Quantitative study of diffuse increased 99mTc-methylene diphosphonate accumulation of both kidneys

Patients with diffuse increased accumulation in both kidneys on 99mTc-MDP bone scintigram were evaluated quantitatively. Among 1,100 cases, 7 (0.63%) showed this finding. The accumulation density ratios of kidneys/lumbal vertebra in A/D exchanged images of these patients were compared with control group, so that these ratios of patient group were higher than control group statistically. In conclusion, the accumulation density ratio was made the index of diffuse increase accumulation in both kidneys on 99mTc-MDP bone scintigram.     

One-pot synthesis of sialo-containing glycosyl amino acids by use of an N-trichloroethoxycarbonyl-beta-thiophenyl sialoside

We describe an efficient synthesis of 2,6- and 2,3-sialyl T antigens linked to serine in a one-pot glycosylation. We first investigated the glycosidation of thiosialosides by varying the N-protecting group. Modification of the C-5 amino group of beta-thiosialosides into the N-9-fluorenylmethoxycarbonyl, N-2,2,2-trichloroethoxycarbonyl (N-Troc), and N-trichloroacetyl derivatives enhanced the reactivity of these compounds towards glycosidation. Addition of a minimum amount of 3 A molecular sieves was also effective in improving the yield of alpha-linked sialosides. Next, we conducted one-pot syntheses of the glycosyl amino acids by using the N-Troc sialyl donor. The N-Troc derivative can be converted into the N-acetyl derivative without racemization of the amino acids. Branched-type one-pot glycosylation, initiated by regioselective glycosylation of the 3,6-dihydroxy galactoside with the N-Troc-beta-thiophenyl sialoside, provided the protected 2,6-sialyl T antigen in good yield. Linear-type one-pot glycosylation, initiated by chemoselective glycosylation of galactosyl fluoride with the N-Troc-beta-thiophenyl sialoside, afforded the protected 2,3-sialyl T antigen in excellent yield. Both protected glycosyl amino acids were converted into the fully deprotected 2,6- and 2,3-sialyl T antigens linked to serine in good yields.     

SERS and FT-IR studies of CO adsorbed on underpotential deposited Ag/Pt electrodes

CO adsorbed on UPD and OPD (under- and overpotential deposited) Ag layers on a Pt electrode surface was studied by SERS and IRRAS in conjunction with cyclic voltammetry. Electrochemical activation of a uniform UPD Ag adlayer produced Ag clusters on the Pt electrode as well as bare Pt sites. The strong adsorption of CO on the UPD Ag/Pt electrode compared with a bulk Ag electrode is explained by the influence of the substrate Pt atoms. The degree of electron back-donation to CO increases the degree of lower frequency shifts of CO on the electrodes in the order Pt electrodes < monolayer Ag/Pt < multilayer Ag/Pt.     

Ionic liquid crystal as a hole transport layer of dye-sensitized solar cells

Use of a new ionic liquid crystal, 1-dodecyl-3-methylimidazolium iodide, and iodine as an electrolyte of dye-sensitized solar cells leads to a high short circuit photocurrent density and a high light-to-electricity conversion efficiency, due to a self-assembled structure of the imidazolium cations, resulting in high conductivity of the electrolyte.     

Synthesis of benzylidene-pendant polyphthalimidines from flexible bisphthalides and various diamines

New polyphthalimidine-forming monomers, 5,5′-(oxydi-p-phenylenedicarbonyl)bis(3-benzylidenephthalide) and the 6,6′-derivative, were synthesized by the Friedel–Crafts reaction of diphenyl ether with 5- and 6-chloroformyl-3-benzylidenephthalide, respectively. The direct polycondensation of these bisphthalides with both aliphatic and aromatic diamines in o-phenylphenol at 200–250°C afforded polyphthalimidines having inherent viscosities of 0.2–1.2 dL/g in almost quantitative yields. Syntheses of aliphatic polyphthalimidines with higher inherent viscosities were also achieved by a two-step procedure involving ring-opening polyaddition and subsequent thermal cyclodehydration. All the polymers were amorphous and readily soluble in N-methyl-2-pyrrolidone (NMP), m-cresol, nitrobenzene, pyridine, and chloroform. Tough and flexible films could be cast from NMP solutions of the polymers. Glass transition temperatures of the polyphthalimidines were in the range of 158–246°C. The thermogravimetry of the aromatic polymers showed 10% weight loss in air and nitrogen at 445–515 and 500–520°C, respectively. The crosslinking reaction of some benzylidenependant polyphthalimidines took place at 300°C through double-bond addition to afford cured polymers with improved thermal stability.     

Synthesis of polyphthalimidines with benzylidene group from aminophthalide monomers

Two aminophthalide monomers, 6-amino-3-benzylidenephthalide (I) and 3-(p-aminobenzylidene)phthalide (II), underwent self-polycondensation in o-phenylphenol at 250°C to yield polyphthalimidines with inherent viscosities up to 0.5 dL/g. These polymers were readily soluble in a variety of solvents such as dimethylformamide, dimethyl sulfoxide, m-cresol, pyridine, and methylene chloride. The temperatures at which a 10% weight loss occurred by thermogravimetry in nitrogen were 460°C for the polymer derived from I and 490°C for the polymer from II. The glass transition temperature of the polymer from I was 332°C, determined by thermomechanical analysis.     

Plaunol A and B,new anti-ulcer diterpenelactones from Crotonsublyratus

Two new diterpenelactones named plaunol A ($\text{2}$) and B ($\text{3}$) exhibiting anti-Shay ulcer activity were isolated from Thai medicinal plant, $\text{Croton}$$\text{sublyratus}$. Structure of $\text{2}$ was determined by X-ray analysis of its $\text{p}$-bromobenzoate and structure of $\text{3}$ was deduced from the results of chemical correlation and the spectral data.     

A new-type photoreaction of a carbonyl compound: Part 2. Photoinduced ω-bond dissociation in p-halomethylbenzophenone studied by time-resolved EPR technique and laser flash photolysis

Photodissociation of the carbon-X (X = Br and Cl) bonds in p-bromo- and p-chloromethylbenzophenone (BMBP and CMBP) in solution were investigated by time-resolved EPR and laser flash photolysis techniques. BMBP and CMBP were found to undergo ω-bond cleavage to yield the p-benzoylbenzyl radical (BBR) at 295 K, and the quantum yields (Φ_BBR) were determined. The CIDEP signal originated from BBR formed upon decomposition of CMBP was obtained while that for BMBP was absent. By using triplet sensitization of acetone, the efficiencies (_BBR) of the CX bond fission in the triplet states of BMBP and CMBP were determined. The agreement between the Φ_BBR and _BBR values for CMBP indicates that the CCl bond dissociation occurs only in the triplet state. In contrast to CMBP, the cleavage of the CBr bond in BMBP upon direct excitation was concluded to be the event only in the excited singlet state without triplet formation, whereas the triplet state was also reactive for ω-bond dissociation. The rate of CBr bond dissociation seemed to be greater than that of intersystem crossing from the S₁ to the T₁ state. Schematic energy diagrams of the excited states of BMBP and CMBP were shown, and the reaction profiles were discussed from the viewpoint of the CX bond enthalpies.     

Fragmentation study of peptides using Fourier transform ion cyclotron resonance with infrared multiphoton dissociation: experiment and simulation

In this study, the fragmentation of gas-phase protonated Angiotensin II is investigated using electrospray ionization (ESI), Fourier-transform ion cyclotron resonance (FT-ICR), and mass spectrometry (MS) with a laser cleavage infrared multiphoton dissociation (IRMPD) technique. The experimental results show that the spectra peaks for the photoproducts are y2/b6- and y7-type ions, corresponding to the cleavage of His-Pro and Asp-Arg in the parent amino acid sequence. The fragmentation of the peptide under collision-free vacuum conditions is modeled using molecular dynamics simulations (MD). The binding energy for the peptide bonds (C'-N bond) of Angiotensin II is estimated from ab initio calculations. The calculations are directed at predicting experimental measurements of the product ions from the photodissociation of the peptide. The product distributions simulated by the MD dissociation trajectories include predominantly y7/b1 and y2/b6 pair ions.     

Structure-activity relationship (SAR) studies on oxazolidinone antibacterial agents. 2. Relationship between lipophilicity and antibacterial activity in 5-thiocarbonyl oxazolidinones

5-Thiourea and 5-dithiocarbamate oxazolidinones were synthesized as a continuation of research on 5-thiocarbonyl oxazolidinone antibacterial agents considering the hydrophobic parameters of the molecule. The structure-activity relationship (SAR) study revealed that the antibacterial activity on 5-thiocarbonyl oxazolidinones was significantly affected by the lipophilicity, especially the calculated log P value and the balance between 5-hydrophilic (or hydrophobic) substituent and hydrophobic (or hydrophilic) substituents on the benzene ring. Some of 5-thiocarbonyl oxazolidinones were found to have good in vitro antibacterial activity against gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE).