(E)‐,(Z)‐Parallel Preparative Methods for Stereodefined β,β‐Diaryl‐ and α,β‐Diaryl‐α,β‐unsaturated Esters: Application to the Stereocomplementary Concise Synthesis of Zimelidine

Parallel and practical methods for the preparation of both (E)‐ and (Z)‐β‐aryl¹‐β‐aryl²‐α,β‐unsaturated esters 1 and (E)‐ and (Z)‐α‐aryl¹‐β‐aryl²‐α,β‐unsaturated esters 2 are described. These methods involve accessible, robust, stereocomplementary N‐methylimidazole (NMI)‐mediated enol tosylations (14 examples, 70–99 % yield), as well as stereoretentive Suzuki–Miyaura cross‐couplings (36 examples, 64–99 % yield). The highlighted feature of the present protocol is the use of parallel and stereocomplementary approaches to obtain highly (E)‐ and (Z)‐pure products 1 and 2 by utilizing sequential enol tosylations and cross‐coupling reactions. An expeditious and parallel synthesis of (E)‐ and (Z)‐zimelidine ( 3 ), which is a highly representative selective serotonin reuptake inhibitor (SSRI), was performed by utilizing the present methods.     

Presence of rhodopsin and porphyropsin in the eyes of 164 fishes, representing marine, diadromous, coastal and freshwater species--a qualitative and comparative study

There are two types of visual pigments in fish eyes; most marine fishes have rhodopsin, while most freshwater fishes have porphyropsin. The biochemical basis for this dichotomy is the nature of the chromophores, retinal (A1) and 3-dehydroretinal (A2), each of which is bound by an opsin. In order to study the regional distribution of these visual pigments, we performed a new survey of the visual pigment chromophores in the eyes of many species of fish. Fish eyes from 164 species were used to examine their chromophores by high-performance liquid chromatography--44 species of freshwater fish, 20 of peripheral freshwater fish (coastal species), 10 of diadromous fish and 90 of seawater fish (marine species) were studied. The eyes of freshwater fish, limb freshwater fish and diadromous fish had both A1 and A2 chromophores, whereas those of marine fish possessed only A1 chromophores. Our results are similar to those of previous studies; however, we made a new finding that fish which live in freshwater possessed A1 if living near the sea and A2 if living far from the sea if they possessed only one type of chromophore.     

Crystallization induced chiral locking of a central labile core in a star-shaped tetra-nuclear complex

The central labile Al(III) core of a star-shaped tetra-nuclear metal complex, [{Delta-Ru(III)(acac)(2)(taet)}(3)Al(III)] (acac = acetylacetonato; taet = tetraacetylethanato), which was synthesized by reacting Delta-[Ru(III)(acac)(2)(taetH)] (taetH = singly protonated taet) with an Al(III) ion in solution, was found to be locked as a Lambda-form in the solid state.     

Magnetic and dielectric properties of InFe2O4, InFeCuO4, and InGaCuO4

The magnetic and dielectric properties of InFe2O4, InFeCuO4, and InGaCuO4 have been investigated. All these materials are isostructural with RFe2O4 (R = Y, Ho-Lu), which shows ferroelectricity due to iron-valence ordering. InFe2O4 exhibits ferrimagnetic ordering at T(C) approximately 242 K and a dielectric constant (epsilon) of approximately 10,000 at around room temperature. These properties resemble those of RFe2O4; the origins of the magnetic and dielectric phenomena are likely common in InFe2O4 and RFe2O4. From measurements of the other two materials, we found that both T(C) and epsilon are decreased in the order of InFe2O4, InFeCuO4, and InGaCuO4. This result strongly supports the previously reported explanation based on an electron transfer between the Fe-site ions for the corresponding rare-earth systems. Therefore, we propose that the dielectric properties of the oxides isostructural with RFe2O4 are plausibly governed by electron transfer; this situation is different from that of ordinary ferroelectrics and dielectrics, in which the displacement of cations and anions is important. In addition, InFeCuO4 and InGaCuO4 exhibit large epsilon values (epsilon > approximately 1500). In consideration of this property, we discuss the possible applications of these oxides.     

Relationships between Raman parameters obtained from cyclic indentation impressions on DLC coatings

Diamond-like carbon (DLC) coatings were indented 3000 to 15 000 times cyclically using a Si₃N₄ sphere having a diameter of 10 mm under a normal load of approximately 107 N. DLC coatings were prepared by unbalanced magnetron (UBM) sputtering under substrate bias voltage of −200 on a heat-treated and polished JIS SCM 415 substrates. SEM images and the energy dispersive X-ray spectrometry (EDX) results of the indented impressions showed that a Cr/C layer or substrate surface partially revealed on the impressions. In order to estimate structural alterations in DLC coatings after cyclic indentations, Raman spectroscopy were performed on the impressions. Relationships between Raman parameters such as the intensity ratio I(D)/I(G) of the disorder peak around 1350 cm⁻¹ and the graphitic peak around 1580 cm⁻¹ and full width of half maximum of the G peak (FWHM(G)) were estimated with the Raman spectroscopy on the impressions. Enclosed area by maximum and minimum of I(D)/I(G) and FWHM(G) was defined as “Safety Zone” in this paper, and it can be used to determine integrity of DLC coatings.     

Water-assisted assembly of (E)-arylvinylpyridine hydrochlorides: effective substrates for solid-state [2+2] photodimerization

Water molecules assist the assembly of (E)-arylvinylpyridine hydrochlorides in a head-to-tail and face-to-face fashion by way of N-HO hydrogen bonds in combination with cation-π interactions between the pyridinium and aromatic rings. Photolysis of the pyridinium salt hydrates provided synHT dimers in high yields.     

Novel chiral recognition beyond the limitation due to the law of mass action: highly enantioselective chiral sensing based on non-linear response in phase transition events

Based on non-linear response in phase transition events exhibiting a sharp transmittance change, an intelligent chiral sensor capable of chirality amplification in aqueous media was designed and constructed as poly(N-isopropylacrylamide) having chiral pseudo-18-crown-6. Both sensitivity and selectivity of the sensor surmount the limitation due to the law of mass action.     

Development of salt-tolerance interface for an high performance liquid chromatography/inductively coupled plasma mass spectrometry system and its application to accurate quantification of DNA samples

Accurate quantification of DNA is highly important in various fields. Determination of phosphorus by ICP-MS is one of the most effective methods for accurate quantification of DNA due to the fixed stoichiometry of phosphate to this molecule. In this paper, a smart and reliable method for accurate quantification of DNA fragments and oligodeoxythymidilic acids by hyphenated HPLC/ICP-MS equipped with a highly efficient interface device is presented. The interface was constructed of a home-made capillary-attached micronebulizer and temperature-controllable cyclonic spray chamber (IsoMist). As a separation column for DNA samples, home-made methacrylate-based weak anion-exchange monolith was employed. Some parameters, which include composition of mobile phase, gradient program, inner and outer diameters of capillary, temperature of spray chamber etc., were optimized to find the best performance for separation and accurate quantification of DNA samples. The proposed system could achieve many advantages, such as total consumption for small amount sample analysis, salt-tolerance for hyphenated analysis, high accuracy and precision for quantitative analysis. Using this proposed system, the samples of 20 bp DNA ladder (20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, 400, 500 base pairs) and oligodeoxythymidilic acids (dT_12–18) were rapidly separated and accurately quantified.     

Degradation of Target Oligosaccharides by Anthraquinone–Lectin Hybrids with Light Switching

Anthraquinone–lectin hybrids were effectively synthesized using water‐soluble anthraquinone derivative 11 with concanavalin A (ConA) and hygrophorus russula lectin (HRL) to give anthraquinone–ConA ( 16 ) and anthraquinone–HRL ( 17 ) hybrids, respectively. These anthraquinone–lectin hybrids effectively and selectively degraded oligosaccharides containing a mannose residue as a non‐reducing terminal sugar, which has affinity for ConA and HRL, under photo‐irradiation with long‐wavelength UV light without additives and under neutral conditions. In addition, anthraquinone–HRL ( 17 ) selectively photo‐degraded only Man(α1,6)Man, which has a high affinity for HRL, among several mannosides by recognition of both the type and glycosidic linkage profile of the sugar in an oligosaccharide.