Cantharimide dimers from the Chinese blister beetle, Mylabris phalerate PALLAS

Five cantharidin-related compounds were isolated from the Chinese blister beetle, Mylabris phalerate PALLAS (Meloidae). Their structures were determined based on spectroscopic and chemical evidence. Three of them were identified as cantharimide dimers, which consist of two units of cantharimide combined with a tri-, tetra-, or penta-methylene group.     

Role of solution structure in the electrochemical intercalation of Ca2+ into graphite layers

In this study, we investigated the electrochemical intercalation of Ca²⁺ into graphite as an anode material for calcium-ion batteries (CIBs). The electrochemical intercalation of Ca²⁺ into a graphite electrode is possible when γ-butyrolactone (GBL) is utilized as a solvent, resulting in a reversible charge/discharge capacity. The GBL-based electrolyte allows a reversible redox reaction, thereby resulting in the intercalation and deintercalation of Ca²⁺ within the graphite electrode. Conversely, Ca²⁺ cannot be intercalated between the graphite layers in the ethylene carbonate–diethyl carbonate (EC–DEC)–based electrolyte. Analyses of the solution structures of both cases indicated that the interaction between the GBL solvent and Ca²⁺ was weak whereas that between the EC–DEC solvent and Ca²⁺ was strong. As a result of analyzing the surface of the negative electrode after charging and discharging from XPS, it was confirmed that a component that seems to be a solid electrolyte interphase (SEI) was confirmed in the graphite electrode using the GBL-based electrolyte.

     

The Dimeric Form of 1,3-Diaminoisoquinoline Derivative Rescued the Mis-splicing of Atp2a1 and Clcn1 Genes in Myotonic Dystrophy Type 1 Mouse Model

Expanded CUG repeat RNA in the dystrophia myotonia protein kinase (DMPK) gene causes myotonic dystrophy type 1 (DM1) and sequesters RNA processing proteins, such as the splicing factor muscleblind-like 1 protein (MBNL1). Sequestration of splicing factors results in the mis-splicing of some pre-mRNAs. Small molecules that rescue the mis-splicing in the DM1 cells have drawn attention as potential drugs to treat DM1. Herein we report a new molecule JM642 consisted of two 1,3-diaminoisoquinoline chromophores having an auxiliary aromatic unit at the C5 position. JM642 alternates the splicing pattern of the pre-mRNA of the Ldb3 gene in the DM1 cell model and Clcn1 and Atp2a1 genes in the DM1 mouse model. In vitro binding analysis by surface plasmon resonance (SPR) assay to the r(CUG) repeat and disruption of ribonuclear foci in the DM1 cell model suggested the binding of JM642 to the expanded r(CUG) repeat in vivo, eventually rescue the mis-splicing.     

Near-Infrared-III-Absorbing and -Emitting Dyes: Energy-Gap Engineering of Expanded Porphyrinoids via Metallation

The synthesis of organometallic complexes of modified 26π-conjugated hexaphyrins with absorption and emission capabilities in the third near-infrared region (NIR-III) is described. Symmetry alteration of the frontier molecular orbitals (MOs) of bis-Pd^II and bis-Pt^II complexes of hexaphyrin via N-confusion modification led to substantial metal d_π–p_π interactions. This MO mixing, in turn, resulted in a significantly narrower HOMO–LUMO energy gap. A remarkable long-wavelength shift of the lowest S₀→S₁ absorption beyond 1700 nm was achieved with the bis-Pt^II complex, t -Pt₂-3 . The emergence of photoacoustic (PA) signals maximized at 1700 nm makes t -Pt₂-3 potentially useful as a NIR-III PA contrast agent. The rigid bis-Pd^II complexes, t -Pd₂-3 and c -Pd₂-3 , are rare examples of NIR emitters beyond 1500 nm. The current study provides new insight into the design of stable, expanded porphyrinic dyes possessing NIR-III-emissive and photoacoustic-response capabilities.     

Ring-closing metathesis within chromium-coordination sphere: Facile access to phosphine-chelate (π-arene)chromium complexes

A variety of phosphine-chelate (π-arene)chromium complexes were prepared in good to excellent yields by the ring-closing metathesis reaction of [η⁶-(ω-alkenyl)benzene][(ω-alkenyl)phosphine]chromium(0) dicarbonyl complexes catalyzed by the Grubbs’ ruthenium-carbene complexes.     

Tandem arrays of TEMPO and nitronyl nitroxide radicals with designed arrangements on DNA

Herein we describe one-dimensional electron-spin arrays consisting of two different organic radicals with the designed arrangement based on the DNA sequence. Two mismatch-binding ligands carrying 2,2,6,6-tetramethylpiperidine N-oxide (TEMPO) and nitronyl nitroxide selectively bind to the predetermined sites on double stranded DNA. By using the two mismatch-binding ligands carrying the organic radicals as the glue for DNA, electron-spin assembly could be successfully synchronized with the hybridization. Periodically and tandemly arranged, two kinds of organic radical molecules at designed positions might be useful for an approach to build up scalable qubits of electron-spin-based quantum computing. The approach using DNA nanostructures as a scaffold to assembly functional small molecules can afford one of the promising ways for the future application of DNA nanostructures and nanotechnology.     

Aromaticity‐Controlled Thermal Stability of Photochromic Systems Based on a Six‐Membered Ring as Ethene Bridges: Photochemical and Kinetic Studies

Three photochromic compounds—2‐butyl‐5,6‐bis[5‐(4‐methoxyphenyl)‐2‐methylthiophen‐3‐yl]‐1 H‐benzo[de]isoquinoline‐1,3(2 H)‐dione (BTE‐NA), 4,5‐bis[5‐(4‐methoxyphenyl)‐2‐methylthiophen‐3‐yl]benzo[c][1,2,5]thiadiazole (BTA), and BTTA, which contain naphthalimide, benzothiadiazole, and benzobisthiadiazole as six‐membered ethene bridges with different aromaticities—were systematically studied in solution, sol–gel, and single‐crystal states. They exhibit typical photochromic performance with considerably high cyclization quantum yields. BTE‐NA, BTA, and BTTA form a typical donor–π–acceptor (D –π–A) system with significant intramolecular charge transfer (ICT) between HOMO and LUMO upon excitation, thus realizing the fluorescence modulation by both photochromism and solvatochromism. The three ethene bridges with different degrees of aromaticity can provide a systematic comparison of the thermal stability evolution for their corresponding closed forms (c‐BTE‐NA, c‐BTA, and c‐BTTA). c‐BTE‐NA shows first‐order decay in various solvents from cyclohexane to acetonitrile. c‐BTA only shows first‐order decay in polar solvents such as chloroform, whereas it is stable in nonpolar solvents like toluene. In contrast, the less aromatic property of BTTA gives rise to its unprecedented thermal stability in various solvents even at elevated temperatures in toluene (328 K). Moreover, the small energy barrier between the parallel and antiparallel conformers allows the full conversion from BTTA to c‐BTTA. In well‐ordered crystal states, all three compounds adopt a parallel conformation. Interestingly, BTTA forms a twin crystal of asymmetric nature with interactions between the electron‐rich oxygen atom of the methoxy group and the carbon atom of the electron‐deficient benzobisthiadiazole moiety. This work contributes to the understanding of aromaticity‐controlled thermal stability of photochromic systems based on a six‐membered ring as an ethene bridge, and a broadening of the novel building blocks for photochromic bisthienylethene systems.     

同时测定无机离子的改良离子色谱法在河水和废水质量监控中的应用（英文）

In this study,our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions(SO2-4,Cl-and NO-3) and cations(Na+,NH+4,K+,Mg2+,and Ca2+),nutrients(phosphate and silicate) and hydrogen ion/alkalinity are summarized first.Then,the applications using these methods for monitoring environmental water quality are also presented.For the determination of common anions and cations with nutrients,the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C(Tosoh,150 mm×6.0 mm i.d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry.For the determination of hydrogen ion/alkalinity,the separation was conducted by TSKgel ODS-100Z column(Tosoh,150 mm×4.5 mm i.d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector.The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant.Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed.From these results,our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.