621-91-0Relevant academic research and scientific papers
Synthesis of functionalized copillar[4+1]arenes and rotaxane as heteromultivalent scaffolds
Chen, Wenzhang,Mohy Ei Dine, Tharwat,Vincent, Stéphane P.
supporting information, p. 492 - 495 (2021/01/25)
In this study, novel copillar[4+1]arenes were used as central heteromultivalent scaffolds via orthogonal couplings with a series of biologically relevant molecules such as carbohydrates, α-amino acids, biotin and phenylboronic acid. Further modifications by introducing maleimides or cyclooctyne groups provided molecular probes adapted to copper-free click chemistry. An octa-azidated fluorescent rotaxane bearing two distinct ligands was also generated in a fully controlled manner.
Substituent effects on the electronic structure of the flat Blatter radical: Correlation analysis of experimental and computational data
Bartos, Paulina,Chrostowska, Anna,Hande, Aniket A.,Kaszyński, Piotr,Pietrzak, Anna
supporting information, p. 22876 - 22887 (2021/12/24)
A series of C(10)-substituted derivatives of 2-Ph-3H-[1,2,4]triazino[5,6,1-kl]phenoxazin-3-yl was obtained using the aza-Pschorr, photochemical and radical-induced cyclization reactions, and through functional group transformations of the C(10)-amino and C(10)-iodo derivatives. The iodo derivative underwent Pd-catalyzed C-C cross coupling reactions leading to the installation of Ph, 2-thienyl and PhCC groups at the C(10) position effectively extending electronic conjugation. The substituent effect on the electronic properties of the 3H-[1,2,4]triazino[5,6,1-kl]phenoxazin-3-yl was investigated in twenty one derivatives with a diverse range of functional groups by spectroscopic (UV-vis and EPR) and electrochemical methods augmented with DFT calculations. Results show that the lowest energy electronic absorption and redox potentials correlate well with the σp substituent parameter, while aN hfcc and the N-H bond dissociation energy (BDE) are well described by the σm parameter. In general, increasing the electron donating ability of the C(10)-X substituent lowers the π-π?(1) excitation energy, cathodically shifts the redox potentials, increases spin delocalization beyond the [1,2,4]triazinyl ring and lowers BDE. The latter two parameters are important indicators of the overall radical stability. Molecular and crystal structures of three radicals were established with the single crystal XRD method. This journal is
A Synthetic Fluorescent Mitochondria-Targeted Sensor for Ratiometric Imaging of Calcium in Live Cells
Pendin, Diana,Norante, Rosa,De Nadai, Andrea,Gherardi, Gaia,Vajente, Nicola,Basso, Emy,Kaludercic, Nina,Mammucari, Cristina,Paradisi, Cristina,Pozzan, Tullio,Mattarei, Andrea
supporting information, p. 9917 - 9922 (2019/06/24)
Ca2+ handling by mitochondria is crucial for cell life and the direct measure of mitochondrial Ca2+ concentration in living cells is of pivotal interest. Genetically-encoded indicators greatly facilitated this task, however they require demanding delivery procedures. On the other hand, existing mitochondria-targeted synthetic Ca2+ indicators are plagued by several drawbacks, for example, non-specific localization, leakage, toxicity. Here we report the synthesis and characterization of a new fluorescent Ca2+ sensor, named mt-fura-2, obtained by coupling two triphenylphosphonium cations to the molecular backbone of the ratiometric Ca2+ indicator fura-2. Mt-fura-2 binds Ca2+ with a dissociation constant of ≈1.5 μm in vitro. When loaded in different cell types as acetoxymethyl ester, the probe shows proper mitochondrial localization and accurately measures matrix [Ca2+] variations, proving its superiority over available dyes. We describe the synthesis, characterization and application of mt-fura-2 to cell types where the delivery of genetically-encoded indicators is troublesome.
Synthesis of an azido-tagged low affinity ratiometric calcium sensor
Caldwell, Stuart T.,Cairns, Andrew G.,Olson, Marnie,Chalmers, Susan,Sandison, Mairi,Mullen, William,McCarron, John G.,Hartley, Richard C.
, p. 9571 - 9578 (2015/12/01)
Changes in high localised concentrations of Ca2+ ions are fundamental to cell signalling. The synthesis of a dual excitation, ratiometric calcium ion sensor with a Kd of 90 μM, is described. It is tagged with an azido group for bioconjugation, and absorbs in the blue/green and emits in the red region of the visible spectrum with a large Stokes shift. The binding modulating nitro group is introduced to the BAPTA core prior to construction of a benzofuran-2-yl carboxaldehyde by an allylation-oxidation-cyclisation sequence, which is followed by condensation with an azido-tagged thiohydantoin. The thiohydantoin unit has to be protected with an acetoxymethyl (AM) caging group to allow CuAAC click reaction and incorporation of the KDEL peptide endoplasmic reticulum (ER) retention sequence.
Intracellular click reaction with a fluorescent chemical Ca2+ indicator to prolong its cytosolic retention
Takei, Yoshiaki,Murata, Atsushi,Yamagishi, Kento,Arai, Satoshi,Nakamura, Hideki,Inoue, Takafumi,Takeoka, Shinji
supporting information, p. 7313 - 7315 (2013/09/23)
The powerful strategy of "intracellular click reaction" was used to retain a chemical Ca2+ indicator in the cytosol. Specifically, a novel clickable Ca2+ indicator "N3-fura-2 AM" was coupled with dibenzylcyclooctyl-modified biomacromolecules via copper-free click reaction in living cells and Ca2+ oscillation was observed for an extended period of time.
Counterattack mode differential acetylative deprotection of phenylmethyl ethers: Applications to solid phase organic reactions
Chakraborti, Asit K.,Chankeshwara, Sunay V.
supporting information; experimental part, p. 1367 - 1370 (2009/07/04)
A counterattack protocol for differential acetylative cleavage of phenylmethyl ether has been developed. The phenylmethyl moiety is liberated as benzyl bromide that is isolated and reused providing advantages in terms of waste minimization/utilization and atom economy. The applicability of this methodology has been extended for solid phase organic reactions with the feasibility of reuse of the solid support.
The synthesis and conformation of oxygenated trianglimine macrocycles
Kuhnert, Nikolai,Lopez-Periago, Ana,Rossignolo, Giulia M.
, p. 524 - 537 (2007/10/03)
The synthesis of series of D2h and C2v symmetric oxygenated aromatic dicarboxaldehydes, using dilithiation methodology, is described along with their reactivity in the [3 + 3] cyclocondensation reaction with (1R,2R)-diaminocyclohexane to give oxygenated trianglimine macrocycles. Macrocycles derived from C2v symmetric dialdehydes give macrocycles with a stereogenic aromatic plane with complete diastereocontrol, as a mixture of retainers.
Pd/C-catalyzed chemoselective hydrogenation in the presence of a phenolic MPM protective group using pyridine as a catalyst poison
Sajiki, Hironao,Hirota, Kosaku
, p. 320 - 324 (2007/10/03)
Employment of a Pd/C-pyridine combination as a catalyst is a very useful method for the selective removal (hydrogenolysis) of phenolic O-benzyl, N-Cbz and benzyl ester protective groups and for the selective hydrogenation of nitro and olefin functions of phenol derivatives protected with the MPM group. These discriminatory results are apparently attributable to the effect of pyridine. The MPM group could be extensively applied to chemoselective hydrogenation as a protective group for phenolic hydroxyl functions.
Analogues of Platelet Activating Factor. 6. Mono- and Bis-Aryl Phosphate Antagonists of Platelet Activating Factor
Wissner, A.,Carroll, M. L.,Green, K. E.,Kerwar, S. S.,Pickett, W. C.,et al.
, p. 1650 - 1662 (2007/10/02)
A series of aryl phosphoglyceride (3, 19-61) and bis-aryl phosphate (67-135) antagonists of platelet activating factor (PAF) were prepared.A group of four bifunctional phosphorus reagents (5a-c and 7) were developed that allowed the preparation of these aryl phosphates in which the position of aromatic substitution can be varied.These compounds were examined for their ability to inhibit PAF-induced platelet aggregation of rabbit platelets.Selected compounds were also evaluated for their ability to displace PAF from its receptor on rabbit platelets.These in vitro data were compared to similar data obtained for a number of known PAF antagonists.The compounds were evaluated in vivo, in both the mouse and rabbit, for their ability to prevent death induced by a lethal challenge of PAF.The relationships between the biological activity and the nature, lipophilicity, and position of substituents of the aromatic rings were studied.Compound 105 (CL 184005) has been selected to undergo further development as a potential therapeutic agent for the treatment of septic shock in man.
Novel Synthesis of N,N-Diarylarylmethanamines from N-(Arylmethylene)arenamines and (Arylmethoxy)arenes
Paventi, Martino,Hay, Allan S.
, p. 5875 - 5882 (2007/10/02)
Various N,N-diarylarylmethanamines were synthesized by the reaction of N-(arylmethylene)arenamines with (arylmethoxy)arenes in dimethylformamide solution in the presence of a strong base as a catalyst which is obtained in situ by reacting metallic sodium with this solvent.In general, the reaction may be depicted as the reduction of the imine and addition, on the original imino nitrogen atom, of the aryl group (of the aryloxy moiety) of the ether and presumably oxidation of the arylmethoxy group of the ether to its corresponding aldehyde.Side reactions and a proposed reaction mechanism are discussed.
