Synthesis of Spinochalcone B and Analogues

An efficient synthesis of spinochalcone B and its analogues is achieved from readily available 2H‐pyran.     

Ca(OH)2-mediated efficient synthesis of 2-amino-5-hydroxy-4H-chromene derivatives with various substituents

A variety of novel 2-amino-5-hydroxy-4H-chromene derivatives with various substituents on the 4H-chromene ring were efficiently synthesized by one-pot reactions of substituted resorcinols and various 2-benzylidenemalononitriles in the presence of calcium hydroxide in methanol at room temperature. This simple method provided 2-amino-5-hydroxy-4H-chromenes with high yields under mild reaction conditions.     

Synthesis and biological evaluation of potential new inhibitors of the bacterial transferase MraY with a β-ketophosphonate structure

Stable analogs of bacterial transferase MraY substrate or product with a pyrophosphate surrogate in their structure are described. β-ketophosphonates were designed as pyrophosphate bioisosteres and were investigated as UDP-GlcNAc mimics. The developed strategy allows introduction of structural diversity at a late stage of the synthesis. The biological activity of the synthesized compounds was evaluated on the MraY enzyme.     

Preparation of a biodegradable superabsorbent polymer and measurements of changes in absorption properties depending on the type of surface‐crosslinker

A superabsorbent polymer (SAP) is a special polymer material that can absorb up to 500 times its own weight of pure water, but has a problem that it does not biodegrade itself and cause environmental pollution. Therefore, we aim to prepare a biodegradable SAP by using biomass‐based IA. The SAP must be able to retain absorbed water and absorb water under a given pressure. We have carried out studies to improve the surface hardness of the SAP to enhance absorption of water under a given pressure by surface‐crosslinking. Four types of surface‐crosslinkers, ethylene glycol diglycidyl ether (EGDGE), ethylene carbonate (EC), 1,4‐butanediol (BD), or glycerol, were used. We confirmed the water absorption capacity of the SAP by measuring its centrifuge retention capacity (CRC) and absorbency under load (AUL). The structural characteristics of the SAP were confirmed by attenuated total reflection (ATR) and X‐ray photoelectron spectroscopy (XPS), and the surface characteristics were confirmed by scanning electron microscopy (SEM).     

Creating cellulose fibres with excellent UV protective properties using moist CF4 plasma and ZnO nanoparticles

Weakly ionised gaseous plasma created in a moist tetrafluoromethane gas at a low pressure with an electrodeless radiofrequency discharge was applied to modify the surface properties of cellulose fibres. The plasma was used to increase the adsorption of zinc oxide (ZnO) nanoparticles such that cellulose fibres with good ultraviolet (UV) protective properties could be created. The UV protection factor (UPF) values of the ZnO-functionalised fibres were determined as a function of the plasma treatment time. The chemical and physical surface properties of the plasma-treated fibres were examined using scanning electron microscopy, X-ray photoelectron spectroscopy, and wettability tests. The quantity of zinc on the fibres was determined using inductively coupled plasma mass spectroscopy. The results indicated that 30 s of plasma treatment resulted in ZnO-functionalised samples with lower UPF values than samples without plasma treatment due to the creation of fluorine-rich functional groups on cellulose fibres and the agglomeration of ZnO nanoparticles. The highest UPF values (50+) were obtained when samples were treated with plasma for 10 s. These high UPF values were a result of the increased adsorption of uniformly distributed ZnO nanoparticles caused by fibres surface functionalization and roughening upon plasma treatment. Furthermore, the mechanical properties of textiles treated with moist CF₄ plasma for 10 s were slightly improved.     

Canonical labels for protein spots of proteomics maps

We consider the problem of canonical labeling for a class of maps, which include proteomics maps, which consist of a set of vertices or protein spots. If this problem is solved and followed, different laboratories studying proteomics maps will arrive at the same numbering of spots, which would facilitate comparisons of data from different sources. In addition, the proposed canonical numberings of protein spots would allow compiling a catalog of proteomics maps just as canonical labeling allows making catalogs graphs, or molecules, and other canonically labeled systems, which would make search for similar sets of maps very efficient. We approach the problem by modifying the algorithm of Jeffrey for graphical representation of DNA based on the chaos game. Graphical representation of DNA as a chaos game map has an important property in that this representation allows one to assign sequential labels to spots in a DNA map. We have modified the approach for sequential labeling of chaos game map representations to graphical representation of any tabular data, such as listing of (x, y) coordinates of protein spots of proteomics maps.     

两种新碗形分子的合成及其纤维状晶的研究

以香兰素为原料,采用三聚法合成了2种外围脂肪族基团碳数分别为3和5的环三亚藜芦基(cyclotriveratrylene,CTV)系衍生物碗形分子--CTV-3和CTV-5,其中,用先关环后衍生化的合成路线克服了因CTV-5的外围基团太长、分子对称性不好而无法用传统方法合成的难题.产物的化学结构经1H NMR、13CNMR、质谱以及元素分析确认.在偏光显微镜下观察到纤维状晶叠加在碗形分子的向列液晶织构上.纤维状晶是从液晶态冷却时形成并装饰在原液晶织构上的一种结晶形态.通过SEM测定,观察到纤维状晶实际上是由厚度约为100-200m、宽度为2-5μm的无限长的单层片晶组成的多层片晶,而片晶则是由直径约为100nm的微纤组成的.微纤可以推断是碗形分子柱的束状聚集体.     

New Synthetic Routes to Biologically Interesting Geranylated Flavanones and Geranylated Chalcones: First Total Synthesis of (±)‐Prostratol F,Xanthoangelol, and (±)‐Lespeol

A new and efficient synthetic approach to biologically interesting geranylated flavanones and geranylated chalcones is described. Thus, the first total syntheses of the geranylated flavanones (±)‐prostratol F ( 1 ), (±)‐8‐geranyl‐3′,4′,7‐trihydroxyflavanone ( 2 ), and (±)‐6‐geranyl‐5,7‐dihydroxy‐3′,4′‐dimethoxyflavanone ( 3 ) were carried out starting from 2,4‐dihydroxyacetophenone ( 10 ) and 2,4,6‐trihydroxyacethophenone ( 17 ) in five to six steps (Schemes 2 and 3). The geranylated chalcones xanthoangelol ( 4 ), 3‐geranyl‐2,3′,4,4′‐tetrahydroxychalcone ( 5 ), (±)‐lespeol ( 6 ), and lespeol derivatives (±)‐ 7 – 9 were synthesized starting from 2,4‐dihydroxyacetophenone ( 10 ) in three to four steps (Schemes 2 and 6).     

An ellipsometric and magneto-optical study of cobalt ferrite single crystals

Spectroscopic ellipsometry and the polar magneto-optical Kerr effect (1.5<hv<5.5 eV) have been used to study the properties of a cobalt ferrite (CoFe₂O₄) single crystal, grown from the flux. The magnitude of the polar Kerr rotation both in-field and in remanence were used to study the polishing action and subsequent etching. For the (111) face studied here essentially the same dielectric functions were obtained as for Fe₃O₄.The polar Kerr rotation spectrum shows extrema at 1.8,2.1,3.5,3.9 and 5.1 eV. The latter two occur also in YIG and have been assigned to charge transfers from oxygen to Fe³⁺ on octahedral and tetrahedral sites respectively.