A biomimetic route to the ergot derailment products,the clavicipitic acids - detection of a reactive intermediate by 31p nmr - some chemical underpinnings for a proposed intermediate in ergot alkaloid biosynthesis.

A biomimetic route to the clavicipitic acids has been developed which is based on the Mitsunobu reaction of the diol 4a.     

Analytical Solutions of Electromagnetic Fields from Current Dipole Moment on Spherical Conductor in a Low-Frequency Approximation

We analytically derive the solutions for electromagnetic fields of electric current dipole moment, which is placed in the exterior of the spherical homogeneous conductor, and is pointed along the radial direction. The dipole moment is driven in the low frequency f = 1 kHz and high frequency f = 1 GHz regimes. The electrical properties of the conductor are appropriately chosen in each frequency. Electromagnetic fields are rigorously formulated at an arbitrary point in a spherical geometry, in which the magnetic vector potential is straightforwardly given by the Biot- Savart formula, and the scalar potential is expanded with the Legendre polynomials, taking into account the appropriate boundary conditions at the spherical surface of the conductor. The induced electric fields are numerically calculated along the several paths in the low and high frequeny excitation. The self-consistent solutions obtained in this work will be of much importance in a wide region of electromagnetic induction problems.     

Classification of polarized manifolds admitting homogeneous varieties as ample divisors

We give a complete classification of smooth polarized varieties (X, L) such that the linear system |L| has a homogeneous member A.     

Reaction dynamics of excited 2-(3-benzoylphenyl)propionic acid (ketoprofen) with histidine

Photoreaction dynamics of 2-(3-benzoylphenyl)propionic acid (ketoprofen, KP), one of nonsteroidal anti-inflammatory drugs, with histidine in a phosphate buffer solution (pH 7.4) was investigated with the laser flash photolysis. The deprotonated form of KP (KP(-)) was decarboxylated via UV laser excitation to form a carbanion. It was found that histidine accelerates the protonation reaction of the carbanion to 3-ethylbenzophenone ketyl biradical (3-EBPH) for the first time. The experimental results of the photoreaction of KP with alanine as well as the photoreaction of KP with 4-methylimidazole (a part of the side chain of histidine) in methanol, clearly showed that the protonated form of histidine is a key species for the protonation reaction of the carbanion. These series of the initial reactions should result in the occurrence of photosensitization in vivo. The reaction mechanism was discussed in detail.     

Electrooptics of beta-FeOOH particle in aqueous media 2. Field-strength dependence of decay and steady-state birefringence, and the hydrodynamic and electrooptic properties

Steady-state and decay birefringence, expressed in terms of the optical phase retardation per cell length delta/d, was measured on beta-FeOOH in aqueous ionic media at 633 nm and at 25 degrees C by an electric square-pulse technique over a wide range of field strength E to ca. 6 kV/cm. The field-strength dependence of both delta/d and field-free rotational relaxation time tau was determined at the sample concentrations between 0.0011 and 0.055 g/L and in the 0.02-2.0 mM NaCl concentration range. Extrapolation of both delta/d and tau values to infinitely high fields (E(2)-->infinity) could yield birefringence- and weight-average quantities, respectively. Observed tau values were decreased at weak fields but leveled off to ca. 0.3 ms at very high fields due to a slight polydispersity regarding the length and volume of particles. The weight-average relaxation time tau(w) was calculated with Perrin's expressions theoretically from the length, width, and volume of beta-FeOOH particles estimated in the dried state from electron micrograph. These quantities were variously averaged. The size distribution was discussed in terms of observed discrete histogram and theoretical (Weibull and Lansing-Kraemer) distribution functions. The sign of observed delta/d value was always positive. The infinitely high-field (delta/d)(infinity) values and the reduced optical anisotropy factor Delta g/n were evaluated by fitting to theoretical orientation functions. The intrinsic birefringence (n3-n1) could be estimated with the mean refractive index n(p) reported in the literature. For the spindle-shaped particle with an axial ratio of ca. 4, the sign of Delta g/n is always positive, whereas the quantity (n3-n1) was either negative (n(p) > 2.35) or positive (n(p) < 2.05) in sign or nearly zero (ca. n(p) = 2.26), depending critically on the n(p) values.     

Increased expression and phosphorylation of liver glutamine synthetase in well-differentiated hepatocellular carcinoma tissues from patients infected with hepatitis C virus

Hepatocellular carcinoma (HCC) is one of the most common fatal cancers, and chronic infection with hepatitis C virus (HCV) is thought to be one of the main causes in Japan. To identify diagnostic or therapeutic biomarkers for HCC associated with HCV (HCV-HCC), we tried to elucidate the factors related to the products from cancerous tissues of HCV-infected patients. From proteomic differential display analysis of liver tissue samples from HCV-HCC cancerous tissues and corresponding non-cancerous tissues from patients, three protein spots of the same molecular mass (42 kDa), whose expression increased in well-differentiated cancerous tissues, were detected. Although their pI were different, they were identified as glutamine synthetase (GS) by PMF with MALDI-TOF MS and by Western blotting using anti-GS specific mAb. Immunohistochemical analysis showed that tumor tissue consists of two parts, GS-positive cell and GS-negative cell regions, suggesting that GS-producing cells grew in the tumor tissue as a nodule in nodules. The tryptic peptides of the most acidic GS isoform lost the signal of 899.5 Da, corresponding a peptide of SASIRIPR, and gained a signal of 1059.5 Da, which was submitted to PSD analysis. PSD analysis showed the neutral loss by elimination of two phosphate groups, supposed to be on serine residues of the 899.5-Da peptide, from serine 320 to arginine 327 in GS. PMF followed by PSD analysis is thought to be useful for the determination of phosphorylation sites of proteins showing molecular heterogeneity.     

Interactions between clusters of self-interstitial atoms via a conservative climb in BCC–Fe

We conduct kinetic Monte Carlo simulations for the conservative climb motion of a cluster of self-interstitial atoms (SIAs) towards another SIA cluster in BCC–Fe; the conservative climb velocity is inversely proportional to the fourth power of the distance between them, as per the prediction based on Einstein’s equation. The size of the climbing cluster significantly affects its conservative climb velocity, while the size of the cluster that originates the stress field does not. The activation energy for the conservative climb is considerably greater than that derived in previous studies and strongly dependent on the climbing cluster size. The results presented in this study are the atomistic evaluation of the behaviour of SIA clusters through three-dimensional motion, which cannot be achieved using molecular dynamics techniques alone.     

Fluorescence imaging of potassium ions in living cells using a fluorescent probe based on a thrombin binding aptamer-peptide conjugate

When a biotinylated FRET probe based on a peptide-thrombin binding aptamer conjugate was introduced together with streptavidin and biotinylated nuclear export signal peptide into HeLa cells, the resulting ternary complex enabled visualization of K(+) concentration changes in the cell.     

New synthesis of β-lactams

α-Methylene-β-lactams 3 were synthesized from the various 2-bromoallylamine derivatives 2 using a catalytic amount of Pd(OAc)₂ or PD(acac)₂ and PPh₃, under 1–4 atom pressure of CO in good yields. Similarly, α-alkylidene-β-lactams 20 were synthesized from 3-alkyl-2-bromoallylamines 19, which were easily prepared from the olefins 14, in the same manner.