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PubMed1988

[Interaction of acetyl-CoA-carboxylase from the rat liver with alkylating amides of ATP and ADP].

The interaction of 4-(N-chloroethyl-N-methylamino)-benzyl-gamma-amide ATP (I) and the corresponding beta-amide of ADP (II) with rat liver acetyl-CoA carboxylase was studied. Both analogs were shown to cause affinity modification of the enzyme. ATP and GoAS Ac protected the enzyme against inactivation. HCO3- increased the rate of carboxylase inactivation by analogs I and II (2.5- and 1.5-fold, respectively). The alkylating amides did not influence the rate of the bicarbonate-dependent [14C]-ADP-ATP exchange and inhibited the enzyme-catalyzed reaction of [14C]-CoAs Ac----CoAS Mal exchange, which testifies to the localization of the modified group in the CoAS Ac-binding site of the enzyme active center. Based on the affinity modification and analog size, it was found that the distance between the ATP- and CoAS Ac-binding sites of the enzyme active center can vary from 0.8 to 1.2 nm.

Acetyl-CoA Carboxylase↗
PubMedDate not supplied

[Amidation of blood proteins during hyperglycemia in experimental diabetes mellitus].

Rates of amidation of blood serum albumin and hemoglobin was studied in hyperglycemia developed during alloxan diabetes mellitus. Content of glucose in blood of the animals with diabetes exceeded 5.2-fold its level in blood of controls; amount of glycosylated hemoglobin was increased by 41.7%. Concentration of total, readily and hardly hydrolyzed amide groups was decreased in hemoglobin of the impaired animals by 13.1%, 17.6% and 10.4%, respectively, as compared with control group. The degree of blood serum albumin amidation was not altered. Hyperglycemia, accompanied by glycosylation of proteins, was the most probable cause of accelerated deamidation of hemoglobin. Participation of the protein deamidation in pathogenesis of diabetes mellitus is discussed.

Amides↗
PubMed1986

Food-borne amines and amides as potential precursors of endogenous carcinogens.

This paper reviews the experimental results of our research in the past several years and other related papers that have been directed toward the occurrence, biotransformation and epidemiological significance of carcinogenic N-nitroso compounds in biosphere. Endogenous carcinogens are a group of cancer-causing compounds produced in vivo from harmless precursors. This category has been exemplified by the well-known carcinogens, N-nitroso compounds. The significance of naturally occurring amines and amides as precursors of carcinogenic N-nitroso compounds in vivo and their implication in the incidence of human cancer have been investigated and emphasized. Extremely high levels of trimethylamine-N-oxide and dimethylamine were detected in squids and other seafoods. More than 90% of trimethylamine-N-oxide were converted to dimethylamine and trimethylamine on pyrolysis. Low levels of dimethylamine and methylamine were also detected in the fermented soybean products, wines and sauces. Both dimethylamine and trimethylamine are excellent precursors of dimethylnitrosamine. Several naturally occurring aromatic amines especially 2-carboline derivatives such as harman, norharman, harmaline, harmalol, harmine and harmol are mutagenic and become more mutagenic to Salmonella typhimurium after nitrosation. Appreciable amounts of piperidine were detected in the popular spice white and black pepper powders. Under acidic condition, piperidine reacts readily with nitrite to form carcinogenic N-nitroso-piperidine. N-Nitrosophenacetin was formed from the reaction of nitrite with the amide drug phenacetin. This new compound showed strong mutagenicity to Salmonella typhimurium and Sarcina lutea and strong teratogenic activity to Leghorn chicken embryos. Studies have shown that the majority of N-nitroso compounds in the body come from in vivo conversion. Most investigators believe that this endogenous pool of N-nitroso compounds may prove to be a major exposure route in man. The presence of naturally occurring amines and amides in the diet then becomes one of the crucial limiting steps in the formation of endogenous N-nitroso compounds in vivo.

Amides↗
PubMed1985

Amides of N-phenyl benzonorbornen-2-endo-amine with hypotensive and other activities.

The synthesis of two series of amides and glycinamides starting from N-phenyl benzonorbornen-2-endo-amine, prepared from benzonorbornen-2-one via sodium borohydride reduction of its N-phenyl imine, is described. Some amides showed a remarkable hypotensive activity in rats, whereas amides and glycinamides usually exhibited a moderate infiltration anesthesia in mice. Effects on heart rate in rats and antiarrhythmic activity in mice are also reported.

Amides↗
PubMed1972

Ceramide-like synthetic amides that inhibit cerebroside galactosidase.

Amides resembling ceramide (fatty acyl sphingosine) were synthesized and tested for their effects on rat brain cerebrosidase (galactosyl ceramide beta-galactosidase). The best inhibitor was N-decanoyl dl-erythro-3-phenyl-2-aminopro-panediol, which exhibited a K(i) of 0.4 mm. A Lineweaver-Burk plot indicated that the amide acted as a noncompetitive inhibitor, presumably by attachment to a site other than the substrate-active site. Preincubation did not affect the degree of inhibition, and inhibition was independent of incubation duration; these observations suggest that the inhibitor does not combine with the enzyme irreversibly. Structural variations produced decreased inhibitory activity: loss of one of the hydroxyl groups, replacement of the aromatic side chain with an aliphatic or substituted phenyl group, or isomeric inversion of the 3-hydroxyl group. It appears that the best activity is obtained with a substance most closely resembling natural ceramide. The cerebrosidases of rat spleen, kidney, and liver are also inhibited by the same amide.

Acylation↗
PubMed1977

Hydrolysis of alkyl ester and amide substrates by papain.

The ratio of the rate constants of acylation of papain with some amino acid ester and amide substrates is unexpectedly low. The contribution to this low ratio by the N-acyl group and the amino acid side chain was studied by measuring the rate constants of substrates containing various acyl groups (benzoyl and benzyloxycarbonyl) and various side chains (glycine, alanine, norleucine, citrulline and arginine). The benzoyl esters were found to be less reactive than the corresponding benzyloxycarbonyl esters, whereas the benzoyl and corresponding benzyloxycarbonyl amides reacted with papain at similar rates. These findings can be explained by the dominance of hydrogen bond formation between the enzyme and amide substrates, which comprensates for the less favourable binding of the benzoyl group. It is also apparent from the similar acylation rate constants for norleucine, citrulline and arginine derivatives that the guanidyl group only slightly affects the reaction of arginine derivatives with papain.

Acylation↗
PubMed1978

[Synthesis of human [11-leucine]minigastrin I--II. Purification of the synthetic tridecapeptide amide and isolation of a side-product (author's transl)].

The preparation of the pure 11-leucine analogue of human minigastrin I, a linear tridecapeptidaemide with full "gastrin activity", from the crude synthetic material obtained after deblocking of the overall protected tridecapeptide amide derivative by means of trifluoroacetic acid, is achieved by ion-exchange chromatography on DEAE-Sephadex A-25 and subsequent partition chromatography on Sephadex G-25. The isolation of a synthetic side-product and its identification as human [10-(Nin-tert-butyl-tryptophan),11-leucine]minigastrin I by means of spectroscopic (UV, fluorescence, 1H-NMR, MS), enzymatic and chromatographic methods is described. The pure tridecapeptide amides human [Leu11]minigastrin I and human [Trp(1'-But)10,Leu11]minigastrin I are isolated in overall yields of 37.4% and 4.6%, respectively (mol-% with regard to the overall protected tridecapeptide amide derivative).

Amides↗
PubMedDate not supplied

[Amide groups of brain and spinal proteins in acute and chronic alcohol intoxication].

Acute and chronic alcohol intoxication causes a considerable deamidation of central nervous system proteins which is most pronounced in the spinal cord. There occurs rearrangement in the amide bonds lability and in the ratio of easy-hydrolyzable and strongly bound amide groups. The metabolic response to the single administration of ethanol is disturbed. Alcohol intoxication causes changes in the amount of amide groups in the central nervous system proteins under conditions of physical exercises and fatigue development.

Alcoholism↗
PubMed1978

[N,N-Di-(1-ethylpropyl)amides of benzoic and naphthoic acids having phytotoxic activity].

N,N-di-(1-ethylpropyl)amides of benzoic and naphthoic acids suitable substituted in the nucleus were prepared and tested for selective phytotoxic activity in both pre- and post-emergence tests against some weed species. All the amides tested showed good generic phytotoxicity, often with good selectivity, on absorbance through the roots of graminaceous weeds. The nature and degree of phytotoxic activity was influenced by the nature, position and number of substituents on the aromatic nucleus. Confirmation was again obtained of the importance of alpha-substitution in the two alkyl substituents on the amide nitrogen in producing selective phytotoxic activity.

Amides↗
PubMedDate not supplied

[Inhibition of aldehyde dehydrogenase activity in rat liver by cyclopropylethyl-containing benzoic acid amides].

Influence of cyclopropylethyl-containing benzoic acid amides on the aldehyde dehydrogenase activity of the rat liver mitochondria was investigated. Values of I50 were measured for each of the compounds. The character of kinetic behavior of these reversible inhibitors was studied. It is shown that 2,5-dichloro-4-methylbenzoic acid amides reveal partially uncompetitive type of inhibition relative to acetaldehyde, while 2,4-dichloro- and 2,4-dichloro-5-methylbenzoic acid amides reveal changes in the character of inhibition from uncompetitive to mixed one. Inhibition was partially competitive with regard to reaction NAD+ cofactor. Though the studied compounds induced inhibition of a certain type with respect to each of the substrates, but on the whole the mechanism promoting a decrease of the ALDH-1 reaction rate appears to be more complex.

Aldehyde Dehydrogenase↗
PubMed1993

Amides and formamidines with antinociceptive activity (note I).

Pursuing our investigations on N-aryl or N-cycloalkyl substituted amides and formamidines with antiinflammatory and/or analgesic activity, two set of cycloalkyl substituted amides and formamidines were prepared and tested for analgesic activity against a chemical stimulus. Some compounds, particularly the amides 7, 11, 17 and the formamidine 35 proved to be endowed with this activity.

Amides↗
PubMed1977

[Study on the amide of 2-chlorobornan-4-carboxylic acid].

During the study of the transpositions undergone by the amide of canphen-4-carboxylic acid on treatment with concentrated hydrochloric acid, the formation of the amide of 2-chlorobornan-4-carboxylic acid alone, arising in two polymorphous forms, has been confirmed. Its reduction produced 2-chloro-4-aminomethylbornane; the detachment of hydrochloric acid at the amide of canphen-1-carboxylic acid.

Amides↗
PubMedDate not supplied

3,4-Dimethoxy cinnamic acid tertiary amides: synthesis and evaluation of antiinflammatory and analgesic activities.

In this study, eight compounds with cinnamoyl amide structure have been synthesized by dicyclohexylcarbodiimide/hydroxybenzotriazol method. The structures of the compounds were elucidated by UV, IR, 1H-NMR, mass spectroscopy and the elementary analysis. The antiinflammatory activities of the synthesized compounds were determined by carrageenan-induced hind paw edema test in mice and the most active compounds were found to be the dimethyl, diethyl and morpholine amide derivatives. Analgesic activities were determined by the modified "Koster" test; diisopentyl and morpholine amide derivatives have shown the highest activity.

Amides↗
PubMed1996

Expression and processing of peptidylglycine alpha-amidating monooxygenase messenger RNA in rat prostate.

The prostate gland contains neuroendocrine cells and amidated neuroendocrine peptides whose presence has been related to aggressive forms of prostate cancer. The enzyme peptidylglycine alpha-amidating monooxygenase (PAM) is critical to the bio-synthesis of amidated peptides and is commonly present in neuroendocrine cells. By northern blot hybridization analysis, PAM mRNA was detected in similar quantities in dorsolateral and ventral prostates of 3-month-old and 13-month-old rats. Multiple forms of PAM mRNA were present whose size distribution was more similar to PAM mRNAs found in pituitary than atrium. Alternative splice sites in PAM mRNA were investigated by reverse-transcriptase polymerase chain reaction. Similar alternatively spliced forms of PAM mRNA were found in both prostate lobes, pituitary, and atrium. However, the distribution of forms in the prostate most resembled that of pituitary. Multiple forms of PAM mRNA are present in prostate and may serve as markers of neuroendocrine differentiation.

Alternative Splicing↗
PubMed1999

Enantioselective Synthesis of Atropisomeric Amides by Dynamic Resolution: Thermodynamic Control with a Proline-Derived Diamine Resolving Agent.

By exploiting the thermal instability about the Ar-CO axis at high temperature, atropisomeric amides can be dynamically resolved to provide material with up to 96.5 % ee in 70-80 % overall yield from racemic starting material. The amides are coupled with a diamine resolving agent and equilibrated to single diastereoisomers. Hydrolysis returns enantiomerically enriched amide (see reaction scheme).

Journal Article↗
PubMed2001

Imide--amide rearangement of cylic phosphorimidates: a mechanistic study.

Studies aimed at the development of new synthetic pathways for the preparation of chiral cyclic oxaza and diaza phosphoramides suitable for use in asymmetric chemistry led us to the investigation of the imide -amide rearrangement of cyclic phosphorimidates. As a result of this work new types of oligomeric organophosphorus compounds, formed by a novel 1,4-addition type ring opening polymerisation, were identified. These compounds are the stable intermediates of the imide-amide rearrangement, which upon heating yield the previously reported rearranged product. A detailed study of the mechanism of the Lewis acid catalysed imide-amide rearrangement and stereochemical control of the final products is reported. As a result, the full mechanism was elucidated and evidence of retention of configuration at the rearranged carbon atom is presented. Substituent effects were rationalised based on molecular modelling calculations.

Journal Article↗
PubMed2002

Stereodynamics of bond rotation in tertiary aromatic amides.

The degree to which the rotations about the C-N and Ar-CO bonds of aromatic amides occur in a concerted manner was investigated by a variety of NMR and kinetic techniques. Otherwise complex kinetic analyses were simplified by exploiting symmetry and asymmetry in the N-substituents of amides. In 2-unsubstituted 1-naphthamides bearing branched N-substituents, most conformational changes about the amide group were by correlated rotation, though uncorrelated Ar-CO rotation also occurred to some extent. In 2-substituted 1-naphthamides, correlated rotation accounted for all of the Ar-CO rotations, though a significant amount of uncorrelated C-N rotation also occurred. Naphthamides bearing branched N-substituents thus turn out to be efficient molecular gears: Compound 12 showed almost no gear slippage.

Journal Article↗
PubMed2002

Homoleptic lanthanide complexes of chelating bis(phosphanyl)amides: synthesis, structure, and ring-opening polymerization of lactones.

Treatment of the bis(phosphanyl)amide (Ph2P)2NH with KH in boiling THF followed by crystallization from THF/n-pentane leads to [K(thf)n][N(PPh2)2] (n = 1.25, 1.5). Reaction of [K(thf)n][N(PPh2)2] with anhydrous yttrium or lanthanide trichlorides in a 3:1 molar ratio afforded homoleptic bis(phosphanyl)amide complexes [Ln[N(PPh2)2]3] (Ln = Y, Er) as large crystals in good yields. [Ln[N(PPh2)2]3] can also be obtained by reaction of the homoleptic bis(trimethylsilyl)amides of Group 3 metals and lanthanides [Ln[N(SiMe3)2]3] (Ln = Y, La, Nd) with three equivalents of (Ph2P)2NH in boiling toluene. The single-crystal X-ray structures of these complexes always show eta 2 coordination of the ligand. Dynamic behavior of the ligand is observed in solution and is caused by rapid exchange of the two different phosphorus atoms. [Ln[N(PPh2)2]3] was used as catalyst for the polymerization of epsilon-caprolactone. Significant differences in terms of correlation of theoretical and experimental molecular weights as well as polydispersities were observed depending on the nature of Ln. On the basis of the crystal structure of the heteroleptic complex [Lu[N(PPh2)2]3(thf)], we suggest that in the initiation step of epsilon-caprolactone polymerization the lactone adds to the lanthanide atom to form a sevenfold coordination sphere around the central atom.

Journal Article↗