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Dive into the research topics where Wojciech Jankowski is active.

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Featured researches published by Wojciech Jankowski.


Acta Crystallographica Section C-crystal Structure Communications | 2006

The 2:1 cocrystal of benzamide and pentafluorobenzoic acid

Wojciech Jankowski; Maria Gdaniec; Tadeusz Połoński

The crystal structure of the title compound, benzamide-2,3,4,5,6-pentafluorobenzoic .acid (2/1), 2C 7 H 7 NO·C 7 HF 5 O 2 , consists of centrosymmetric hexameric supermolecules composed of four amide and two carboxylic acid molecules connected via O-H···O and N-H···O hydrogen bonds. No phenyl-perfluorophenyl π-π stacking interactions are observed in this cocrystal.


Journal of Medical Internet Research | 2016

Can Google Searches Predict the Popularity and Harm of Psychoactive Agents

Wojciech Jankowski; Marcin Hoffmann

Background Predicting the popularity of and harm caused by psychoactive agents is a serious problem that would be difficult to do by a single simple method. However, because of the growing number of drugs it is very important to provide a simple and fast tool for predicting some characteristics of these substances. We were inspired by the Google Flu Trends study on the activity of the influenza virus, which showed that influenza virus activity worldwide can be monitored based on queries entered into the Google search engine. Objective Our aim was to propose a fast method for ranking the most popular and most harmful drugs based on easily available data gathered from the Internet. Methods We used the Google search engine to acquire data for the ranking lists. Subsequently, using the resulting list and the frequency of hits for the respective psychoactive drugs combined with the word “harm” or “harmful”, we estimated quickly how much harm is associated with each drug. Results We ranked the most popular and harmful psychoactive drugs. As we conducted the research over a period of several months, we noted that the relative popularity indexes tended to change depending on when we obtained them. This suggests that the data may be useful in monitoring changes over time in the use of each of these psychoactive agents. Conclusions Our data correlate well with the results from a multicriteria decision analysis of drug harms in the United Kingdom. We showed that Google search data can be a valuable source of information to assess the popularity of and harm caused by psychoactive agents and may help in monitoring drug use trends.


Journal of Mass Spectrometry | 2018

Methyl group transfer upon gas phase decomposition of protonated methyl benzoate and similar compounds

Rafał Frański; Błażej Gierczyk; Maciej Zalas; Wojciech Jankowski; Marcin Hoffmann

Gas phase decompositions of protonated methyl benzoate and its conjugates have been studied by using electrospray ionization-collision induced dissociation-tandem mass spectrometry. Loss of CO2 molecule, thus transfer of methyl group, has been observed. In order to better understand this process, the theoretical calculations have been performed. For methyl benzoate conjugates, it has been found that position of substituent affects the loss of CO2 molecule, not the electron donor/withdrawing properties of the substituent. Therefore, electrospray ionization-mass spectrometry in positive ion mode may be useful for differentiation of isomers of methyl benzoate conjugates.


Journal of Molecular Modeling | 2017

Quantum-chemical, NMR, FT IR, and ESI MS studies of complexes of colchicine with Zn(II)

Wojciech Jankowski; Joanna Kurek; P. Barczyński; Marcin Hoffmann

AbstractColchicine is a tropolone alkaloid from Colchicinum autumnale. It shows antifibrotic, antimitotic, and anti-inflammatory activities, and is used to treat gout and Mediterranean fever. In this work, complexes of colchicine with zinc(II) nitrate were synthesized and investigated using DFT, 1H and 13C NMR, FT IR, and ESI MS. The counterpoise-corrected and uncorrected interaction energies of these complexes were calculated. We also calculated their 1H, 13C NMR, and IR spectra and compared them with the corresponding experimentally obtained data. According to the ESI MS mass spectra, colchicine forms stable complexes with zinc(II) nitrate that have various stoichiometries: 2:1, 1:1:1, and 2:1:1 with respect to colchichine, Zn(II), and nitrate ion. All of the complexes were investigated using the quantum theory of atoms in molecules (QTAIM). The calculated and the measured spectra showed differences before and after the complexation process. Calculated electron densities and bond critical points indicated the presence of bonds between the ligands and the central cation in the investigated complexes that satisfied the quantum theory of atoms in molecules. Graphical AbstractDFT, NMR, FT IR, ESI MS, QTAIM and puckering studies of complexes of colchicine with Zn(II).


ACS Omega | 2017

Generation of Low-Dimensional Architectures through the Self-Assembly of Pyromellitic Diimide Derivatives

Chiara Musumeci; Monika Wałęsa-Chorab; Adam Gorczyński; Grzegorz Markiewicz; Andrzej Bogucki; Roman Świetlik; Zbigniew Hnatejko; Wojciech Jankowski; Marcin Hoffmann; Emanuele Orgiu; Artur R. Stefankiewicz; Violetta Patroniak; Artur Ciesielski; Paolo Samorì

Small π-conjugated molecules can be designed and synthesized to undergo controlled self-assembly forming low-dimensional architectures, with programmed order at the supramolecular level. Such order is of paramount importance because it defines the property of the obtained material. Here, we have focused our attention to four pyromellitic diimide derivatives exposing different types of side chains. The joint effect of different noncovalent interactions including π–π stacking, H-bonding, and van der Waals forces on the four derivatives yielded different self-assembled architectures. Atomic force microscopy studies, corroborated with infrared and nuclear magnetic resonance spectroscopic measurements, provided complementary multiscale insight into these assemblies.


IOSR Journal of Pharmacy | 2016

Human Body Fluid Ions In colchicine complexes ESI MS, MADLI MS, Spectroscopic, DFT Studies and Fungicidal Activity of colchicine complexes With Sodium, Potassium, Magnesium and calcium carbonates and Sulphates

Joanna Kurek; Grażyna Bartkowiak; Wojciech Jankowski; Patrycja Kwaśniewska-Sip; Grzegorz Schroeder; Marcin Hoffmann; Grzegorz Cofta; P. Barczyński

Colchicine is an alkaloid characterised by good water solubility. After administration of colchicine as a medicine for example for the treatment of gout, colchicine probably forms some more or less stable structures with cations and/or anions present in human body fluid. The colchicine complexes with Na + , K + Mg 2+ and Ca 2+


Free Radical Research | 2018

Antioxidant and cytotoxic activity of new di- and polyamine caffeine analogues

Beata Jasiewicz; Arleta Sierakowska; Wojciech Jankowski; Marcin Hoffmann; Weronika Piorońska; Agnieszka Górnicka; Anna Bielawska; Krzysztof Bielawski; Lucyna Mrówczyńska

Abstract A series of new di- and polyamine-caffeine analogues were synthesised and characterised by NMR, FT-IR, and MS spectroscopic methods. To access the stability of the investigated caffeine analogues, molecular dynamic simulations were performed in NAMD 2.9 assuming CHARMM36 force field. To evaluate the antioxidant capacity of new compounds, three different antioxidant assays were used, namely 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH•) scavenging activity, ferrous ions (Fe2+) chelating activity, and Fe3+→Fe2+reducing ability. In vitro, the ability of new derivatives to protect human erythrocytes against oxidative haemolysis induced by free radical from 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH) was estimated. The cytotoxic activity was tested using MCF-7 breast cancer cells and human erythrocytes. All compounds showed the antioxidant capacity depending mostly on their ferrous ions chelating activity. In the presence of AAPH, some derivatives were able to effectively inhibit the oxidative haemolysis. Two derivatives, namely 8-(methyl(2-(methylamino)ethyl)-amino)caffeine and 8-(methyl(3-(methylamino)propyl)amino)caffeine, showed cytotoxic activity against MCF-7 breast cancer cells but not against human erythrocytes. Therefore, it is concluded that the selected di- and polyamine caffeine analogues, depending on their chemical structure, were able to minimise the oxidative stress and to inhibit the tumour cell growth. The confirmed antioxidant and cytotoxic properties of some caffeine derivatives make them attractive for potential applications in food or pharmaceutical industries.


Angewandte Chemie | 2003

Supramolecular Assemblies of Hydrogen-Bonded Carboxylic Acid Dimers Mediated by Phenyl–Pentafluorophenyl Stacking Interactions

Maria Gdaniec; Wojciech Jankowski; Maria J. Milewska; Tadeusz Połoński


Acta Crystallographica Section C-crystal Structure Communications | 2002

The β-polymorph of phenazine

Wojciech Jankowski; Maria Gdaniec


Polyhedron | 2015

Experimental and quantum-chemical studies of anabasine complexes with copper(II) and zinc(II) ions

Romualda Bregier-Jarzebowska; Karolina Malczewska-Jaskóła; Wojciech Jankowski; Beata Jasiewicz; Marcin Hoffmann; Anna Gąsowska; Renata Jastrząb

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Marcin Hoffmann

Adam Mickiewicz University in Poznań

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Beata Jasiewicz

Adam Mickiewicz University in Poznań

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Maria Gdaniec

Adam Mickiewicz University in Poznań

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Błażej Gierczyk

Adam Mickiewicz University in Poznań

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Joanna Kurek

Adam Mickiewicz University in Poznań

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Karolina Malczewska-Jaskóła

Adam Mickiewicz University in Poznań

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Maciej Zalas

Adam Mickiewicz University in Poznań

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P. Barczyński

Adam Mickiewicz University in Poznań

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Rafał Frański

Adam Mickiewicz University in Poznań

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