Pyrroline-5-carboxylate, the intermediate in the interconversion of proline, ornithine, and glutamate, increases 5-phosphoribosyl 1-pyrophosphate (PP-ribose-P) and purine nucleotide formation in intact human erythrocytes. We proposed that: 1) pyrroline-5-carboxylate is converted to proline by pyrroline-5-carboxylate reductase with concomitant oxidation of NADPH, 2) NADP+ augments glucose-6-phos...

The molecules of ethyl 5-amino-1-(4-cyanophenyl)-1H-imidazole-4-carboxylate, C13H12N4O2, are linked into a chain of alternating R(2)2(10) and R(4)4(34) rings by a combination of N-H...N and C-H...N hydrogen bonds. In ethyl 5-amino-1-(4-chlorophenyl)-1H-imidazole-4-carboxylate, C12H12ClN3O2, where the ethyl group is disordered over two sets of sites, a combination of N-H...O, N-H...N, C-H...N an...

In order to establish the way in which the hydration characteristics of R-amino acids influence their noncovalent interactions with other solutes in aqueous solution, we measured medium effects for the water-catalyzed hydrolysis of an activated amide in aqueous solution in the presence of R-amino acids and some of their derivatives at 25 °C and pH 4. With the exception of phenylalanine and 3-ph...

We explored the inhibition mode of group IIA secreted phospholipase A(2) (GIIA sPLA(2)) selective inhibitors and tested their ability to inhibit GIIA sPLA(2) activity as chemical conjugates with hyaluronic acid (HA). Analogues of a benzo-fused indole sPLA(2) inhibitor were developed in which the carboxylate group on the inhibitor scaffold, which has been shown to coordinate to a Ca(2+) ligand i...

β-Lactam resistance in Acinetobacter baumannii presents one of the greatest challenges to contemporary antimicrobial chemotherapy. Much of this resistance to cephalosporins derives from the expression of the class C β-lactamase enzymes, known as Acinetobacter-derived cephalosporinases (ADCs). Currently, β-lactamase inhibitors are structurally similar to β-lactam substrates and are not effective...

The mechanism of ketonization of acetic acid over SiO2 was investigated by semiempirical quantum chemical AM1 method using the cluster approach. It has been found that the adjacent acid-base pair of the catalytic sites provokes dissociative adsorption of the acetic acid molecules resulting in the formation of surface carboxylate species. The adsorption process proceeds spontaneously. After bloc...

A series of thiourea and guanidinium derivatives have been prepared and their ability to bind a carboxylate group has been investigated. Guanidinium 33, featuring two additional amides and a pyridine moiety, proved to be the most potent carboxylate binding site and was able to bind acetate in aqueous solvent systems (K(ass) = 480 M(-1) in 30% H(2)O-DMSO). The pyridine moiety is critical to obta...

Herein we report a direct and efficient method for the synthesis of four new carboxylate-isostere analogs of daptomycin. The side chain carboxylic acid moieties of the aspartic acids (Asp-3, Asp-7 and Asp-9) and β-methyl glutamic acid (MeGlu-12) were all converted into the corresponding carboxylate isosteres using direct synthetic procedures. The present study also describes an esterification p...