Artykuły IChO PAN

Displaying 1 - 5 of 217 records

Donor–Acceptor Pentacene Analogues With Near-Infrared Emission and Tunable Aromaticity
(Wiley, 2026) Nowak, Krzysztof; Morawski, Olaf; Mehboob, Muhammad Yasir; Morawiak, Maja; Noworyta, Krzysztof; Foroutan-Nejad, Cina; Grzybowski, Marek; Institute of Organic Chemistry, Polish Academy of Sciences; Institute of Physics, Polish Academy of Sciences
Strategic substitution of the 5 and 12 positions in pentacene with an electron-donating nitrogen and electron-accepting phosphine oxide, sulfone and carbonyl groups results in highly polarized para-quinodimethane (pQDM) derivatives with large dipole moments exceeding 10 D. These push-pull systems feature narrow HOMO-LUMO gaps (1.0–1.7 eV), reversible redox properties and near-infrared (NIR) absorption and emission with maxima between 800 and 1100 nm. Remarkably, the polarization induces aromaticity switching: unlike their non-aromatic double–donor and double–acceptor counterparts, the donor–acceptor analogues develop weak aromatic character in the central quinoidal ring, which is further enhanced in polar solvents, as confirmed by theoretical calculations, NMR spectroscopy and X-ray crystallography. These findings demonstrate how molecular polarization can modulate aromaticity and electronic structure, providing a design platform for functional quinoidal π-systems with tunable optical and redox properties.
Synthesis and chiral optical activity of a quadruple heterohelicene based on 1,4-dihydropyrrolo[3,2-b]pyrrole–picene hybrid
(Royal Society of Chemistry, 2026) Kochanowski, Krzysztof J.; Górski, Krzysztof; Kusy, Damian; Vanthuyne, Nicolas; Landi, Alessandro; Bertocchi, Francesco; Ciesielski, Arkadiusz; Cyrański, Michał K.; Monaco, Guglielmo; Terenziani, Francesca; Gryko, Daniel T.; Institute of Organic Chemistry, Polish Academy of Sciences; Aix Marseille Univ, CNRS, Centrale Med, FSCM, Chiropole, Marseille, France; Dipartimento di Chimica, Università degli Studi di Salerno, Italy; Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy; Faculty of Chemistry, University of Warsaw; Inter-faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw
The synthesis and structural elucidation of a diaza-quadruple helicene, comprising a double [6]helicene and two [5]helicene subunits fused around a 1,4-dihydropyrrolo[3,2-b]pyrrole (DHPP) core with appended picene units, is reported. The target compound was accessed via a straightforward protocol involving a multicomponent reaction to form a tetraarylpyrrolo[3,2-b]pyrrole (TAPP) intermediate, followed by regioselective bromination and a twofold intramolecular direct arylation. X-ray crystallography confirmed the highly twisted, quadruple helical architecture, while separation of the enantiomers of the double anti-S2-[6]helicene fragment by chiral HPLC enabled comprehensive chiroptical analysis via electronic circular dichroism (ECD) and circularly polarized luminescence (CPL) spectroscopy. Density functional theory (DFT) calculations support the experimental findings by revealing pronounced π-expansion, a distinct charge-transfer character in the excited state, and enhanced alignment of electric and magnetic transition dipole moments, and allow assigning a PP helicity to the central helicenes for the enantiomer whose ECD spectrum has a negative Cotton effect at low energy. Consequently, the structural and chiroptical properties of the diaza-quadruple helicene are thoroughly characterized.
Rab geranylgeranyl transferase activity is required for proper sterol biosynthesis in Arabidopsis thaliana
(Oxford University Press on behalf of the Japanese Society of Plant Physiologists, 2026) Gutkowska, Małgorzata; Zajbt-Łuczniewska, Marta; Buszewicz, Daniel; Anielska-Mazur, Anna; Lipko, Agata; Pączkowski, Cezary; Spólnik, Grzegorz; Sojka, Maciej; Jaźwiec, Radosław; Samborowska, Emilia; Swiezewska, Ewa; Hoffman, Marta; Department of Biochemistry and Microbiology, Institute of Biology, Warsaw University of Life Sciences; Institute of Biochemistry and Biophysics, Polish Academy of Sciences; Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences; Department of Plant Biochemistry, Institute of Biochemistry, Faculty of Biology, University of Warsaw; Institute of Organic Chemistry, Polish Academy of Sciences
In all eukaryotic cells, protein prenylation and cytoplasmic isoprenoid biosynthesis pathways leading to sterols, dolichols, and other isoprenoid compounds share a common precursor pool of isopentenyl diphosphate and the isomeric dimethylallyl diphosphate. Despite this, little is known about the interplay between these processes. Here we ask whether perturbation of protein prenylation in plants influences isoprenoid biosynthesis in the endoplasmic reticulum, and in particular if it affects sterol and dolichol biosynthesis. We use an Arabidopsis thaliana mutant with defects in the Rab geranylgeranyl transferase as a viable model of protein hypoprenylation, and we show that sterol and dolichol content is significantly elevated in the mutant plants. Also sterol composition is changed: cholesterol content is increased and some atypical sterol pathway intermediates are accumulating. Our results show that plant sterol biosynthesis involves high levels of crosstalk between pathway branches than previously reported and receives regulatory input from protein prenylation pathways.
Stable ultrabright nanoprobes for two-photon excitation microscopy based on octupolar merocyanine-loaded nanovesicles
(Royal Society of Chemistry, 2026) Garrido-Rodríguez, Sara; Poronik, Yevgen M.; Delledonne, Andrea; Pescina, Silvia; Vargas-Nadal, Guillem; Morla-Folch, Judit; Racchi, Ottavia; Di Maiolo, Francesco; Ventosa, Nora; Sissa, Cristina; Gryko, Daniel T.; Köber, Mariana; Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Spain; Centro de Investigacion Biomedica en Red: Bioingenierıa, Biomateriales y Nanomedicina (CIBER-BBN), Spain; Institute of Organic Chemistry, Polish Academy of Sciences; Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Italy; ADDRes Lab, Department of Food and Drug, University of Parma, Italy; Nanomol Technologies S.L., Campus UAB, Spain
Two-photon microscopy is a powerful technique for deep-tissue and in vivo fluorescence imaging, yet its full potential is often constrained by the low two-photon absorption efficiency of conventional fluorophores. In this work, for the first time non-liposomal, unilamellar quatsome nanovesicles were loaded with octupolar fluorophores. Molecular engineering of centrosymmetric merocyanines led to dyes emitting in the 600–700 nm range with a fluorescence quantum yield ≈ 0.16 in polar solvents. Centrosymmetric architecture made it possible to perform heretofore unachievable systematic investigation of the impact of hydrophobic and hydrophilic (triethylene glycol) moieties on the stability of nanocarriers. It was discovered that two long alkyl chains are prerequisites to achieving stable incorporation of dyes within nanovesicles. Through systematic formulation screening, we identified a lead nanoprobe exhibiting high brightness, in the order of 107 M−1 cm−1, combined with strong and broad nonlinear optical properties leading to large two-photon brightness, in the order of 104 GM, in a highly stable nanoparticle. The performance of these very bright nanoprobes in two-photon microscopy was assessed in ex vivo permeation studies using porcine tissues, demonstrating their potential for bioimaging applications. This work underscores the synergy between molecular design and nanocarrier engineering in advancing next-generation fluorescent probes for nonlinear optical imaging.
Salts of Antifolate Pyrimethamine with Isomeric Aminobenzoic Acids: Exploring Packing Interactions and Pre-Crystallization Aggregation
(MDPI, 2026) Cichocka, Karolina; Zimnicka, Magdalena; Kędra, Karolina; Gajek, Arkadiusz; Ceborska, Magdalena; Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszyński University; Institute of Organic Chemistry, Polish Academy of Sciences; Institute of Physical Chemistry, Polish Academy of Sciences
Pyrimethamine (PYR), a drug approved for the treatment of infections caused by protozoan parasites, is a multifunctional API based on 2,4-diaminopyrimidine scaffold. The present study aims toward the development of novel solid forms of PYR, by combining it with three isomeric aminobenzoic acids—2-aminobenzoic acid (2NH2-BA), 3-aminobenzoic acid (3NH2-BA), and 4-aminobenzoic acid (4NH2-BA). Solution crystallization led to the formation of three new solvated salts of PYR (PYR/2NH2-BA/EtOH/H2O, PYR/3NH2-BA/EtOH, and PYR/4NH2-BA/EtOH/H2O). The detailed physicochemical properties of the formed compounds were characterized by single-crystal X-ray diffraction (SC-XRD), FTIR, PXRD, thermogravimetry (TG), and differential scanning calorimetry (DSC). Additionally, the pre-crystallization solutions of PYR with 2NH2-BA, 3NH2-BA, and 4NH2-BA were studied by electrospray ionization mass spectrometry technique (ESI-MS), which enabled the observation of peaks corresponding to noncovalently bonded molecules, providing insight into their specific aggregation in a solution/gas phase environment. We identified different non-covalent aggregates, including self-aggregates of aminobenzoic acids and PYR/aminobenzoic acid associates of different stoichiometries.

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