Automated synthesis of PET radiotracers by copperâ mediated 18Fâ fluorination of organoborons: Importance of the order of addition and competing protodeborylation

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142980/1/jlcr3583_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142980/2/jlcr3583.pd

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

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

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

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