Direct synthesis of H2O2 catalyzed by Pd nanoparticles encapsulated in the multi-layered polyelectrolyte nanoreactors on a charged sphere

A highly efficient and industrially viable catalyst design for the direct synthesis of H(2)O(2) from H(2) and O(2) was realized by the encapsulation of Pd nanoparticles in polyelectrolyte multi-layers on a sulfonated resin. The continuous production of 9.9 wt% H(2)O(2) was achieved under intrinsically safe and non-corrosive conditions without any loss of activity.     

Fusarisetin A, an acinar morphogenesis inhibitor from a soil fungus, Fusarium sp. FN080326

An acinar morphogenesis inhibitor named fusarisetin A (1) that possesses both an unprecedented carbon skeleton and a new pentacyclic ring system has been identified from an in-house fractionated fungal library using a three-dimensional matrigel-induced acinar morphogenesis assay system. The structure of 1 was determined in detail by NMR and circular dichroism spectroscopy, X-ray analysis, and chemical reaction experiments.     

Synthesis and characterization of dithienylbenzobis(thiadiazole)-based low band-gap polymers for organic electronics

New donor-acceptor alternating conjugated polymers were synthesized and characterized. Among them, PCPBBT exhibited a band-gap of 1.01 eV and ambipolar characteristics with μ(h) = 7.1 × 10(-4) cm(2) V(-1) s(-1) and μ(e) = 3.3 × 10(-3) cm(2) V(-1) s(-1).     

Control of molecular weight of polystyrene using the reverse iodine transfer polymerization (RITP)-emulsion technique

The RITP-emulsion polymerization of styrene in the presence of molecular iodine has been successfully performed using potassium persulfate (KPS) as an initiator and 1-hexadecanesulfonate as an emulsifier under argon atmosphere at 80°C for 7 hrs in the absence of light. The effects of the iodine concentration, molar ratio between KPS and iodine, and solid contents on the molecular weight of polystyrene (PS) were studied. As the iodine concentration increased from 0.05 to 0.504 mmol under the fixed [KPS]/[I(2)] ratio at 4.5, the weight-average molecular weight of PS substantially decreased from 126,120 to 35,690 g/mol, the conversion increased from 85.0% to 95.2%, and the weight-average particle diameter decreased from 159 to 103 nm. In addition, as the ratio of [KPS]/[I(2)] increased from 0.5 to 6.0 at the fixed [I(2)] of 0.504 mmol, the weight-average molecular weight of PS decreased from 72,170 to 30,640 g/mol with high conversion between 81.7% and 96.5%. Moreover, when the styrene solid content increased from 10 to 40 wt.% at the fixed [KPS]/[I(2)] ratio of 4.5, the weight-average molecular weight of PS varied between 33,500 and 37,200 g/mol, the conversion varied between 94.9% and 89.7% and the weight-average diameter varied from 122 to 205 nm. Thus, the control of molecular weight of PS less than 100,000g/mol with high conversion (95%) and particle stability of up to 40 wt.% solid content were easily achieved through the usage of iodine with suitable ratio of [KPS]/[I(2)] in the RITP-emulsion polymerization technique, which is of great industrial importance.     

Novel pyrrolopyrimidine-based α-helix mimetics: cell-permeable inhibitors of protein−protein interactions

There is considerable interest in developing non-peptidic, small-molecule α-helix mimetics to disrupt α-helix-mediated protein?protein interactions. Herein, we report the design of a novel pyrrolopyrimidine-based scaffold for such α-helix mimetics with increased conformational rigidity. We also developed a facile solid-phase synthetic route that is amenable to divergent synthesis of a large library. Using a fluorescence polarization-based assay, we identified cell-permeable, dual MDMX/MDM2 inhibitors, demonstrating that the designed molecules can act as α-helix mimetics.     

Measurement of half-lives for 87m,gY and 196m,g,194Au produced from the photon and neutron induced reactions of 89Y and 197Au

Journal of Radioanalytical and Nuclear Chemistry - We have measured the half-lives of 87mY and 87gY produced from the 89Y(γ, 2n) and 89Y(n, 3n) reactions with the bremsstrahlung end-point...     

Synthesis and structural characterization of novel ruthenium(II) complexes featuring an N,N,O-scorpionate ligand: A versatile synthetic precursor for open-face scorpionatoruthenium(II) complexes

The syntheses and characterization of novel ruthenium(II) complexes containing bis(3,5-dimethylpyrazol-1-yl)acetato (bdmpza), a new class of scorpionate ligands, are reported herein. [RuCl(bdmpza)(η⁴-1,5-cyclooctadiene)] (1) was found to be a versatile precursor to synthesize a wide range of new ruthenium(II) complexes with the bdmpza ligand. The treatment of 1 with pyridine (py), diphenylphosphinoethane (dppe), 2,2′-bipyridyl (bpy), 1,10-phenanethroline (phen), or bispicolylamine (Hbpica) in refluxing N,N-dimethylformamide resulted in displacement of the 1,5-cyclooctadiene ligand to afford [RuCl(bdmpza)(py)₂] (2), [RuCl(bdmpza)(dppe)] (3), [RuCl(bdmpza)(bpy)] (4), [RuCl(bdmpza)(phen)] (5), and [Ru(bdmpza)(Hbpica)]Cl (6Cl) in good yields, respectively. The structures of 1–4, and 6 were determined by X-ray structure analyses.     

Synthesis and crystal structure of dehydrated, deaminated, and dealuminated zeolite Y (FAU): single-crystal structure of |Na33H26(Al5O4)|[Si126Al66O384]-FAU

Host–guest complexes of Docetaxel 1, an anti-cancer drug have been isolated and crystal structures are described. Docetaxel crystallized in the 1:1 molar ratio with n-butanol, dimethylformamide (DMF) and acetonitrile (ACN) during crystallization from the respective solvents. In all the three complexes (1 · n-butanol, 1 · DMF and 1 · ACN), docetaxel formed a host framework through hydrogen bonds and the guest solvent molecules occupied the channels. The host is hydrogen bonded to the guest molecules through hydroxyl moieties. Interestingly, 1 · n-butanol, 1 · DMF and a literature 1 · CH₃OH · H₂O (1:1:1) host–guest complexes are isomorphs. Further, 1 · ACN complex unit cell parameters are similar (same space group) to the marketed docetaxel trihydrate polymorph (form A).     

Inhibition of NF-κB prevents high glucose-induced proliferation and plasminogen activator inhibitor-1 expression in vascular smooth muscle cells

Recent epidemiologic studies clearly showed that early intensive glucose control has a legacy effect for preventing diabetic macrovascular complications. However, the cellular and molecular processes by which high glucose leads to macrovascular complications are poorly understood. Vascular smooth muscle cell (VSMC) dysfunction due to high glucose is a characteristic of diabetic vascular complications. Activation of nuclear factor-κB (NF-κB) may play a key role in the regulation of inflammation and proliferation of VSMCs. We examined whether VSMC proliferation and plasminogen activator inhibitor-1 (PAI-1) expression induced by high glucose were mediated by NF-κB activation. Also, we determined whether selective inhibition of NF-κB would inhibit proliferation and PAI-1 expression in VSMCs. VSMCs of the aorta of male SD rats were treated with various concentrations of glucose (5.6, 11.1, 16.7, and 22.2 mM) with or without an inhibitor of NF-κB or expression of a recombinant adenovirus vector encoding an IκB-α mutant (Ad-IκBαM). VSMC proliferation was examined using an MTT assay. PAI-1 expression was assayed by real-time PCR and PAI-1 protein in the media was measured by ELISA. NF-κB activation was determined by immunohistochemical staining, NF-κB reporter assay, and immunoblotting. We found that glucose stimulated VSMC proliferation and PAI-1 expression in a dose-dependent manner up to 22.2 mM. High glucose (22.2 mM) alone induced an increase in NF-κB activity. Treatment with inhibitors of NF-κB such as MG132, PDTC or expression of Ad-IκB-αM in VSMCs prevented VSMC proliferation and PAI-1 expression induced by high glucose. In conclusion, inhibition of NF-κB activity prevented high glucose-induced VSMC proliferation and PAI-1 expression.     

Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.