Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-20567 Wissenschaftlicher Artikel Letzel, Matthias C.; Synstad, Bjoenar; Eijsink, Vincent G. H.; Peter-Katalinic, Jasna; Peter, Martin G. Libraries of chito-oligosaccharides of mixed acetylation patterns and their interactions with chitinases 1999 3-9806494-5-8 Institut für Chemie OPUS4-30861 Wissenschaftlicher Artikel Yenesew, Abiy; Twinomuhwezi, Hannington; Kiremire, Bernard T.; Mbugua, Martin N.; Gitu, Peter M.; Heydenreich, Matthias; Peter, Martin G. 8-Methoxyneorautenol and radical scavenging flavonoids from Erythrina abyssinica A new pterocarpan (named 8-methoxyneorautenol) was isolated from the acetone ext. of the root bark of Erythrina abyssinica. In addn., the known isoflavonoid derivs. eryvarin L, erycristagallin and shinpterocarpin were identified for the first time from the roots of this plant. The structures were detd. on the basis of spectroscopic evidence. The new compd. showed selective antimicrobial activity against Trichophyton mentagrophytes. The acetone ext. of the root bark of E. abyssinica showed radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The pterocarpenes, 3-hydroxy-9-methoxy-10-(3,3-dimethylallyl)pterocarpene and erycristagallin, were the most active constituents of the roots of this plant and showing dose-dependent activities similar to that of the std. quercetin. [on SciFinder (R)] 2009 Institut für Chemie OPUS4-1545 misc Peter, Martin G.; Boldt, Peter C.; Niederstein, Yvonne; Peter-Katalinić, Jasna Synthesen von Galactose-Cluster-haltigen Steroid-Derivaten The synthesis of galactose clusters that are linked to a steroid moiety by a peptide-like spacer unit is described. The galactose cluster is obtained by Koenigs-Knorr glycosylation of TRIS-Gly-Fmoc (2b) under Helferich conditions. Peptide and ester bonds are formed after activation of carboxylic acids as diphenylthiophene dioxide (TDO) esters. 6a is synthesized in a convergent way by coupling of (Ac4Gal)3-TRIS-Gly (3e) with cholesteryl TDO succinate (5b). Coupling of (Ac4Gal)3-TRIS-Gly hydrogen succinate (3f) with Gly-O-Chol (5d) by means of EEDQ yields 6d. Reaction of (Ac4Gal)3-TRIS-Gly-SUCC-O-TDO (3g) with 25-hydroxycholesterol leads in a linear sequence to the oxysterol derivative 6f. Selective cleavage of the acetyl groups from galactose units yields the known compound 6b and the new derivatives 6e and 6g. 1990 urn:nbn:de:kobv:517-opus-16783 Institut für Chemie OPUS4-15396 Wissenschaftlicher Artikel Vaaje-Kolstad, G.; Vasella, A.; Peter, Martin G.; Netter, C.; Houston, Douglas R.; Westereng, B.; Synstad, Bjoenar; Eijsink, Vincent G. H.; van Aalten, Daan M. F. Interactions of a family 18 chitinase with the designed inhibitor HM508 and its degradation product, chitobiono- delta-lactone We describe enzymological and structural analyses of the interaction between the family 18 chitinase ChiB from Serratia marcescens and the designed inhibitor N,N'-diacetylchitobionoxime-N-phenylcarbamate (HM508). HM508 acts as a competitive inhibitor of this enzyme with a K-i in the 50 muM range. Active site mutants of ChiB show K-i values ranging from 1 to 200 muM, providing insight into some of the interactions that determine inhibitor affinity. Interestingly, the wild type enzyme slowly degrades HM508, but the inhibitor is essentially stable in the presence of the moderately active D142N mutant of ChiB. The crystal structure of the D142N-HM508 complex revealed that the two sugar moieties bind to the -2 and -1 subsites, whereas the phenyl group interacts with aromatic side chains that line the +1 and +2 subsites. Enzymatic degradation of HM508, as well as a Trp-->Ala mutation in the +2 subsite of ChiB, led to reduced affinity for the inhibitor, showing that interactions between the phenyl group and the enzyme contribute to binding. Interestingly, a complex of enzymatically degraded HM508 with the wild type enzyme showed a chitobiono-delta- lactone bound in the -2 and -1 subsites, despite the fact that the equilibrium between the lactone and the hydroxy acid forms in solution lies far toward the latter. This shows that the active site preferentially binds the E-4 conformation of the -1 sugar, which resembles the proposed transition state of the reaction 2004 Institut für Chemie OPUS4-20595 Wissenschaftlicher Artikel Rottmann, Antje; Synstad, Bjoenar; Thiele, G.; Schanzenbach, Dirk; Eijsink, Vincent G. H.; Peter, Martin G. Approaches towards the design of new chitinase inhibitors 1999 3-9806494-5-8 Institut für Chemie OPUS4-16462 Dissertation Bahrke, Sven; Einarsson, Jon M.; Gislason, Johannes; Haebel, Sophie; Peter-Katalinic, Jasna; Peter, Martin G. Characterization of chitooligosaccharides by mass spectrometry 2003 82-47-15901-5 Institut für Chemie OPUS4-13819 Wissenschaftlicher Artikel Rusu, Viorel Marin; Ng, C. H.; Wilke, Max; Tiersch, Brigitte; Fratzl, Peter; Peter, Martin G. Size-controlled hydroxyapatite nanoparticles as self-organized organic-in organic composite materials This paper presents some results concerning the size-controlled hydroxyapatite nanoparticles obtained in aqueous media in a biopolymer matrix from soluble precursors salts. Taking the inspiration from nature, where composite materials made of a polymer matrix and inorganic fillers are often found, e.g. bone, shell of crustaceans, shell of eggs, etc., the feasibility on making composite materials containing chitosan and nanosized hydroxyapatite was investigated. A stepwise co-precipitation approach was used to obtain different types of composites by means of different ratio between components. The synthesis of hydroxyapatite was carried out in the chitosan matrix from calcium chloride and sodium dihydrogenphosphate in alkaline solutions at moderate pH of 10-11 for 24 h. Our research is focused on studying and understanding the structure of this class of composites, aiming at the development of novel materials, controlled at the nanolevel scale. The X-ray diffraction technique was employed in order to study the kinetic of hydroxyapatite formation in the chitosan matrix as well as to determine the HAp crystallite sizes in the composite samples. The hydroxyapatite synthesized using this route was found to be nano-sized (15-50nm). Moreover, applying an original approach to analyze the (002) XRD diffraction peak profile of hydroxyapatite by using a sum of two Gauss functions, the bimodal distribution of nanosized hydroxyapatite within the chitosan matrix was revealed. Two types of size distribution domains such as cluster-like (between 200 and 400 nm), which are the habitat of "small" hydroxyapatite nanocrystallites and scattered-like, which are the habitat of "large" hydroxyapatite nanocrystallites was probed by TEM and CSLM. The structural features of composites suggest that self-assembly processes might be involved. The composites contain nanosized hydroxyapatite with structural features close to those of biological apatites that make them attractive for bone tissue engineering applications. (c) 2005 Elsevier Ltd. All rights reserved 2005 Institut für Chemie OPUS4-25913 Wissenschaftlicher Artikel Andersen, S. O.; Peter, Martin G.; Roepstorff, Peter Cuticular sclerotization in insects 1996 Institut für Chemie OPUS4-24443 Wissenschaftlicher Artikel Haebel, Sophie; Peter-Katalinic, Jasna; Peter, Martin G. Mass spectrometry of chitooligosaccharides 1997 88-86889- 01-1 Institut für Chemie OPUS4-17375 Wissenschaftlicher Artikel Bahrke, Sven; Einarsson, Jon M.; Gislason, Johannes; Haebel, Sophie; Letzel, Matthias C.; Peter-Katalinic, Jasna; Peter, Martin G. Sequence analysis of chitooligosaccharides by matrix-assisted laser desorption ionization postsource decay mass spectrometry Oligosaccharides composed of 2-acetamido-2-deoxy-D-glucopyranose (GlcNAc) and/or 2-amino-2-deoxy-D- glucopyranose (GlcN) were prepd. by chem. degrdn. of chitin or chitosan and sepd. by gel permeation chromatog. Oligosaccharides obtained after enzymic hydrolysis of chitosan [FA 0.19] with a fungal chitinase were derivatized by reductive amination with 2-aminoacridone and sequenced by matrix-assisted laser desorption ionization time-of-flight postsource decay (PSD) mass spectrometry (MS). The sequence of a trimer, D1A2, was established as D-A-A. The compn. of a hexamer D3A3 was .apprx.65% D-A-D-D-A-A and 35% D-D-A-D-A-A. The PSD MS of a nonamer D5A4-amac revealed four isobaric species D-X-Y-D-X-Y-D-A-A, where A is GlcNAc, D is GlcN, and X and Y (X ¹ Y) are mutually either D or A. This structure motif was also obsd. in a dodecamer D7A5 which was composed of eight isobaric sequences of the general formula (D-X-Y)3- D-A-A. 2002 Institut für Chemie