Search results for "boronic acid"
showing 10 items of 48 documents
Inhibition of Proteasomal Glucocorticoid Receptor Degradation Restores Dexamethasone-Mediated Stabilization of the Blood–Brain Barrier After Traumati…
2013
To establish the molecular background for glucocorticoid insensitivity, that is, failure to reduce edema formation and to protect blood-brain barrier integrity after acute traumatic brain injury.Controlled animal study.University research laboratory.Male C57Bl/6N mice.Mechanical brain lesion by controlled cortical impact.Our study demonstrates that 1) proteasomal glucocorticoid receptor degradation is established in brain endothelial cells after traumatic brain injury as a form of posttranslational glucocorticoid receptor modification; 2) inhibition of the proteasomal degradation pathway with bortezomib (0.2 mg/kg) in combination with the glucocorticoid dexamethasone (10 mg/kg) by subcutane…
(Trifluoromethoxy)Phenylboronic Acids: Structures, Properties, and Antibacterial Activity.
2021
Three isomers of (trifluoromethoxy)phenylboronic acids were studied in the context of their physicochemical, structural, antimicrobial and spectroscopic properties. They were characterized by 1H, 13C, 11B and 19F NMR spectroscopy. The acidity of all the isomers was evaluated by both spectrophotometric and potentiometric titrations. The introduction of the -OCF3 group influences the acidity, depending, however, on the position of a substituent, with the ortho isomer being the least acidic. Molecular and crystal structures of ortho and para isomers were determined by the single crystal XRD method. Hydrogen bonded dimers are the basic structural motives of the investigated molecules in the sol…
Multifaceted Palladium Catalysts Towards the Tandem Diboration-Arylation Reactions of Alkenes
2008
Novel Pd(2) (6+) compounds have been synthesized in high yield. These compounds and their Pd(2) (4+) counterparts as synthetic precursors mediate the diboration of vinylarenes and aliphatic 1-alkenes, and under mild and basic reaction conditions they produce a variety of 1,2-diboronate esters with excellent conversions and chemoselectivities. The presence of bis(catecholato)diboron (B(2)cat(2)) favours the reduction of Pd(III) to Pd(II), while the catalytic precursor of Pd(II) is transformed into Pd(0)-nanoparticles. An "in situ" catalytic tandem reaction has been designed to transform the diboronate intermediates into the monoarylated product, which after oxidative workup, provides the car…
Bortezomib induction, reduced-intensity transplantation, and lenalidomide consolidation-maintenance for myeloma: updated results.
2013
A sequential approach including bortezomib induction, intermediate-dose melphalan, and autologous stem cell transplantation (ASCT), followed by lenalidomide consolidation-maintenance, has been evaluated. Efficacy and safety data have been analyzed on intention-to-treat and results updated. Newly diagnosed myeloma patients 65 to 75 years of age (n = 102) received 4 cycles of bortezomib-pegylated liposomal doxorubicin-dexamethasone, tandem melphalan (100 mg/m(2)) followed by ASCT (MEL100-ASCT), 4 cycles of lenalidomide-prednisone consolidation (LP), and lenalidomide maintenance (L) until disease progression. The complete response (CR) rate was 33% after MEL100-ASCT, 48% after LP and 53% after…
Apoptosis: a relevant tool for anticancer therapy.
2006
Apoptosis is a form of cell death that permits the removal of damaged, senescent or unwanted cells in multicellular organisms, without damage to the cellular microenvironment. Defective apoptosis represents a major causative factor in the development and progression of cancer. The majority of chemotherapeutic agents, as well as radiation, utilize the apoptotic pathway to induce cancer cell death. Resistance to standard chemotherapeutic strategies also seems to be due to alterations in the apoptotic pathway of cancer cells. Recent knowledge on apoptosis has provided the basis for novel targeted therapies that exploit apoptosis to treat cancer. These new target include those acting in the ext…
MYC and EGR1 synergize to trigger tumor cell death by controlling NOXA and BIM transcription upon treatment with the proteasome inhibitor bortezomib
2014
The c-MYC (MYC afterward) oncogene is well known for driving numerous oncogenic programs. However, MYC can also induce apoptosis and this function of MYC warrants further clarification. We report here that a clinically relevant proteasome inhibitor significantly increases MYC protein levels and that endogenous MYC is necessary for the induction of apoptosis. This kind of MYC-induced cell death is mediated by enhanced expression of the pro-apoptotic BCL2 family members NOXA and BIM. Quantitative promoter-scanning chromatin immunoprecipitations (qChIP) further revealed binding of MYC to the promoters of NOXA and BIM upon proteasome inhibition, correlating with increased transcription. Both pr…
Bortezomib Partially Improves Laminin α2 Chain–Deficient Muscular Dystrophy
2014
Congenital muscular dystrophy, caused by mutations in LAMA2 (the gene encoding laminin α2 chain), is a severe and incapacitating disease for which no therapy is yet available. We have recently demonstrated that proteasome activity is increased in laminin α2 chain-deficient muscle and that treatment with the nonpharmaceutical proteasome inhibitor MG-132 reduces muscle pathology in laminin α2 chain-deficient dy(3K)/dy(3K) mice. Here, we explore the use of the selective and therapeutic proteasome inhibitor bortezomib (currently used for treatment of relapsed multiple myeloma and mantle cell lymphoma) in dy(3K)/dy(3K) mice and in congenital muscular dystrophy type 1A muscle cells. Outcome measu…
Development of Novel Selective Peptidomimetics Containing a Boronic Acid Moiety, Targeting the 20S Proteasome as Anticancer Agents
2014
This paper describes the design, synthesis, and biological evaluation of peptidomimetic boronates as inhibitors of the 20S proteasome, a validated target in the treatment of multiple myeloma. The synthesized compounds showed a good inhibitory profile against the ChT-L activity of 20S proteasome. Compounds bearing a β-alanine residue at the P2 position were the most active, that is, 3-ethylphenylamino and 4-methoxyphenylamino (R)-1-{3-[4-(substituted)-2-oxopyridin-1(2H)-yl]propanamido}-3-methylbutylboronic acids (3 c and 3 d, respectively), and these derivatives showed inhibition constants (Ki ) of 17 and 20 nM, respectively. In addition, they co-inhibited post glutamyl peptide hydrolase act…
Optimization of peptidomimetic boronates bearing a P3 bicyclic scaffold as proteasome inhibitors
2014
Abstract A new series of pseudopeptide boronate proteasome inhibitors (2–3) was developed, through optimization of our previously described analogs of bortezomib, bearing a bicyclic 1,6-naphthyridin-5(6H)-one scaffold as P3 fragment (1). The biological evaluation on human 20S proteasome displayed a promising inhibition profile, especially for compounds bearing a P2 ethylene fragment, which exhibited Ki values in the nanomolar range for the ChT-L activity (e.g. 2a, Ki = 0.057 μM) and considerable selectivity for proteasome over bovine pancreatic α-chymotrypsin. Docking experiments into the yeast 20S proteasome revealed that the ligands are accommodated predominantly into the ChT-L site and t…
Enantioselective Palladium-Catalyzed Oxidative β,β-Fluoroarylation of α,β-Unsaturated Carbonyl Derivatives
2016
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The site-selective palladium-catalyzed three-component coupling of deactivated alkenes, arylboronic acids, and N-fluorobenzenesulfonimide is disclosed herein. The developed methodology establishes a general, modular, and step-economical approach to the stereoselective β-fluorination of α,β-unsaturated systems.