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11 result(s) for "Żurawiński, Remigiusz"
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Anticancer Activity of Enantiomeric Neplanocins A: Exploring the Role of Chirality in Tumor Suppression
Neplanocin A (NPA) is a natural carbocyclic analogue of adenosine that was isolated from Ampullariella regularis, which is known for its antibacterial, antiviral, and anticancer activity. Although the activity of this compound has been demonstrated in many biological models, the mechanism of its anticancer activity is not fully understood. In the current work, we present the comparison of the biological activity of two enantiomers of neplanocin A in the series of cancerous and non-cancerous cell types. In all tested cell lines, the compound with natural stereochemistry, (-)-NPA, was found to be more cytotoxic than its synthetic (+)-NPA derivative; however, sensitivity to neplanocins A varied between cell types. To determine possible reasons for the observed differences in individual cancer cell types, the expression level and effects of individual genes of adenosine-interacting enzymes were analyzed. Bioinformatic analysis of the interaction between (-)-NPA and (+)-NPA with major adenosine-interacting enzymes, such as adenosine kinase (ADK), adenosine deaminases (ADA and ADA2), and S-adenosylhomocysteine hydrolase (SAHH, AHCY), was performed. The molecular docking results revealed differences in the binding energy of the individual enantiomers of neplanocin A with the targets, which sheds new light on the mechanism of action of these adenosine analogues.
Modulation of Properties in 1Benzothieno3,2-b1benzothiophene Derivatives through Sulfur Oxidation
This study explores the impact of sulfur oxidation on the structural, optical, and electronic properties of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives, specifically focusing on 2,7-dibromo BTBT (2,7-diBr-BTBT) and its oxidized forms, 5,5-dioxide (2,7-diBr-BTBTDO) and 5,5,10,10–tetraoxide (2,7-diBr-BTBTTO). The bromination of BTBT followed by sequential oxidation with m-chloroperoxybenzoic acid yielded the target compounds in good yields. They were characterized using a wide array of analytical techniques including different spectroscopic methods, X-ray analysis, thermal analysis, and quantum chemical calculations. The results revealed that sulfur oxidation significantly alters the crystal packing, thermal stability, and optoelectronic properties of BTBT derivatives. Notably, the oxidized forms exhibited increased thermal stability and enhanced emission properties, with quantum yields exceeding 99%. These findings provide valuable insights for designing advanced organic semiconductors and fluorescent materials with tunable properties, based on the BTBT core.
Selenonium Ylides: Syntheses, Structural Aspects, and Synthetic Applications
The goals of this mini review constitute (a) a presentation of the synthetic protocols applied to the preparation of achiral and non-racemic selenonium ylides; (b) discussion of their basic structural features, including their optical activity; and (c) a description of their synthetic applications in general synthetic methodology and in asymmetric synthesis.
Visualization of Cellular Membranes in 2D and 3D Conditions Using a New Fluorescent Dithienothiophene S,S-Dioxide Derivative
Cellular membranes play a key role in cell communication with the extracellular environment and neighboring cells. Any changes, including their composition, packing, physicochemical properties and formation of membrane protrusions may affect cells feature. Despite its great importance, tracking membrane changes in living cells is still a challenge. For investigation of processes related to tissue regeneration and cancer metastasis, such as the induction of epithelial-mesenchymal transition, increased cell motility, and blebbing, the possibility to conduct prolonged observation of membrane changes is beneficial, albeit difficult. A particular challenge is conducting this type of research under detachment conditions. In the current manuscript, a new dithienothiophene S,S-dioxide (DTTDO) derivative is presented as an effective dye for staining the membranes of living cells. The synthetic procedures, physicochemical properties, and biological activity of the new compound are presented herein. In addition to the labeling of the membranes in a monolayer culture, its usefulness for visualization of membranes under detachment conditions is also demonstrated. Obtained data have proven that a new DTTDO derivative may be used to stain membranes in various types of experimental procedures, from traditional 2D cell cultures to unanchored conditions. Moreover, due to the specific optical properties, the background signal is reduced and, thus, observation may be performed without washing.
Unexpected Formation of a Chiral spiro‐system in the Reaction of the Dilithium Derivative of Hexafluorocumyl Alcohol with N‐(t–butylsulfenyl)phthalimide
An unexpected course of the reaction of hexafluorocumyl alcohol dilithium derivative 2 with N‐(t‐butylsulfenyl)phthalimide (3) has been presented. The process proceeded under mild conditions and resulted in previously undescribed chiral spiro‐system‐ 3′,3′‐bis(trifluoromethyl)‐3H,3′H‐1,1′‐spirobis(isobenzofuran)‐3‐one (5) as the only product. A detailed spectral analysis of the product has been provided, and mechanistic aspects have been investigated. Attempts to separate the enantiomers of compound 5 using a semipreparative HPLC method with a chiral stationary phase column have been described. The repeatability of the reaction using analogs of alcohol 4 has also been tested. DFT calculations of absolute configuration assignment have been performed successfully. The reaction of the hexafluorocumyl alcohol dilithium derivative with N‐(t‐butylsulfenyl)phthalimide unexpectedly resulted in the formation of a chiral spiro compound, which was fully characterized employing spectroscopic, chromatographic, and crystallographic analyses, as well as DFT calculations. A theoretical mechanism of the reaction was proposed. The versatility of the reaction was tested.
Red-Emitting Dithienothiophene S,S-Dioxide Dyes for Cellular Membrane Staining
A series of dithienothiophene S,S-dioxide (DTTDO) dyes was designed, synthesized, and investigated for their suitability in fluorescent cell imaging. Synthetized (D-π-A-π-D)-type DTTDO derivatives have molecule lengths close to the thickness of the phospholipid membrane, and they contain on both ends two positively charged or neutral polar groups to increase their solubility in water and to ensure simultaneous interaction with polar groups of the inner and outer part of the cellular membrane. DTTDO derivatives exhibit absorbance and emission maxima in the 517–538 nm and 622–694 nm range, respectively, and a large Stokes shift up to 174 nm. Fluorescence microscopy experiments revealed that these compounds selectively intercalate into cell membranes. Moreover, a cytotoxicity assay conducted on a model human live cells indicates low toxicity of these compounds at the concentrations required for effective staining. With suitable optical properties, low cytotoxicity, and high selectivity against cellular structures, DTTDO derivatives are proven to be attractive dyes for fluorescence-based bioimaging.
A new and expeditious synthesis of all enantiomerically pure stereoisomers of rosaprostol, an antiulcer drug
Four enantiomerically pure stereoisomers of rosaprostol ( 1 ), an antiulcer drug, were efficiently synthesized from the enantiomers of 2-(dimethoxyphosphoryl)-3-hexylcyclopentanone ( 3 ) as chiral substrates. The latter were obtained by resolution of racemic 3 with (+)-( R )-1-(1-naphthyl)ethylamine. The conversion of (+)- 3 into rosaprostol stereoisomer (−)- 1a was accomplished in four steps in 56% overall yield. According to the same protocol, the second stereoisomer (+)- 1c was obtained from (−)- 3 in 55% overall yield. A slightly improved procedure of the last two steps of the transformation of (+)- 3 into (−)- 1a allowed an increase in the overall yield to 64%. The remaining two stereoisomers, (−)- 1b and (+)- 1d , were obtained from (−)- 1a and (+)- 1c in 71 and 68% yield, respectively, by a two-reaction sequence, in which a Mitsunobu inversion of configuration at C-5 was the key step.
Modulation of Properties in 1Benzothieno3,2-b1benzothiophene Derivatives through Sulfur Oxidation
This study explores the impact of sulfur oxidation on the structural, optical, and electronic properties of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives, specifically focusing on 2,7-dibromo BTBT (2,7-diBr-BTBT) and its oxidized forms, 5,5-dioxide (2,7-diBr-BTBTDO) and 5,5,10,10-tetraoxide (2,7-diBr-BTBTTO). The bromination of BTBT followed by sequential oxidation with m-chloroperoxybenzoic acid yielded the target compounds in good yields. They were characterized using a wide array of analytical techniques including different spectroscopic methods, X-ray analysis, thermal analysis, and quantum chemical calculations. The results revealed that sulfur oxidation significantly alters the crystal packing, thermal stability, and optoelectronic properties of BTBT derivatives. Notably, the oxidized forms exhibited increased thermal stability and enhanced emission properties, with quantum yields exceeding 99%. These findings provide valuable insights for designing advanced organic semiconductors and fluorescent materials with tunable properties, based on the BTBT core.This study explores the impact of sulfur oxidation on the structural, optical, and electronic properties of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) derivatives, specifically focusing on 2,7-dibromo BTBT (2,7-diBr-BTBT) and its oxidized forms, 5,5-dioxide (2,7-diBr-BTBTDO) and 5,5,10,10-tetraoxide (2,7-diBr-BTBTTO). The bromination of BTBT followed by sequential oxidation with m-chloroperoxybenzoic acid yielded the target compounds in good yields. They were characterized using a wide array of analytical techniques including different spectroscopic methods, X-ray analysis, thermal analysis, and quantum chemical calculations. The results revealed that sulfur oxidation significantly alters the crystal packing, thermal stability, and optoelectronic properties of BTBT derivatives. Notably, the oxidized forms exhibited increased thermal stability and enhanced emission properties, with quantum yields exceeding 99%. These findings provide valuable insights for designing advanced organic semiconductors and fluorescent materials with tunable properties, based on the BTBT core.
Visualization of Cellular Membranes in 2D and 3D Conditions Using a New Fluorescent Dithienothiophene IS,S/I-Dioxide Derivative
Cellular membranes play a key role in cell communication with the extracellular environment and neighboring cells. Any changes, including their composition, packing, physicochemical properties and formation of membrane protrusions may affect cells feature. Despite its great importance, tracking membrane changes in living cells is still a challenge. For investigation of processes related to tissue regeneration and cancer metastasis, such as the induction of epithelial-mesenchymal transition, increased cell motility, and blebbing, the possibility to conduct prolonged observation of membrane changes is beneficial, albeit difficult. A particular challenge is conducting this type of research under detachment conditions. In the current manuscript, a new dithienothiophene S,S-dioxide (DTTDO) derivative is presented as an effective dye for staining the membranes of living cells. The synthetic procedures, physicochemical properties, and biological activity of the new compound are presented herein. In addition to the labeling of the membranes in a monolayer culture, its usefulness for visualization of membranes under detachment conditions is also demonstrated. Obtained data have proven that a new DTTDO derivative may be used to stain membranes in various types of experimental procedures, from traditional 2D cell cultures to unanchored conditions. Moreover, due to the specific optical properties, the background signal is reduced and, thus, observation may be performed without washing.
Red-Emitting Dithienothiophene IS/I,IS/I-Dioxide Dyes for Cellular Membrane Staining
A series of dithienothiophene S,S-dioxide (DTTDO) dyes was designed, synthesized, and investigated for their suitability in fluorescent cell imaging. Synthetized (D-π-A-π-D)-type DTTDO derivatives have molecule lengths close to the thickness of the phospholipid membrane, and they contain on both ends two positively charged or neutral polar groups to increase their solubility in water and to ensure simultaneous interaction with polar groups of the inner and outer part of the cellular membrane. DTTDO derivatives exhibit absorbance and emission maxima in the 517–538 nm and 622–694 nm range, respectively, and a large Stokes shift up to 174 nm. Fluorescence microscopy experiments revealed that these compounds selectively intercalate into cell membranes. Moreover, a cytotoxicity assay conducted on a model human live cells indicates low toxicity of these compounds at the concentrations required for effective staining. With suitable optical properties, low cytotoxicity, and high selectivity against cellular structures, DTTDO derivatives are proven to be attractive dyes for fluorescence-based bioimaging.