A perspective on the contribution of surfactants and lipids toward “Green Chemistry”: Present states and future potential

“Green Chemistry” has become a subject of increasing interest in recent years. The goal of efforts in this area is to develop environmentally friendly methods and processes to replace traditional reactions that use organic solvents, consume much energy, and generate undesirable by-products and/or waste. Utilization of renewable resources is an important component of Green Chemistry. Fats and oils represent one such resource. They can give rise to many types of surfactants and lipids that can modify properties of boundary phases between different phases. Thus, phase-transfer catalysts (PTC) based on surfactants or lipids have been reported to be useful in reactions such as oxidation and hydration reactions and in glycidyl ether formation. Another approach to satisfying Green Chemistry requirements is the recovery and recycling of reactants and/or substrates used. In the preparation of alkyl glyceryl ethers, the intermediate 1,3-dioxolane compounds prepared by addition of acetone to alkyl glycidyl ethers can be hydrolyzed to regenerate reusable acetone. Other examples of methodologies based on surfactants or lipids are summarized, and their potential contribution to Green Chemistry is discussed.     

Phenethyl isothiocyanate suppresses nitric oxide production via inhibition of phosphoinositide 3‐kinase/Akt‐induced IFN‐γ secretion in LPS‐activated peritoneal macrophages

Phenethyl isothiocyanate (PEITC), a constituent of many cruciferous vegetables, is well known to have versatile physiological activities, including chemopreventive effects. On the other hand, its anti‐inflammatory effects are poorly reported. Nitric oxide (NO) is associated with a wide variety of inflammatory diseases. In this study, we investigated the effects of PEITC on NO production in LPS‐activated peritoneal macrophages from ICR mice. The signaling pathway of LPS‐induced NO production was examined using neutralizing antibodies [anti‐interferon (IFN)‐γ and anti‐interleukin (IL‐12)] and specific protein kinase inhibitors, as well as others. The activity of PEITC toward NOx production was assessed in mice that received LPS via intraperitoneal administration. The neutralizing antibody of anti‐IFN‐γ, but not anti‐IL‐12, suppressed LPS‐induced NO production by 90%. LY294002, a specific inhibitor of phosphoinositide‐3‐kinase, suppressed Akt and IFN‐γ mRNA expression up‐regulated by LPS, whereas PEITC exhibited a similar inhibition profile. Furthermore, oral administration of PEITC significantly suppressed the serum concentration of NOx in ICR mice. Our results suggest that PEITC suppresses LPS‐induced NO production via inhibition of Akt activation and the resultant decrease in expression of IFN‐γ. This is one of the first reports to demonstrate a marked anti‐inflammatory effect of PEITC following its oral administration.     

A new etching technique for revealing the plastic deformation zone in an Al–Cu–Mg alloy

A new etching technique for revealing the plastic deformation zone in an Al–Cu–Mg alloy has been developed. The etching with the proposed etching agent was conducted on the deformed sample after being heated to 673 K for 3 h. With this etching technique, the plastic deformation zone was clearly observed even under low magnification. This was due to the change of microstructural characteristics in the plastic deformation zone after the heating process, in which there is significant precipitation of Al₂Cu and Mg₂Si, caused by the high energy arising from the severe deformation.     

First-principles simulations of removal process in EEM (Elastic Emission Machining)

Interactions between ultra-fine powder [SiO₂] and work [Si (1 0 0) surface] in EEM (Elastic Emission Machining) has been investigated by employing first-principles molecular dynamics (MD) simulations. Calculated results show the possibilities of the atomic removal through the solid phase chemical interaction between surfaces of ultra-fine powders and works.     

C49-TiSi2 epitaxial orientation dependence of C49-to-C54 phase transformation rate

We investigated the C49-TiSi₂ epitaxial orientation dependence of the C49-to-C54 phase transformation rate for samples with different pre-amorphizing As implantation (PAI) conditions. The C49 epitaxial orientation to the Si(001) substrate is characterized on the basis of the (131) rocking curves obtained from grazing-incidence X-ray diffraction (GIXD) measurements. We found that the phase transformation rate increases with decreasing C49 epitaxial orientation, and this dependence is very sensitive for the samples with PAI. For comparison with the orientation dependence, the C49 grain size dependence was also examined. The C49 grain size distributions were obtained from transmission electron microscope (TEM) images. Although the phase transformation rate seems to roughly increase with increasing C49 grain size, it does not show a clear relationship. Therefore, we conclude that the C49-to-C54 phase transformation rate is largely determined by the C49 epitaxial orientation, although the effects of C49 grain size and the density of As-ions cannot be ignored for the PAI process.     

Microstructure evolution and texture development during high-temperature uniaxial compression of magnesium alloy AZ31

Texture development in magnesium alloy AZ31 was studied by uniaxial compression tests at temperatures, strain rates and final strains ranging from 573 to 773 K, 1.0 × 10⁻³ to 5.0 × 10⁻⁵ s⁻¹ and −0.2 to −1.5, respectively. Fiber texture was formed in all of the deformation conditions. The main component of the texture varied depending on deformation conditions; it appeared about 33–38° away from the basal pole after the deformation at higher temperatures and lower strain rates. This can be attributed to the increased activity of the secondary pyramidal slip system. With a decrease in temperatures and an increase in strain rate, the tilting angle of the main component (compression plane) from the basal pole decreased down to about 20°. Construction of a basal fiber texture was detected after deformations at the lowest temperature and high strain rates.     

Applications of protecting groups in the synthesis of surfactants, lipids, and related compounds

Several types of alkyl ether lipids were prepared in high yield and high purity using protecting groups such as 1,3-dioxolane compounds or allyl ethers. We also succeeded in the industrial production of alkyl glyceryl ethers using the reaction of alkyl glycidyl ethers with acetone to give 1,3-dioxolane compounds, from which the desired alkyl glyceryl ethers were obtained in high quantities. 1,3-Dioxolane (ketal) compounds based on acetone were used in the enzymatic preparation of monoglyceride on an industrial scale. On the basis of these protecting groups, we extended our studies concerning both the preparations and properties of novel polyol ether compounds, beginning with alkyl glycidyl ethers. Another typical property of surfactants containing 1,3-dioxolane units and acetal is degradability under acidic conditions. Several types of destructible/cleavable surfactants based on polyols, such as carbohydrates and polyethyleneglycol, were prepared. As for natural products containing polyol skeletons, much attention has been paid to their molecular design, in which protecting groups such as 1,3-dioxolane compounds or allyl ether have contributed to synthetic strategies.     

Applications of phase-transfer catalytic reactions to fatty acids and their derivatives: Present state and future potential

Phase-transfer catalysts (PTC), which accelerate reactions between liquid(organic)-liquid(water) and liquidsolid heterogeneous states, have been investigated and developed. Several processes with PTC have succeeded in industrial processes involving fatty acids and their derivatives. For example, preparation of fatty alkyl glycidyl ethers, from which fatty alkyl glyceryl ethers and their derivatives can be obtained, has been carried out with PTC. However, some problems remain to be solved. For example, preparation of the fatty alkyl glycidyl ether by a PTC reaction was considered, but typical problems to be solved included: (i) how to reuse or recover the catalysts; (ii) how to control the heterogeneous reaction without obstacles to produce useful chemical materials; (iii) how to satisfy the environmental requirements for the catalysts; and (iv) are there more effective catalysts? We address these problems based on our own experiences with phase-transfer catalytic Williamson ether syntheses of fatty alkyl glycidyl ethers. Moreover, we describe recent developments in phase-transfer catalytic reactions related to oleochemistry, such as transition metal-catalyzed reactions of long-chain olefins in liquid(organic)-liquid(water) or liquid-solid heterogeneous states. Based on these results, we have considered the potential of PTC as a synthetic tool in oleochemistry.     

A case of herpes simplex encephalitis presenting complete destruction of the medial portions in the bilateral temporal lobes

A 57-year old man, who had suffered from herpes simplex encephalitis and had been cured without antiviral agents, was admitted to our hospital three years after the encephalitis. He had a complete loss of memory for events subsequent to the encephalitis and a retrograde amnesia for the several years leading up the encephalitis. MRI revealed the abnormalities located in the limbic system, especially the medial portions in the bilateral temporal lobes of the cerebrum were completely destroyed. We consider that this case suggests the specific affinity of herpes simplex virus especially for the medial portions in the temporal lobes of the cerebrum.     

B-90063, a novel endothelin converting enzyme inhibitor isolated from a new marine bacterium, Blastobacter sp. SANK 71894

We raised mAbs to whole L5178Y leukemia/lymphoma (LL) cells to identify adhesion proteins involved in adherence between LL cells and marrow stromal cells. One mAb, 4C, and its subclones 4C.1 and 4C.2 inhibited adherence of L5178Y LL cells to MLT. a nontransformed murine marrow stromal cell line. These MoAbs are directed against CD45RA. Control anti-CD45 mAbs and isotype mAbs were non-inhibitory. Other anti-CD45 mAbs, M1/9.3, RA3-3A1/6.1 and RA3-2C2/1 do not compete with mAb 4C.1 for binding to the L5178Y cell surface, but mAb 4C.1 competes for binding of mAb RA3-2C2/1. Effects of mAb 4C on tyrosine-phosphatase activity of CD45 in L5178Y cells are minimal, suggesting direct involvement of CD45 as an adhesion protein.