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 - 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 - 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 - 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 - Loth, Fritz A1 - Peter, Martin G. T1 - Analysis of deacetylation deree in chitosans from various sources Y1 - 1998 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 - 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 - 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 - 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 - GEN A1 - Peter, Martin G. A1 - Yenesew, Abiy A1 - Twinomuhwezi, Hannington A1 - Kabaru, Jacques M. A1 - Akala, Hoseah M. A1 - Kiremire, Bernard T. A1 - Heydenreich, Matthias A1 - Eyase, Fredrick A1 - Waters, Norman C. A1 - Walsh, Douglas S. T1 - Antiplasmodial and larvicidal flavonoids from Derris trifoliata N2 - From the dichloromethane-methanol (1:1) extract of the seed pods of Derris trifoliata, a new flavanone derivative (S)-lupinifolin 4´-methyl ether was isolated. In addition, the known flavonoids lupinifolin and rotenone were identified. The structures were determined on the basis of spectroscopic evidence. Lupinfolin showed moderate in vitro antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquineresistant) strains of Plasmodium falciparum. The different parts of this plant showed larvicidal activities against Aedes aegypti and rotenoids were identified as the active principles. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 121 KW - Derris trifoliata KW - Leguminosae KW - Flavanone KW - (S)-Lupinifolin 4´-methyl ether KW - Lupinifolin Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44614 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 - GEN A1 - Peter, Martin G. A1 - Muiva, Lois M. A1 - Yenesew, Abiy A1 - Derese, Solomon A1 - Heydenreich, Matthias A1 - Akala, Hoseah M. A1 - Eyase, Fredrick A1 - Waters, Norman C. A1 - Mutai, Charles A1 - Keriko, Joseph M. A1 - Walsh, Douglas S. T1 - Antiplasmodial β-hydroxydihydrochalcone from seedpods of Tephrosia elata N2 - From the seedpods of Tephrosia elata, a new β-hydroxydihydrochalcone named (S)-elatadihydrochalcone was isolated. In addition, the known flavonoids obovatachalcone, obovatin, obovatin methyl ether and deguelin were identified. The structures were determined on the basis of spectroscopic evidence. The crude extract and the flavonoids obtained from the seedpods of this plant showed antiplasmodial activities. The literature NMR data on β-hydroxydihydrochalcones is reviewed and the identity of some of the compounds assigned β-hydroxydihydrochalcone skeleton is questioned. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 118 KW - Tephrosia elata KW - Leguminosae KW - Seedpods KW - (S)-Elatadihydrochalcone KW - β-Hydroxydihydrochalcone Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44437 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 - Peter, Martin G. T1 - Applications and environmental aspects of chitin and chitosan Y1 - 1995 SN - 0022-233X 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 - 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 - 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 - 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 - 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 - 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 -