Syntheses of cyclic hydroxamic acid derivatives, and their chelating abilities and biological activities.

Protonation equilibria studies of the standard α-amino acids in NaNO3 solutions in water and in mixtures of water and dioxane

“…The protonation constants determined for the amino acids studied at T = 298.15 K in 0.1 mol AE dm À3 NaNO 3 aqueous solutions agree fairly well with data reported previously in the literature [1][2][3][4][5][6][7][8][9][10][11][12], after allowing for changes in experimental conditions as well as methods of calculation. It is worth mentioning that the pK a1 values of the amino acids investigated are too low (62.30) and exist only in strongly acidic solutions.…”

“…Despite their recognized importance, there are only a few experimental contributions on their acid-base behaviour in different environments. A search of the literature showed that the studies on the thermodynamic protonation constants of amino acids using a variety of experimental and theoretical tools have been few [1][2][3][4][5][6][7][8][9][10][11][12]. No work seems to have been done on the determination of the dissociation constants of glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, tyrosine, tryptophan, cysteine, methionine, serine, threonine, aspartate, glutamate, asparagine, glutamine, lysine, arginine, and histidine in different NaNO 3 solutions and in various (water + dioxane) mixtures at different temperatures.…”

Fragment‐Based Lead Discovery: Screening and Optimizing Fragments for Thermolysin Inhibition

“…As a major by-product, the corresponding noncyclic carboxylic acid was obtained. 3-Hydroxy-2-methylquinazolin-4(3H)-one (30 a): [36,38,53] According to the general procedure B using 0.145 g (0.75 mmol) of 29 a, 0.041 g (31 %) of 30 a was obtained after reversed-phase chromatography (CH 3 …”

Synthesis of N-Hydroxypyrazin-2(1H)-ones via Selective O-Debenzylation of 1-Benzyloxypyrazin-2(1H)-ones Using Flow Methodology

“…In the current paper, we focus on our newly developed synthesis of N-hydroxypyrazinones. These can be prepared via the base catalyzed condensation of a glyoxal derivative with either an α-amino hydroxamic acid (previous work) [15][16][17][18][19][20] or an O-protected α-amino hydroxamic acid (this work). The latter synthesis requires a deprotection step [21][22][23][24] but is warranted to have a better compatibility with different classes of functional groups as well as reaction conditions.…”