| | 84 | Author
| Frauke Neuser, Holger Zorn, RalfG. Berger | Requires cookie* | | | Title
| by Zygosaccharomyces bisporus  | | | | Abstract
| Fax: 0 0 4 9 -5 1 1 -7 6 2 4 5 4 7 . E-mail: rg.berger@m box.lci.uni-hannover.de The wild-type yeast strain Zygosaccharomyces bisporus CBS 702 produced a-hydroxy-ketones (acyloins) from amino acid precursors after transamination to the corresponding 2-oxo acids. The key enzyme of the subsequent decarboxylation and C -C bond forming reaction, pyruvate decarboxylase (P D C), was examined for its substrate-and stereo-specific-ity. A wide variety of saturated and unsaturated aliphatic and aromatic aldehydes was suc cessfully converted to acyloins. 19 of the biotransformation products identified had not been reported as natural substances before. Product yields were strongly affected by substrate structure. | | | |
Reference
| Z. Naturforsch. 55c, 560—5 (2000); received February 22/M arch 10 2000 | | | |
Published
| 2000 | | | |
Keywords
| Zygosaccharomyces bisporus, Acyloin Form ation, Pyruvate Decarboxylase | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0560.pdf | | | | Identifier
| ZNC-2000-55c-0560 | | | | Volume
| 55 | |
| 86 | Author
| Andre Buche, Rafael Picorel | Requires cookie* | | | Title
| Ectothiorhodospira sp | | | | Abstract
| Alkaline treatm ent of the Ectothiorhodospira sp. light harvesting system II induces mono-merisation of the bacteriochlorophylls and a bleaching of the carotenoid absorption bands in the visible region. Concomitantly, the maximum of absorption observed around 373 nm shifts towards 354 nm. This shift does not result from the Soret band but from a change of the absorption properties of the carotenoids. Furtherm ore, these pigments are not modified chemically but the spectral conversion results from environmental changes. It is assumed that the dissociation of the bacteriochlorophylls in alkaline medium is accompanied by a struc tural reorganisation of the complex which reinforces the interactions between the polypep tides and the carotenoids. | | | |
Reference
| Z. Naturforsch. 55c, 576 (2000); : 3 4 -9 7 6 -5 7 5 6 2 0. received February 25/April 4 2000 | | | |
Published
| 2000 | | | |
Keywords
| Carotenoid, Soret, Shift, Spirilloxanthin | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0576.pdf | | | | Identifier
| ZNC-2000-55c-0576 | | | | Volume
| 55 | |
| 89 | Author
| Jorge Saad-Nehme3b, JersonL. Silva3, JoseRoberto Meyer-Fernandes3 | Requires cookie* | | | Title
| Carbohydrates Protect Mitochondrial F0F j-ATPase Complex against Thermal Inactivation | | | | Abstract
| Federal do Rio de Janeiro, llha do Fundäo, 2 1 9 4 1 -5 9 0 . Rio de Janeiro, RJ, Brazil. Fax: (+ 55) (+21) 2 7 0 -8 6 4 7 . E-mail: meyer@bioqmed.ufrj.br Organisms and cellular systems are required to adapt to stress conditions like high tem per ature, often responding by accumulating organic solutes, such as sugars. This accumulation is associated with the effectiveness of these osmolytes in minimizing protein denaturation and membrane damage under stress conditions. In this work, we have studied the effect of sugars on the protection against thermal inactivation of mitochondrial FoFj-ATPase complex, in preparations of submitochondrial particles containing or depleted of inhibitor protein. We observed that after 15 min of pre-incubation at 70 °C of latent MgATP-submitochondrial particles (with inhibitor protein) in the presence of 1.5 m of sucrose or trehalose, or 3.0 m of glucose or fructose, about 80% of enzyme activity remained active. In the same conditions, but in the absence of sugars, the activity of the particles was completely abolished. Submi-tochondrial particles depleted of the inhibitor protein (A S-particles) were almost completely inactivated after 3 min of pre-incubation at 70 °C in the absence of sugars and more than 60% of the enzyme activity remained active when these particles were pre-incubated in the presence of sugars. In such condition, the enzyme acquires a more com pact and heat-stable conformation. Sugars, as well as the inhibitor protein, inhibit reversibly F 0F r ATPase com plex activity and protect this enzyme against inactivation by high temperature. Interestingly, the protection, promoted by sugars, of particles containing inhibitor protein is higher than of particles depleted of inhibitor protein, suggesting a synergism between sugar and inhibi tor protein. | | | |
Reference
| Z. Naturforsch. 55c, 594—5 (2000); received February 10/March 31 2000 | | | |
Published
| 2000 | | | |
Keywords
| Carbohydrates, Thermal Stabilization, Mitochondrial F 0F r ATPase | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0594.pdf | | | | Identifier
| ZNC-2000-55c-0594 | | | | Volume
| 55 | |
| 90 | Author
| PaavoH. Hynninen3, Riikka Räisänen3, Pia Elovaarab, Eila Nokelainenb | Requires cookie* | | | Title
| Preparative Isolation of Anthraquinones from the Fungus Dermocybe sanguined Using Enzymatic Hydrolysis by the Endogenous ß-Glucosidase | | | | Abstract
| A new and simple enzymatic method was developed for preparative isolation of anthraqui none pigments from Dermocybe sanguined. The endogenous ß-glucosidase of the fungus was used to catalyze the hydrolysis of the O-glycosyl linkage in emodin-and dermocybin-1-ß-D-glucopyranosides. The developed enzymatic method was found to be effective for the pig ment isolation, as the hydrolysis occurred virtually completely, thus leading to a high pigment yield. Two fractions were obtained by the method: Fraction 1 (94% of the total pigment amount), containing almost exclusively the main pigments emodin and dermocybin, and Frac tion 2 (6 %), containing the anthraquinone carboxylic acids. A 10.5 kg amount of fresh fungi yielded 56 g of Fraction 1 and 3.3 g of Fraction 2 anthraquinones. The anthraquinones in each fraction were separated by thin-layer chromatography using tolu en e-eth yl acetate-eth anol-form ic acid (10:8:1:2, v/v/v/v) as eluent. The components on the chromatograms were detected and characterized by measurements on a densitom eter-spectrophotom eter. Combined gas chromatography-mass spectrom etry was applied to determine the anthraqui none derivatives of Fraction 1 after methylation and acetylation. | | | |
Reference
| Z. Naturforsch. 55c, 600 (2000); received March 22/April 25 2000 | | | |
Published
| 2000 | | | |
Keywords
| ß-Glucosidase, Enzymatic Hydrolysis, Natural Anthraquinone | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0600.pdf | | | | Identifier
| ZNC-2000-55c-0600 | | | | Volume
| 55 | |
| 93 | Author
| Lahoucine Achnineb, Julio Alarcón0, José Becerrad, Blas Lotina-Hennsenb | Requires cookie* | | | Title
| P | | | | Abstract
| h o to s y n th e tic In h ib ito ry A c tiv ity o f D ih y d ro -ß -a g a ro fu ra n s S e s q u ite rp e n e s fro m M a y te n u s d is tic h a a n d M a y te n u s b o a r i a (C e la s tra c e a e) Carlos Céspedes3' Maytenus Species, ß-Agarofuran, Hill Reaction Inhibitor The effects of 9ß-benzoyloxy-la, 2a, 6ß, 8a, 15-pentaacetoxy-dihydro-ß-agarofuran and 9ß-furoyloxy-la, 6ß, 8a-triacetoxy-dihydro-ß-agarofuran, major phytogrowth inhibitors isolated from the aerial parts of Maytenus disticha (Celastraceae) and seeds of Maytenus boaria (Cel-astaraceae), respectively, on different photosynthetic activities of isolated spinach chloro plasts have been investigated. Photophosphorylation and electron transport (basal, phosphor-ylating and uncoupled) were inhibited in a concentration dependent manner by both compounds, therefore acting as Hill reaction inhibitors. The site of action of these natural compounds was located in the span from P680 to QA. 9ß-benzoyloxy-l,2,6,8,15-pentaacetoxy-dihydro-ß-agarofuran was one order of magnitude more potent (I50 = 2.6 jim) than 9ß-furoy-loxy-l,6,8,-triacetoxydihydro-ß-agarofuran, suggesting that the substitution at C-9 and the acetoxy groups at carbons 2 and 15 are important structural requirements for the displayed inhibitory activity. | | | |
Reference
| Z. Naturforsch. 55c, 631—637 (2000); received January 28/March 22 2000 | | | |
Published
| 2000 | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0631.pdf | | | | Identifier
| ZNC-2000-55c-0631 | | | | Volume
| 55 | |
| 94 | Author
| Vijay Kumar, Sharma3, Wolfgang Engelmannb, Anders Johnssonc | Requires cookie* | | | Title
| Effects of Static Magnetic Field on the Ultradian Lateral Leaflet Movement Rhythm in Desmodium gyrans | | | | Abstract
| The rhythmic leaflet movements of the plant Desmodium gyrans (L.f.) DC slow down in the presence of a static magnetic field. The leaflet positions were digitally retrieved from sequential CCD cam era images of the moving leaflets. The experiments were performed under constant light (ca. 500 lux) and tem perature (about 20 °C) conditions. The period of the leaflet was then around 5 min. Leaflets moving up and down in a magnetic field of approximately 50 mT flux density increased the period by about 10% due to a slower motion in the "up" position. Since during this position a rapid change of the extracellular potentials of the pulvinus occurs, it is proposed that the effects are mediated via the electric processes in the pulvinus tissue. | | | |
Reference
| Z. Naturforsch. 55c, 638 (2000); received January 18/M arch 20 2000 | | | |
Published
| 2000 | | | |
Keywords
| Oscillations, Video Imaging, Ion Movements | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0638.pdf | | | | Identifier
| ZNC-2000-55c-0638 | | | | Volume
| 55 | |
| 95 | Author
| Claus Fuchs, Gerhard Spiteller | Requires cookie* | | | Title
| Iron Release from the Active Site of Lipoxygenase | | | | Abstract
| In the course of the lipoxygenase-catalyzed transformation of linoleic acid to 135-hydro-p eroxy-9Z ,ll£'-octad ecad ien oic acid, iron ions are liberated. This iron release has been de termined using a spectrophotom etric assay based on the complexation of ferrous iron by 3-(2-pyridyl)-5,6-bis-(4-phenylsulfonic acid)-l,2,4-triazine disodium salt (ferrozine). Further comparative measurements demonstrated that iron release correlates to deficient oxygen supply. We speculate that release of iron ions is caused by modifications of histidine residues located at the active site of the enzyme. Liberation of iron ions may be responsible for increased generation of lipid peroxidation (L P O) products observed after a myocardial in farction since iron ions induce nonenzymic LPO processes. | | | |
Reference
| Z. Naturforsch. 55c, 643 (2000); received March 23/April 17 2000 | | | |
Published
| 2000 | | | |
Keywords
| Lipoxygenase, Iron Release, Myocardial Infarction | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0643.pdf | | | | Identifier
| ZNC-2000-55c-0643 | | | | Volume
| 55 | |
| 96 | Author
| RenetaA. Toshkova3, PetiaA. Dimitrova, EmiliaH. Ivanovab, PavlinaA. Dolashkac, M. Aria, B. Angelovab, SvetlanaB. Pashovab, LudmilaS. Slokoskab, Wolfgang Voelterd | Requires cookie* | | | Title
| Immunoprotective Effect of Cu/Zn Superoxide Dismutase on Myeloid Graffi Tumor-Bearing Hamsters | | | | Abstract
| Superoxide Dismutase, Humicola lutea, Tumors, Immunotherapy Investigation on the immunoprotective activity of Cu/Zn superoxide dismutase from H u micola lutea 103 A L (HLSOD) in hamsters with transplanted myeloid tumor was performed. Survivability, tum or growth and tum or transplantability were followed. The immune status of tumor-bearing animals, injected with the optimal protective HLSOD dose, was examined during 27 days after tumor transplantation by the following parameters: (i) the number, migration and phagocytic activity of peritoneal macrophages, (ii) the phagocytic activity of blood polymorphonuclear leukocytes (PMNs), (iii) the responsibility in vitro of spleen lym phocytes to T and B cell mitogens. It was established that intraperitoneal inoculation of HLSOD produced a protective effect on the development of tumors. Elongation of the latent time for tumor appearance and inhibition of the tumor growth were observed. The decreased percentage of mortality in early stage of tum or progression was established. Immunological studies on tumor-bearing hamsters (TBH) induced a tem porary immunorestoring effect on the suppressed phagocytic activities of peritoneal macrophages and blood PMNs during the first 14 days of tumor devel opment. Moreover, HLSOD showed an expressed stimulating effect on proliferative activity in vitro of spleen B lymphocytes from healthy and TBH as well. The immunorestoring and protective effect of the enzyme was probably due to improve of the oxidant-antioxidant balance in peritoneal phagocytes. The tem porary character of the effect can be explained with the interference of immunosuppressing factors produced by tumor tissue as well as by the presence of tumor antigens, tumor cells and antigen-antibody complexes in the circula tion. | | | |
Reference
| Z. Naturforsch. 55c, 649—656 (2000); received November 23 1999/February 10 2000 | | | |
Published
| 2000 | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0649.pdf | | | | Identifier
| ZNC-2000-55c-0649 | | | | Volume
| 55 | |
| 98 | Author
| Nelly Nikolova3, TomasR. Ezankab, Boryana Nikolova-Damyanova | Requires cookie* | | | Title
| Fatty Acid Profiles of Main Lipid Classes in Adult Chrysomela vigintipunctata (Scopoli) (ColeopteraiChrysomelidae) | | | | Abstract
| Leaf Beetle, Lipids Oxazoline Derivatives The fatty acid composition of the willow leaf beetle Chrysomela vigintipunctata (Scopoli) (Coleoptera: Chrysomelidae) is presented in this paper. Fatty acids in the total lipid extract, triacylglycerols, free fatty acids and polar lipids were compared. O ne hundred and fifteen fatty acids were identified in the total lipids. The mixture comprised compounds with normal and branched-chains of 12-30 carbon atoms and zero to six double bonds in different posi tions in the carbon chain. Substantial amounts of unsaturated eicosanoic fatty acids known as important precursor of eicosanoids in insects were detected in the lipids as were biologically significant positionally isomeric dienes, trienes and tetraenes of the series (n-3) and (n-6) of C16, C18, and C22 fatty acids. Also present was a mixture of hydroxy-FA. Triacylglycerols contained mostly saturated and monounsaturated fatty acids. Polyunsaturated fatty acids were found mostly in free fatty acids and especially in polar lipids. | | | |
Reference
| Z. Naturforsch. 55c, 661—666 (2000); received December 6 1999/February 7 2000 | | | |
Published
| 2000 | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0661.pdf | | | | Identifier
| ZNC-2000-55c-0661 | | | | Volume
| 55 | |
| 100 | Author
| Hans Beiderbeck3, Kambiz Taraz3, H. Erbert Budzikiewicz3, AnthonyE. Walsbyb | Requires cookie* | | | Title
| Anachelin, the Siderophore of the Cyanobacterium Anabaena cylindrica CCAP 1403/2A# | | | | Abstract
| Anabaena cylindrica, Anachelin, Siderophore A catecholate siderophore -anachelin -has been isolated from the cyanobacterium A na baena cylindrica CCAP 1403/2A. The central part of the siderophore is a tripeptide consisting of L-Thr, D-Ser and L-Ser. Its C-terminus is linked amidically to a l,l-dimethyl-3-amino-l,2,3,4-tetrahydro-7,8-dihydroxyquinolinium system and its N-terminus to 6-amino-3,5,7-tri-hydroxyheptanoic acid. The 7-hydroxyl group of the latter is esterified with salicylic acid whose carboxyl group is condensed with the 6-amino group to an oxazoline ring. Anachelin is the first genuine siderophore of a cyanobacterium whose structure has been elucidated. | | | |
Reference
| Z. Naturforsch. 55c, 681—687 (2000); received May 8 2000 | | | |
Published
| 2000 | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/55/ZNC-2000-55c-0681.pdf | | | | Identifier
| ZNC-2000-55c-0681 | | | | Volume
| 55 | |
|
