Novel spirocyclic trichothecanes, spirotenuipesine A and B, isolated from entomopathogenic fungus, Paecilomyces tenuipes

Entomopathogenic fungi forming fruiting bodies have been employed as tonics and antitussives from ancient times. Paecilomyces tenuipes, which is also called Isaria japonica, is a very popular entomopathogenic fungus and is often considered a health food in northeast Asian countries such as China, Korea, and Japan. We cultivated the fruiting bodies of Paecilomyces tenuipes. Among the large-scale cultivations, fruiting body grown in barley grain contained two novel spirocyclic trichothecane derivatives, spirotenuipesine A (1) and B (2), and known trichothecane mycotoxins. Compounds 1 and 2 showed potent activity in neurotrophic factor biosynthesis in glial cells. The isolation of these compounds indicated that P. tenuipes is a promising source for producing various biologically active substances including trichothecanes. It is noteworthy that trichothecane mycotoxins are present in Paecilomyces tenuipes, which is typically used in medicinal health food.     

Charge‐Transfer Phase Transition of a Cyanide‐Bridged FeII/FeIII Coordination Polymer

Heterometallic Prussian blue analogues are known to exhibit thermally induced charge transfer, resulting in switching of optical and magnetic properties. However, charge‐transfer phase transitions have not been reported for the simplest FeFe cyanide‐bridged systems. A mixed‐valence Fe^II/Fe^III cyanide‐bridged coordination polymer, {[Fe(Tp)(CN)₃]₂Fe(bpe)?5 H₂O}_n, which demonstrates a thermally induced charge‐transfer phase transition, is described. As a result of the charge transfer during this phase transition, the high‐spin state of the whole system does not change to a low‐spin state. This result is in contrast to FeCo cyanide‐bridged systems that exhibit charge‐transfer‐induced spin transitions.     

Inhomogeneous spin state in the organic conductor κ-(BEDT-TTF)4Hg2.78Cl8

The static and dynamical local spin susceptibility of the nonstoichiometric organic conductor, κ-(BEDT-TTF)₄Hg_2.78Cl₈, is studied by ¹³C NMR spectroscopy from room temperature down to 1.7 K. We observe a gradual growth of inhomogeneity in the spin state as a spectral broadening down to the lowest temperature, which is sustained even under 0.4 GPa but suppressed under 0.8 GPa. The emergence of the inhomogeneity is discussed in the light of the doped triangular-lattice Mott insulator.     

Cassaine diterpenoid dimers isolated from Erythrophleum succirubrum with TRAIL-resistance overcoming activity

Activity-guided fractionation of Erythrophleum succirubrum for TRAIL resistance-overcoming activity led to the isolation of four new cassaine diterpenoid dimers, named erythrophlesins A-D (1-4). Their structures were elucidated by spectral data to show that they have an unsymmetrical dimeric structure through an ester bond between two cassaine diterpenoids. These new compounds were revealed to have a significant reversal effect on TRAIL resistance in human gastric adenocarcinoma (AGS) cells.     

Measurement of a pauli and orbital paramagnetic state in bulk gold using x-ray magnetic circular dichroism spectroscopy

We show that bulk gold (Au) exhibits temperature-independent paramagnetism in an external magnetic field by x-ray magnetic circular dichroism spectroscopy at the Au L(2) and L(3) edges. Using the sum-rule analysis, we obtained a magnetic moment of 1.3 × 10(-4) μB/atom in an external magnetic field of 10 T and a paramagnetic susceptibility of 8.9 × 10(-6) for the 5d orbit. The induced paramagnetism in bulk Au is characterized by a large (≈ 30%) orbital contribution. This orbital component was retained even when Au atoms formed nanoparticles, playing an important role in stabilizing the spontaneous spin polarization in the Au nanoparticles.     

Photo-curable organically modified silicate-phosphate alternating copolymer for photonics applications

Photo-curable vinyl modified silicate-phosphate alternating copolymers were prepared by a direct condensation of organochlorosilane and organophosphoric acid in a solvent-free condition. The obtained copolymers have complete alternating copolymer structure of silicate and phosphate unit, where the main oxo chain consist of –(Si–O–P–O) _n -network. They exhibited an excellent solubility of ionic species such as ionic organic dyes. It was also demonstrated the photo-reduction of Au⁺ ions to form Au nano particles for plasmonics applications. Micro patterns were also fabricated by soft lithographic processes. These results indicate that the photo-curable alternating copolymers are one of promising materials for advanced optical information processing devices.     

Alternative methods of globotrioside production using Vero cells: a microcarrier system procedure

Background  

Glycolipids are one component of cell membranes, and are found most prevalently at the surface of the plasma membrane. Animal cells take in amphipathic glycosides, which are later glycosylated after assimilation in biosynthetic pathways. Gycosylated glycosides are released outside of cells to the surrounding culture medium. This represents an accessible method of obtaining complex glycosides.