Analysis of swertiamarin in Swertia herb and preparations containing this crude drug by capillary electrophoresis.

Swertia herb (florescent whole plantof Swertia japonica, Gentianaceae) has long been utilized as a folk medicine in Japan. It is often blended in general gastroenteric drugs as a bitter stomachic. Swertiamarin, a bitter secoiridoid glycoside, is the representative constituent of this crude drug and Swertia herb is normally evaluated by the swertiamarin content. To date, papers have described the discrimination of Swertia herbs from other bitter crude drugs, estimation of swertiamarin and seasonal variation in swertiamarin content using thin-layer chromatography, while other papers have reported quantitative determination of swertiamarin using high-performance liquid chromatography (HPLC). In our previous papers, we reported analyses of the constituents of some crude drugs using capillary electrophoresis (CE). To aid in the evaluation of crude drugs, we succeeded in our attempt to separate and determine the quantity of swertiamarin in Swertia herb. Subsequently, we applied the same analytical condition to estimate the swertiamarin contents in Japanese pharmacopoeia stomachic preparations, in OTC gastroenteric drugs and in OTC hair tonics containing Swertia herb.     

Gaussian Beta Ensembles at High Temperature: Eigenvalue Fluctuations and Bulk Statistics

We study the limiting behavior of Gaussian beta ensembles in the regime where \(\beta n = const\) as \(n \rightarrow \infty \). The results are (1) Gaussian fluctuations for linear statistics of the eigenvalues, and (2) Poisson convergence of the bulk statistics. (2) is an alternative proof of the result by Benaych-Georges and Péché (J Stat Phys 161(3):633–656, 2015) with the explicit form of the intensity measure.     

Atomic-layer resolved magnetic and electronic structure analysis of ni thin film on a Cu(001) surface by diffraction spectroscopy

Up until now there has been no direct method for detecting the electronic and magnetic structure of each atomic layer at the surface, which is an essential analysis technique for nanotechnology. For this purpose, we have developed a new method, diffraction spectroscopy, based on the photon energy dependence of the angular distribution of Auger electron emission. We have applied this method to analyze the magnetic structure of a Ni ultrathin film on a Cu(001) surface around the spin reorientation transition. Atomic-layer resolved x-ray absorption and magnetic circular dichroism spectra were obtained. Surface and interior core-level shifts and magnetic moments are determined for each atomic layer individually.     

Analysis of relationship between magnetic property and crystal structure of La1−xSrxCrO3 (x=0.13, 0.15)

Dependence of dc magnetization, $M$, of La_1?xSr_xCrO₃ ($x=0.13$, 0.15) polycrystalline specimens on external magnetic field, $H$, was measured at various temperatures. At higher temperatures above 274 K and 265 K for the specimens with $x=0.13$ and 0.15, respectively, almost linear relationships were observed, indicating paramagnetic property. At the lower temperatures, hystereses, indicating canted antiferromagnetic property, were observed in $M\text{–}H$ curves. The temperatures where the magnetic phase transition was observed showed agreement with those where base line shift was observed in differential scanning calorimetry (DSC) measurement. In the $M\text{–}H$ curves of La_1?xSr_xCrO₃ ($x=0.13$, 0.15), saturation magnetization, $M_s$, was not observed at external magnetic fields as high as 70 kOe. At 226 K and 189 K for the specimens with $x=0.13$ and 0.15, respectively, structural phase transition from orthorhombic- to rhombohedral-distorted perovskite was observed in DSC curves. At the temperature, abrupt decreases of residual magnetization, $M_r$, and variation of temperature dependence of coercive force, $H_c$, were detected. We regard that the abrupt decrease of $M_r$ and the variation of temperature dependence of $H_c$ at the structural phase transition temperature can be ascribed to discontinuous variation of Cr–O–Cr angles.     

Evaluation of angelicae radix (Touki) by the inhibitory effect on platelet aggregation.

Quality evaluation of Angelicae Radix (Touki) was discussed referring to its inhibitory effect on platelet aggregation. No better correlation was observed in quality determined morphologically from the above-ground part of Touki and that determined by anti-platelet aggregation (APA) effects. Phthalides and adenosine, known to be the major components of Touki, were found not sufficient to evaluate the Touki quality as regards APA active components have been studied and it was concluded that the APA effect of Touki results from the combined action of plural components. The importance of determining quality based on the action of total extract to meet the purpose for which the substance is to be used was suggested.     

Efficient construction of the kedarcidin chromophore ansamacrolide

[Structure: see text] The streamlined assembly of the ansamacrolide framework of the kedarcidin chromophore via an efficient atropselective Sonogashira coupling step is described. To this end, two newly improved practical syntheses of the cyclopentene and diyne fragments have been developed, which feature 0.2 mol % catalytic loadings for an RCM step and i-PrMgCl/CH2I2 as a new entry to gem-disubstituted epoxides from ketones, both being applicable to 49-g scales.