Crystal structure and hydrogen bonding in N-(1-deoxy-β-d-fructopyranos-1-yl)-2-aminoisobutyric acid

The title compound, alternatively called d-fructose-2-aminoisobutyric acid (FruAib), C10H19NO7, (I), crystallizes exclusively in the β-pyranose form, with two conformationally non-equivalent molecules [(IA) and (IB)] in the asymmetric unit. In solution, FruAib establishes an equilibrium, with 75.6% of the population consisting of β-pyranose, 10.4% β-furanose, 10.1% α-furanose, 3.0% α-pyranose and <0.7% the acyclic forms. The carbohydrate ring in (I) has the normal 2C5 chair conformation and the amino acid portion is in the zwitterion form. Bond lengths and valence angles compare well with the average values from related pyranose structures. All carboxyl, hydroxy and ammonium groups are involved in hydrogen bonding and form a three-dimensional network of infinite chains that are connected through homodromic rings and short chains. Intramolecular hydrogen bonds bridge the amino acid and sugar portions in both molecules. A comparative Hirshfeld surfaces analysis of FruAib and four other sugar–amino acids suggests an increasing role of intramolecular heteroatom interactions in crystal structures with an increasing proportion of C—H bonds

1-Deoxy-1-(N-methyl-4-fluorophenylamino)-d-arabino-hexulose

The title compound, C13H18FNO5, consists of d-fructose with an aromatic amine. The carbohydrate chain is in the acyclic keto form and has the zigzag conformation, while the solid-state NMR data suggests a conformational dimorphism at the aromatic amine group. The carbohydrate portion is involved in extensive O—H...O hydrogen bonding, which forms a two-dimensional network parallel to (001) and organized into fused homodromic ring patterns. The Hirshfeld surface fingerprint plots reveal a major contribution of the non-polar H...H and C...H interactions to the crystal packing forces

N-(1-Deoxy-α-d-tagatopyranos-1-yl)-N-methylaniline (“d-Tagatose-N-methylaniline”)

Tagatosamines form in thermally-processed dairy products and contribute to the foods’ organoleptic and nutritional value. d-Tagatose-N-methylaniline (N-(1-deoxy-d-tagatos-1-yl)-N-methylaniline, 1-deoxy-1-(N-methylphenylamino)-d-tagatose) was synthesized from d-galactose via the Amadori rearrangement. In aqueous solution, it established an anomeric equilibrium consisting of 62.8% α-pyranose, 21.3% β-pyranose, 1.5% α-furanose, 8.1% β-furanose, and 6.2% acyclic keto tautomer. The crystalline α-pyranose anomer of d-tagatose-N-methylaniline adopted the 5C2 chair conformation. All hydroxyl and ring oxygen atoms and the amino nitrogen are involved in an extensive H-bonding network dominated by infinite homodromic chains. The Hirshfeld surface analysis suggests a significant contribution of non-polar intermolecular contacts to the crystal structure

Crystal structure of (E)-3-methoxy-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide, C15H15N3O2

C15H15N3O2, orthorhombic, Pca21 (no. 29), a = 7.9831(2) Å, b = 10.6486(3) Å, c = 15.7222(4) Å, V = 1336.53(6) Å3, Z = 4, Rgt(F) = 0.0340, wRref(F2) = 0.0799, T = 100 K

piggyBac transposon plus insulators overcome epigenetic silencing to provide for stable signaling pathway reporter cell lines.

Genetically modified hematopoietic progenitors represent an important testing platform for a variety of cell-based therapies, pharmaceuticals, diagnostics and other applications. Stable expression of a transfected gene of interest in the cells is often obstructed by its silencing. DNA transposons offer an attractive non-viral alternative of transgene integration into the host genome, but their broad applicability to leukocytes and other "transgene unfriendly" cells has not been fully demonstrated. Here we assess stability of piggyBac transposon-based reporter expression in murine prostate adenocarcinoma TRAMP-C2, human monocyte THP-1 and erythroleukemia K562 cell lines, along with macrophages and dendritic cells (DCs) that have differentiated from the THP-1 transfects. The most efficient and stable reporter activity was observed for combinations of the transposon inverted terminal repeats and one 5'- or two cHS4 core insulators flanking a green fluorescent protein reporter construct, with no detectable silencing over 10 months of continuous cell culture in absence of any selective pressure. In monocytic THP-1 cells, the functional activity of luciferase reporters for NF-κB, Nrf2, or HIF-1α has not decreased over time and was retained following differentiation into macrophages and DCs, as well. These results imply pB as a versatile tool for gene integration in monocytic cells in general, and as a convenient access route to DC-based signaling pathway reporters suitable for high-throughput assays, in particular

Structural and Functional Studies of S-(2-Carboxyethyl)-L-Cysteine and S-(2-Carboxyethyl)-l-Cysteine Sulfoxide

Insecticidal non-proteinogenic amino acid S-(2-carboxyethyl)-L-cysteine (&beta;-CEC) and its assumed metabolite, S-(2-carboxyethyl)-l-cysteine sulfoxide (&beta;-CECO), are present abundantly in a number of plants of the legume family. In humans, these amino acids may occur as a result of exposure to environmental acrylonitrile or acrylamide, and due to consumption of the legumes. The &beta;-CEC molecule is a homolog of S-carboxymethyl-l-cysteine (carbocisteine, CMC), a clinically employed antioxidant and mucolytic drug. We report here detailed structural data for &beta;-CEC and &beta;-CECO, as well as results of in vitro studies evaluating cytotoxicity and the protective potential of the amino acids in renal tubular epithelial cells (RTECs) equipped with reporters for activity of seven stress-responsive transcription factors. In RTECs, &beta;-CEC and the sulfoxide were not acutely cytotoxic, but activated the antioxidant Nrf2 pathway. &beta;-CEC, but not the sulfoxide, induced the amino acid stress signaling, which could be moderated by cysteine, methionine, histidine, and tryptophan. &beta;-CEC enhanced the cytotoxic effects of arsenic, cadmium, lead, and mercury, but inhibited the cytotoxic stress induced by cisplatin, oxaliplatin, and CuO nanoparticles and acted as an antioxidant in a copper-dependent oxidative DNA degradation assay. In these experiments, the structure and activities of &beta;-CEC closely resembled those of CMC. Our data suggest that &beta;-CEC may act as a mild activator of the cytoprotective pathways and as a protector from platinum drugs and environmental copper cytotoxicity

Structure, Antioxidant and Anti-inflammatory Activities of the (4R)- and (4S)-epimers of S-Carboxymethyl-L-cysteine Sulfoxide

S-Carboxymethyl-L-cysteine (CMC) is an antioxidant and mucolytic commonly prescribed to patients with chronic obstructive pulmonary disease. In humans, CMC is rapidly metabolized to S-carboxymethyl-L-cysteine sulfoxide (CMCO). In this study, we assessed structural and functional similarities between CMC and CMCO. X-Ray diffraction analysis provided detailed structural information about CMCO, which exists as a 1:1 mixture of epimers, due to the emergence of a new chiral center at the sulfur atom. Both CMC and CMCO epimers protected model DNA from copper-mediated hydroxyl free radical damage. Using an insulated transposable construct for reporting activity of the cellular stress-responsive transcription factors Nrf2, p53, NF-&kappa;B, and AP-1, we demonstrate that CMCO, especially its (4R)-epimer, is comparable to CMC in their ability to mitigate the effects of oxidative stress and pro-inflammatory stimuli in human alveolar (A549) and bronchial epithelial (BEAS-2B) cells. The results of these in vitro studies suggest that CMCO retains, at least partially, the antioxidant potential of CMC and may inform pharmacodynamics considerations of CMC use in clinics