On the Hydrogen Bonding of Succinimide Derivatives: Crystal Structure of 3(4-Pyridil-methyl)amino-pyrrolidine-2,5-dione

The structure of 3(4-pyridil-methyl)amino-pyrrolidine-2,5-dione has been established by X-ray crystallography from diffractometer data with an F2 refinement to R = 0.0526 for 1999 observed reflections. The close packing of orthorhombic crystals space group Pbca (No. 61) with a = 11.595(4), b = 8.325(1), c = 20.452(4) Å, V = 1974.2(8) Å3, Z = 8, Dc = 1.381 Mg/m3, m = 0.824 mm–1 is built of herringbone-like molecular layers folded along the c axis and fused together by infinite chains of NH⋅⋅⋅O and NH⋅⋅⋅N hydrogen bonds perpendicular to one another. This prompted us to review and characterize the hydrogen bond networks formed by succinimides possessing an unsubstituted >NH group by the use of the Cambridge Structural Database (CSD), and our own earlier structure determinations. The common motifs of the hydrogen bond systems are analyzed using graph descriptions suggested by M. C. Etter. The influence of the hydrogen bonds on molecular close packing is also discussed

Ligand-Specific Regulation of the Endogenous Mu-Opioid Receptor by Chronic Treatment with Mu-Opioid Peptide Agonist

Since the discovery of the endomorphins (EM), the postulated endogenous peptide agonists of the mu-opioid receptors, several analogues have been synthesized to improve their binding and pharmacological profiles. We have shown previously that a new analogue, cis-1S,2R-aminocyclohexanecarboxylic acid2-endomorphin-2 (ACHC-EM2), had elevated mu-receptor affinity, selectivity, and proteolytic stability over the parent compound. In the present work, we have studied its antinociceptive effects and receptor regulatory processes. ACHC-EM2 displayed a somewhat higher (60%) acute antinociceptive response than the parent peptide, EM2 (45%), which peaked at 10 min after intracerebroventricular (icv) administration in the rat tail-flick test. Analgesic tolerance developed to the antinociceptive effect of ACHC-EM2 upon its repeated icv injection that was complete by a 10-day treatment. This was accompanied by attenuated coupling of mu-sites to G-proteins in subcellular fractions of rat brain. Also, the density of mu-receptors was upregulated by about 40% in the light membrane fraction, with no detectable changes in surface binding. Distinct receptor regulatory processes were noted in subcellular fractions of rat brains made tolerant by the prototypic full mu-agonist peptide, DAMGO, and its chloromethyl ketone derivative, DAMCK. These results are discussed in light of the recently discovered phenomenon, that is, the “so-called biased agonism” or “functional selectivity

Magyar Tanítóképző 51 (1938) 8

Magyar Tanítóképző A Tanítóképző-intézeti Tanárok Országos Egyesületének folyóirata 51. évfolyam, 8. szám Budapest, 1938. októbe

Familiae Bálint ex librise

Fábiánhttp://www.lib.unideb.huDebreceni Egyetem Egyetemi és Nemzeti KönyvtárAz ex librisen egy térdelő íjász látható fegyverének használata közben. Ősi magyar öltözetben van. A háttérben további harcosok láthatók. Lábánál tulipán nyílik és szívek hevernek szerteszét.metsze