Trehalose Molecules Research Articles

Thehalose mycolates from Nocardia asteroides, Nocardia farcinica, Gordona lentifragmenta and Gordona bronchialis

Isolation of glycolipids from Nocardia asteroides, N. farcinica, Gordona lentifragmenta and G. bronchialis, by column chromatography of lipid extracts on a 50% (w/w) mixture of silicic acid and silica gel H, is described. The isolated materials were partially characterized by infrared spectroscopy, optical rotation and refractive index measurements, and by identifying the products of alkaline hydrolysis. Analytical studies showed that the glycolipids released only trehalose in the aqueous phase while mycolic acids were the constituent fatty acids identified. The isolated lipids are trehalose esters in which the trehalose molecule is esterified with mycolic acids.

Isolation and partial characterization of esters of trehalose from Corynebacterium ovis (C. pseudotuberculosis)

A glycolipid fraction was isolated from Corynebacterium ovis (C. pseudotuberculosis). It had [ α] D 25 = + 63.2° (C = 0.5, CHCl 3) and m.p. 43–46°C; the sugar content was 26%, determined as trehalose. Alkaline hydrolysis of the isolated fraction found trehalose as the sole water-soluble component, while glucose was found only after acid hydrolysis of the aqueous phase. Saturated and unsaturated short-chain mycolic acids with carbon atoms ranging from C 30 to C 36 were the constituents of the fatty acid moiety. The glycolipid fraction of C. ovis is therefore assumed to be a mixture of trehalose esters in which the trehalose molecule is esterified by saturated and unsaturated short-chain (C 30–C 36) mycolic acids.

Mass spectrometry of acylated sugars as trimethylsilyl ether derivatives. A way for location of long chain fatty acyl groups

The mass spectra of the trimethylsilyl ethers of the four positional isomers of methyl-O-palmitoyl-alpha-D-glucopyranoside have been studied, and the structures of the principal ions assigned by the use of exact mass measurements and deuterium labelling on the aliphatic chain, the trimethylsilyl group and the glucosidic methyl group. The origin of some fragments has been elucidated by analysis of reactions of metastable ions. The mass spectra of the different isomers exhibit major differences, which depend upon the presence or absence of the aliphatic chain. These results indicate that this is a useful method for determining the position of an acyl group in a methyl glucoside. The applicability of this mass spectrometric method in structural determination of unknown acylated sugars is discussed. The structure of a corynomycoloyl-alpha-D-trehalose, isolated from Corynebacterium diphtheriae, has been determined by mass spectrometry as an application of the method. The molecular weight of this compound has been determined by field desorption mass spectrometry (cationization method), and the study of the electron impact spectrum of the trimethylsilyl derivatives clearly demonstrates that the corynomycolic acid is linked by an ester group to position 6 of the trehalose molecule.

Calcium interactions with d-glucans: crystal structure of α,α-Trehalose-calcium bromide monohydrate

Three-dimensional X-ray diffraction data were used to determine the crystal structure of α,α-trehalose-calcium bromide monohydrate, a model system for investigation of factors involved in the binding of calcium ions to d-glucans of dental plaques. Crystals of C 12H 22O 11 ·CaBr 2·H 2O are orthorhombic, space group C222 1, with a  11.058(1) b  11.537(1), c  15.101(1) Å, and Z  4. Intensity data for 925 independent reflections were measured with an automated diffractometer. A trial structure, obtained by the heavy-atom method, was refined by least-squares to R  0.03. An outstanding feature of the crystal packing is the interaction of trehalose molecules with calcium ions. Each calcium is coordinated to hydroxyl groups from four symmetry-related d-glucose moieties, thereby cross-linking the trehalose molecules. Similar interactions between calcium ions and the d-glucose residues of extracellular d-glucans may be of importance in the agglutination processes involved in dental-plaque formation.

The crystal and molecular structure of trehalose dihydrate

The crystal structure of trehalose dihydrate has been solved by direct methods and refined to an R index of 0-057 using anisotropic refinement. The space group is P212121 and four formula units of C12HzzOz~.2HzO are contained in the unit cell of dimensions a= 17.90, b= 12.21 and c= 7.586 A. The two glucopyranose residues in the trehalose molecule have the chair 4C1 form, and are bonded by the a 1 --+ 1 glycosidic link in approximate twofold symmetry. Departures from symmetry are found in torsion angles about the e 1 -+ 1 link and in conformations of the primary alcohol groups O(6)H and O(6')H. The C-O bond lengths show systematic trends similar to those in other e-pyranose sugars and at the same time show some characteristic features related to the e 1 -~1 link of the two glucose residues. There are two indirect intramolecular hydrogen bonds incorporating water molecules. Neither the ring oxygens nor the glycosidic linkage oxygen accept hydrogen bonds. The molecular packing in the crystal is mainly determined by the hydrogen bonds.

The Nutrition of the Central Nervous System in the Cockroach Periplaneta Americana L

ABSTRACT 14C-labelled glucose injected into the cockroach was found to be rapidly converted to trehalose, only small amounts remaining in equilibrium with the disaccharide in the haemolymph. The entry of these sugars into the cockroach central nervous system was studied by following the increase in radioactivity within the abdominal nerve cord after the injection of radioactive glucose into the haemolymph. The levels of radioactivity increased at closely similar rates in different parts of the abdominal nerve cord. The influx of sugars into the nerve cord was calculated to be equivalent to 1·09 mM. glucose/l. of nerve cord water/min. The greater part of the 14C entering the nerve cord originated from the trehalose, only about 7% being derived from the small amount of glucose in the haemolymph. The movement of the relatively small number of glucose molecules into the nerve cord occurred, nevertheless, at approximately 2·5 times the rate of the larger trehalose molecules. Chromatographic analysis revealed that more than half of the absorbed 14C was incorporated as glutamic acid and glutamine in the nerve cord. Smaller amounts of glycogen, trehalose, glucose, aspartic acid and occasional traces of alanine were found. In the isolated nerve cord substantial amounts of alanine accumulated, the formation of the other amino acids being reduced. 14CO2 production in vitro was found, after 1 hr., to represent only about 1 % of the total activity within the nerve cord. The results demonstrate a linkage of carbohydrate and amino acid metabolism and represent circumstantial evidence for the presence of the tricarboxylic acid cycle enzymes in the central nervous system of this insect.