TY  - GEN
A1  - Peter, Martin G.
T1  - Products of in vitro oxidation of N-acetyldopamine as possible components in the sclerotization of insect cuticle
N2  - [1-14C]-N-Acetyldopamine (NADA) was oxidized in the presence of methyl [3-3H]-β-alanate with mushroom tyrosinase. The complex mixture of reaction products was partly resolved by chromatographic procedures and analyzed by spectroscopic methods. Methyl-β-alanate is incorporated to only a small extent into oxidation products of NADA which inter alia are presumed to be oligomeric hydroxyquinones. After oxidation of [1-14C, 2-3H]-NADA with preparations from tanning Manduca sexta pupal cuticle, N-acetylnoradrenalin was identified as one of the products. Binding of radioactivity to melanin-like material was also observed. These results suggest that oxidation products different from those formulated usually for the crosslinkages between protein amino groups and N-acetyldopaquinone are deposited in darkly brown coloured insect cuticles during sclerotization.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 041 
KW  - N-acetyldopamine
KW  - sclerotization
KW  - tyrosinase; o-quinones
KW  - tanning agents
Y1  - 1980
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16759
ER  - 
TY  - GEN
A1  - Ferenz, Hans-Jürgen
A1  - Peter, Martin G.
A1  - Berg, Dieter
T1  - Inhibition of farnesoic acid methyltransferase by sinefungin
N2  - Sinefungin inhibited the S-adenosylmethionine-dependent farnesoic acid methyltransferase in a cell-free system containing a homogenate of corpora allata from female locusts, Locusta migratoria. The enzyme catalyzed the penultimate step of juvenile hormone biosynthesis in the insects. Culturing corpora allata in the presence of sinefungin greatly suppressed juvenile hormone production. The following in vivo effects were visible after injection of the inhibitor: increase in mortality and reduction of total haemolymph protein liter and ovary fresh weight, as well as length of terminal oocytes. Attempts to reverse these effects by topical application of the juvenile hormone analog ZR-515 (methoprene) were only partly successful. Therefore, the in vivo effects may be due to a general inhibition of methyltransferase enzymes in the insect. Sinefungin appeared to be of potential interest as the first representative of a new class of insect growth regulators.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 077 
KW  - Juvenile hormone analogue
KW  - Orthoptera
KW  - Juvenile hormone
KW  - Biosynthesis
KW  - Enzyme
KW  - Corpora allata
KW  - In vitro
KW  - Biological activity
KW  - Enzyme inhibitor
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17016
ER  - 
TY  - GEN
A1  - Kort, C. A. D. de
A1  - Peter, Martin G.
A1  - Koopmanschap, A. B.
T1  - Binding and degradation of juvenile hormone III by haemolymph proteins of the Colorado potato beetle: a re-examination
N2  - The haemolymph of the adult Colorado potato beetle, Lepinotarsa decemlineata Say, contains a high molecular weight (MW > 200,000) JH-III specific binding protein. The Kd value of the protein for racemic JH-III is 1.3 ± 0.2 × 10−7 M. It has a lower affinity for racemic JH-I and it does not bind JH-III-diol or JH-III-acid. The binding protein does discriminate between the enantiomers of synthetic, racemic JH-III as was determined by stereochemical anaysis of the bound and the free JH-III. Incubation of racemic JH-III with crude haemolymph results in preferential formation of (10S)-JH-III-acid, the unnatural configuration. The JH-esterase present in L. decemlineata haemolymph is not enantioselective. It is concluded that the most important function of the binding protein is that of a specific carrier, protecting the natural hormone against degradation by esterases. The carrier does not protect JH-I as efficiently as the lower homologue.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 068 
KW  - Juvenile hormone
KW  - Leptinotarsa decemlineata
KW  - JH-III-specific carrier protein
KW  - enantioselectivity
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16777
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Stupp, Hans-Peter
A1  - Lentes, Klaus-Ulrich
T1  - Umkehr der Enantioselektivität bei der enzymatischen Hydrolyse von Juvenilhormon als Ergebnis einer Proteinfraktionierung
N2  - Aus dem Inhalt: Die Juvenilhormone 1a-c werden im Blut von Insekten enzymatisch zu den biologisch inaktiven Sluren hydrolysiert. Bei der Hydrolyse von racemischem 1c im Blut der Wanderheuschrecke Locusta migratoria wird ein Umsatz von 40-60% erreicht. Das unumgesetzte Edukt enthällt einen Überschuß an natürlich konfiguriertem (10R)-1c (e.e. 47.2%). Wir konnten zeigen, daß das in der Hämolymphe vorhandene Hormon-Bindungsprotein bevorzugt mit (10R)- 1c assoziiert.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 052 
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17001
ER  - 
TY  - GEN
A1  - Ferenz, Hans-Jörg
A1  - Peter, Martin G.
T1  - The inhibitory effect of sinefungin on juvenile hormone biosynthesis and development in locusts
N2  - The antibiotic fungal metabolite sinefungin is a potent inhibitor of S-adenosylmethionine-acceptor methyltransferases. Its effect on insect metabolism and especially on corpora allata farnesoic acid methyltransferase, which catalyzes the penultimate step of juvenile hormone biosynthesis, was investigated in Locusta migratoria. Injection of sinefungin results in a delay of imaginal molt and in suppression of ovary development. Isolated corpora allata are unable to synthesize juvenile hormone III in the presence of more than 1.0 mM sinefungin. In a cell-free system containing the S-adenosylmethionine-dependent farnesoic acid methyltransferase from corpora allata sinefungin is a competitive inhibitor of the synthesis of methylfarnesoate with Ki of 1 μM.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 076 
KW  - Locust
KW  - sinefungin
KW  - O-methyltransferase
KW  - juvenile hormone biosynthesis
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16811
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Förster, Hans
T1  - On the structure of Eumelanins : identification of constitutional patterns by solid-state NMR spectroscopy
N2  - Aus dem Inhalt: Melanins are complex polyphenolic polymers. They are usually formed in nature by enzyme-catalyzed oxidative polymerization of o-diphenols. The deep black eumelanins, derived from Dopa 1 or dopamine 3, are distinguished from the yellow to brown phaeomelanins obtained from Dopa in the presence of cysteine. Characteristic of eumelanins are the indole units, which are formed from catecholamines by intramolecular addition of the amino groups to the oxidatively generated o-quinones. [...]
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 053 
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17027
ER  - 
TY  - GEN
A1  - Peter, Martin G.
T1  - Chemische Modifikation von Biopolymeren durch Chinone und Chinonmethide
N2  - Chinone und Vorstufen, die oxidativ in Chinone und/oder Chinonmethide umgewandelt werden können, sind in der Natur weit verbreitet. Als sekundäre Naturstoffe wirken sie häufig antibiotisch, cytotoxisch, aber auch pathogen, und eine Reihe von Pflanzen und Tieren benutzt chinoide Substanzen als Abwehrstoffe, oft mit spektakulärem Erfolg. Auf makromolekularer Ebene spielen Chinonmethide im Pflanzenreich eine Schlüsselrolle bei der Biosynthese von Lignin, während die Bildung von Melanoproteinen ein Beispiel für Reaktionen von o-Chinonen im Tierreich ist. Bei den Insekten dienen Chinone und Chinonmethide zur Bildung des lebensnotwendigen Exoskeletts. Die Reaktivität von Chinonen in biologischen Systemen hat auch für den Menschen unmittelbare Bedeutung in pharmazeutischer, toxikologischer und technologischer Hinsicht. Den Beispielen in diesem Aufsatz liegt ein gemeinsames Prinzip zugrunde, nämlich die chemische Modifikation von Biopolymeren durch Chinone und Chinonmethide. Wie sich besonders bei einer detaillierteren Betrachtung der Reaktionen zeigt, die zur Sklerotisierung der Insektencuticula führen, sind in den letzten Jahren wichtige neue Erkenntnisse hinzugekommen, die vor allem durch die modernen Methoden der Stofftrennung und der Festkörper-NMR-Spektroskopie ermöglicht worden sind.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 043 
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16802
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Förster, Hans
T1  - Zur Struktur von Eumelaninen : Identifizierung von Konstitutionsmustern durch Festkörper-NMR-Spektroskopie
T1  - On the Structure of Eumelanins : Identification of Constitutional Patterns by Solid-state NMR Spectroscopy
N2  - Aus dem Inhalt: Melanine sind komplexe polyphenolische Polymere. In der Natur entstehen sie durch meist enzymkatalysierte oxidative Polymerisation von o-Diphenolen. Man unterscheidet die aus Dopa 1 oder Dopamin 3 hervorgehenden, tiefschwarzen Eumelanine von den aus Dopa in Gegenwart von Cystein entstehenden, gelben bis braunen Phaomelaninen. [...]
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 054 
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17038
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Boldt, Peter C.
A1  - Niederstein, Yvonne
A1  - Peter-Katalinić, Jasna
T1  - Synthesen von Galactose-Cluster-haltigen Steroid-Derivaten
N2  - 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.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 042 
KW  - Glycoconjugates
KW  - Galactosides
KW  - Steroid esters
KW  - Amphiphiles
KW  - Glycopeptides
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16783
ER  - 
TY  - GEN
A1  - Peter, Martin G.
A1  - Andersen, Svend Olav
A1  - Hartmann, Rudolf
A1  - Miessner, Merle
A1  - Roepstorff, Peter
T1  - Catecholamine-protein conjugates : isolation of 4-phenylphenoxazin-2-ones from oxidative coupling of N-acetyldopamine with alipathic amino acids
N2  - 4-Phenylphenoxazinones were isolated after biomimetic oxidation, using diphenoloxidases of insect cuticle, mushroom tyrosinase, or after autoxidation of N-acetyldopamine (Image ) in the presence of β-alanine, β-alanine methyl ester or N-acetyl-L-lysine. They are formed presumably by addition of 2-aminoalkyl-5-alkylphenols to the o-quinone of biphenyltetrol which, in turn, arises from oxidative coupling of. The structures of present the first examples for the assembly of reasonably stable intermediates in the rather complex process of chemical modifications of aliphatic amino acid residues by o-quinones.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 062 
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17571
ER  - 
TY  - GEN
A1  - Andersen, Svend Olav
A1  - Perter, Martin G.
A1  - Roepstorff, Peter
T1  - Cuticle-catalyzed coupling between N-acetylhistidine and N-acetyldopamine
N2  - Several types of insect cuticle contain enzymes catalyzing the formation ofof adducts between N-acetyldopamine (NADA) and N-acetylhistidine (NAH). Two such adducts, NAH-NADA-I and NAH NADA-II, have been isolated and their structures determined. In one of the adducts the link connecting the two residues occurs between the I-position (ß-position) in the NADA side chain and the 1-N atom (τ-N) in the imidazole ring of histidine. Diphenoloxidase activity alone is not sufficient for formation of this adduct, whereas extracts containing both diphenoloxidase and o-quinone-p-quinone methide isomerase activities catalyze the coupling reaction. The adduct consists of a mixture of two diastereomers and they are presumably formed by spontaneous reaction between enzymatically produced NADA-p-quinone methide and N-acetylhistidine. The other adduct has been identified as a ring addition product of N-acetylhistidine and NADA. In contrast to the former adduct it can be formed by incubation of the two substrates with mushroom tyrosinase alone. An adduct between N-acetylhistidine and the benzodioxan-type NADA-dimer is produced in vitro, when the N-acetylhistidine-NADA adduct is incubated with NADA and locust cuticle containing a 1,2-dehydro-NADA generating enzyme system. Trimeric NADA-polymerization products of the substituted benzodioxan-type have been obtained from in vivo sclerotized locust cuticle, confirming the ability of cuticle to produce NADA-oligomers. The results indicate that some insect cuticles contain enzymes promoting linkage of oxidized NADA to histidine residues. It is suggested that histidine residues in the cuticular proteins can serve as acceptors for oxidized NADA and that further addition of NADA-residues to the phenolic groups of bound NADA can occur, resulting in formation of protein-linked NADA-oligomers. The coupling reactions identified may be an important step in natural cuticular sclerotization.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 072 
KW  - sclerotization
KW  - quinone
KW  - quinone methide
KW  - o-quinone isomerase
KW  - Hyalophora cecropia
KW  - Locusta migratoria
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16762
ER  - 
TY  - JOUR
A1  - Ley, J. P.
A1  - Peter, Martin G.
T1  - Synthesis of N-(2-Acetamido-2-deoxy-ß-D-glucopyranosyl)- and of N-(N,N-Diacetylchitobiosyl)-amide of lhistidine
Y1  - 1994
SN  - 0039-7881
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
A1  - Andersen, S. O.
T1  - The molecular architecture of the insect exoskeleton
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Schumacher-Wandersleb, Michael H. M. G.
A1  - Petersen, Stefan
A1  - Peter, Martin G.
T1  - Preparation of the N-Acetylglucosaminidase inhibitor 1-Acetamido-1,2,5-tride oxy-2,5-imino-D-glucitol from methyl a-D-Mannopyranoside
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
A1  - Ley, J. P.
A1  - Petersen, Stefan
A1  - Londershausen, M.
A1  - Schumacher-Wandersleb, Michael H. M. G.
A1  - Spindler, Klaus-Dieter
A1  - Spindler-Barth, Margarethe
A1  - Turberg, Andreas
T1  - Synthesis of chitinase inhibitors
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Krösche, Christian
A1  - Crescenzi, Orlando
A1  - Hoffbauer, Wilfried
A1  - Jansen, Martin
A1  - Napolitano, Alessandra
A1  - Prota, Guiseppe
A1  - Peter, Martin G.
T1  - Synthesis of dopamines labelled with 13C in the alpha- or beta-side chain positions, and their application for structure studies on melanins by solid state NMR spectroscopy
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Applications and environmental aspects of chitin and chitosan
Y1  - 1995
SN  - 0022-233X
ER  - 
TY  - JOUR
A1  - Schumacher-Wandersleb, Michael H. M. G.
A1  - Peter, Martin G.
T1  - Synthesis of chitobiosyl pyrrolidines
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Abegaz, Berhanu M.
A1  - Peter, Martin G.
T1  - Emodine and emodinanthrone rhamnoside acetates from fruits of rhamnus prinoides
Y1  - 1995
SN  - 0031-9422
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - The Bio-organic chemistry of melanogenesis
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Chemie i Biochemia Zewnetrznego Szkieletu Owadow : (Chemistry and biochemistry of the insect exoskeleton)
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Chemistry and biochemistry of the insect exoskeleton
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Chitin in den Startlöchern
Y1  - 1995
SN  - 0009-2959
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
A1  - Merz, A.
T1  - Stereoselective benzylic deprotonation in the enzymatic rearrangement of N-acetyldopamine derived o-Quinone to the p-Quinone methide
Y1  - 1995
SN  - 0957-4166
ER  - 
TY  - JOUR
A1  - Buss, U.
A1  - Varum, K. M.
A1  - Peter, Martin G.
A1  - Spindler-Barth, Margarethe
T1  - ELISA for quantitation of chitin, chitosan and related compounds
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Andersen, S. O.
A1  - Peter, Martin G.
A1  - Roepstorff, Peter
T1  - Cuticular sclerotization in insects
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Krösche, Ch.
A1  - Peter, Martin G.
T1  - Detection of melanochromes by MALDI-TOF mass spectrometry
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Ley, J. P.
A1  - Peter, Martin G.
T1  - Synthesis of L-histidine and (-)-spinacine chitooligosyl amides
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Londershausen, M.
A1  - Turberg, Andreas
A1  - Bieseler, Barbara
A1  - Lennarz, M.
A1  - Peter, Martin G.
T1  - Characterization and Inhibitor Studies of Chitinases from Parasitic Blowfly (Lucilia cuprina), Tick (Boophilus micoplus), Intestinale Nematode (Haemonchus contortus), and a Bean (Phaseolus vulgaris)
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Londershausen, M.
A1  - Turberg, Andreas
A1  - Spindler-Barth, Margarethe
A1  - Peter, Martin G.
T1  - Screening Test for Insecticides Interfering with Cuticular Sclerotization
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
A1  - Köhler, L. A.
T1  - Chitin und Chitosan : nachwachsende Rohstoffe aus dem Meer
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
A1  - Wollenberger, Ursula
T1  - Phenol-oxidizing enzymes : mechanisms and applications
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Haebel, Sophie
A1  - Peter-Katalinic, Jasna
A1  - Peter, Martin G.
T1  - Mass spectrometry of chitooligosaccharides
Y1  - 1997
SN  - 88-86889- 01-1
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
A1  - Miessner, Merle
T1  - Primärstoffwechsel, Shikimat- und Phenylpropan-Gruppe, Vitamine, Coenzyme, Pflanzeninhaltsstoffe
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Ratajska, M.
A1  - Struszczyk, Marcin Henryk
A1  - Boryniec, Stefan
A1  - Peter, Martin G.
A1  - Loth, Fritz
T1  - The degree of acetylation of chitosan : optimization of the IR Method
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Ley, J. P.
A1  - Schweikart, F.
A1  - Peter, Martin G.
T1  - Chitinase inhibitors
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Ratajska, M.
A1  - Boryniec, Stefan
A1  - Peter, Martin G.
A1  - Loth, Fritz
T1  - The determination of the degree of N-acetylation of chitosan
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schanzenbach, Dirk
A1  - Matern, Christa-Maria
A1  - Peter, Martin G.
T1  - Cleavage of chitin by means of sulfurice acid/acetc anhydride and isolation of peracetylated chito- oligosaccharides
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - NMR spectroscopy of chito-oligosaccharides
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schanzenbach, Dirk
A1  - Matern, Christa-Maria
A1  - Peter, Martin G.
T1  - Synthesis of glycosylamines and glycopeptides
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Chromatography of chito-oligosaccarides
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Berth, Gisela
A1  - Dautzenberg, Herbert
A1  - Peter, Martin G.
T1  - Physica-chemical characterization of chitosans in dilute solution
Y1  - 1998
SN  - 2-907922-57-2
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Meisner, M.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Two prenylated flavanones from stem bark of erythrina burttii
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Four isoflavanones from stem bark of erythrina sacleuxii
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Berth, Gisela
A1  - Dautzenberg, Herbert
A1  - Peter, Martin G.
T1  - Physico-chemical characterization of chitosans varying in degree of acetylation
Y1  - 1998
SN  - 0144-8617
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Köhler, L. A.
A1  - Peter, Martin G.
T1  - Characterization of chitosan
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Analysis of deacetylation deree in chitosans from various sources
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Calibration of methods for the determination of the degree of decatetylation of chitosan
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rawel, Harshadrai Manilal
A1  - Kroll, Jürgen
A1  - Haebel, Sophie
A1  - Peter, Martin G.
T1  - Reactions of a glucosinolate breakdown product (benzyl-isothiocyanate) with myoglobin
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Streffer, Katrin
A1  - Kaatz, Helvi
A1  - Bauer, Christian G.
A1  - Makower, Alexander
A1  - Schulmeister, Thomas
A1  - Scheller, Frieder W.
A1  - Peter, Martin G.
A1  - Wollenberger, Ursula
T1  - Application of a sensitive catechol detector for determination of tyrosinase inhibitors
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Alarcon, Julio
A1  - Alderete, Joel B.
A1  - Peter, Martin G.
A1  - Becerra, Juan J.
A1  - Silva, M.
T1  - Study on synthesis of 3 alpha,4 alpha-dihydroxy-dihydro-beta-agarofuran
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Pospieszny, Henryk
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Biodegradation of chitosan
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rottmann, Antje
A1  - Synstad, Bjoenar
A1  - Eijsink, Vincent G. H.
A1  - Peter, Martin G.
T1  - Synthesis of N-acetylglucosaminyl and diacetylchitobiosyl amides of heterocyclic carboxylic acids as potential chitinase inhibitors
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Halweg, R.
A1  - Peter, Martin G.
T1  - Comparative analysis of chitosans from insects and crustacea
Y1  - 1999
SN  - 3-9806494-5-8
ER  - 
TY  - JOUR
A1  - Letzel, Matthias C.
A1  - Synstad, Bjoenar
A1  - Eijsink, Vincent G. H.
A1  - Peter-Katalinic, Jasna
A1  - Peter, Martin G.
T1  - Libraries of chito-oligosaccharides of mixed acetylation patterns and their interactions with chitinases
Y1  - 1999
SN  - 3-9806494-5-8
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Preparation of paper sheets containing microcrystalline chitosan
Y1  - 1999
SN  - 3-9806494-5-8
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Method of microcrystalline chitosan-protein films preparation
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Kaatz, Helvi
A1  - Streffer, Katrin
A1  - Wollenberger, Ursula
A1  - Peter, Martin G.
T1  - Inhibition of mushroom tyrosinase by kojic acid octanoates
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Kamlage, Stefan
A1  - Sefkow, Michael
A1  - Peter, Martin G.
T1  - Cross coupling of benzylic bromides and vinyl stannanes
Y1  - 1999
ER  - 
TY  - BOOK
A1  - Peter, Martin G.
T1  - EUCHIS'99 : 3rd International Conference of the European Chitin Society ; Potsdam, Germany, Aug. 31 - Sept. 3, 1999 ; abstracts
Y1  - 1999
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Rottmann, Antje
A1  - Synstad, Bjoenar
A1  - Thiele, G.
A1  - Schanzenbach, Dirk
A1  - Eijsink, Vincent G. H.
A1  - Peter, Martin G.
T1  - Approaches towards the design of new chitinase inhibitors
Y1  - 1999
SN  - 3-9806494-5-8
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Pospieszny, Henryk
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Biodegradation of chitosan
Y1  - 1999
SN  - 83-87202-68-1
ER  - 
TY  - JOUR
A1  - Becker, Thomas W.
A1  - Peter, Martin G.
A1  - Pool-Zobel, Beatrice L.
T1  - Cellular effects of lignans : modulation of growth, oxidative DNA damage and cell metabolism in human colon cancer cells
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Properties of microcrystalline chitosan gel-like dispersion and formed films
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Two Isoflavanones from the Stem Bark of Erythrina sacleuxii
N2  - From the stem bark of Erythrina sacleuxii two new isoflavanones, (R)-5,7-dihydroxy-2',4',5'- trimethoxyisoflavanone (trivial name, (R)-2,3-dihydro-7-demethylrobustigenin) and (R)-5-hydroxy- 2',4',5'-trimethoxy-2'',2''- dimethylpyrano[5'',6'':6,7]isoflavanone (trivial name, (R)-saclenone) were isolated. In addition the known compounds shinpterocarpin, 2,3-dehydrokievitone, abyssinone V, abyssinone V-4'-methyl ether, erythrinasinate and 4'-O-methylsigmoidin B were isolated. The structures were determined on the basis of spectroscopic evidence.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Norledge, Brian V.
A1  - Lambeir, Anne M.
A1  - Abagyan, Ruben
A1  - Rottmann, Antje
A1  - Fernendez, Anna M.
A1  - Filimonov, Vladimir V.
A1  - Peter, Martin G.
A1  - Wierenga, Rik K.
T1  - Modeling, mutagenesis, and structural studies on the fully conserved phoshate-binding loop (Loop 8) of triosephosphate isomerase : toward a new substrate specificity
Y1  - 2001
UR  - http://www3.interscience.wiley.com/journal/36176/toc
SN  - 0887-2585
ER  - 
TY  - JOUR
A1  - Miessner, Merle
A1  - Peter, Martin G.
A1  - Vincent, Julian F. V.
T1  - Preparation of Insect-Cuticle-Like Biomimetic Materials
N2  - A model system of tanning of a protein matrix within a fibrous structure, such as most commonly found in insect cuticle, was developed, using the cellulose of paper in place of chitin. The paper was impregnated with a tripeptide, DOPA-Gly-Gly, or a protein (BSA) plus catechol and treated with tyrosinase to oxidize the catechol. The resulting material was waterproof and had very high wet strength. If the material was wetted and dried repeatedly its water retention decreased by a factor of at least two.
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Natürliche Klebstoffe : von Muscheln, Seepocken, Spinnen und anderem Klebe-Getier
Y1  - 2001
SN  - 3-519-16195-8
ER  - 
TY  - JOUR
A1  - Zala, Eva
A1  - Struszczyk, Marcin Henryk
A1  - Peter, Martin G.
T1  - Effects of preparation methods for chitosan films on their properties
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Structures of Chitinases and the Design of Inhibitors
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Letzel, Matthias C.
A1  - Peter-Katalinic, Jasna
A1  - Peter, Martin G.
T1  - Mass spectrometry of chitin and chitosan oligosaccharides
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Pospieszny, Henryk
A1  - Peter, Martin G.
T1  - Biodegradation of films and paper sheets containing chitosan
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Kamlage, Stefan
A1  - Sefkow, Michael
A1  - Peter, Martin G.
T1  - A short synthesis of biologically active lignan analogues
N2  - beta-Benzyl-gamma-butyrolactones were synthesized in four transition metal catalysed reactions from butynediol, and alkylated to afford new, biologically active lignan analogues.
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Struszczyk, Marcin Henryk
A1  - Pospieszny, Henryk
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Biodegradation of various chitosans using Aspergillus fumigatus
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Kamlage, Stefan
A1  - Sefkow, Michael
A1  - Zimmermann, Nicole
A1  - Peter, Martin G.
T1  - Concise synthesis of (+)-beta-benzyl gamma-butyrolactones from butynediol
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Chitin and Chitosan from Animal Sources
N2  - A review on the chem. and biochem. of chitin and the chem. and application of chitosan. The following topics were discussed: structure of chitin and chitosan; occurrence and physiol. functions of chitin; detection of chitin in animals and anal. of chitin and chitosan; biosynthesis and biodegrdn. of chitin in animals; prodn. of chitin and chitosan; properties of chitin and chitosan; and applications of chitin and chitosan.
Y1  - 2002
SN  - 3-527-30227-1
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - Chitin and Chitosan from Fungi
Y1  - 2002
SN  - 3-527-30227-1
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Guchu, S. M.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Three iosoflav-3-enes and a 2-arylbenzofuran from the root bark of Erythrina burttii
N2  - From the root bark of Erythrina burttii three new isoflav-3-enes, 7,4'-dihydroxy-2'-methoxy-6- (1'',1''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-A), 4'-hydroxy-2'- methoxy-(2'',2''-dimethylpyrano[5'',6'':8,7]isoflav-3-ene (trivial name, burttinol-B), 7,4'-dihydroxy-2'-methoxy-8-(3'',3''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-C), and a new 2-arylbenzofuran, 6,4'-dihydroxy-2'-methoxy-5- (1'',1''-dimethylallyl)-2-arylbenzofuran (trivial name, burttinol-D) were isolated. In addition, the known compounds, abyssinone V-4'-methyl ether, bidwillol A, calopocarpin, erybraedin A, erythrabyssin II, isobavachalcone, phaseollidin and phaseollin were identified. The structures were determined on the basis of spectroscopic evidence.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Bahrke, Sven
A1  - Einarsson, Jon M.
A1  - Gislason, Johannes
A1  - Haebel, Sophie
A1  - Letzel, Matthias C.
A1  - Peter-Katalinic, Jasna
A1  - Peter, Martin G.
T1  - Sequence analysis of chitooligosaccharides by matrix-assisted laser desorption ionization postsource decay mass spectrometry
N2  - 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.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Houston, Douglas R.
A1  - Shiomi, Kazuro
A1  - Arai, Noriko
A1  - Omura, Satoshi
A1  - Peter, Martin G.
A1  - Turberg, Andreas
A1  - Synstad, Bjoenar
A1  - Eijsink, Vincent G. H.
A1  - Van Aalten, Daan M. F.
T1  - High-resolution structures of a chitinase complexed with natural product cyclopentapeptide inhibitors : mimicry of carbohydrate substrate
N2  - Over the past years, family 18 chitinases have been validated as potential targets for the design of drugs against human pathogens that contain or interact with chitin during their normal life cycles. Thus far, only one potent chitinase inhibitor has been described in detail, the pseudotrisaccharide allosamidin. Recently, however, two potent natural-product cyclopentapeptide chitinase inhibitors, argifin and argadin, were reported. Here, we describe high- resoln. crystal structures that reveal the details of the interactions of these cyclopeptides with a family 18 chitinase. The structures are examples of complexes of a carbohydrate-processing enzyme with high-affinity peptide-based inhibitors and show in detail how the peptide backbone and side chains mimic the interactions of the enzyme with chitooligosaccharides. Together with enzymol. characterization, the structures explain why argadin shows an order of magnitude stronger inhibition than allosamidin, whereas argifin shows weaker inhibition. The peptides bind to the chitinase in remarkably different ways, which may explain the differences in inhibition consts. The two complexes provide a basis for structure-based design of potent chitinase inhibitors, accessible by std. peptide chem.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - van Aalten, Daan M. F.
A1  - Komander, David
A1  - Synstad, Bjoenar
A1  - Gaseidnes, Sigrid
A1  - Peter, Martin G.
A1  - Eijsink, Vincent G. H.
T1  - Structural Insights into the catalytic mechanism of a family 18 exochitinase
N2  - Chitinase B (ChiB) from Serratia marcescens is a family 18 exochitinase whose catalytic domain has a TIM-barrel fold with a tunnel-shaped active site. We have solved structures of three ChiB complexes that reveal details of substrate binding, substrateassisted catalysis, and product displacement. The structure of an inactive ChiB mutant (E144Q) complexed with a pentameric substrate (binding in subsites 22 to 13) shows closure of the ''roof'' of the active site tunnel. It also shows that the sugar in the 21 position is distorted to a boat conformation, thus providing structural evidence in support of a previously proposed catalytic mechanism. The structures of the active enzyme complexed to Allosamidin (an analogue of a proposed reaction intermediate) and of the active enzyme soaked with pentameric substrate show events after cleavage of the glycosidic bond. The latter structure shows reopening of the roof of the active site tunnel and enzyme-assisted product displacement in the 11 and 12 sites, allowing a water molecule to approach the reaction center. Catalysis is accompanied by correlated structural changes in the core of the TIM barrel that involve conserved polar residues whose functions were hitherto unknown. These changes simultaneously contribute to stabilization of the reaction intermediate and alternation of the pKa of the catalytic acid during the catalytic cycle.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Thiele, Gabriela
A1  - Rottmann, Antje
A1  - Germer, Antje
A1  - Kleinpeter, Erich
A1  - Spindler, Klaus-Dieter
A1  - Synstad, Bjoenar
A1  - Eijsink, Vincent G. H.
A1  - Peter, Martin G.
T1  - Synthesis and conformational analysis of pseudosugar analogues of chitotriose
N2  - In this article, the synthesis of analogs of N,N',N''-triacetylchitotriose in which the central sugar residue was replaced by a succinic acid is presented. Mol. modeling calcns. revealed that the pseudotrisaccharides exist in low energy extended conformations which show similar space filling as N,N',N''-triacetylchitotriose. Of the N,N',N''-triacetylchitotriose pseudosugar analogs tested as chitinase inhibitors, none showed any appreciable competition (numerical data not presented). The conformational anal. along with further synthetic efforts will hopefully lead to more efficient pseudosaccharides as chitinase inhibitors.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Neumann, Bernhard
A1  - Horstkemper, Marianne
A1  - Krüger, Wolfgang
A1  - Wilkens, Martin
A1  - Bohlen, Andreas
A1  - Frübing, Peter
A1  - Wegener, Michael
A1  - Scheff, Ullrich
A1  - Neher, Dieter
A1  - Brehmer, Ludwig
A1  - Kleinpeter, Erich
A1  - Wolf, Gunter
A1  - Koetz, Joachim
A1  - Peter, Martin G.
A1  - Senkbeil, Sigrid
A1  - Meyer, Till
T1  - Portal = Im Trend: Physiker und Chemiker erforschen "Soft Matter"
BT  - Die Potsdamer Universitätszeitung
N2  - Aus dem Inhalt:
Im Trend: Physiker und Chemiker erforschen „Soft Matter“
-Brandenburger Netzwerk für Existenzgründer erhält Förderung
-Universität leistet Beitrag zum Romantik-Jahr
-Musiksender MTV und Bryan Adams auf dem Campus
T3  - Portal: Das Potsdamer Universitätsmagazin - 06/2002 
Y1  - 2002
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-501441
SN  - 1618-6893
VL  - 2002
ER  - 
TY  - JOUR
A1  - Germer, Antje
A1  - Peter, Martin G.
A1  - Kleinpeter, Erich
T1  - Solution-state conformational study of the hevamine inhibitor allosamidin and six potential inhibitor analogues by NMR spectroscopy and molecular modeling
N2  - The soln.-state conformations of the hevamine inhibitor allosamidin and six potential inhibitor analogs were studied by various NMR spectroscopic techniques and mol. modeling using force field calcns. Detn. solely of the global energy min. conformation was found to be insufficient for consensus with the NMR results, and agreement between the NMR exptl. data and the theor. calcns. was only reached by assessing the structures as population-weighted av. conformers on the basis of Boltzmann distributions derived from the calcd. relative energies. The conformations of the glycosidic linkages in the compds. were found to be similar when the sugar residues were the same, but differences were markedly evident otherwise and also for the various heterocyclic group linkages. The binding of the compds. to hevamine, which may also complex to chitinases in general, was assessed using HMQC, transfer-NOESY, and both 1-D and 2-D satn. transfer difference NMR expts. Under the conditions employed, only allosamidin was implicated to be bound to hevamine, and then only by HMQC with the dipolar coupling-based expts. failing to substantiate the formation of the complex. However, the results are consistent with the biochem. activities of the compds. whereby only allosamidin has been shown to act as a competitive inhibitor.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Germer, Antje
A1  - Klod, Sabrina
A1  - Peter, Martin G.
A1  - Kleinpeter, Erich
T1  - NMR spectroscopic and theoretical study of the complexation of the inhibitor allosamidin in the binding pocket of the plant chitinase hevamine
N2  - Based on NMR spectroscopic information about the allosamidin-hevamine complex, ab initio MO calcns. of the ring current effect of the arom. moieties of Trp255, Tyr183 and Tyr6 of hevamine were carried out to investigate the role of these amino acid residues in binding interactions with allosamidin in soln. In addn., the intermol. steric compression effect on the 13C chem. shifts of the allosamizoline carbon atoms and the hydrogen bonding to Glu127 was identified. It can be inferred that the binding forces are strongest in the allosamizoline moiety of allosamidin.
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Eijsink, Vincent G. H.
A1  - Synstad, Bjoenar
A1  - Gaseidnes, Sigrid
A1  - Komander, David
A1  - Houston, Douglas R.
A1  - Peter, Martin G.
A1  - van Aalten, Daan M. F.
T1  - Structure and function of chitinolytic enzymes
N2  - The recent work on a variety of family 18 chitonolytic enzymes has yielded important data concerning the structure, substrate-binding, catalysis, inhibitor-binding and even dynamics. These data have been useful in helping to better understand the roles of various types of chitinases in chitin hydrolysis, to rationally engineer the properties of these enzymes, thus making them more suitable as biocatalysts, and to study and understand the effectiveness of natural and designed chitinase inhibitors, which may be of medical interest. On the other hand, the recent work on ChiB shows that catalysis in family 18 chitinases is a highly complicated process, involving larger parts of the enzyme and dynamics. Thus, despite recent discoveries, there is still a lot more to discover about how these enzyme work.
Y1  - 2003
SN  - 82-471-5901-5
ER  - 
TY  - THES
A1  - Bahrke, Sven
A1  - Einarsson, Jon M.
A1  - Gislason, Johannes
A1  - Haebel, Sophie
A1  - Peter-Katalinic, Jasna
A1  - Peter, Martin G.
T1  - Characterization of chitooligosaccharides by mass spectrometry
Y1  - 2003
SN  - 82-47-15901-5
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Irungu, Beatrice
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Two prenylated flavonoids from the stem bark of Erythrina burttii
N2  - From the stem bark of Erythrina burttii, a new isoflavone, 5,2',4'-trihydroxy-7-methoxy-6-(3- methylbut-2-enyl)isoflavone (trivial name, 7-O-methylluteone) and a new flavanone, 5,7-dihydroxy-4'-methoxy- 3'-(3-methylbutadienyl)-5'-(3-methylbut-2-enyl)flavanone (trivial name, burttinonedehydrate) along with three known isoflavonoids (8-prenylluteone, 3-O-methylcalopocarpin and genistein) were isolated. The structures were detd. on the basis of spectroscopic evidence.
Y1  - 2003
ER  - 
TY  - THES
A1  - Derese, Solomon
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - A new isoflavone from stem bark of Millettia dura
Y1  - 2003
SN  - 1011-3924
ER  - 
TY  - JOUR
A1  - Grott, Saskia
A1  - Peter, Martin G.
A1  - Linker, Torsten
A1  - Sefkow, Michael
A1  - Kroll, Jürgen
A1  - Koetz, Joachim
A1  - Laschewsky, André
A1  - Lokatis, Siegfried
A1  - Rheinberg, Falko
A1  - Manig, Yvette
T1  - Portal = Chemie: Werkstoffe, Wirkstoffe, Lebensvorgänge
BT  - Die Potsdamer Universitätszeitung
N2  - Aus dem Inhalt:
- Chemie: Werkstoffe, Wirkstoffe, Lebensvorgänge
- Institut für Kirchenrecht gegründet
- Computerlinguisten erstellen digitales Wörterbuch
- Vom Spaß am Graffiti-Sprayen
T3  - Portal: Das Potsdamer Universitätsmagazin - 01-02/2003 
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439713
SN  - 1618-6893
IS  - 01-02/2003
ER  - 
TY  - JOUR
A1  - Germer, Antje
A1  - Mugge, Clemens
A1  - Peter, Martin G.
A1  - Rottmann, Antje
A1  - Kleinpeter, Erich
T1  - Solution- and bound-state conformational study of N,N',N''-triacetyl chitotriose and other analogous potential inhibitors of hevamine: Application of trNOESY and STD NMR spectroscopy
N2  - The soln.-state conformations of N,N',N''-triacetyl chitotriose (1) and other potential chitinase inhibitors 2-4 were studied using a combination of NMR spectroscopy (NOESY) and mol. mechanics calcns. Detn. solely of the global energy min. conformation was found to be insufficient for an agreement with the NMR results. An appropriate consistency between the NMR exptl. data and theor. calcns. was only reached by assessing the structures as population-weighted av. conformers based on Boltzmann distributions derived from the calcd. relative energies. Analogies, but also particular differences, between the synthetic compds. 2-4 and the naturally-occurring N,N',N''-triacetyl chitotriose were found. Furthermore, the conformation of compds. 1 and 2 when bound to hevamine was also studied using transferred NOESY expts. and the binding process was found to impart a level of conformational restriction on the ligands. The preferred conformation as detd. for 1 in the bound state to hevamine belonged to one of the conformational families found for the compd. when free in soln., although full characterization of the bound-state conformations was impeded due to severe signal overlap. Satn. transfer difference NMR expts. were also employed to analyze the binding epitopes of the bound compds. We thus detd. that it is mainly the acetyl amido groups of the trisaccharide and the heterocyclic moiety which are in close contact with hevamine.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Fotie, J.
A1  - Nkengfack, A. E.
A1  - Peter, Martin G.
A1  - Heydenreich, Matthias
A1  - Fomum, Z. T.
T1  - Chemical constituents of the ethyl acetate extracts of the stem bark and fruits of Dichrostachys cinerea and the roots of Parkia bicolor
N2  - The antibacterial activities of ethyl acetate, methanol and aqueous extracts of the stem bark of Dichrostachys cinerea and the roots of Parkia bicolor have been evaluated. Ethyl acetate extracts have been investigated, studies that led to a series of known compounds, amongst which many are reported here for the very first time from both the species
Y1  - 2004
SN  - 1011-3924
ER  - 
TY  - JOUR
A1  - Vaaje-Kolstad, G.
A1  - Vasella, A.
A1  - Peter, Martin G.
A1  - Netter, C.
A1  - Houston, Douglas R.
A1  - Westereng, B.
A1  - Synstad, Bjoenar
A1  - Eijsink, Vincent G. H.
A1  - van Aalten, Daan M. F.
T1  - Interactions of a family 18 chitinase with the designed inhibitor HM508 and its degradation product, chitobiono- delta-lactone
N2  - 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
Y1  - 2004
SN  - 0021-9258
ER  - 
TY  - JOUR
A1  - Vaaje-Kolstad, G.
A1  - Houston, Douglas R.
A1  - Rao, F. V.
A1  - Peter, Martin G.
A1  - Synstad, Bjoenar
A1  - van Aalten, Daan M. F.
A1  - Eijsink, Vincent G. H.
T1  - Structure of the D142N mutant of the family 18 chitinase ChiB from Serratia marcescens and its complex with allosamidin
N2  - Catalysis by ChiB, a family 18 chitinase from Serratia marcescens, involves a conformational change of Asp142 which is part of a characteristic D140XD142XE144 sequence motif In the free enzyme Asp142 points towards Asp140, whereas it rotates towards the catalytic acid, Glu144, upon ligand binding. Mutation of Asp142 to Asn reduced k(cat) and affinity for allosamidin, a competitive inhibitor. The X-ray structure of the D142N mutant showed that Asn142 points towards Glu144 in the absence of a ligand. The active site also showed other structural adjustments (Tyr10, Ser93) that had previously been observed in the wild-type enzyme upon substrate binding. The X-ray structure of a complex of D142N with allosamidin, a pseudotrisaccharide competitive inhibitor, was essentially identical to that of the wild-type enzyme in complex with the same compound. Thus, the reduced allosamidin affinity in the mutant is not caused by structural changes but solely by the loss of electrostatic interactions with Asp142. The importance of electrostatics was further confirmed by the pH dependence of catalysis and allosamidin inhibition. The pH-dependent apparent affinities for allosamidin were not correlated with k(cat), indicating that it is probably better to view the inhibitor as a mimic of the oxazolinium ion reaction intermediate than as a transition state analogue. (C) 2003 Elsevier B.V. All rights reserved
Y1  - 2004
SN  - 1570-9639
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Induli, M.
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
A1  - Akala, Hoseah M.
A1  - Wangui, Julia
A1  - Liyala, Pamela
A1  - Waters, Norman C.
T1  - Anti-plasmodial flavonoids from the stem bark of Erythrina abyssinica
N2  - The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 7.9 +/- 1.1 and 5.3 +/- 0.7 mug/ml, respectively. From this extract, a new chalcone, 2,3,4,4'-tetrahydroxy-5- prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 4',7-dihydroxy-3'-methoxy-5'- prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti- plasmodial principles. The structures were determined on the basis of spectroscopic evidence. (C) 2004 Elsevier Ltd. All rights reserved
Y1  - 2004
SN  - 0031-9422
ER  - 
TY  - JOUR
A1  - Peikow, Dirk
A1  - Matern, Christa-Maria
A1  - Peter, Martin G.
A1  - Schilde, Uwe
T1  - Crystal structure of (1,4,7,10,13-pentaoxacyclopentadecane-O,O ',O '',O ''')(trifluoromethanesulfonato-O,O ')sodium, Na(C10H20O5)(CF3SO3)
N2  - C11H20F3NaO8S, monoclinic, P121/nil (no. 11), a = 7.947(1) angstrom, b = 12.056(1) angstrom, c = 9.083(1) angstrom, P = 106.01 (1)degrees, V = 836.4 angstrom(3), Z = 2, R-gt(F) = 0.043, wR(ref)(F-2) = 0.120, T = 210 K.
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Alarcon, Julio
A1  - Alderete, Joel B.
A1  - Aguila, Sergio
A1  - Peter, Martin G.
T1  - Regio and stereoselective hydroxylation of alpha-agarofuran by biotransformation of rhizopus nigricans
N2  - A new synthesis of 9 alpha-hydroxy-alpha-agarofuran (6 alpha) is described, using a microbiological hydroxylation alpha-agarofuran (5) as the key reaction. The stereochemistry of the biohydroxylation was determined on the basis of a NOESY-experiment and GIAO calculations at the B3LYP/cc-pVDZ level. A strong gamma-effect was observed at C15 of the agarofuran ring which was correctly predicted by the GIAO-B3LYP calculations
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Wanjohi, John M.
A1  - Yenesew, Abiy
A1  - Midiwo, Jacob O.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
A1  - Dreyer, M.
A1  - Reichert, M.
A1  - Bringmann, Gerhard
T1  - Three dimeric anthracene derivatives from the fruits of Bulbine abyssinica
N2  - From the fruits of Bulbine abyssinica three new dimeric anthracene derivatives, (P)-8,9,1',8'- tetrahydroxy-3,3'-dimethyl[10,7'-bianthracene]-1,4,9',10'- tetraone (trivial name abyquinone A), (10R)-1,4,8,1',8-pentahydroxy-3,3'-dimethyl-[10,7'-bianthracene]9,9',10' (10H)-trione (trivial name abyquinone B), and (10R)-3,4'-dihydro-1,4,8,3',8',9'-hexahydroxy-3,3'- dimethyl-[10,7'-biant hracene]9,1'(10H,2'H)-dione (trivial name abyquinone Q were isolated. Despite their structural differences, these three compounds are connected to each other by the apparently biomimetic conversion of abyquinone C (a preanthraquinonylanthrone with two stereogenic centers) into B (an anthraquinonylanthrone with one stereogenic center) and finally into A (an axially chiral bianthraquinone) under mild conditions, involving a highly efficient center-to-axis chirality transfer. In addition, the known anthraquinones islandicin and chrysophanol were identified. The structures were determined on the basis of spectroscopical evidences, chemical transformations, and quantum chemical CD calculations. (C) 2005 Elsevier Ltd. All rights reserved
Y1  - 2005
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Mushibe, E. K.
A1  - Induli, M.
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Kabaru, Jacques M.
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Peter, Martin G.
T1  - 7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoloata
N2  - From the acetone extract of the roots of Derris trifoliata an isollavonoid derivative, named 7a-O- methyldeguelol, a modified rotenoid with an open ring-C, representing a new sub-class of isollavonoids (the sub-class is here named as rotenoloid), was isolated and characterised. In addition, the known rotenoids, rotenone, deguelin and alpha-toxicarol, were identified. The structures were determined on the basis of spectroscopic evidence. Rotenone and deguelin were identified as the larvicidal principles of the acetone extract of the roots of Derris trifoliata. (c) 2005 Elsevier Ltd. All rights reserved
Y1  - 2005
SN  - 0031-9422
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Bii, Christine C.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Antimicrobial flavonoids from the stem bark of Erythrina burttii
N2  - The chloroform extract of the stem bark of Erythrina burttii showed antifungal and antibacterial activities using the disk diffusion method. Flavonoids were identified as the active principles. Activities were observed against fungi and Gram(+) bacteria, but the Gram(-) bacteria Escherichia coli was resistant. (c) 2005 Elsevier B.V. All rights reserved
Y1  - 2005
SN  - 0367-326X
ER  -