N-benzoylamino Acids Research Articles

Nickel peroxide as a glycine-selective chemical model of peptidylglycine α-amidating monooxygenase

In a process, which is analogous to that catalysed by peptidylglycine α-amidating monooxygenase, nickel peroxide cleaves N-benzoylamino acid methyl esters to give benzamide, with a selectivity for reaction of the glycine derivative.

Asymmetric Induction during the Aminolysis of 5(4H)-Oxazolones from N-Benzoyl Amino Acids; Almost Specific Formation of One Epimer in the Reaction of the Oxazolone from N-Benzoyl-Dl-t-leucine with Methyl l-Prolinate

Abstract Asymmetric induction during the aminolysis of 5(4H)-oxazolones from N-benzoyl amino acids was investigated using a series of amino acid esters as amine nucleophiles. The reaction of the oxazolone from N-benzoyl-Dl-t-Meucine with methyl l-prolinate was found to produce the diastereomeric Dl isomer, almost specifically, under appropriate conditions.

Salicylurate-hydrolyzing enzyme from intestinal bacterium in rabbit: purification and characterization.

An enzyme which hydrolyzes salicylurate (salicyluric acid) into salicylic acid and glycine was found in a cell-free extract of an intestinal bacterium in rabbit.This enzyme, tentatively named salicylurate-hydrolyzing enzyme, was found to be membrane-bound and was purified from the extract by ammonium sulfate fractionation and column chromatography.Two protein fractions with the enzyme activity were observed on diethylaminoethyl-Toyopearl.The first peak (enzyme I) was further purified by chromatography on carboxymethyl-cellulose and on hydroxyapatite, and its enzymatic properties were characterized.The isoelectric point was 8.7, and the molecular weight was estimated to be 170000 by gel filtration on Sephadex G-150 and 27000 by sodium dodecyl sulfate gel electrophoresis, suggesting that the enzyme exists as a hexamer.The enzyme was strongly inhibited by p-chloromercuribenzoate (PCMB), Hg2+and o-phenanthroline.The activities lost on incubation with PCMB and o-phenanthroline were restored by the addition of 2-mercaptoethanol and Zn2+, respectively.The enzyme catalyzed hydrolysis of N-benzoyl (Bz) amino acids and their derivatives, while it was inert toward n-benzoyl-protected peptides such as p-HO-Bz-Gly-Gly and Bz-Gly-L-His-L-Leu.We conclude that salicylurate hydrolase presented here is a kind of hippurate hydrolase (EC 3.5.1.32).

Preparation and the infrared, Mössbauer and 1H, 13C and 119Sn NMR spectra of some triorganotin(IV) derivatives of N-benzoyl- dl-alanine and N-benzoyl- dl-alanylglycine

The triorganotin(IV) derivatives of N-benzoyl- dl-alanine (HA), R 3SnA, and N-benzoyl- dl-alanylglycine (HDP), R 3SnDP (R  methyl, n-propyl, n-butyl, phenyl and cyclohexyl, respectively,) have been prepared from the triorganotin(IV) chlorides R 3SnCl and the appropriate N-benzoylamino acid. The compounds are five-coordinate and polymeric in the solid state. The tin atoms in triorganotin(IV) groups R 3Sn are coordinated by the unidentate carboxylic group and by the oxygen atom of the amidocarbonyl group of adjacent molecule. The compounds are essentially monomeric in non-coordinating solvents (CHCl 3, benzene, nitrobenzene and camphor, respectively), in coordinating solvents (dimethyl sulphoxide, hexamethylphosphortriamide) coordination by one molecule of solvent occurs to form trans-trigonal bypyramid five-coordinate complexes.

ChemInform Abstract: Ethyl Esters of N‐(3‐ and N‐(4‐Amidinobenzoyl) L‐Amino Acids: Synthesis and Antiproteolytic Activity Towards Bovine Trypsin and Porcine Pancreatic Kallikresin.

Ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids (namely, glycine, alanine, valine, leucine and phenylalanine) were synthesized and their inhibitory effect on the bovine trypsin and porcine pancreatic kallikrein catalyzed hydrolysis of p-nitroanilides of amino acids was investigated, at pH 8.1 and 37 degrees, in parallel with the effect of ethyl and/or methyl esters of N-benzoyl(-L-)amino acids and benzamidine. For both proteinases, the inhibitory effect of ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids is independent of the aminoacidic side chain, is closely similar to that of benzamidine (which binds at the S1 subsite of the proteinases examined and is commonly taken as a molecular inhibitor-model), and is higher by at least 10-fold than that of ethyl and/or methyl esters of N-benzoyl(-L-)amino acids (depending on the aminoacidic residue). On structural grounds, the peculiar inhibitory behaviour of ethyl esters of N-(3- and N-(4-amidinobenzoyl)(-L-)amino acids has been related to the interaction of the positively charged substituent at the N-position with the Asp189 residue present in the primary specificity subsite (S1) of bovine trypsin and porcine pancreatic kallikrein. The consistently lower affinity for porcine pancreatic kallikrein of all the inhibitors considered, as compared to bovine trypsin, may be related to the marked structural differences of the primary specificity subsite of these two serine proteinases.

Asymmetric hydrogenation catalyzed by aminophosphine-phosphiniterhodium complexes derived from natural aminoalcohols and x-ray crystal structure of (1,5-cyclooctadiene)-( S)- N-(diphenylphosphino)-2-diphenylphosphinoxymethylpyrrolidinerhodium(I) perchlorate

From the cheap and readily available amino alcohols ( S)-pyrrolidinemethanol (( S)-prolinol), and ( S)-α- N-ethyl-aminobutanol, we have obtained two new aminophosphine-phosphinite ligands: ( S)- N-(diphenylphospino)-2-diphenylphos- phinooxymethylpyrrolidine (( S)-Prolophos) and ( S)-1-diphenylphosphinoxy-2- N-ethyl- N-diphenylphosphinoaminobutane (( S)-Butaphos). The rhodium(I) complexes of these phosphines act as efficient homogeneous hydrogenation catalysts at ambient temperature and pressures for dehydro N-acetyl amino acids, dehydro N-benzoyl amino acids and itaconic acid. An X-ray diffraction study of the complex [Rh(COD)(( S)-Prolophos)][ClO 4]· THF has been shown that the crystals belong to the monoclinic space group P2 1 with a 10.680(2), b 10.448(2), c 18.207(3) Å and β 104.97(1)ldg. Refinements based on 2105 significant counter reflections led to a final R value of 0.060. The cation is in a distorted square planar geometry, the rhodium atom being bound to the two phosphorus atoms and to the two double bonds of the diene molecule.

The interaction of dimethyl sulfoxide with N-benzoyl amino acids

The interaction of dimethyl sulfoxide with N-benzoyl amino acids in deuterochloroform has been investigated by 13C n.m.r. spectroscopy. Examination of the chemical shifts of the benzene ring reveals that intermolecular hydrogen bonding between dimethyl sulfoxide and the amido-hydrogen atom increase the effective steric size of the amino hydrogen, resulting in an increase in the torsional angle between the benzene ring and the C(O)NHCH(R)COOH side chain. Self-association of N- benzoyl amino acids in deuterochloroform occurs largely through two COOH...O=C hydrogen bonds and does not involve intermolecular hydrogen bonding to the N-H proton.

RACEMIZATION IN PEPTIDE SYNTHESIS

A laboratory experiment involving the coupling of N-benzoylamino acids with methyl N epsilon-benzyloxycarbonyl-L-lysinate using various methods is described. The extents of racemization are determined by analysis for the protected diastereomeric dipeptide ester products by quantitation of the separated ester methyl proton peaks of their nuclear magnetic resonance (60 MHz) spectra. Synthesis of the starting materials and additional exercises are included as options.

Studies on the use of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline for the synthesis of acylamino acid anilides and p-nitroanilides.

The use of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) for coupling acyl-L-amino acids with aniline and p-nitroaniline has been investigated. Optically pure anlides are obtained in good yield but partial racemization occurred in one case. p-Nitroanlides cannot be obtained under similar conditions but if the reaction solvent is removed and the residue left for several days, coupling occurs giving a racemic product in moderate yields. Reaction mechanisms are proposed on the basis of isolated and characterized intermediates. It has been found that N-benzoylamino acid anilides and p-nitroanilides are cleaved within a few minutes by hydrogen bromide in acetic acid to give the N-benzoylamino acid and the amine.

Polyphosphate Ester as a Synthetic Agent. XI. Synthesis of 2-(1'-Aminoalkyl) benzimidazoles from N-Benzoylamino Acids

Polyphosphate Ester as a Synthetic Agent. XI. Synthesis of 2-(1'-Aminoalkyl) benzimidazoles from N-Benzoylamino Acids

A New Reaction of Nitriles. IV. Synthesis of N-Benzoylamino Acids

A New Reaction of Nitriles. IV. Synthesis of N-Benzoylamino Acids