Synthesis of tumor-associated glycopeptide antigens for the development of tumor-selective vaccines

In contrast to normal cells, the glycoprotein profile on epithelial tumor cells is distinctly altered. Due to an incomplete formation of the glycan side-chains resulting from a premature sialylation, additional peptide epitopes become accessible to the immune system in mucin-type glycoproteins on tumor cells. These tumor-associated structure alterations constitute the basis for a selective immunological attack on cancer cells. For the construction of immunostimulating antigens, glycopeptide partial structures from the mucins MUC1 and MUC4 carrying the tumor-associated sialyl-T(N), alpha2,6-sialyl-T and alpha2,3-sialyl-T antigens have been synthesized. Employing different linkers such as the allylic HYCRON or the fluoride-sensitive PTMSEL anchor, the antigenic glycopeptide structures were constructed on the solid phase utilizing pre-assembled glycosyl amino acid building blocks prepared in solution by convergent chemical or chemoenzymatic strategies. The proliferation of cytotoxic T cells has been induced applying a construct composed of a sialyl-T(N) MUC1-glycopeptide conjugated with a tetanus toxin T cell peptide epitope.     

‘Face-to-Face’-Benzo-anellierte homologe Hypostrophene. Synthesen,Röntgenstrukturanalysen und PE-Spektren

‘Face-to-Face’ Benzo-anellated Homologous Hypostrophenes. Syntheses, X-Ray-Structure Analyses and PE Spectra ‘Face-to-face’ Benzo-anellated homologous hypostrophenes (series M ), of interest as substrates for [6 + 6]-photocycloaddition reactions, have been synthesized. From X-ray structural analyses of 13b and 13c shortest C? C distances of 2.80(2.76)/2.71 Å and interorbital angles (ω) of 129° (128°)/130° between the benzene rings have been determined. The PE spectra are discussed in the context of transannular π,π interactions.     

Polyselenide mit langkettigen Tetraalkylammoniumionen Die Kristallstruktur von Trimethyl-tetradecyl-ammonium-hexaselenid

Polyselenides with Long-chain Tetraalkylammonium Ions. Crystal Structure of Trimethyltetradecyl-ammonium Hexaselenide Na₂Se₂ and Na₂Se react with various tetraalkylammonium halides in ethanol and in presence of grey selenium and catalytic quantities of iodine forming different polyselenides Se_n^2? (n = 3, 5—9). In the solutions equilibria of polyselenides seem to occur; cooling of saturated solutions causes crystallization of polyselenides with a composition depending on the cation. Tri- and pentaselenide are dark green. The higher members form black crystals, all compounds are sensitive to oxygen. The i.r. spectra are reported. [(CH₃)₃N(CH₂)₁₃CH₃]₂Se₆ is characterized by a crystallographic structure determination with X-ray data: space group P2₁2₁2, Z = 4, a = 5043, b = 734.2, c = 600.3 pm (986 observed independent reflexions. R = 0.072). The compound consists of trimethyl tetradecylammonium ions and angular Se₆^2? chains of symmetry C₂ with Se? Se bond lengths of 227 and 235 pm.     

Die Kristallstruktur des Natriumorthogermanats,Na4GeO4

The crystal structure of the title compound has been determined from single crystal X-ray diffraction data and refined toR=0.125. The unit cell is triclinic, space group P, (No. 2),a=5.688(1),b=5.701(1),c=8.583(1) Å, =81.32(1), =71.50(1), =67.95(1)° andZ=2. The structure consists of isolated [GeO₄] tetrahedra linked together by four- and five-coordinate sodium atoms. Na₄GeO₄ is isostructural with Na₄CoO₄ (which has been described to be non-centrosymmetric and for which a centrosymmetric model is presented), K₄GeO₄, K₄SnO₄ and K₄PbO₄.

     

Template-Reaktion von Bis(acetylacetonato)-dioxo-molybdän(VI) mit Benzoylhydrazin

Template Reaction of Bis(acetylacetonato)-dioxo-molybdenum(VI) with Benzoylhydrazone By reaction of bis(acetylacetonato)-dioxo-molybdenum(VI) with benzoylhydrazine benzoylhydrazido(2?)-acetylacetonebenzoylhydrazonato(2?)-oxo-molybdenum(VI) was formed beside another species. The compound was characterized by mass spectrometry and X-ray structural analysis. Crystallographic data see ?Inhaltsübersicht”?.     

Spektroskopische Bestimmung der Doppelbindungslage in Phospholinen

Zusammenfassung Die Spin-Spin-Kopplungskonstanten der olefinischen Protonen mit dem ³¹P sowie die Feinstruktur der ¹H-NMR-Spektren sind charakteristisch für die Lage der Doppelbindung. Vielfach kann auch die Intensität der _C=C-Schwingung im IR zur Bestimmung der Doppelbindungslage benutzt werden. Massenspektren geben nur in Ausnahmefällen Hinweise, können jedoch zur exakten Bestimmung des Molekulargewichts dienen.

---

Summary The spin-spin coupling constants of the olefinic protons with the phosphorus-31 as well as the fine structure of the nmr-spectra are characteristic for the position of the double bond. In the infrared, the intensity of the _C=C-frequency may often serve as indication of the position of the double bond. The applicability of mass spectra is limited to a small number of compounds. They may be used, however, for an accurate determination of the molecular weight.

---

---

Die Ausführung der Untersuchungen erfolgte unter Mitarbeit von Herrn F. Dlugosch, Herrn H. Au und Fräulein R. Barth.

---

Herrn Dr. C. A. Reilly, Shell-Development Company, Emeryville, USA, danken wir für die Überlassung getesteter Programmkartensätze zur Berechnung der NMR-Spektren.