Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Characterization of (2S,2′R,3′R)-2-(2′,3′-[3H]-Dicarboxycyclopropyl)glycine Binding in Rat Brain (1998)
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 71 (1998), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: [(2S,2′R,3′R)-2-(2′,3′-[3H]Dicarboxycyclopropyl)glycine ([3H]DCG IV) binding was characterized in vitro in rat brain cortex homogenates and rat brain sections. In cortex homogenates, the binding was saturable and the saturation isotherm indicated the presence of a single binding site with a KD value of 180 ± 33 nM and a Bmax of 780 ± 70 fmol/mg of protein. The nonspecific binding, measured using 100 µM LY354740, was 〈30%. NMDA, AMPA, kainate, l(−)-threo-3-hydroxyaspartic acid, and (S)-3,5-dihydroxyphenylglycine were all inactive in [3H]DCG IV binding up to 1 mM. However, several compounds inhibited [3H]DCG IV binding in a concentration-dependent manner with the following rank order of potency: LY341495 = LY354740 〉 DCG IV = (2S,1′S,2′S)-2-(2-carboxycyclopropyl)glycine 〉 (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid 〉 (2S,1′S,2′S)-2-methyl-2-(2-carboxycyclopropyl)glycine 〉 l-glutamate = ibotenate 〉 quisqualate 〉 (RS)-α-methyl-4-phosphonophenylglycine = l(+)-2-amino-3-phosphonopropionic acid 〉 (S)-α-methyl-4-carboxyphenylglycine 〉 (2S)-α-ethylglutamic acid 〉 l(+)-2-amino-4-phosphonobutyric acid. N-Acetyl-l-aspartyl-l-glutamic acid inhibited the binding in a biphasic manner with an IC50 of 0.2 µM for the high-affinity component. The binding was also affected by GTPγS, reducing agents, and CdCl2. In parasagittal sections of rat brain, a high density of specific binding was observed in the accessory olfactory bulb, cortical regions (layers 1, 3, and 4 〉 2, 5, and 6), caudate putamen, molecular layers of the hippocampus and dentate gyrus, subiculum, presubiculum, retrosplenial cortex, anteroventral thalamic nuclei, and cerebellar granular layer, reflecting its preferential (perhaps not exclusive) affinity for pre- and postsynaptic metabotropic glutamate mGlu2 receptors. Thus, the pharmacology, tissue distribution, and sensitivity to GTPγS show that [3H]DCG IV binding is probably to group II metabotropic glutamate receptors in rat brain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1471-4159.1998.71062558.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Characterization of [3H]Quisqualate Binding to Recombinant Rat Metabotropic Glutamate 1a and 5a Receptors and to Rat and Human Brain Sections (2000)
    Oxford UK : Blackwell Science Ltd.
    Journal of neurochemistry 75 (2000), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: We have investigated the binding properties of[3H]quisqualate to rat metabotropic glutamate (mGlu) 1a and 5areceptors and to rat and human brain sections. Saturation isotherms gaveKD values of 27 ± 4 and 81 ± 22 nMfor mGlu1a and mGlu5a receptors, respectively. Several compounds inhibited thebinding to mGlu1a and mGlu5a receptors concentration-dependently.(S)-4-Carboxyphenylglycine,(S)-4-carboxy-3-hydroxyphenylglycine, and(R,S)-1-aminoindan-1,5-dicarboxylic acid, which completely inhibited[3H]quisqualate binding to the mGlu5a receptor, were inactive in afunctional assay using this receptor. The distribution and abundance ofbinding sites in rat and human brain sections were studied by quantitativereceptor radioautography and image analysis. Using 10 nM[3H]quisqualate, a high density of binding was detected in variousbrain regions with the following rank order of increasing levels: medulla,thalamus, olfactory bulb, cerebral cortex, spinal cord dorsal horn, olfactorytubercle, dentate gyrus molecular layer, CA1-3 oriens layer of hippocampus,striatum, and cerebellar molecular layer. The ionotropic component of thisbinding could be inhibited by 30 μM kainate, revealing thedistribution of mGlu1+5 receptors. The latter were almost completely inhibitedby the group I agonist (S)-3,5-dihydroxyphenylglycine. The bindingprofile correlated well with the cellular sites of synthesis and regionalexpression of the respective group I receptor proteins revealed by in situhybridization histochemistry and immunohistochemistry, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1471-4159.2000.0752590.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Total synthesis of (+)-gloeosporone: assignment of absolute configuration (1987)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 109 (1987), S. 6176-6177 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00254a043
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A Highly Convergent Total Synthesis of (+)-Myxovirescine M2. Preliminary Communication (1991)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 74 (1991), S. 2112-2118 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The antibiotic myxovirescine M2 was synthesized from seven building blocks (1-7, Scheme 1), with the following chiral starting materials being employed: (S)-malic acid, (+)-D-ribonolactone, (S)-2-(hydroxymethyl)butanoate, and (2R,4S)-5-hydroxy-2,4-dimethylpenLanoate. Three new nucleophilic reagents, 8-10, for C-C bond formation have been used. The key steps of the synthesis are: a Suzuki coupling between an alkyl borane and a vinyl bromide (4 + 12e → 13), a Julia olefinalion (14 + 17 → 18), and a Yamaguchi macrolactonizalion to form the 28-membered lactone (18 → 19), This extremely convergenl synthetic approach will allow the preparation of a number of the 31 known myxovirescine molecules.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19910740846
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Scope and limitations of the TiCl4-mediated additions of isocyanides to aldehydes and ketones with formation of α-hydroxycarboxylic acid amides (1988)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 507-517 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anwendungsbreite der TiCl4-induzierten Addition von Isocyaniden an Aldehyde und Ketone unter Bildung von α-HydroxycarbonsäureamidenDie Umsetzung der aus achiralen (8-12) oder chiralen (13-22) Isocyaniden und TiCl4 gebildeten Addukte mit aliphatischen oder aromatischen Aldehyden oder mit Ketonen (Aceton, Cyclohexanon, Acetophenon) liefert nach wäßriger Aufarbeitung α-Hydroxyamide (27-55) in einer Passerini-artigen Reaktion. Dies ist mit Substraten durchführbar, Welche die verschiedensten funktionellen Gruppen enthalten: aromatische, auch methoxysubstituierte Ringe, Heterocyclen, Amino-, Ether-, Ester- und Amidgruppen, Halogen- und Phosphonatsubstituenten. Die Ausbeuten liegen zwischen 14 und über 95%, wobei die tieferen Werte bei höher funktionalisierten Isocyaniden auftreten. Mit den chiralen Isocyaniden wird keine Diastereoselektivität beobachtet. Bei Derivaten R—NC, deren R-Gruppe relativ stabile Kationen bildet (z. B. t-Alkyl-, Benzyl-), kommt es zu einer Cyanhydrine liefernden Konkurrenzreaktion (s. Schema 2).
    Notes: The adducts obtained from TiCl4 and achiral (8-12) or chiral, nonracemic (13-22) isocyanides are combined with aldehydes (aromatic or aliphatic) and ketones (acetone, cyclohexanone, acetophenone) to give, after aqueous workup, α-hydroxyamides (27-55) [Passerini-type reaction]. The transformation is compatible with a variety of functional groups (aromatic and heterocyclic rings, amino, ether, ester, and amido groups, halides, and phosphonate substituents). The yields range from 14 to over 95% (with the lower values in the case of more highly functionalised isocyanides). No diastereoselectivity is observed with chiral isocyanides. If the R groups of the isocyanide (R—NC) form a rather stable cation (t-alkyl or benzylic), cyanohydrins may result from the reaction, rather than the N-substituted α-hydroxyamides (see Scheme 2).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19881210319
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A Short and Efficient Synthesis of   (2S,2′R,3′R)-2-(2′,3′-Dicarboxylcyclopropyl)glycine (DCG-IV) (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 3131-3133 
    Details
    ISSN: 1434-193X
    Keywords: Amino acids ; DCG-IV ; Drug research ; m-Glu receptors ; Stereocontrol ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Feist′s acid (5) was used in enantiomerically pure form as starting material for the synthesis of (2S,2′R,3′R)-2-(2′,3′-dicarboxylcyclopropyl)-glycine (DCG-IV) (2). This conformationally restricted analog of L-glutamic acid (L-Glu) 1 is a potent group II mGlu receptor agonist.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 7
    Electronic Resource
    Electronic Resource
    Gloeosporone - A Macrolide Fungal Germination Self-Inhibitor Total Synthesis and Activity (1989)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 1233-1240 
    Details
    ISSN: 0170-2041
    Keywords: Gloeosporone ; Colletotrichum gloeosporioides ; 4-Pentynoic acid ; Oxidation, alkyne → 1,2-diketone ; 23Na NMR ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Gloeosporon - Ein Pilzkeimungs-Selbsthemmer mit Macrolidstruktur. - Totalsynthese und AktivitätAusgehend von (S)- oder (R)-4-Brom-1,2-epoxybutan [kommerziell erhältlich oder leicht und in hoher Ausbeute aus (S)- bzw. (R)- Apfelsäure zugänglich] wurden die beiden Enantiomeren des Keimungs-Selbstinhibitors Gloeosporon hergestellt. Die absolute Konfiguration des Naturstoffes wurde damit als 4S,7R,13R bewiesen. Mikrobiologische Tests zeigen, daß beide Enantiomere von Gloeosporon die Keimungshemmung der Sporen von Colletotrichum gloeosporioides bewirken, und daß (-)-Gloeosporon gegenüber einer Reihe von anderen Pilzen aktiv ist. Zur Aufklärung des Wirkungsmechanismus wurden 23Na-NMR- sowie Ionenselektivitätsmessungen durchgeführt; es konnten keine Gloeosporon-Metallion-Wechselwirkungen nachgewiesen werden.
    Notes: Starting with (S)- or (R)-4-Bromo-1,2-epoxybutane [commercially available or readily made from (S)- or (R)-malic acid], both enantiomers of the germination self-inhibitor gloeosporone were synthesized. The absolute configuration of the natural product was thus proven to be 4S,7R,13R. Microbiological studies showed that both enantiomers of the compound cause inhibition of germination in spores of Colletotrichum gloeosporioides, and that (-)-gloeosporone is also active against a variety of other fungi. In order to gain some insight into the mode of action, 23Na NMR measurements and ion-selectivity studies were undertaken; none of these experiments provided evidence for a gloeosporone-metal ion interaction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198919890294
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    EPC-synthesis and fungistatic activity of a gloeosporone analog with an ω-hydroxybutyl instead of the pentyl side chain on the macrocyclic ring (1990)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 1007-1012 
    Details
    ISSN: 0170-2041
    Keywords: Gloeosporone, analog of ; Colletotrichum gloeosporioides ; Oxidation, alkyne → 1,2-diketone ; Antifungal agent ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (+)-5′-Oxa-gloeosporone (2), an analog of the natural germination self-inhibitor (-)-gloeosporone (1), is synthesized, largely following our previously published route to the parent compound. Thus, the hydroxybutyl side chain of 2 was introduced by hydroboration of a butenyl group (→ 14) which had been carried along throughout the synthesis up to the stage of the 14-membered yne-lactone 13. Silyl protection (→ 15), oxidation of the acetylene to a 1,2-diketone moiety (→ 16), and deprotection with spontaneous intramolecular hemiacetal formation completed the synthesis of (+)-2. The (+)-oxa-gloeosporone 2 exhibits an in vitro and in vivo antifungal activity spectrum with 14 microorganisms very similar to both the natural (1) and the unnatural enantiomer (ent-1) of gloeosporone, indicating that neither the sense of chirality nor the side-chain structure is important for the mode of action.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1990199001182
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Total Synthesis of Myxovirescins, 1 Strategy and Construction of the “Southeastern” Part [O(1)-C(14)] (1994)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1994 (1994), S. 701-717 
    Details
    ISSN: 0170-2041
    Keywords: Myxovirescins ; Myxococeus virescens MX v48 ; Suzuki coupling ; Macrolides ; Lactones ; Lactams ; 1,3-Dioxolanes ; 1,3-Dithianes ; Antibiotics ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this and the following two papers the synthesis of myxovirescins A1, A2 and M2, 28-membered macrocyclic lactam-lactones with antibiotic acitivity, is described. A retrosynthetic analysis of the myxovirescin family of ca. 30 target molecules leads to a strategy which could be applied to approximately half of them by slight variations of the building blocks used (Schemes 1-3 and following paper). The southeastern part of the molecule, containing the atoms O(1)-C(14) of myxovirescins A and M is described in this first paper (Scheme 3). The assembly is achieved by using the following appropriately protected units: (S)-2-hydroxy-pentanoic acid, ([1,3]dithian-2-ylmethyl)-amine (Scheme 4), the triflate of (S,R)-2,2-dimethyl-5-vinyl-[1,3]dioxolan-4-ylmethanol, (E)-3-bromo-2-buten-1-ol, and (E)-2-bromo-2-buten-1,4-diol (Scheme 5), the starting materials for these being malic acid, aminoacetaldehyde, ribose, crotyl alcohol and butyne-1,4-diol. The building blocks are put together by using the following key steps: Kolbe electrolysis, amide formation, lithiodithiane alkylation, and Suzuki coupling (Schemes 6 and 8). The only newly created chirality center [C(6) of the target molecules] is generated stereoselectively by a Li-selectride reduction/Mitsunobu inversion (Table 1, Scheme 7). The termini of the O(1)-C(14) fragment (2 in Scheme 8) carry a (protected) hydroxy acid and an aldehyde group for the Julia coupling and lactonization, respectively, in the final steps of the synthesis. All intermediates are fully characterized. The X-ray crystal structures of two compounds prepared for incorporation as N(4)-C(11) and as C(12)-C(14) of the target molecules are also described (Figures 1 and 2).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199419940712
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...