receptor. The results show that deuteration signi...
Article
Metal complexes of iminodiacetamide (imda) ligands and metal ions Zn(II), Cu(II), Ni(II), and Co(II) were prepared using eight imda ligands (L1-L8) substituted with groups of different steric and electronic properties on the central amine N atom (H atom, methyl, isopropyl, and benzyl) and the para position of the phenyl rings (nitro and dimethylami...
Article
Full-text available
We used a combination of MD simulations and DFT calculations to reveal the precise chemical mechanism underlying the conversion of boronated nucleosides to natural nucleosides in the presence of hydrogen peroxide, which was recently experimentally demonstrated by Morihiro and Obika et al. (Chem. Sci. 2018, 9, 1112). Our results show that this proce...
Article
Full-text available
We present the synthesis of a range of benzimidazole/benzothiazole-2-carboxamides with a variable number of methoxy and hydroxy groups, substituted with nitro, amino, or amino protonated moieties, which were evaluated for their antiproliferative activity in vitro and the antioxidant capacity. Antiproliferative features were tested on three human ca...
Article
This work presents a systematic evaluation of 2-amino, 5-amino and 2,5-diamino substituted benzimidazo[1,2-a]quinoline-6-carbonitriles as novel pH probes with a potential application in pH sensing materials or as H+ fluoroionophores in bulk optode membranes. The study was carried out by varying the length, type and position of amino substituents in...
Article
Full-text available
The basicities of simple organic bases – aliphatic and aromatic amines, amidines, phosphazenes, as well as saturated and unsaturated nitrogen heterocycles – are examined in acetonitrile, dimethyl sulfoxide, tetrahydrofuran, water and the gas phase. The basicities (pKaH values) of conjugate acids of a large variety of bases in these media are presen...
Article
The gas phase acidity of organosulfuric acid derivatives with two cyclopentadiene rings replacing the doubly‐bonded oxygen atoms was computationally assessed using the B3LYP DFT functional and 6–311++G(d,p) basis set. Introduced five‐membered rings increased the acidity through the delocalization of the excess negative charge in conjugates bases an...
Article
In the reaction of purines with ferrocenoyl chloride in dimethylformamide (DMF), a regioselective acylation occurred. The two products have been isolated and, according to detailed NMR analysis, identified as N7- and N9-ferrocenoylated isomers. In more polar solvent, e.g. in dimethylsulfoxide (DMSO), the two isomers interconvert to each other. The...
Article
Monoamine oxidases (MAO) are FAD-containing flavoenzymes that catalyze the degradation of a range of brain neurotransmitters, whose imbalance is extensively linked with the pathology of various neurological disorders. This is why MAOs have been the central pharmacological targets in treating neurodegeneration for more than 60 years. Still, despite...