2,6-Dicarboxypyridine N-oxide

Oligoanthranilamides. Non-Peptide Subunits That Show Formation of Specific Secondary Structure

“…2,6-Pyridinedicarboxylic acid (8.81 g) was dissolved in H 2 O 2 (50 mL) and AcOH (20 mL), and the mixture was stirred at 100 °C for 6 h. The reaction mixture was evaporated and solidified from THF (100 mL) and hexane (150 mL). The solid was collected and washed with hexane (2 × 30 mL) to obtain the desired compound as a white solid (5.46 g, 60%): mp 155−157 °C (lit 21c. 155−157 °C); 1 H NMR (300 MHz, DMSO- d 6 ) δ 8.23 (d, J = 7.8 Hz, 2H), 7.94 (t, J = 8.0 Hz, 1H); 13 C NMR (300 MHz, DMSO- d 6 ) δ 161.0, 139.4, 132.4, 129.0; HRMS m / e calcd for C 7 H 5 NO 5 183.0168, found 183.0171.…”

“…Because a key goal of this work is to maintain structure by intramolecular hydrogen bonding, an interesting candidate was pyridine-2,6-dicarboxamide N -oxide 26 and its derivatives. A crystal structure of the corresponding dicarboxylic acid 27 shows two very short, six-membered ring intramolecular hydrogen bonds between the acidic hydrogens and the N -oxide (O···O; 2.48 and 2.45 Å). Analogous interactions would be expected to stabilize a turn between two anthranilamide units (where R = 2-benzoate) with an approximately 120° angle between the phenyl-N bonds.…”

Mononuclear gold(iii) complexes withl-histidine-containing dipeptides: tuning the structural and biological properties by variation of the N-terminal amino acid and counter anion

“…26,31,32 Methionine oxidation to its sulfoxide in the presence of Au(III) has been evidenced by X-ray diffraction analysis. 33 The fact that Au(III) can act as relatively strong oxidizing agent has been connected to its inhibiting activity of various proteins. 25 The importance of coordination chemistry of Au(III) ion with Lhistidine-containing peptides, and the finding that some of these complexes have shown promising cytotoxic activity toward different human tumor cell lines, 24 data, including the crystal structures of 1a, 1b and 2b, has already been reported.…”