scholarly journals THE AMPHOTERIC PROPERTIES OF SOME AMINO-ACIDS AND PEPTIDES

1921 ◽  
Vol 3 (3) ◽  
pp. 291-308 ◽  
Author(s):  
Herbert Eckweiler ◽  
Helen Miller Noyes ◽  
K. George Falk
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Butyric Acid ◽  
Method Of Calculation ◽  
Chemical Structures ◽  
Titration Curves ◽  
Isoelectric Points ◽  
Theoretical Significance ◽  
Definition Of ◽  
Amphoteric Properties

The titration curves of solutions of glycine, alanine, α-ammo-butyric acid, leucine, glycyl-glycine, alanyl-glycine, alanyl-alanine, acetone, acetamide, urea, acetic acid, and aceturic acid were determined and some of the relations as dependent upon the chemical structures discussed. The isoelectric points of some of the amphoteric electrolytes were found experimentally. The definition of isoelectric point, its theoretical significance, and method of calculation were considered in some detail.

scholarly journals Differential Electrolytic Potentiometric Determination of Some Amino Acids in Dosage Forms

2004 ◽  
Vol 87 (3) ◽  
pp. 671-676
Author(s):  
Sheikha M Al-Ghannam ◽  
Abdalla M S Abulkibash ◽  
Abeer M Al-Olyyan
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Direct Current ◽  
Current Density ◽  
Perchloric Acid ◽  
Dosage Forms ◽  
Basic Character ◽  
Direct Titration ◽  
Titration Curves

Abstract The application of direct-current differential electrolytic potentiometry to the nonaqueous titration of amino acids was investigated. The basic character of amino acids in acetic acid was enhanced to permit their direct titration with perchloric acid. A pair of antimony electrodes was used as an indicating system. The shapes of the titration curves obtained were almost symmetrical with sharp peaks. The optimum current density for those titrations was found to be 1–2 μA/cm2. The procedure was applied successfully to the determination of certain amino acids in drug formulations, and the results were favorably compared statistically with those obtained by official methods.

scholarly journals Decarboxylation 2'-dicarboxy-5-(methyl-5'-indolyl-3')- indolyl-3-acetic acid with use of salts of copper

2019 ◽  
Vol 58 (4) ◽  
pp. 58-61
Author(s):  
Alexander V. Syromolotov ◽  
◽  
Alexander A. Kimyashov ◽  
Sergey V. Sukhorukov ◽  
◽  
...  
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Condensation Reaction ◽  
Product Yield ◽  
Co2 Removal ◽  
Optimal Conditions ◽  
Chemical Structures ◽  
Kolbe Reaction ◽  
Living Organisms ◽  
Removal Group

In this article a decarboxylation method based on the use of quinoline with a copper salt is discussed. Decarboxylation is the elimination of CO2 from the carboxylic group of carboxylic acids or the carboxylate group of their salts. The process is used to produce a large number of organic compounds, such classes as alkanes, alkenes, alcohols, ketones, ethers and esters. Decarboxylation plays an important role in the metabolism of living organisms, namely in the decarboxylation of amino acids. From this we can conclude that the process is important to study. Decarboxylation proceeds in different ways. The most common methods of decarboxylation includes heating in various conditions. For example, such as heating in the presence of acids and alkalis, under severe conditions with quinoline, thermal oxidation in the presence of transition metal salts, Kolbe reaction. In the procces of the CO2 removal group in relation to amino acids there are several types: α-decarboxylation, decarboxylation, associated with the trans-amination reaction and the condensation reaction of molecules. In the synthesis of substituted auxin 2'-dicarboxy-5-(methyl-5'indolyl-3')-indolyl-3-acetic acid, the yield of the product was not high. The usual heating in the presence of alkali output was less than 5%, and in this work it was decided to use other methods of decarboxylation to increase the yield of the product. The aim of the work is to improve the method of decarboxylation of carboxyindolyl substrates for increasing product yield and to compare with the result obtained by ordinary heating of this substances in the presence of alkali. At the end of the work summed up. Found the optimal conditions for the process of decarboxylation of investigated substrates. Optimal conditions chosen based on product yield. To confirm the chemical structures of the substances, 1H NMR, IR spectroscopy, and elemental analysis were used.

METHODOLOGICAL APPROACHES TO SEARCH FOR RESERVES OF DECREASING COSTS IN THE BRANCHES OF AGRICULTURAL PRODUCTION

2019 ◽  
Keyword(s):  
Agricultural Production ◽  
Raw Materials ◽  
Cost Calculation ◽  
Cattle Breeding ◽  
Method Of Calculation ◽  
Prime Cost ◽  
Dairy Cattle Breeding ◽  
Methodological Approaches ◽  
Definition Of ◽  
Qualitative Characteristics

In this article approaches to search for reserves of decrease in cost of agricultural production are considered. The methods of cost calculation of dairy cattle breeding products used at the studied enter-prise are analysed, short characteristic of the standard method offered by the Ministry of Agriculture is given, and calculations of alternative options are also carried out. Today creation of accounting of a production unit is very important so that not only weight units must be considered in it, but also the quali-tative structure of products must be reflected. Definition of qualitative characteristics and technological properties by production of milk which depend on use purposes can be an example. The raw materials consumption on a unit of production and its quality and also firmness of storage depends on technologi-cal properties of milk. At calculation of prime cost taking into account qualitative characteristics for cal-culation milk in terms of basic fat content undertakes. The method of calculation of prime cost consider-ing qualitative characteristics is the most expedient as prime cost of 1 c of milk unlike the operating tech-nique is lower. In the article analytical methods of reserves calculation for decrease in prime cost taking into account various factors are proved. The revealed reserves will allow an enterprise to expand its in-vestment opportunities in the future, they will give an additional incentive of modernization of the worn-out machinery and equipment in branches of agriculture.

Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihydroisoquinoline-2(1H)-yl)methyl) oxazol-5(4H)-one Derivatives Using 1,2,3,Tetrahydroisoquinoline and their Antimicrobial Activity

2020 ◽  
Vol 17 (5) ◽  
pp. 396-403
Author(s):  
Nalla Krishna Rao ◽  
Tentu Nageswara Rao ◽  
Botsa Parvatamma ◽  
Y. Prashanthi ◽  
Ravi Kumar Cheedarala
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Acetic Acid ◽  
Sodium Acetate ◽  
Good Activity ◽  
Activity Profile ◽  
Aryl Aldehydes ◽  
Chemical Structures ◽  
Novel Synthesis ◽  
Target Molecules

Aims: A series of six 4-benzylidene-2-((1-phenyl-3,4-dihydro isoquinoline-2(1H)-yl)methyloxazol- 5(4H)-one derivatives were synthesized by condensation of substituted aryl aldehydes with 2-(2-(1-phenyl-3,4- dihydro isoquinoline-2(1H)-acetamido)acetic acid in the presence of sodium acetate, acetic anhydride and zinc oxide as catalysts. Background: Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihy droisoquinoline-2(1H)-yl)methyl)oxazol- 5(4H)-one derivatives using 1,2,3,Tetrahydroisoquinoline and their antimicrobial activity. Objective: The title compounds can be synthesized from 1,2,3,4-tetrahydroisoquinoline. Methods: The target molecules, i.e., 4-benzylidene-2-((1-phenyl-3, 4-dihydro isoquinoline-2(1H)-yl) methyl) oxazol-5(4H)-one derivatives (8a-8f) have been synthesized from 1,2,3,4-tetrahydroisoquinoline which was prepared from benzoic acid in few steps. Results: All the six compounds were evaluated based on advanced spectral data (1H NMR, 13C NMR & LCMS), and the chemical structures of all compounds were determined by elemental analysis. Conclusion: Antibacterial activity of the derivatives was examined for the synthesized compounds and results indicate that compound with bromine substitution has a good activity profile.

Racemization rates of 3,4-didehydro-2-amino acids

1989 ◽  
Vol 54 (12) ◽  
pp. 3381-3386 ◽  
Author(s):  
Libor Havlíček ◽  
Jan Hanuš ◽  
Jan Němeček
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Acidic Medium

The racemization rates of amino acids in acidic medium (acetic acid) were studied. The sensitivity to racemization decreases in the order (E)-3,4-didehydroornithine > (E)-Nδ-Z-3,4-didehydroornithine >> (Z)-3,4-didehydronorvaline > ornithine, norvaline. (E)-3,4-Didehydroornithine is also relatively rapidly racemized on heating with 5 M or 0.05 M-HCl (100 °C).

An enumeration of natural products from microbial, marine and terrestrial sources

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Fidele Ntie-Kang ◽  
Daniel Svozil
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Biologically Active ◽  
Lead Compound ◽  
Chemical Databases ◽  
Natural Sources ◽  
Chemical Structures ◽  
Chemically Modified ◽  
Marine Habitats ◽  
Metabolic Properties

AbstractThe discovery of a new drug is a multidisciplinary and very costly task. One of the major steps is the identification of a lead compound, i.e. a compound with a certain degree of potency and that can be chemically modified to improve its activity, metabolic properties, and pharmacokinetics profiles. Terrestrial sources (plants and fungi), microbes and marine organisms are abundant resources for the discovery of new structurally diverse and biologically active compounds. In this chapter, an attempt has been made to quantify the numbers of known published chemical structures (available in chemical databases) from natural sources. Emphasis has been laid on the number of unique compounds, the most abundant compound classes and the distribution of compounds in terrestrial and marine habitats. It was observed, from the recent investigations, that ~500,000 known natural products (NPs) exist in the literature. About 70 % of all NPs come from plants, terpenoids being the most represented compound class (except in bacteria, where amino acids, peptides, and polyketides are the most abundant compound classes). About 2,000 NPs have been co-crystallized in PDB structures.

Erythroid differentiation ability of butyric acid analogues: Identification of basal chemical structures of new inducers of foetal haemoglobin

2015 ◽  
Vol 752 ◽  
pp. 84-91 ◽  
Author(s):  
Nicoletta Bianchi ◽  
Cristiano Chiarabelli ◽  
Cristina Zuccato ◽  
Ilaria Lampronti ◽  
Monica Borgatti ◽  
...  
Keyword(s):  
Butyric Acid ◽  
Erythroid Differentiation ◽  
Foetal Haemoglobin ◽  
Chemical Structures

scholarly journals Structural comparisons lead to the definition of a new superfamily of NAD(P)(H)-accepting oxidoreductases: the single-domain reductases/epimerases/dehydrogenases (the ‘RED’ family)

1994 ◽  
Vol 304 (1) ◽  
pp. 95-99 ◽  
Author(s):  
G Labesse ◽  
A Vidal-Cros ◽  
J Chomilier ◽  
M Gaudry ◽  
J P Mornon
Keyword(s):  
Amino Acids ◽  
Sequence Alignment ◽  
Active Site ◽  
Tertiary Structure ◽  
Binding Specificity ◽  
Single Domain ◽  
Divergent Evolution ◽  
Cofactor Binding ◽  
Sequence Identity ◽  
Definition Of

Using both primary- and tertiary-structure comparisons, we have established new structural similarities shared by reductases, epimerases and dehydrogenases not previously known to be related. Despite the low sequence identity (down to 10%), short consensus segments are identified. We show that the sequence, the active site and the supersecondary structure are well conserved in these proteins. New homologues (the protochlorophyllide reductases) are detected, and we define a new superfamily composed of single-domain dinucleotide-binding enzymes. Rules for the cofactor-binding specificity are deduced from our sequence alignment. The involvement of some amino acids in catalysis is discussed. Comparison with two-domain dehydrogenases allows us to distinguish two general mechanisms of divergent evolution.

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