TY  - GEN
A1  - Moerschbacher, Bruno
A1  - Jaworska, Małgorzata
A1  - Peter, Martin G.
T1  - Obituary of George A.F. Roberts (1939-2018)
T2  - Reactive & functional polymers
Y1  - 2020
U6  - https://doi.org/10.1016/j.reactfunctpolym.2020.104711
SN  - 1381-5148
SN  - 1873-166X
VL  - 156
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Pereira, Fernanda S.
A1  - Nascimento, Heliara D. L.
A1  - Magalhaes, Alvicler
A1  - Peter, Martin G.
A1  - Bataglion, Giovana Anceski
A1  - Eberlin, Marcos N.
A1  - Gonzalez, Eduardo R. P.
T1  - ESI(+)-MS and GC-MS study of the hydrolysis of N-azobenzyl derivatives of chitosan
JF  - Molecules
N2  - New N-p-chloro-, N-p-bromo-, and N-p-nitrophenylazobenzylchitosan derivatives, as well as the corresponding azophenyl and azophenyl-p-sulfonic acids, were synthesized by coupling N-benzylvchitosan with aryl diazonium salts. The synthesized molecules were analyzed by UV-Vis, FT-IR, H-1-NMR and N-15-NMR spectroscopy. The capacity of copper chelation by these materials was studied by AAS. Chitosan and the derivatives were subjected to hydrolysis and the products were analyzed by ESI(+)-MS and GC-MS, confirming the formation of N-benzyl chitosan. Furthermore, the MS results indicate that a nucleophilic aromatic substitution (SnAr) reaction occurs under hydrolysis conditions, yielding chloroaniline from N-p-bromo-, and N-p-nitrophenylazo-benzylchitosan as well as bromoaniline from N-p-chloro-, and N-p-nitrophenylazobenzyl-chitosan.
KW  - chitosan
KW  - N-azobenzylchitosan
KW  - ESI-MS
KW  - GC-MS
KW  - SnAr reaction
Y1  - 2014
U6  - https://doi.org/10.3390/molecules191117604
SN  - 1420-3049
VL  - 19
IS  - 11
SP  - 17604
EP  - 17618
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Mengibar, M.
A1  - Ganan, M.
A1  - Miralles, B.
A1  - Carrascosa, A. V.
A1  - Martinez-Rodriguez, Adolfo J.
A1  - Peter, Martin G.
A1  - Heras, A.
T1  - Antibacterial activity of products of depolymerization of chitosans with lysozyme and chitosanase against Campylobacter jejuni
JF  - Carbohydrate polymers : an international journal devoted to scientific and technological aspects of industrially important polysaccharides
N2  - Chitosan has several biological properties useful for the food industry, but the most attractive is its potential use as a food preservative of natural origin due to its antimicrobial activity against a wide range of food-borne microorganisms. Among food-borne pathogens, Campylobacter jejuni and related species are recognised as the most common causes of bacterial food-borne diarrhoeal disease throughout the world. Recently, it has been demonstrated that campylobacters are highly sensitive to chitosan. Even though chitosan is known to have important functional activities, poor solubility makes them difficult to use in food and biomedical applications. Unlike chitosan, the low viscosity and good solubility of chitosan oligosaccharides (COS) make them especially attractive in an important number of useful applications. In the present work, the effect of different COS on C. jejuni was investigated. Variables such as the physicochemical characteristics of chitosan and the enzyme used in COS preparation were studied. The COS had been fractioned using ultrafiltration membranes and each fraction was characterized regarding its FA and molecular weight distribution. It has been demonstrated that the biological properties of COS on Campylobacter depend on the composition of the fraction analysed. COS prepared by enzymatic hydrolysis with chitosanase were more active against Campylobacter that lysozyme-derived COS, and this behaviour seems to be related with the acetylation of the chains. On the other hand. the 10-30 kDa fraction was the most active COS fraction, independently of the enzyme used for the hydrolysis. These results have shown that COS could be useful as antimicrobial in the control of C. jejuni.
KW  - Campylobacter jejuni
KW  - Chitooligosaccharides
KW  - Chitosanase
KW  - Lysozyme
KW  - Depolymerization
Y1  - 2011
U6  - https://doi.org/10.1016/j.carbpol.2010.04.042
SN  - 0144-8617
VL  - 84
IS  - 2
SP  - 844
EP  - 848
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Vijayakrishnan, Balakumar
A1  - Issaree, Arisara
A1  - Corilo, Yuri E.
A1  - Ferreira, Christina Ramires
A1  - Eberlin, Marcos N.
A1  - Peter, Martin G.
T1  - MSn of the six isomers of (GlcN)(2)(GlcNAc)(2) aminoglucan tetrasaccharides (diacetylchitotetraoses) rules of fragmentation for the sodiated molecules and application to sequence analysis of hetero-chitooligosaccharides
JF  - Carbohydrate polymers : an international journal devoted to scientific and technological aspects of industrially important polysaccharides
N2  - The six possible isomers of di-N-acetylchitotetraoses [AADD, ADDA, ADAD, DADA, DAAD, and DDAA, where D stands for 2-amino-2-deoxy-3-D-glucose (GlcN) and A for 2-acetamido-2-deoxy-beta-D-glucose (GlcNAc)] were analyzed by ESI(+)-MSn. Collision induced dissociation via MSn experiments were performed for the sodiated molecules of m/z 769 [M+Na](+) for each isomer, and fragments were generated mainly by glycosidic bond and cross-ring cleavages. Rules of fragmentation were then established. A reducing end D residue yields the (O.2)A(4) cross-ring [M-59+Na](+) fragment of m/z 710 as the most abundant, whereas isomers containing a reducing end A prefer to lose water to form the [M-18+Na](+) ion of m/z 751, as well as abundant (O.2)A(4) cross-ring [M-101+Na](+) fragments of m/z 668 and B-3 [M-221+Na](+) ions of m/z 548. MS3 of C- and Y-type ions shows analogous fragmentation behaviour that allows identification of the reducing end next-neighbour residue. Due to gas-phase anchimeric assistance, B-type cleavage between the glycosidic oxygen and the anomeric carbon atom is favoured when the glycon is an A residue. Relative ion abundances are generally in the order B >> C > Y, but may vary depending on the next neighbour towards the non-reducing end. These fragmentation rules were used for partial sequence analysis of hetero-chitooligosaccharides of the composition D(2)A(3), D(3)A(3), D(2)A(4), D(4)A(3), and D(3)A(4).
KW  - Chitosan
KW  - Fragmentation
KW  - Oligosaccharides
KW  - Sequence analysis
KW  - Tandem mass spectrometry
Y1  - 2011
U6  - https://doi.org/10.1016/j.carbpol.2010.04.041
SN  - 0144-8617
VL  - 84
IS  - 2
SP  - 713
EP  - 726
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Juma, Wanyama P.
A1  - Akala, Hoseah M.
A1  - Eyase, Fredrick L.
A1  - Muiva, Lois M.
A1  - Heydenreich, Matthias
A1  - Okalebo, Faith A.
A1  - Gitu, Peter M.
A1  - Peter, Martin G.
A1  - Walsh, Douglas S.
A1  - Imbuga, Mabel
A1  - Yenesew, Abiy
T1  - Terpurinflavone an antiplasmodial flavone from the stem of Tephrosia Purpurea
JF  - Phytochemistry letters
N2  - The stem extract of Tephrosia purpurea showed antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum with IC(50) values of 10.47 +/- 2.22 mu g/ml and 12.06 +/- 2.54 mu g/ml, respectively. A new prenylated flavone, named terpurinflavone, along with the known compounds lanceolatin A, (-)-semiglabrin and lanceolatin B have been isolated from this extract. The new compound, terpurinflavone, showed the highest antiplasmodial activity with IC(50) values of 3.12 +/- 0.28 mu M (D6) and 6.26 +/- 2.66 mu M (W2). The structures were determined on the basis of spectroscopic evidence.
KW  - Tephrosia purpurea
KW  - Leguminosae
KW  - Stem
KW  - Flavone
KW  - Terpurinflavone
KW  - Antiplasmodial
Y1  - 2011
U6  - https://doi.org/10.1016/j.phytol.2011.02.010
SN  - 1874-3900
VL  - 4
IS  - 2
SP  - 176
EP  - 178
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Paz, Cristian
A1  - Peter, Martin G.
A1  - Schmidt, Bernd
A1  - Becerra, Jose
A1  - Gutierrez, Margarita
A1  - Astudillo, Luis
A1  - Silva, Mario
T1  - Synthesis and AChE inhibiting activity of 2, 4 substituted 6-Phenyl Pyrimidines
JF  - Journal of the Chilean Chemical Society
N2  - Novel substituted pyrimidines were synthesized from methyl 2,4-dioxo-4-phenyl-butanoate (I-A) and urea, followed by Mitsunobu coupling of I-A with benzyl or allyl alcohol to give the corresponding 2-hydroxypyrimidine ethers in good yields. Saponification of I-A, followed by reaction with benzyl or allyl amines in the presence of TBTU yielded 2-hydroxy-6-phenyl-pyrimidine 4-carboxamides. AChE and BuChE assays revealed 2-hydroxy-6-phenyl-pyrimidine-4-carboxyallyamide as the most active compound, IC50=90 mu M, with no inhibition of BuChE.
KW  - Pyrimidines
KW  - inhibition AChE
KW  - mitsunobu
KW  - TBTU
Y1  - 2012
SN  - 0717-9324
VL  - 57
IS  - 3
SP  - 1292
EP  - 1294
PB  - Sociedad Chilena De Quimica
CY  - Concepcion
ER  - 
TY  - JOUR
A1  - Fasciotti, Maira
A1  - Sanvido, Gustavo B.
A1  - Santos, Vanessa G.
A1  - Lalli, Priscila M.
A1  - McCullagh, Michael
A1  - de Sa, Gilberto F.
A1  - Daroda, Romeu J.
A1  - Peter, Martin G.
A1  - Eberlin, Marcos N.
T1  - Separation of isomeric disaccharides by traveling wave ion mobility mass spectrometry using CO2 as drift gas
JF  - Journal of mass spectrometr
N2  - The use of CO2 as a massive and polarizable drift gas is shown to greatly improve peak-to-peak resolution (Rp-p), as compared with N2, for the separation of disaccharides in a Synapt G2 traveling wave ion mobility cell. Near or baseline Rp-p was achieved for three pairs of sodiated molecules of disaccharide isomers, that is, cellobiose and sucrose (Rp-p?=?0.76), maltose and sucrose (Rp-p?=?1.04), and maltose and lactose (Rp-p?=?0.74). Ion mobility mass spectrometry using CO2 as the drift gas offers therefore an attractive alternative for fast and efficient separation of isomeric disaccharides.
KW  - isomer resolution
KW  - oligosaccharides
KW  - traveling wave ion mobility mass spectrometry
KW  - polarizable drift gases
Y1  - 2012
U6  - https://doi.org/10.1002/jms.3089
SN  - 1076-5174
VL  - 47
IS  - 12
SP  - 1643
EP  - 1647
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Andayi, Andrew W.
A1  - Yenesew, Abiy
A1  - Derese, Solomon
A1  - Midiwo, Jacob O.
A1  - Gitu, Peter M.
A1  - Jondiko, Ogoche J. I.
A1  - Akala, Hoseah M.
A1  - Liyala, Pamela
A1  - Wangui, Julia
A1  - Waters, Norman C.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - Antiplasmodial flavonoids from Erythrina sacleuxii
N2  - The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4 -methoxy-3'- prenylisoflavone (trivial name 5-deoxy-3' - prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sucleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence
Y1  - 2006
UR  - http://www.thieme-connect.com/ejournals/toc/plantamedica
U6  - https://doi.org/10.1055/s-2005-873200
SN  - 0032-0943
ER  - 
TY  - JOUR
A1  - Haebel, Sophie
A1  - Bahrke, Sven
A1  - Peter, Martin G.
T1  - Quantitative sequencing of complex mixtures of heterochitooligosaccharides by vMALDI-linear ion trap mass spectrometry
N2  - Heterochitooligosaccharides possess interesting biol. properties. Isobaric mixts. of such linear heterochitooligosaccharides can be obtained by chem. or enzymic degrdn. of chitosan. However, the sepn. of such mixts. is a challenging anal. problem which is so far unresolved. It is shown that these isobaric mixts. can be sequenced and quantified simultaneously using std. derivatization and multistage tandem mass spectrometric techniques. A linear ion trap mass spectrometer equipped with a vacuum matrix-assisted laser desorption ionization (vMALDI) source is used to perform MS2 as well as MS3 expts. [on SciFinder (R)].
Y1  - 2007
UR  - http://pubs.acs.org/loi/ancham
U6  - https://doi.org/10.1021/Ac062254u
SN  - 0003-2700
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  - Tsukamoto, Junko
A1  - Haebel, Sophie
A1  - Valenca, Gustavo P.
A1  - Peter, Martin G.
A1  - FRanco, Telma T.
T1  - Enzymatic direct synthesis of acrylic acid esters of mono- and disaccharides
N2  - Background: There is an increased need to replace materials derived from fossil sources by renewables. Sugar- cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the prepn. of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous prepn. of protected sugar derivs., such as glycosides, or activated acrylates, such as vinyl acrylate. Results: Lipase catalyzed esterification of three mono- and two disaccharides with acrylic acid, in the presence or absence of mol. sieves was investigated. The reactions were monitored by high-performance liq. chromatog. (HPLC) and the products were analyzed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The main products are mono- and diacrylates, while higher esters are formed as minor products. The highest conversion to sugar acrylates was obsd. for the D-glucose and D- fructose, followed by D-xylose and D-maltose. Mol. sieves had no pronounced effect on the conversion. Conclusions: A feasible method is described to produce and to characterize sugar acrylates, including those contg. more than two acrylate groups. The process for prodn. of these higher esters could potentially be optimized further to produce mols. for crosslinking in acrylate polymn. and other applications. The direct enzymic esterification of free carbohydrates with acrylic acid is unprecedented. [on SciFinder (R)].
Y1  - 2008
UR  - http://www3.interscience.wiley.com/journal/117946200/grouphome/home.html
SN  - 0268-2575
ER  - 
TY  - JOUR
A1  - López-Franco, Yolanda L.
A1  - Calderón de la Barca, Ana M.
A1  - Valdez, Miguel A.
A1  - Peter, Martin G.
A1  - Rinaudo, Marguerite
A1  - Chambat, Gérard
A1  - Goycoolea, Francisco M.
T1  - Structural characterization of mesquite (Prosopis velutina) gum and its fractions
N2  - Structural and physicochem. characteristics of mesquite gum (from Prosopis velutina) were investigated using FT- IR spectroscopic, mass spectrometric and chromatog. methods. Four fractions (F-I, F-IIa, F-IIb and F-III) were isolated by hydrophobic interaction chromatog. The samples were characterized and analyzed for their monosaccharide and oligomers compn. by high performance anion-exchange chromatog. with pulsed amperometric detection (HPAEC-PAD). L-Arabinose (L-Ara) and D-galactose (D-Gal) were found as the main carbohydrate constituent residues in the polysaccharides from mesquite gum and their ratio (L-Ara/D-Gal) varied within the range 2.54 to 3.06 among the various fractions. Small amts. of D- glucose (D-Glc), D-mannose (D-Man) and D-xylose (D-Xyl) were also detected, particularly in Fractions IIa, IIb and III. IR spectroscopy identified polysaccharides and protein in all the samples. Data from mass spectrometry (MALDI-TOF MS) was consistent with the idea that the structure corresponding to the periphereal chains of Fraction I is predominantly a chain of pentoses attached to uronic acid. [on SciFinder (R)].
Y1  - 2008
UR  - http://www3.interscience.wiley.com/journal/77002860/home?CRETRY=1&SRETRY=0
U6  - https://doi.org/10.1002/mabi.200700285
SN  - 1616-5187
ER  - 
TY  - JOUR
A1  - Yenesew, Abiy
A1  - Twinomuhwezi, Hannington
A1  - Kiremire, Bernard T.
A1  - Mbugua, Martin N.
A1  - Gitu, Peter M.
A1  - Heydenreich, Matthias
A1  - Peter, Martin G.
T1  - 8-Methoxyneorautenol and radical scavenging flavonoids from Erythrina abyssinica
N2  - 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)]
Y1  - 2009
UR  - http://www.ajol.info/journal_index.php?jid=120&ab=bcse
SN  - 1011-3924
ER  - 
TY  - JOUR
A1  - Fettke, Anja
A1  - Peikow, Dirk
A1  - Peter, Martin G.
A1  - Kleinpeter, Erich
T1  - Synthesis and conformational analysis of glycomimetic analogs of thiochitobiose
N2  - The synthesis of six analogs of N,N;-diacetylchitobiose is reported, including a novel transglycosylation reaction for the preparation of S-aryl thioglycosides. The conformations of the compounds were studied by a combination of NMR spectroscopy and molecular modeling, using force field calculations. In the case of the S-aryl thioglycosides with exclusively S-glycosidic linkages, dihedral angles of the disaccharidic S-glycosidic bonds, ;; and ;; and of the S-arylglycoside bonds, ; and ;, were found to be similar, whereas they were different in mixed glycosides and in a thiazoline derivative. An adequate correlation between the calculated H,H-distances of the local minima and the measured NOE contacts was achieved by applying population-weighted averages over participating conformers based on weighted relative energies.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00404020
U6  - https://doi.org/10.1016/j.tet.2009.03.067
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Menezes, Bruno M.
A1  - Grigolon, Lisanne
A1  - Todorovic, Zoran
A1  - Peter, Martin G.
A1  - Franco, Telma T.
T1  - On the depolymerization of chitosan by papain : a re-assessment
Y1  - 2009
ER  - 
TY  - JOUR
A1  - Oliveira, Enio N.
A1  - el Gueddari, Nour E.
A1  - Moerschbacher, Bruno M.
A1  - Peter, Martin G.
A1  - Franco, Telma T.
T1  - Growth of phytopathogenic fungi in the presence of partially acetylated chitooligosaccharides
N2  - Four phytopathogenic fungi were cultivated up to six days in media contg. chitooligosaccharide mixts. differing in av. DP and F A. The three different mixts. were named Q3 (which contained oligosaccharides of DP2-DP10, with DP2-DP7 as main components), Q2 (which contained oligosaccharides of DP2-DP12, with DP2-DP10 as main components) and Q1 (which derived from Q2 and contained oligomers of DP5-DP8 with hexamer and a heptamer as the main components). The novel aspect of this work is the description of the effect of mixts. of oligosaccharides with different and known compn. on fungal growth rates. The growth rate of Alternaria alternata and Rhizopus stolonifer was initially inhibited by Q3 and Q2 at higher concns. Q1 had a growth stimulating effect on these two fungi. Growth of Botrytis cinerea was inhibited by Q3 and Q2, while Q1 had no effect on the growth of this fungus. Growth of Penicillium expansum was only slightly inhibited by higher concns. of sample Q3, while Q2 and Q1 had no effect. The inhibition of growth rates or their resistance toward chitooligosaccharides correlated with the absence or presence of chitinolytic enzymes in the culture media, resp. [on SciFinder (R)]
Y1  - 2008
UR  - http://www.springerlink.com/content/102966
SN  - 0301-486X
ER  - 
TY  - JOUR
A1  - Bringmann, Gerhard
A1  - Mutanyatta-Comar, Joan
A1  - Maksimenka, Katja
A1  - Wanjohi, John M.
A1  - Heydenreich, Matthias
A1  - Brun, Reto
A1  - Müller, Werner E. G.
A1  - Peter, Martin G.
A1  - Midiwo, Jacob O.
A1  - Yenesew, Abiy
T1  - Joziknipholones A and B : the first dimeric phenylanthraquinones, from the roots of Bulbine frutescens
N2  - From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P- configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells.
Y1  - 2008
UR  - http://www3.interscience.wiley.com/journal/26293/home?CRETRY=1&SRETRY=0
SN  - 0947-6539
ER  - 
TY  - JOUR
A1  - Rukunga, G. M.
A1  - Muregi, F. W.
A1  - Omar, S. A.
A1  - Gathirwa, J. W.
A1  - Muthaura, C. N.
A1  - Peter, Martin G.
T1  - Anti-plasmodial activity of the extracts and two sesquiterpenes from Cyperus articulatus
N2  - Two sesquiterpenes, corymbolone and mustakone, isolated from the chloroform extract of the rhizomes of Cyperus articulatus, exhibited significant anti-plasmodial properties. Mustakone was approximately ten times more active than corymbolone against the sensitive strains of the Plasmodium falciparum.
Y1  - 2008
SN  - 0367-326X
ER  - 
TY  - JOUR
A1  - Issaree, Arisara
A1  - Vijayakrishnan, Balakumar
A1  - Abdelnur, Patricia V.
A1  - Corilo, Yuri E.
A1  - Riccio, Maria F.
A1  - Sanvido, Gustavo B.
A1  - Eberlin, Marcos N.
A1  - Peter, Martin G.
T1  - Mass spectrometry of aminoglucan oligosaccharides using electrospray ionization MS/MS and MS/MS/MS
Y1  - 2009
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  - 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  - Andersen, S. O.
T1  - The molecular architecture of the insect exoskeleton
Y1  - 1994
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  - Schumacher-Wandersleb, Michael H. M. G.
A1  - Peter, Martin G.
T1  - Synthesis of chitobiosyl pyrrolidines
Y1  - 1995
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  - Peter, Martin G.
T1  - Chitin in den Startlöchern
Y1  - 1995
SN  - 0009-2959
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  - Chemie i Biochemia Zewnetrznego Szkieletu Owadow : (Chemistry and biochemistry of the insect exoskeleton)
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Peter, Martin G.
T1  - The Bio-organic chemistry of melanogenesis
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  - Applications and environmental aspects of chitin and chitosan
Y1  - 1995
SN  - 0022-233X
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  - Ley, J. P.
A1  - Peter, Martin G.
T1  - Synthesis of L-histidine and (-)-spinacine chitooligosyl amides
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  - Andersen, S. O.
A1  - Peter, Martin G.
A1  - Roepstorff, Peter
T1  - Cuticular sclerotization in insects
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  - 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  - Peter, Martin G.
A1  - Miessner, Merle
T1  - Primärstoffwechsel, Shikimat- und Phenylpropan-Gruppe, Vitamine, Coenzyme, Pflanzeninhaltsstoffe
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schanzenbach, Dirk
A1  - Peter, Martin G.
T1  - Chromatography of chito-oligosaccarides
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  - 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  - NMR spectroscopy of chito-oligosaccharides
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  - 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  - 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  - 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  - 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  - Köhler, L. A.
A1  - Peter, Martin G.
T1  - Characterization of chitosan
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  - 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  - 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  - 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  - 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  - 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  - Kamlage, Stefan
A1  - Sefkow, Michael
A1  - Peter, Martin G.
T1  - Cross coupling of benzylic bromides and vinyl stannanes
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  - Struszczyk, Marcin Henryk
A1  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Method of microcrystalline chitosan-protein films preparation
Y1  - 1999
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  - 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  - 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  - 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  - Loth, Fritz
A1  - Peter, Martin G.
T1  - Properties of microcrystalline chitosan gel-like dispersion and formed films
Y1  - 2000
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  - 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  - 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  - 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  - 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  - 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  - Peter, Martin G.
T1  - Structures of Chitinases and the Design of Inhibitors
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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - 
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  - Rusu, Viorel Marin
A1  - Ng, C. H.
A1  - Wilke, Max
A1  - Tiersch, Brigitte
A1  - Fratzl, Peter
A1  - Peter, Martin G.
T1  - Size-controlled hydroxyapatite nanoparticles as self-organized organic-in organic composite materials
N2  - 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
Y1  - 2005
SN  - 0142-9612
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  - 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  -