Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89Linked to original sources
PubMed2002

[Capillary electrophoretic enantioseparation of arylglycine amides with highly sulfated beta-cyclodextrin as chiral selector].

Enantiomers of nine arylglycine amides synthesized were successfully separated by capillary electrophoresis (CE) using highly sulfated beta-cyclodextrin (HS-beta-CD) as a chiral selector. Baseline enantioseparation of the analytes was obtained within 6 min at neutral pH but not the commonly used acidic condition. HS-beta-CD content, buffer type and concentration, and non-chiral additive were studied and optimized for high resolution and fast speed. A reproducible running buffer system composed of 15 g/L HS-beta-CD, 0 or 10% (volume fraction) methanol and 20 mmol/L 3-(N-morpholino) propane sulfonic acid at pH 6.5 was obtained. The D-enantiomer always migrated ahead of the L-enantiomer for all the 9 pairs of arylglycine amides. The migration order was found to be dependent on the structure of the solutes.

Amides↗
PubMed1991

Synthesis and anti-inflammatory activity of 5-(1,4-dihydropyridyl)-tetrazol-2-acetic acids, esters and amides.

Thirteen 5-[3-(1,4-dihydropyridyl)]-2H-tetrazol-2-acetic acids (18-30), seventeen esters (4-17, 32, 35, 41) and eight amides (31, 32-34, 36-40) were synthesized in order to investigate the effect of alpha-substituents (R1 = H, Me) and 1,4-dihydropyridyl substituents (R2 = aryl, alkyl; R3 = phenoxy, methoxy or amino) on anti-inflammatory activity. The effects of the R1, R2 or R3-substituents were variable but highly interdependent. The relative order of anti-inflammatory potency was generally acid greater than amide and ester. Methyl 2-methyl-2-(5-[3-(4-phenyl-1-carbamoyl-1,4-dihydropyridyl)]-2H- tetrazol-2-yl) acetate (35) was the most effective anti-inflammatory agent in the group, reducing inflammation 96% at 5 hr after a 50 mg/kg po dose, relative to ibuprofen's 52% inhibition at 5 hr after a 100 mg/kg po dose.

Acetates↗
PubMedDate not supplied

Synthesis and resolution of novel 3'-substituted phenylalanine amides.

A convenient approach to the synthesis of ring-substituted phenylalanine amides is described. Phase transfer alkylation of N-(diphenylmethylene)amino acetonitrile or N-(diphenylmethylene)glycine ethyl ester provides alpha-substituted imines 2 and 6. After acid hydrolysis and esterification, resolution with alpha-chymotrypsin provided 3'-substituted phenylalanine analogs 9a-d which could easily be converted to N alpha-t-butyloxycarbonyl-phenylalanine amides for use in the synthesis of peptide analogs. The approach described here is amenable to the synthesis of 3-substituted phenylalanines with a wide variety of substituents for determination of structure-activity relationships of peptides.

Amides↗
PubMed1989

Amides of 1,3,3-trimethyl-n-[(2-pyridyl)methyl]-2-oxabicyclo [2.2.2]octan-6-amine with depressant and antiarrhythmic activities.

The synthesis of 1,3,3-trimethyl-N-[(2-pyridyl)methyl]-2- oxabicyclo [2.2.2]octan-6-amine (II) (exo, endo mixture) starting from 1,3,3-trimethyl-N-nitro-2-oxabicyclo [2.2.2]octan-6-imine (I), as well as of a series of amides (III) derived from the above amine, is described. Some compounds (III) showed remarkable depressant and antiarrhythmic activities in rats and mice, respectively, whereas the clofibric acid amide (III e) showed an appreciable hypolipidemic activity in rats. Moreover, the above compounds usually exhibited a moderate infiltration anesthesia in mice, as well as a weak hypotensive and bradycardic activity in rats.

Amides↗
PubMed1987

Synthesis and antiinflammatory activity of N-substituted-dihydropyridylacetic acids, esters, and amides.

A group of N-substituted-1,4-dihydropyridylacetic acids (13-16), esters (4-12), and amides (17-23) were synthesized in order to investigate the effect of 4-substituents (R2 = Ph, n-Bu or Me) and alpha-substituents (R3 = H, Me) on antiinflammatory activity. In the acetic ester class of compounds, the relative activities (R2-substituents) were Ph greater than n-Bu greater than Me. The presence of an R3 methyl substituent enhanced activity. Increasing the length of the alkyl ester substituent enhanced activity, since the tri-ester (7) was more active than the bis-ester (6), and the bis-ester (11) was more active than the mono-ester (10). The relative order of antiinflammatory potency was generally ester greater than amide greater than acid. Methyl 2-methyl-2-(-1-[4-phenyl-3-(4,4-dimethyloxazolin-2-yl)-1,4-dihy dropyridyl]) acetate (9) was the most active antiinflammatory agent in the series, reducing inflammation 73.9% at 3 hr after a 100 mg/kg po dose.

Acetates↗
PubMed1986

Contact sensitivity to the amide anesthetics lidocaine, prilocaine, and mepivacaine. Case report and review of the literature.

Multiple sensitivities to amide local anesthetics occurred in a 70-year-old woman following dental treatment. Soft-tissue swelling of the cheek was the clinical presentation. Patch testing confirmed type IV hypersensitivity to lidocaine, prilocaine, mepivacaine, and dibucaine. We review the classification of local anesthetics and the literature relating to contact sensitivity to the amide group.

Aged↗
PubMed1979

[Metabolism of dicarboxylic amino acids and their amides in bacteria of the genus Citrobacter].

In 58 Citrobacter strains the pathways of the utilization of dicarbonic amino acids and their amides were studied. These organisms were found to be incapable of decarboxylating glutaminic and asparaginic acids, as well as their amides. All the strains could actively desamidizate asparagine. Not all of these strains showed glutaminase activity. Aspartate-aminotransferase occurred twice as often as alanine-aminotransferase, the level of activity being approximately the same. The Citrobacter strains desamidizated asparaginic acid with great constancy, but only in 1/3 of them this reaction occurred via an aspartase route. The desamidization of asparaginic acid in Citrobacter seemed to proceed in different ways. The desamidization of glutaminic acid was observed only in a part of the strains, and the reaction proceeded less actively.

Amides↗
PubMedDate not supplied

[Protein amidation in the aging organism].

The role of protein amide groups was studied in the process of the organism ageing. It is shown that with ageing there occurs the asparagin deamidation in water-soluble and water-insolbule proteins of the rat brain, liver and heart. The glutamine content in the old rat tissues remains at the level determined in the young animal tissues. Tissue proteins of old rats are better substrates for protein--a complex of proteinases of a wide specificity that those of young animals. An increased attack of the old animals proteins by nonspecific proteinases is due to a decrease in their amidation degree during ageing.

Aging↗
PubMedDate not supplied

[Kinetics of alpha-chymotrypsin catalyzed hydrolysis in equilibrium. II. Comparison of ester and amide substrates].

Kinetic of the alpha-chymotrypsin catalyzed reversible hydrolytic reaction of methyl N-acetyl-L-phenylalaninate and N-acetyl-L-phenylalanylglycinamide at pH 5.5 and equilibrium conditions has been studied. The rates of the labeled reaction products incorporated into the substrate a different methanol concentrations shows that the reaction proceeds by a compulsory mechanism with the formation of N-acetyl-L-phenylalanine-alpha-chymotrypsin complex. For the amide substrate the data obtained are also in agreement with the compulsory mechanism of its hydrolysis. Equilibrium kinetics of ester and amide substrates hydrolysis has been compared.

Amides↗
PubMed1983

[Synthetic serine proteinase inhibitors. 30. Synthesis of alpha-benzoylamino-4-amidinocinnamic acid and alpha-(4-amidinobenzoylamino) cinnamic acid amides, and their inhibitory effect on trypsin-like enzymes].

To test their inhibitory activity against enzymes, the authors synthetized the compounds named in the title. The synthesis started from the corresponding azlactones 1 and 9. Subsequent aminolysis led to the alpha-benzoyl-aminocinnamic acid amides 2 and 10 which contain a cyano function. The acid amides were converted, in different ways, to the desired amidine salts 4, 7, 12 and 15. The amidines obtained showed but little inhibitory activity against the serine proteinases thrombin, trypsin and plasmin.

Amides↗
PubMedDate not supplied

[Several properties of complexes of polynucleotides with aromatic amino acid amides of oligonucleotides].

Residues of Phe, Tyr and Trp in the complexes of their oligonucleotide amidates and polynucleotides of A-U of G-C nucleotide composition are most likely localized in the minor groove of the Watson--Crick part of the triple helix where they interact with bases but do not intercalate into the helix. Formation of the complexes is accompanied with a change in the relative localization of amino acids and bases. The major geometrical parameters of the triple helices of the complexes are not changed by the residues of aromatic amino acids (according to CD data). A slight violation of stacking interactions between bases is observed along with an increase of the cooperativity of melting of the complexes of A-U composition (according to UV absorption data). The effect of the residues of aromatic amino acids on the stability of triple helices is determined by the nucleotide composition of the latter, i.e. complexes of A-U composition are destabilized with the Phe, Tyr and Trp residues, whereas the Trp residue does not affect the stability of the complexes of G-C composition. The hydrophobic character of aromatic amino acids and their different affinity for bases of different structure seem to account for this difference in stability. The dependence of the thermal stability of RNH-dp(An).2poly(U)-complexes on the structure of the amide radical (residues of glycin, aromatic amino acids, alkyl- and arylalkyl amines) testifies the ability of the radical to "regulate" the interaction between the oligomer and the complementary polynucleotide. This capacity for "regulation" is not observed in the system of G-C composition.

Amides↗
PubMed1982

Correlation of partition coefficients with antisickling activity of simple alcohols, amides and ureas.

The resultant increase of the solubility of hemoglobin S in the presence of various alcohols, amides, and ureas has been found to correlate with the individual partition coefficients of each agent. Comparisons have been made using the log of the slope of the curves obtained from standard ultracentrifugation gelation assays with the antisickling agents and is expressed in terms of log (slope Cs/[A]) = k log P + k' where Cs is the solubility of HbS in gm/dL, [A] is the concentration of the agent in moles/liter, P is the partition coefficient of A, and k (slope) and k' (y intercept) constants. These results are similar to other structure activity relationships developed by Corwin Hansch and co-workers [5-8, 10]. Such comparisons illustrate in part the quantitative binding capabilities of organic molecules to proteins based upon their inherent hydrophobic character which can be calculated and predicted a priori after a few initial observations. This paper demonstrates that the solubility increase of hemoglobin S by various simple alcohols, amides and ureas results directly from the hydrophobic qualities of each additive in a given series. It is further reasoned that these small molecules interact with hydrophobic areas on hemoglobin S and that this conjugal hydrophobic interaction explains in part their mechanism of action and polymer destabilization. The role of the polar group is also shown to be important for activity.

Alcohols↗
PubMedDate not supplied

Pharmacological studies of certain amides of substituted ethylenediamines - I.

Five substituted amides of ethylenediamines produced hypotension in dogs, which was not blocked by atropine, mepyramine and propranolol. The amides potentiated the pressor responses to Adr and NA and antagonised the depressor responses to Ach and histamine. The compounds also antagonised Ach-induced contractions on the frog rectus abdominis muscle and of carbachol on rat isolated colon suggesting d-tc and atropine-like actions respectively. Antihistaminic activity was observed on guinea pig isolated ileum as on dog blood pressure. Adr and NA-induced relaxation of rabbit isolated jejunum was potentiated. Finally Adr and NA-induced contractions of rat isolated seminal vesicle was antagonised.

Amides↗
PubMed1981

Cyclic peptides. XI. Synthesis of AM-toxin analogs by intramolecular condensation of pyruvyl-tripeptide amides.

In order to establish possible routes for the synthesis of AM-toxins, cyclotetradepsipeptides containing Dha, Pyr-L-Ala-L-Hmb-L-Tyr-NH2 were prepared and treated with TFA or anhydrous HF. The product was identified to be cyclo (-alpha-Hyala-L-Ala-L-Hmb-L-Tyr-), resulting from intramolecular condensation of the alpha-keto and amide group with the formation of the alpha-Hyala residue. Cyclo (-alpha-Hyala-L-Ala-L-Hmb-L-Phe-) and cyclo (-alpha-Hyala-L-Ala-L-Val-L-Phe-) were obtained by acid-treatment of the corresponding pyruvyl-tripeptide amides. The cyclic tetrapeptides did not show the activity of AM-toxin.

Amides↗
PubMed1995

Structure and epitope specificity of the O-specific polysaccharide of Proteus penneri strain 12 (ATCC 33519) containing the amide of D-galacturonic acid with L-threonine.

O-specific polysaccharide was isolated from Proteus penneri strain 12 (ATCC 33519) lipopolysaccharide (LPS) and studied using NMR spectroscopy, including selective spin-decoupling, one-dimensional NOE, two-dimensional homonuclear correlation spectroscopy, 13C,1H heteronuclear correlation spectroscopy and chemical methods (O-deacetylation, Smith degradation, partial acid hydrolysis followed by borohydride reduction and methylation). The amide of D-galacturonic acid with L-threonine [D-GalA(L-Thr)] was identified as a constituent of the polysaccharide and the following structure of the tetrasaccharide repeating unit was established: [formula: see text] where the degree of O-acetylation at either position varies over 20-40%. Serological study with LPS, its degradation products and related synthetic glycoconjugates (2-acrylamidoethyl glycosides of amides of alpha-D-GalA with L-amino acids copolymerised with acrylamide) showed that D-GalA(L-Thr) plays an important role in manifesting the serological specificity of the P. penneri 12 O-antigen. Serological cross reactions between LPSs of P. penneri 12 and Proteus mirabilis S1959, R14/S1959 (transient-like form), O23 and O28 are discussed.

Amides↗
PubMedDate not supplied

[Simple derivatives of amino acid neurotransmitters. Anticonvulsant evaluation of derived amides, carbamates and esters of glycine and beta-alanine].

With GABA, glycine and beta-alanine are inhibitory amino acids. They act mainly in the spinal cord and in the brain stem via the strychnine sensitive glycine receptor. Glycine exhibits also a key rule in the excitatory neurotransmission in the N-methyl-D-aspartate receptor complex. These two hydrophilic molecules suffer from the lack of small neutral amino acid carriers at the luminal side of the blood-brain barrier. The purpose of this study is to design molecular entities able, by an enhanced lipophilicity, to increase the pharmacological properties of these amino acids. From the synthesis and from the anticonvulsant evaluation in the maximal electroshock seizure test, we can underline: 1) In the case of a monosubstitution, a N-substitution is more important than amidation or esterification of the carboxylate. 2) Specially in the case of N-substitution, carbamates derivatives are the most active compounds compared to the correspondent amides. N-benzyloxycarbonylglycine is really attractive. The pharmacological properties, the tentative schedule of the mode of action are presented too.

Amides↗