Using broadband dielectric spectroscopy, we have studied different types of relaxation processes, namely, primary (α), secondary (β), and another sub-Tg process called γ-process, in the supercooled state of d-lyxose, over a wide frequency (10-2–109Hz) and temperature range (120–340 K). In a...

l-ribose and d-tagatose are biochemically synthesized using sugar isomerases. The l-arabinose isomerase gene from Shigella flexneri (Sf-AI) was cloned and expressed in Escherichia coli BL-21. Sf-AI was applied for the bioproduction of d-tagatose from d-galactose. l-ribose synthesis was performed...

α-Galactosyl ceramide is synthesized from d-lyxose in 32% overall yield in five steps. The short and efficient protocol involves a one-pot protection and glycosidation of d-lyxose with d-galactosyl iodide as a key step. The α-linked disaccharide obtained was subsequently transformed into α-ga...

The influence of microwave irradiation on hydrolysis of xylan and simultaneous epimerization of the d-xylose to d-lyxose has been studied. An acidic solution of xylan was treated with catalytic amount of sodium molybdate and the composition of the reaction mixture was analyzed. Short reaction ti...

The specific activity and catalytic efficiency (kcat/Km) of the recombinant putative protein from Providencia stuartii was the highest for d-lyxose among the aldose substrates, indicating that it is a d-lyxose isomerase. Gel filtration analysis suggested that the native enzyme is a dimer with a ...

d-Mannose has prebiotic effect and potential medical application. Besides, it can be used as substrate to produce mannitol, a functional polyol widely used in food industry. As this result, it has attracted many researchers’ attention. In this work, a thermostable d-mannose-producing d-lyxose i...

d-Mannose is the aldose isomer of d-fructose and displays unique physiological functions and health applications. As a result, it has attracted increasing interest from the public. Because of its wide substrate specificity, d-lyxose isomerase (D-LI) has been applied to d-mannose bioproduction. I...

SummaryIncorporation of radiocarbon from L-ascorbic acid-1-14C into L-tartaric acid in developing grapevine leaves was found to follow a time-course pattern indicating a consecutive formation of 2-keto-L-idonic, L-idonic, and 5-keto-D-gluconic (= 5-keto-L-idonic) acids. In mature leaves, tartrat...

The residues of salt lake brine from which potassium had been removed were used to extract Rb+ and Cs+ together with a sulphonated kerosene (SK) solution of 1.0 mol/L 4-tert-butyl-2-(α-methylbenzyl) phenol (t-BAMBP). Rb+ and Cs+ were enriched and separated effectively by precipitating Mg2+ befo...

Complexes of type A4[VO(tart)]2·nH2O, where A = Rb or Cs and tart =d,l-tartrate(4−) (n = 2) or d,d-tartrate(4−) (n = 2 for Rb and n = 3 for Cs), were prepared from an aqueous mixture of V2O5, AOH and H4tart. These complexes were studied by single-crystal X-ray diffraction methods: Rb4[VO(d,l-ta...

A mixed potassium-copper hexacyanoferrate (II) K2CuFe(CN)6 was prepared by local growth on solid cupric sulfate in an aqueous solution of potassium hexacyanoferrate (II) and by growth in a gel. Powders having this composition and separable by filtration could not be obtained by normal precipitat...

Humic substances (HS), including humic and fulvic acids, play a significant role in the fate of metals in soils. The interaction of metal cations with HS occurs predominantly through the ionized (anionic) acidic functions. In the context of the effect of HS on transport of radioactive cesium iso...

Racemic dimetal tartrate hydrates were obtained from the reaction of d,l-tartaric acid with LiOH and MOH, where M = Li, Na, K, Rb, Cs, NH4. Dilithium trihydrate Li2(C4H4O6) · 3H2O (1) consists of two distinct two-dimensional coordination networks [Li6(C4H4O6)3(H2O)9]n (A) and [Li2(C4H4O6)(H2O)3...

SummaryCesium templated Staudinger-aza-Wittig tandem reaction (S.A.W.) has been used in the synthesis of a bis-diazacrown-bis-cellobiosyl-tetra-ureido cryptand. A novel macrotricyclic compound having a “cone-shaped” configuration was selectively obtained. Additionally, first results on potenti...

The effect of non-chelating oximes on the extraction of several transition and nontransition metals by solutions of organophosphoric acids (H2A2) in xylene has been investigated. Synergistic enhancements of extraction of divalent transition metal ions were found with the oximes of aliphatic alde...

The selenyl triflate generated from the reaction of di-2-[(1S)-1-(methylthio)ethyl]phenyl diselenide with silver triflate reacts with various substituted O-allyl oximes to promote ring closure, which affords optically active isoxazolidines in high yields and with good diastereoselectivity (up to...

Six-, five-, four- and three-membered 1,1-cycloalkanedicarboxylic acid (2a–d) were synthesized by alkaline hydrolysis of the corresponding diesters (1a–d) and the reactions of the formers with SF4 were investigated. 1,1-Bis(trifluoromethyl)cycloalkanes (3a–d) were the products of the reaction...

Palladium catalyzed bis-Suzuki coupling reactions of 2-trifluoromethyl-1,1-dibromoalkenes with aryl and hetero-aryl boronic acids afford 2-trifluoromethyl tetra-substituted alkenes in excellent yield.

Viologen (V) based molecules are classic and prestigious electrochromic (EC) materials which have dramatic optical contrast and tunable coloring states in solution-type electrochromic devices (ECDs). However, the stability of viologen based ECDs was significantly reduced by the dimer formation, ...

A new, simple synthesis of 1,1-bis(trifluoromethyl)cyclopropanes has been discovered. It is based on the reaction of readily available 2,2-bis(trifluoromethyl)thietanes with tertiary phosphines in a polar solvent, which leads to an unusual desulfurization process, resulting in the formation of 1...