Image of the solid-state rotary motion encoded in the dielectric response.

The future development of advanced molecular systems with controlled rotation requires the development of an effective methodology for assessing the rotational performance of artificial machine components. We identified two patterns of the dielectric behavior for polar rotators in a static non-polar framework of sizable crystal showing relations between the spectral and molecular-level features of solid-state rotary motion. Various functionalization of phenylene rotors with a fluorine atom(s) changed rotational performance from high to low with rotational barriers ranging from 6.

Advanced Mass Spectrometric Techniques for the Comprehensive Study of Synthesized Silicon-Based Silyl Organic Compounds: Identifying Fragmentation Pathways and Characterization.

The primary objective of this study was to synthesize and characterize novel silicon-based silyl organic compounds in order to gain a deeper understanding of their potential applications and interactions with other compounds. Four new artificial silyl organic compounds were successfully synthesized: 1-O-(Trimethylsilyl)-2,3,4,6-tetra-O-acetyl-β-d-glucopyranose (compound ), 1-[(1,1-dimethylehtyl)diphenylsilyl]-1H-indole (compound ), O-tert-butyldiphenylsilyl-(3-hydroxypropyl)oleate (compound ), and 1-O-tert-Butyldiphenylsilyl-myo-inositol (compound ). To thoroughly characterize these synthesized compounds, a combination of advanced mass spectrometric techniques was employed, including nanoparticle-assisted laser desorption/ionization mass spectrometry (NALDI-MS), Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and triple quadrupole electrospray tandem mass spectrometry (QqQ ESI-MS/MS).

Cyclic Analogs of Desferrioxamine E Siderophore for Ga Nuclear Imaging: Coordination Chemistry and Biological Activity in .

As multidrug-resistant bacteria are an emerging problem and threat to humanity, novel strategies for treatment and diagnostics are actively sought. We aim to utilize siderophores, iron-specific strong chelating agents produced by microbes, as gallium ion carriers for diagnosis, applying that Fe(III) can be successfully replaced by Ga(III) without losing biological properties of the investigated complex, which allows molecular imaging by positron emission tomography (PET). Here, we report synthesis, full solution chemistry, thermodynamic characterization, and the preliminary biological evaluation of biomimetic derivatives (FOX) of desferrioxamine E (FOXE) siderophore, radiolabeled with Ga for possible applications in PET imaging of .

Novel Double-Modified Colchicine Derivatives Bearing 1,2,3-Triazole: Design, Synthesis, and Biological Activity Evaluation.

A series of 1,4-disubstituted 1,2,3-triazoles having 10-demethoxy-10--methylaminocolchicine core were designed and synthesized the Cu(I)-catalyzed "click" reaction and screened for their cytotoxicity against four cancer cell lines (A549, MCF-7, LoVo, LoVo/DX) and one noncancerous cell line (BALB/3T3). Indexes of resistance (RI) and selectivity (SI) were also determined to assess the potential of the analogues to break drug resistance of the LoVo/DX cells and to verify their selectivity toward killing cancer cells over normal cells. The compounds with an ester or amide moiety in the fourth position of 1,2,3-triazole of 10--methylaminocolchicine turned out to have the greatest therapeutic potential (low IC values and favorable SI values), much better than that of unmodified colchicine or doxorubicin and cisplatin.

Synthesis and antiproliferative screening of novel doubly modified colchicines containing urea, thiourea and guanidine moieties.

A new series of 10-demethoxy-10-methylaminocolchicines bearing urea, thiourea or aguanidine moieties at position C7 has been designed, synthesized and evaluated for in vitro anticancer activity against different cancer cell lines (A549, MCF-7, LoVo, LoVo/DX). The majority of the new derivatives were active in the nanomolar range and were characterized by lower IC values than cisplatin or doxorubicin. Two ureas (4 and 8) and thioureas (19 and 25) were found to be good antiproliferative agents (low IC values and high SI) and could prove to be promising candidates for further research in the field of anticancer drugs based on the colchicine skeleton.

New Series of Double-Modified Colchicine Derivatives: Synthesis, Cytotoxic Effect and Molecular Docking.

Colchicine is a well-known anticancer compound showing antimitotic effect on cells. Its high cytotoxic activity against different cancer cell lines has been demonstrated many times. In this paper we report the syntheses and spectroscopic analyses of novel colchicine derivatives obtained by structural modifications at C7 (carbon-nitrogen single bond) and C10 (methylamino group) positions.

Synthesis, Antiproliferative Activity and Molecular Docking Studies of Novel Doubly Modified Colchicine Amides and Sulfonamides as Anticancer Agents.

Colchicine is a well-known compound with strong antiproliferative activity that has had limited use in chemotherapy because of its toxicity. In order to create more potent anticancer agents, a series of novel colchicine derivatives have been obtained by simultaneous modification at C7 (amides and sulfonamides) and at C10 (methylamino group) positions and characterized by spectroscopic methods. All the synthesized compounds have been tested in vitro to evaluate their cytotoxicity toward A549, MCF-7, LoVo, LoVo/DX and BALB/3T3 cell lines.

Synthesis and activity of opioid peptidomimetics with β- and β-amino acids.

Morphiceptin (Tyr-Pro-Phe-Pro-NH) is a selective ligand of the mu opioid receptor, an important target in pain regulation. In this study, morphiceptin was modified at positions 2 or 3 by introduction of β- or β-amino acids and additionally in position 1 by replacing Tyr by Dmt (2',6'-dimethyltyrosine), which resulted in obtaining enzymatically stable analogs with mixed opioid receptor affinity profiles. An analog of the sequence Dmt-d-Ala-(R)-β-1-Nal-Pro-NH [Nal=3-(1-naphthyl)-alanine] showed very high activity at the mu and delta receptors in the calcium mobilization functional test but did not cross the artificial membrane imitating the blood-brain barrier.