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1.
Prof. Piotr Bałczewski Dr. Emilia Kowalska Dr. Ewa Różycka-Sokołowska Dr. Joanna Skalik Dr. Krzysztof Owsianik Dr. Marek Koprowski Dr. Bernard Marciniak Dr. Dariusz Guziejewski Prof. Witold Ciesielski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(62):14148-14161
The highly substituted mono-aryl/alkylthio-(hetero)acenes prepared in this study have been found to be thermally more stable (Tdecomp.=331–354 °C) than the known di-aryl/alkylthio-substituted acenes by an average of 25 °C. They are also much more photostable at 254 and 365 nm (in both argon and air) than the parent anthracene and other reported anthracenes. The most photostable aryl/alkylthio-anthracenes at 254 nm were found to be 60–70 (in air) and 130 (in argon) times more stable in solution than the unsubstituted anthracene, and much more stable than known EDG/EWG-substituted anthracenes (EDG=electron-donating group, EWG=electron-withdrawing group) with an extended aromatic core. Furthermore, the acenes showed significantly higher photostability at 365 nm in both air and argon. The anthracenes were obtained by the novel thio-Friedel–Crafts/Bradsher cyclization reaction of hitherto unknown [o-(1,3-dithian-2-yl)aryl](aryl)methyl thioethers. The developed approach provides a general access to mono-aryl/alkylthio-substituted (hetero)acene frameworks containing at least three fused (hetero)aromatic rings. The characteristic feature of this approach, which leads to highly substituted acenes, is that the substituents, unlike in other methods, may be introduced at an early stage of the synthesis. DFT and TD-DFT calculations confirmed the stabilizing role of the aryl/alkylthio substituent in the mono-aryl/alkylthio-substituted anthracenes, which are the most stable anthracenes prepared to date. Their high photostability is mainly due to the quenching of singlet oxygen by the acene and the quenching of the acene S1 state by molecular oxygen. 相似文献
2.
JPC – Journal of Planar Chromatography – Modern TLC - Recently, a growing interest has been observed in preventive and “anti-ageing” medicine, accompanied by a dynamic... 相似文献
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Dr. Anaïs Depaix Agnieszka Mlynarska-Cieslak Dr. Marcin Warminski Dr. Pawel J. Sikorski Prof. Dr. Jacek Jemielity Dr. Joanna Kowalska 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(47):12190-12197
Labeled RNAs are invaluable probes for investigation of RNA function and localization. However, mRNA labeling remains challenging. Here, we developed an improved method for 3′-end labeling of in vitro transcribed RNAs. We synthesized novel adenosine 3′,5′-bisphosphate analogues modified at the N6 or C2 position of adenosine with an azide-containing linker, fluorescent label, or biotin and assessed these constructs as substrates for RNA labeling directly by T4 ligase or via postenzymatic strain-promoted alkyne-azide cycloaddition (SPAAC). All analogues were substrates for T4 RNA ligase. Analogues containing bulky fluorescent labels or biotin showed better overall labeling yields than postenzymatic SPAAC. We successfully labeled uncapped RNAs, NAD-capped RNAs, and 5′-fluorescently labeled m7Gp3Am-capped mRNAs. The obtained highly homogenous dually labeled mRNA was translationally active and enabled fluorescence-based monitoring of decapping. This method will facilitate the use of various functionalized mRNA-based probes. 相似文献
6.
Isothiocyanato-functionalized cyanine dyes 7 and 11 for labelling of proteins at amino groups have been synthesized. The dyes and their adducts with amines show strong absorbance and fluorescence in the near-infrared region of 750-850 nm. 相似文献
7.
The syntheses of boronates derived from the reaction of dioxaborolanes and dioxaborinanes with either organolithium or organomagnesium reagents are investigated along with their subsequent use in the palladium cross coupling reaction. The intrinsic stability of these cyclic esters contributes to their facile reaction with both lithium and magnesium nucleophiles at mild and safe conditions. We have found that many of the reactions proceed at room temperature which is a significant improvement over the traditional routes which require cryogenic temperatures. The scope of these reactions and their practical application to large scale process synthesis is described. 相似文献
8.
Monika Szulc Justyna Samaszko-Fiertek Rafał Ślusarz Kornelia Kowalska Artur Sikorski 《Journal of carbohydrate chemistry》2016,35(3):161-171
Solid phase peptide synthesis (SPPS) of two selected muramyl pentapeptide derivatives is described. The simplicity of removing the protecting groups via one-step deprotection and cleavage from the resin is the biggest advantage of SPPS. Using this method, two muramyl pentapeptide derivatives, D-MurN3-L-Ala-D-iGlu-L-Lys-D-Ala-D-Ser (5) and D-MurN3-L-Ala-D-iGlu-L-Lys-D-Ala-D-Ala (6), were obtained. Their chemical structures were confirmed by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy. To determine the absolute configuration of the carbon atom in the side chain of the muramic acid derivative, single-crystal X-ray diffraction measurements were recorded. 相似文献
9.
Irina V. Terekhova Malgorzata Koźbiał Roman S. Kumeev Gennady A. Alper 《Journal of solution chemistry》2011,40(8):1435-1446
Inclusion complex formation of hydroxypropylated α-, β- and γ-cyclodextrins with riboflavin (vitamin B2) and alloxazine was studied by spectroscopic and solubility methods. Alloxazine, which is a structural analog of riboflavin,
was considered in order to evaluate the role of ribityl and methyl substituents in complexation. Thermodynamic parameters
for 1:1 complex formation were obtained and analyzed in terms of influence of the reagent structure on the binding process.
It was shown that the cavity of hydroxypropyl-β-cyclodextrin is more appropriate for formation of stable complexes. The complexes are enthalpy stabilized, due to prevalence
of van der Waals interactions and possible hydrogen bonding. The partial insertion of riboflavin into the cyclodextrin cavity
was revealed by 1H NMR and computer modeling. The ribityl side chain, which prevents deep inclusion, is located nearby the wider rim of the
cyclodextrin molecule and can undergo destruction. Penetration of the alloxazine molecule into the macrocyclic cavity is deeper
and accompanied by formation of more stable inclusion complexes. Hydroxypropyl-β-cyclodextrin was found to be the more efficient solubilizing agent for riboflavin and alloxazine, whereas a stabilization
action of cyclodextrins towards riboflavin was not observed. 相似文献
10.
A sensitive and specific liquid chromatography electrospray ionisation-tandem mass spectrometry method for determination of new non-imidazole histamine H(3) receptor antagonist 1-[3-(4-tert-butylphenoxy)propyl]piperidine (DL76) in rat serum has been developed and validated. Chromatography was performed on a XBridge? C18 analytical column (2.1?×?30?mm, 3.5?μm, Waters, Ireland) with gradient elution using a mobile phase containing acetonitrile and water with an addition of 0.1% of formic acid. Detection was achieved by an Applied Biosystems MDS Sciex (Concord, Ontario, Canada) API 2000 triple quadrupole mass spectrometer. Electrospray ionization (ESI) was used for ion production. The limit of detection in the SRM mode was found to be 0.5?ng?mL(-1). The limit of quantification was 1?ng?mL(-1). The precision and accuracy for both intra- and inter-day determination of DL76 ranged from 1.65 to 15.09% and from 88.74 to 113.43%. The results of this analytical method validation allow to carry out pharmacokinetic studies in rats. The method was used for the pilot study of the pharmacokinetic behavior of DL76 in rats after intravenous administration. 相似文献