LIVIVO - Das Suchportal für Lebenswissenschaften

switch to English language
Erweiterte Suche

Suchergebnis

Treffer 1 - 10 von insgesamt 12

Suchoptionen

  1. Artikel: Gyógyszerek okozta fényérzékenységi reakciók és gyógyszerészi kémiai háitterük.

    Rácz, Ákos / Tóth, Lívia

    Acta pharmaceutica Hungarica

    2015  Band 85, Heft 2, Seite(n) 51–70

    Abstract: The photosensitivity originated from drugs is a common problem in medical and pharmaceutical practice. It is of prominent importance in drug development and in regulatory issues. The photosensitizer effect of drug substances is determined by their ... ...

    Titelübersetzung Pharmaceutical chemistry of drug-initiated photosensitivity.
    Abstract The photosensitivity originated from drugs is a common problem in medical and pharmaceutical practice. It is of prominent importance in drug development and in regulatory issues. The photosensitizer effect of drug substances is determined by their chemical structures, and it mainly originates from aromatic chromophore systems and photo-dissociable bonds forming free radicals. The photodegradation may happen in many different types of chemical reaction pathways. Our aim is to demonstrate in this review the interrelations between structure and photodegradation. We show examples for the different reaction types, with drugs from different pharmacologic therapeutic classes. The in vivo chemical reactivity of photodegradates of pharmaceutical substances, the in vitro methods of investigation for testing photoreactivity and phototoxicity, and briefly the clinical tests for photosensitivity disorders are also discussed.
    Mesh-Begriff(e) Chemistry, Pharmaceutical/methods ; Dermatitis, Phototoxic/prevention & control ; Humans ; Photolysis/drug effects ; Photosensitivity Disorders/chemically induced ; Photosensitivity Disorders/diagnosis ; Photosensitivity Disorders/prevention & control ; Photosensitizing Agents/adverse effects ; Photosensitizing Agents/chemistry ; Structure-Activity Relationship ; Ultraviolet Rays/adverse effects
    Chemische Substanzen Photosensitizing Agents
    Sprache Ungarisch
    Erscheinungsdatum 2015
    Erscheinungsland Hungary
    Dokumenttyp English Abstract ; Journal Article ; Review
    ZDB-ID 392228-5
    ISSN 0001-6659
    ISSN 0001-6659
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  2. Artikel ; Online: Identification and characterization of a new dapoxetine impurity by NMR: Transformation of N-oxide by Cope elimination.

    Darcsi, András / Rácz, Ákos / Béni, Szabolcs

    Journal of pharmaceutical and biomedical analysis

    2017  Band 134, Seite(n) 187–194

    Abstract: Unknown impurity associated with the degradation process of dapoxetine base was isolated. The structure elucidation of this new compound using accurate mass data, IR and NMR spectroscopy is presented herein. The unambiguous resonance assignment concluded ...

    Abstract Unknown impurity associated with the degradation process of dapoxetine base was isolated. The structure elucidation of this new compound using accurate mass data, IR and NMR spectroscopy is presented herein. The unambiguous resonance assignment concluded to the formation of geometrical isomers of cinnamyloxynaphtalenes via Cope elimination of dapoxetin-N-oxide, the major oxidative and metabolic degradation product of dapoxetine. An efficient and simple synthetic approach has also been developed for the synthesis of dapoxetine-N-oxide for the first time and cinnamyloxynaphtalene in order to confirm the proposed degradation pathway and structures of the degradation products. It was observed that the main degradation product of dapoxetine base when exposed to air is 1-(2E)-cinnamyloxynaphthalene, while its Z isomer was also confirmed as a minor impurity.
    Mesh-Begriff(e) Benzylamines/analysis ; Benzylamines/chemistry ; Drug Contamination ; Magnetic Resonance Spectroscopy/methods ; Naphthalenes/analysis ; Naphthalenes/chemistry
    Chemische Substanzen Benzylamines ; Naphthalenes ; dapoxetine-N-oxide ; dapoxetine (GB2433A4M3)
    Sprache Englisch
    Erscheinungsdatum 2017-02-05
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 604917-5
    ISSN 1873-264X ; 0731-7085
    ISSN (online) 1873-264X
    ISSN 0731-7085
    DOI 10.1016/j.jpba.2016.11.029
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  3. Artikel: NMR, CD and UV spectroscopic studies reveal uncommon binding modes of dapoxetine to native cyclodextrins

    Darcsi, András / Szakács, Zoltán / Zsila, Ferenc / Tóth, Gergő / Rácz, Ákos / Béni, Szabolcs

    RSC advances. 2016 Oct. 27, v. 6, no. 104

    2016  

    Abstract: Complex formation between the selective serotonin reuptake inhibitor drug (S)-dapoxetine (Dpx) and β-, γ-, and methylated γ-cyclodextrins (CyDs) was studied by complementary experimental techniques. Phase solubility studies indicated 1 : 1 stoichiometry ... ...

    Abstract Complex formation between the selective serotonin reuptake inhibitor drug (S)-dapoxetine (Dpx) and β-, γ-, and methylated γ-cyclodextrins (CyDs) was studied by complementary experimental techniques. Phase solubility studies indicated 1 : 1 stoichiometry for all CyDs, with β-CyD being the most effective to enhance the solubility of and form the most stable complex with Dpx. 1H NMR titrations and Job's method of continuous variation were also employed to corroborate the stoichiometry and association constants with γ- and β-CyDs. The simultaneous evaluation of titration datasets of several Dpx and CyD protons revealed for both CyDs that the best fit was achieved when the coexistence of Dpx·CyD and 2Dpx·CyD complexes were assumed. This finding was rather unanticipated considering the smaller cavity size of β-CyD, which inspired further investigations. The UV hypochromism and circular dichroism spectroscopic data suggested the inclusion of two Dpx molecules into the CyD cavity (albeit to a less extent with β-CyD). This conclusion was fully supported by 2D ROESY and 1D NOESY NMR spectra, observing NOEs between the inner methine protons of CyDs and both the phenyl and naphthyl ring protons of Dpx. Additional molecular dynamics calculations identified the energetically most favoured species for both the Dpx·CyD and 2Dpx·CyD complexes.
    Schlagwörter circular dichroism spectroscopy ; data collection ; drugs ; gamma-cyclodextrin ; methylation ; molecular dynamics ; nuclear magnetic resonance spectroscopy ; protons ; serotonin ; solubility ; spectral analysis ; stoichiometry ; titration
    Sprache Englisch
    Erscheinungsverlauf 2016-1027
    Umfang p. 102315-102328.
    Erscheinungsort The Royal Society of Chemistry
    Dokumenttyp Artikel
    ISSN 2046-2069
    DOI 10.1039/c6ra22431h
    Datenquelle NAL Katalog (AGRICOLA)

    Zusatzmaterialien

    Kategorien

  4. Artikel ; Online: Site-specific basicities regulate molecular recognition in receptor binding: in silico docking of thyroid hormones.

    Tóth, Gergő / Baska, Ferenc / Schretner, András / Rácz, Akos / Noszál, Béla

    European biophysics journal : EBJ

    2013  Band 42, Heft 9, Seite(n) 721–730

    Abstract: Interactions between thyroid hormone α and β receptors and the eight protonation microspecies of each of the main thyroid hormones (thyroxine, liothyronine, and reverse liothyronine) were investigated and quantitated by molecular modeling. Flexible ... ...

    Abstract Interactions between thyroid hormone α and β receptors and the eight protonation microspecies of each of the main thyroid hormones (thyroxine, liothyronine, and reverse liothyronine) were investigated and quantitated by molecular modeling. Flexible docking of the various protonation forms of thyroid hormones and high-affinity thyromimetics to the two thyroid receptors was carried out. In this method the role of the ionization state of each basic site could be studied in the composite process of molecular recognition. Our results quantitate at the molecular level how the ionization state and the charge distribution influence the protein binding. The anionic form of the carboxyl group (i.e., carboxylate site) is essential for protein binding, whereas the protonated form of amino group worsens the binding. The protonation state of the phenolate plays a less important role in the receptor affinity; its protonation, however, alters the electron density and the concomitant stacking propensity of the aromatic rings, resulting in a different binding score. The combined results of docking and microspeciation studies show that microspecies with the highest concentration at the pH of blood are not the strongest binding ones. The calculated binding free energy values can be well interpreted in terms of the interactions between the actual sites of the microspecies and the receptor amino acids. Our docking results were validated and compared with biological data from the literature. Since the thyroid hormone receptors influence several physiologic functions, such as metabolic rate, cholesterol and triglyceride levels, and heart frequency, our binding results provide a molecular basis for drug design and development in related therapeutic indications.
    Mesh-Begriff(e) Hydrogen-Ion Concentration ; Molecular Docking Simulation ; Protein Binding ; Protein Conformation ; Receptors, Thyroid Hormone/chemistry ; Receptors, Thyroid Hormone/metabolism ; Substrate Specificity ; Thyroid Hormones/chemistry ; Thyroid Hormones/metabolism
    Chemische Substanzen Receptors, Thyroid Hormone ; Thyroid Hormones
    Sprache Englisch
    Erscheinungsdatum 2013-08-02
    Erscheinungsland Germany
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 283671-3
    ISSN 1432-1017 ; 0175-7571
    ISSN (online) 1432-1017
    ISSN 0175-7571
    DOI 10.1007/s00249-013-0921-1
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  5. Artikel ; Online: Synthetic and quantum chemical study on the regioselective addition of amines to methyl maleamate.

    Rácz, Akos / Váradi, András / Mazák, Károly / Kökösi, József / Noszál, Béla

    Journal of molecular modeling

    2013  Band 19, Heft 9, Seite(n) 3683–3694

    Abstract: Synthetic and theoretical studies were performed to gain insight into the regioselectivity in the mechanism of aspartyl-isoaspartyl formation, modeled by additions of ammonia and primary amines to methyl maleamate. Reactions between maleamate and ... ...

    Abstract Synthetic and theoretical studies were performed to gain insight into the regioselectivity in the mechanism of aspartyl-isoaspartyl formation, modeled by additions of ammonia and primary amines to methyl maleamate. Reactions between maleamate and aliphatic, araliphatic amines or O-methyl acetimidate lead to the formation of N-substituted isoasparaginates. The size of the amine and the activating effect of the amide and ester group on the double bond are the determining factors of the site of addition. The formation of both isomers was observed only in the case of ammonia addition. The regioselectivity was predicted on the basis of the charge distribution for low-energy methyl maleamate conformers, calculated at the B3LYP/6-311++G(2df,2pd)//B3LYP/6-31+G(d) level, both in gas phase and in methanol. The methyl isoasparaginate over methyl asparaginate product ratio was computed based on the free energy Boltzmann distribution of their conformers. The calculated 2 : 1 ratio is in agreement with the experimental regioselectivity of the addition of nitrogen nucleophiles.
    Sprache Englisch
    Erscheinungsdatum 2013-06-19
    Erscheinungsland Germany
    Dokumenttyp Journal Article
    ZDB-ID 1284729-X
    ISSN 0948-5023 ; 1610-2940
    ISSN (online) 0948-5023
    ISSN 1610-2940
    DOI 10.1007/s00894-013-1905-x
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  6. Artikel ; Online: Characterization of aspartame-cyclodextrin complexation.

    Sohajda, Tamás / Béni, Szabolcs / Varga, Erzsébet / Iványi, Róbert / Rácz, Akos / Szente, Lajos / Noszál, Béla

    Journal of pharmaceutical and biomedical analysis

    2009  Band 50, Heft 5, Seite(n) 737–745

    Abstract: The inclusion complex formation of aspartame (guest) and various cyclodextrins (host) were examined using 1H NMR titration and capillary electrophoresis. Initially the protonation constants of aspartame were determined by NMR-pH titration with in situ pH ...

    Abstract The inclusion complex formation of aspartame (guest) and various cyclodextrins (host) were examined using 1H NMR titration and capillary electrophoresis. Initially the protonation constants of aspartame were determined by NMR-pH titration with in situ pH measurement to yield log K1=7.83 and log K2=2.96. Based on these values the stability of the complexes formed by aspartame and 21 different cyclodextrins (CDs) were studied at pH 2.5, pH 5.2 and pH 9.0 values where aspartame exists predominantly in monocationic, zwitterionic and monoanionic form, respectively. The host cyclodextrin derivatives differed in various sidechains, degree of substitution, charge and purity so that the effect of these properties could be examined systematically. Concerning size, the seven-membered beta-cyclodextrin and its derivatives have been found to be the most suitable host molecules for complexation. Highest stability was observed for the acetylated derivative with a degree of substitution of 7. The purity of the CD enhanced the complexation while the degree of substitution did not provide obvious consequences. Finally, geometric aspects of the inclusion complex were assessed by 2D ROESY NMR and molecular modelling which proved that the guest's aromatic ring enters the wider end of the host cavity.
    Mesh-Begriff(e) Aspartame/analysis ; Aspartame/chemistry ; Cations ; Chemistry, Pharmaceutical/methods ; Circular Dichroism ; Electrophoresis, Capillary/methods ; Hydrogen-Ion Concentration ; Magnetic Resonance Spectroscopy/methods ; Models, Molecular ; Molecular Conformation ; Molecular Structure ; Protons ; alpha-Cyclodextrins/analysis ; alpha-Cyclodextrins/chemistry ; beta-Cyclodextrins/analysis ; beta-Cyclodextrins/chemistry
    Chemische Substanzen Cations ; Protons ; alpha-Cyclodextrins ; beta-Cyclodextrins ; betadex (JV039JZZ3A) ; Aspartame (Z0H242BBR1) ; alpha-cyclodextrin (Z1LH97KTRM)
    Sprache Englisch
    Erscheinungsdatum 2009-12-05
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 604917-5
    ISSN 1873-264X ; 0731-7085
    ISSN (online) 1873-264X
    ISSN 0731-7085
    DOI 10.1016/j.jpba.2009.06.010
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  7. Artikel ; Online: Solution-state NMR spectroscopy of famotidine revisited: spectral assignment, protonation sites, and their structural consequences.

    Marosi, Attila / Szalay, Zsófia / Béni, Szabolcs / Szakács, Zoltán / Gáti, Tamás / Rácz, Ákos / Noszál, Béla / Demeter, Ádám

    Analytical and bioanalytical chemistry

    2012  Band 402, Heft 4, Seite(n) 1653–1666

    Abstract: Multinuclear one (1D-) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopic investigations of famotidine, the most potent and widely used histamine H(2)-receptor antagonist, were carried out in dimethyl sulfoxide-d(6) (DMSO-d(6)) and ... ...

    Abstract Multinuclear one (1D-) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopic investigations of famotidine, the most potent and widely used histamine H(2)-receptor antagonist, were carried out in dimethyl sulfoxide-d(6) (DMSO-d(6)) and water. Previous NMR assignments were either incomplete or full assignment was based only on 1D spectra and quantum-chemical calculations. Our work revealed several literature misassignments of the (1)H, (13)C, and (15)N NMR signals and clarified the acid-base properties of the compound at the site-specific level. The erroneous assignment of Baranska et al. (J. Mol. Struct. 2001, 563) probably originates from an incorrect hypothesis about the major conformation of famotidine in DMSO-d(6). A folded conformation similar to that observed in the solid-state was also assumed in solution, stabilized by an intramolecular hydrogen bond involving one of the sulphonamide NH(2) protons and the thiazole nitrogen. Our detailed 1D and 2D NMR experiments enabled complete ab initio (1)H, (13)C, and (15)N assignments and disproved the existence of the sulphonamide NH hydrogen bond in the major conformer. Rather, the molecule is predominantly present in an extended conformation in DMSO-d(6). The aqueous acid-base properties of famotidine were studied by 1D (1)H- and 2D (1)H/(13)C heteronuclear multiple-bond correlation (HMBC) NMR-pH titrations. The experiments identified its basic centers including a new protonation step at highly acidic conditions, which was also confirmed by titrations and quantum-chemical calculations on a model compound, 2-[4-(sulfanylmethyl)-1,3-thiazol-2-yl]guanidine. Famotidine is now proved to have four protonation steps in the following basicity order: the sulfonamidate anion protonates at pH = 11.3, followed by the protonation of the guanidine group at pH = 6.8, whereas, in strong acidic solutions, two overlapping protonation processes occur involving the amidine and thiazole moieties.
    Mesh-Begriff(e) Dimethyl Sulfoxide/chemistry ; Famotidine/chemistry ; Histamine H2 Antagonists/chemistry ; Magnetic Resonance Spectroscopy/methods ; Models, Molecular ; Molecular Conformation ; Protons ; Water/chemistry
    Chemische Substanzen Histamine H2 Antagonists ; Protons ; Water (059QF0KO0R) ; Famotidine (5QZO15J2Z8) ; Dimethyl Sulfoxide (YOW8V9698H)
    Sprache Englisch
    Erscheinungsdatum 2012-02
    Erscheinungsland Germany
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 201093-8
    ISSN 1618-2650 ; 0016-1152 ; 0372-7920
    ISSN (online) 1618-2650
    ISSN 0016-1152 ; 0372-7920
    DOI 10.1007/s00216-011-5599-6
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  8. Artikel: Binding mode analysis and enrichment studies on homology models of the human histamine H4 receptor.

    Kiss, Róbert / Noszál, Béla / Rácz, Akos / Falus, András / Eros, Dániel / Keseru, György M

    European journal of medicinal chemistry

    2007  Band 43, Heft 5, Seite(n) 1059–1070

    Abstract: Ligand-supported homology models of the human histamine H4 receptor (hH4R) were developed based on the crystal structure of bovine rhodopsin and different known H4 ligands (histamine, OUP-16, JNJ7777120). Enrichment tests were performed to analyze ... ...

    Abstract Ligand-supported homology models of the human histamine H4 receptor (hH4R) were developed based on the crystal structure of bovine rhodopsin and different known H4 ligands (histamine, OUP-16, JNJ7777120). Enrichment tests were performed to analyze whether our hH4R models can select known actives from random decoys. The impact of receptor conformation and the effect of different sets of random decoys, docking methods (FlexX, FlexX-Pharm) and scoring functions (FlexX-Score, D-Score, PMF-Score, G-Score, ChemScore) were investigated. We found that two agonists (histamine and OUP-16) form complementary interactions with Asp94 (3.32), Glu182 (5.46) and Thr323 (6.55), whereas JNJ7777120 interacts with Asp94 (3.32) and Glu182 (5.46) only. These results suggest a role of Thr323 (6.55) in ligand binding and presumably also in receptor activation. The models optimized in the presence of an agonist (histamine) and an antagonist (JNJ7777120) were compared in more detail. We conclude that the ligand used in the model building process can significantly influence the efficacy of virtual screening.
    Mesh-Begriff(e) Amino Acid Sequence ; Animals ; Binding Sites ; Cattle ; Crystallography, X-Ray ; Histamine/chemistry ; Histamine Agonists/chemistry ; Histamine Antagonists/chemistry ; Humans ; Indoles/chemistry ; Models, Molecular ; Molecular Sequence Data ; Piperazines/chemistry ; Protein Conformation ; Receptors, G-Protein-Coupled/chemistry ; Receptors, Histamine/chemistry ; Receptors, Histamine H4 ; Rhodopsin/chemistry ; Sequence Homology, Amino Acid
    Chemische Substanzen HRH4 protein, human ; Histamine Agonists ; Histamine Antagonists ; Indoles ; Piperazines ; Receptors, G-Protein-Coupled ; Receptors, Histamine ; Receptors, Histamine H4 ; 1-((5-chloro-1H-indol-2-yl)carbonyl)-4-methylpiperazine (4H1AU2V37X) ; Histamine (820484N8I3) ; Rhodopsin (9009-81-8)
    Sprache Englisch
    Erscheinungsdatum 2007-08-06
    Erscheinungsland France
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 188597-2
    ISSN 1768-3254 ; 0223-5234 ; 0009-4374
    ISSN (online) 1768-3254
    ISSN 0223-5234 ; 0009-4374
    DOI 10.1016/j.ejmech.2007.07.014
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  9. Artikel: Lipophilicity of vinpocetine and related compounds characterized by reversed-phase thin-layer chromatography.

    Károly, Mazák / Vámos, József / Nemes, András / Rácz, Akos / Noszál, Béla

    Journal of chromatography. A

    2003  Band 996, Heft 1-2, Seite(n) 195–203

    Abstract: A reversed-phase thin-layer chromatographic method was developed and applied to quantitate the lipophilicity of sparingly water-soluble eburnane alkaloids of therapeutic interest. Our method development included calibration, optimization and validation ... ...

    Abstract A reversed-phase thin-layer chromatographic method was developed and applied to quantitate the lipophilicity of sparingly water-soluble eburnane alkaloids of therapeutic interest. Our method development included calibration, optimization and validation procedures, using also sets of auxiliary compounds. The log P(TLC) values of five relatively hydrophilic eburnanes were verified by stir-flask studies. The alkaloids were found to have lipophilicity values in the 2.9-4.8 log P(TLC) range. Conclusions on structure-lipophilicity relationships were drawn in terms of ring anellation, character and length of side chain, conformational preferences and moiety-solvent interactions, also supported by molecular mechanics studies.
    Mesh-Begriff(e) Calibration ; Chemical Phenomena ; Chemistry, Physical ; Chromatography, High Pressure Liquid/methods ; Chromatography, Thin Layer/methods ; Lipids/chemistry ; Molecular Conformation ; Quantitative Structure-Activity Relationship ; Solubility ; Solvents/chemistry ; Vinca Alkaloids/chemistry ; Vincamine/chemistry
    Chemische Substanzen Lipids ; Solvents ; Vinca Alkaloids ; apovincaminic acid (27773-65-5) ; vinpocetine (543512OBTC) ; Vincamine (996XVD0JHT)
    Sprache Englisch
    Erscheinungsdatum 2003-05-09
    Erscheinungsland Netherlands
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1171488-8
    ISSN 1873-3778 ; 0021-9673
    ISSN (online) 1873-3778
    ISSN 0021-9673
    DOI 10.1016/s0021-9673(03)00617-4
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

  10. Artikel: Amidcsoport szelektív kialakítása dikarbonsavakban.

    Boros, Miklós / Vámos, József / Kökösi, József / Szókán, Gyula / Rácz, Akos / Noszál, Béla

    Acta pharmaceutica Hungarica

    2003  Band 73, Heft 1, Seite(n) 51–59

    Abstract: The pharmaceutical and biological importance of the amide moiety is briefly surveyed. Relationships between the electron density and chemical reactivity of the amide site are shortly described. Synthetic methods for the selective formation of monoamino- ... ...

    Titelübersetzung Synthesis of dicarboxylic acid monoamides.
    Abstract The pharmaceutical and biological importance of the amide moiety is briefly surveyed. Relationships between the electron density and chemical reactivity of the amide site are shortly described. Synthetic methods for the selective formation of monoamino-dicarboxylic acid alpha and beta monoamides are summarised. The three major selective synthesis routes for the preparation of monoamides are introduced. The first class of synthetic methods consists of non selective formation of a- and b-esters, followed by their separation on the basis of different solubilities. Amidation of these esters results in the alpha- or beta-amides respectively. The second class of the reactions utilises the orientating capacity of the amino (ammonium) site, producing first various cyclic anhydrides, lactames, lactones, which are then decomposed in hydrolytic, aminolytic, etc. reactions, resulting selectively in the alpha- or beta-amides or esters. Reactants in the third class of the reactions are dicarboxylic acids with carbon-carbon pi-bonds, and ammonia (or alkyl-amine) which form the appropriate compound in addition reactions. Reactivities and selectivities are interpreted in terms of inductive effects, acidity differences and electronic effects of the various protecting groups. Some important analytical properties of monoamino-dicarboxylic acids and their monoamides are compiled.
    Mesh-Begriff(e) Amides/chemical synthesis ; Amides/chemistry ; Asparagine/chemistry ; Dicarboxylic Acids/chemical synthesis ; Dicarboxylic Acids/chemistry ; Kinetics ; Molecular Structure ; Stereoisomerism
    Chemische Substanzen Amides ; Dicarboxylic Acids ; Asparagine (7006-34-0)
    Sprache Ungarisch
    Erscheinungsdatum 2003
    Erscheinungsland Hungary
    Dokumenttyp English Abstract ; Journal Article
    ZDB-ID 392228-5
    ISSN 0001-6659
    ISSN 0001-6659
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

    Zusatzmaterialien

    Kategorien

Zum Seitenanfang