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2001[X]
81Author    Nikolay Youhnovski, Christa Werner, M.Anfred HesseRequires cookie*
 Title    iV,./V',./V'-Trifeniloylspermidine, a New UY Absorbing Polyamine Derivative from Pollen of Hippeastrum x hortorum  
 Abstract    Amaryllidaceae. Anthers, Hydroxycinnamoyl polyamines A new hydroxycinnamoyl polyamine derivative, /V,/V',/V"-triferuloylspermidine (= (E)-N-(4-aminobutyI)-3,3',3"-tris(4-hydroxy-3-methoxyphenyl)-N.N',N"-(butane-l,4-diyl)tris [prop-2-enamide]) (1) was detected in the H 20 /M e 0 H extract of pollen from Hippeastrum x hor­ torum. The compound was identified by on-line-coupled high-performance liquid chrom ato­ graphy and atmospheric-pressure chemical-ionization mass spectrometry (HPLC-U V(D AD)/ APCI-MS and MS/MS). The structure was proven by comparing the HPLC/MS data after UV-induced (£) ^ (Z) photoisomerization and catalytic hydrogenation of the natural com­ pound and the synthetic reference compound. This is the first report of a triferuloylspermi-dine in nature. 
  Reference    Z. Naturforsch. 56c, 526—530 (2001); received March 27 2001 
  Published    2001 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0526.pdf 
 Identifier    ZNC-2001-56c-0526 
 Volume    56 
82Author    GazmendZ. Eneliab, Christina Tsitsimpikouc, PanosV. Petrakisd, George Naxakis3, Dalip Habilib, Vassilios RoussisRequires cookie*
 Title    Foliar and Cortex Oleoresin Variability of Silver Fir (Abies alba Mill.) in Albania  
 Abstract    A bies alba, O leoresin, Terpenes Terpene com position o f needle and cortical oleoresin from lateral shoots were analyzed by GC/MS for four Silver fir (A bies alba Mill.) populations scattered in natural species range in Albania. More than sixty compounds were detected in the needle oleoresin, which was characterized by a high content of a-pinene, camphene, ß-pinene, limonene and bornyl ace­ tate. Three m onoterpenes, a-pinene, ß-pinene and limonene, and two sesquiterpenes, ß-caryophyllene and germacrene D, comprised the majority of cortical oleoresin. The terpene composition differences among the populations that led to the recognition o f two chemo-types. The needle oleoresin from the provinces of Puka, Bulqiza and Llogara were character­ ised by high amounts of ß-pinene, camphene and a-pinene and low amounts of limonene, while that from D renova had high amounts of ß-pinene and limonene. A similar pattern was found in the cortical oleoresin with the exception of camphene that was a minor contributor. Geographical and seasonal variation between the populations was, also, investigated. Multi­ variate analysis o f both needle and cortical oleoresin separated D renova (southeastern pop­ ulation) from the other sites. W hen both major m onoterpenes and sesquiterpenes were con­ sidered four chemical profiles could be attributed. Based on their chemical profiles, the populations can be divided into two groups: • Populations with high content of ß-pinene and a-pinene but a low content of limonene (Puka, Bulqiza and Llogara), typical of most of A. alba populations in all its distribution range. • Population with a high content of limonene and a moderate content of ß-pinene and a-pinene (D renova). 
  Reference    Z. Naturforsch. 56c, 531 (2001); received January 9/March 5 2001 
  Published    2001 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0531.pdf 
 Identifier    ZNC-2001-56c-0531 
 Volume    56 
83Author    Michael Meyer3, Rüdiger Schnurreb, Rolf Reissbrodtc, Wolfram Trowitzsch-KienastbRequires cookie*
 Title    Computer-Aided Design of Novel Siderophores: Pyridinochelin  
 Abstract    Catecholate-Type Siderophore, Iron Transport, M olecular M odelling Pyridinochelin, a novel tetradentate catecholate-type siderophore, has been designed on the basis of the active analog enterobactin and was then synthesized. Growth promotion tests indicate that this synthetic siderophore feeds various pathogenic bacteria most effectively with iron even though it lacks one catecholate group compared to enterobactin. The superpo­ sition of the mentioned siderophore structures suggests that the structure of the skeleton connecting the catecholate groups might be an important factor for the iron transport. 
  Reference    Z. Naturforsch. 56c, 540 (2001); received February 13/March 14 2001 
  Published    2001 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0540.pdf 
 Identifier    ZNC-2001-56c-0540 
 Volume    56 
84Author    MatthewO. Ilori, Dan-Israel AmundRequires cookie*
 Title    Production of a Peptidoglycolipid Bioemulsifier by Pseudomonas aeruginosa Grown on Hydrocarbon  
 Abstract    A strain of Pseudomonas aeruginosa isolated from a polluted soil was found to produce an extracellular bioemulsifier when cultivated on hexadecane as sole carbon source. The emulsifier was precipitated with acetone and redissolved in sterile water. D odecane, crude oil and kerosene were found to be good substrates for emulsification by the bioemulsifier. Growth and bioemulsifier production reached the optimal levels on the fourth and fifth day, respectively. Emulsifying activity was observed over a pH range o f 3.5 to 10.0 with a maxi­ mum at pH 7.0. The activity o f the bioemulsifier was heat stable up to 70 °C while about 50 percent of its activity was retained at 100 °C. The com ponents of the bioem ulsifier were determined, it was found to contain carbohydrate, protein and lipid. The protein complex was precipitated with ammonium sulphate and fractionated on a Sephadex G-100. Gel elec­ trophoresis of the bioemulsifier showed a single band whose molecular weight was estimated as 14,322 Da. The bioemulsifier was classified as a peptidoglycolipid. Certain strains of P. aeruginosa produce peptidoglycolipid in place o f rhamnolipid. 
  Reference    Z. Naturforsch. 56c, 547 (2001); received February 6 /March 8 2001 
  Published    2001 
  Keywords    Pseudom onas, Hydrocarbon, Peptidoglycolipid 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0547.pdf 
 Identifier    ZNC-2001-56c-0547 
 Volume    56 
85Author    Elena Horozova, Nina Dimcheva, Zinaida JordanovaRequires cookie*
 Title    Enzyme-Catalyzed Decomposition of Dibenzoyl Peroxide in Organic Solvents  
 Abstract    Im mobilized Catalase, Aprotic Solvents, Catalytic Activity Catalytic activity o f catalase (CAT, EC 1.11.1.6), immobilized on carbon black N ORIT and soot PM-100, with respect to decomposition of dibenzoyl peroxide (B P O) in non-aque-ous media (acetonitrile and tetrachloromethane), was investigated with a quantitative UV-spectrophotom etrical approach. Progress of the above reaction was controlled by selected kinetic parameters: the apparent Michaelis constant (/Cmapp), the specific rate constant (A:sp), the activation energy (Ea), the maximum reaction rate (Vmax), and the A rrhenius' pre-expo­ nential factor (Z0). Conclusions on the tentative mechanism of the catalytic process observed were drawn from the calculated values of the Gibbs energy o f activation (A G *), the enthalpy o f activation (A H *), and entropy of activation (zdS*). 
  Reference    Z. Naturforsch. 56c, 553 (2001); received January 25/March 12 2001 
  Published    2001 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0553.pdf 
 Identifier    ZNC-2001-56c-0553 
 Volume    56 
86Author    Klaus Grossm, Stefan Tresch3, Peter PlathbRequires cookie*
 Title    Triaziflam and Diaminotriazine Derivatives Affect Enantioselectively Multiple Herbicide Target Sites  
 Abstract    Enantiomers of triaziflam and structurally related diaminotriazines were synthesized and their herbicidal mode o f action was investigated. The compounds caused light and dark-dependent effects in multiple test systems including heterotrophic cleaver and photoauto-trophic algal cell suspensions, the Hill reaction o f isolated thylakoids and germinating cress seeds. Dose-response experim ents revealed that the fSj-enantiomers of the compounds pref­ erentially inhibited photosystem II electron transport (PET) and algae growth with efficacies similar to that of the herbicide atrazine. In contrast, the (R)-enantiomers of the diaminotri­ azines were up to 100 times more potent inhibitors of growth in cleaver cell suspensions and cress seedlings in the dark than the (S)-enantiomers. The most active compound, the (R)-enantiomer of triaziflam, inhibited shoot and root elongation of cress and maize seedlings at concentrations below 1 (j.m. The meristematic root tips swelled into a club shape which is typical for the action of mitotic disrupter herbicides and cellulose biosynthesis inhibitors. Microscopic examination using histochemical techniques revealed that triaziflam (7?)-enan-tiomer blocks cell division in maize root tips 4 h after treatment. The chromosomes pro­ ceeded to a condensed state of prometaphase but were unable to progress further in the mitotic cycle. Disruption of mitosis was accompanied by a loss o f spindle and phragmoplast micotubule arrays. Concomitantly, cortical microtubules decreased which could lead to iso-diametric cell growth and consequently to root swelling. In addition, a decline in cellulose deposition in cell walls was found 24 h after treatment. Compared to the (7?)-form, triaziflam (S)-enantiomer was clearly less active. The results suggest that triaziflam and related di­ aminotriazines affect enantioselectively multiple sites o f action which include PET inhibitory activity, mitotic disruption by inhibiting microtubule formation and inhibition of cellulose synthesis. 
  Reference    Z. Naturforsch. 56c, 559 (2001); received April 19 2001 
  Published    2001 
  Keywords    Diaminotriazines, Cellulose Synthesis, Mitotic Disrupter Herbicides, Photosynthetic Electron Transport Inhibitors 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0559.pdf 
 Identifier    ZNC-2001-56c-0559 
 Volume    56 
87Author    M. Aique, W. Biavatti3, PauloC. Vieira3, M. Fatima, G. F. Da Silva3, JoäoB. Fernandes3, Sergio Albuquerque1, Ribeiräo Preto, SäoPaulo BrazilRequires cookie*
 Title    Limonoids from the Endemic Brazilian Species Raulinoa echinata  
 Abstract    Phytochemical survey of stems and leaves of the South Brazilian endemic Raulinoa echi­ nata Cowan, Rutaceae led to the isolation of five limonoid derivatives: the widespread li-monin, limonexic acid, kihadalactone B, a m ethoxylated limonexic acid derivative and a degraded limonoid structurally related to fraxinellone. The two latter com pounds have been isolated for the first time. These compounds displayed weak inhibitory activity when assayed in vitro against trypomastigote forms of Trypanosoma cruzi. In this paper, the isolation, structure elucidation and bioactivity of these compounds are reported. 
  Reference    Z. Naturforsch. 56c, 570—5 (2001); received March 24 2001 
  Published    2001 
  Keywords    Raulinoa echinata, Limonoids, Trypanosoma cruzi 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0570.pdf 
 Identifier    ZNC-2001-56c-0570 
 Volume    56 
88Author    Joseph Rauscher, RosaM. Guillén3, M. Artha Albores-Velasco3, G. Ilberto, Gonzá Lez, Otto Vostrowskyb, HansJ. BestmRequires cookie*
 Title    The Repellence of Aristolochia aff. orbicularis Roots against the Corn Borer Sitophilus zeamais  
 Abstract    Essential Oils, A ristolochia aff. orbicularis, Sitophilus zeam ais The repellence o f Aristolochia aff orbicularis root, a native of Xochipala, Guerrero, M exico, to the corn borer Sitophilus zeamais (C oleoptera) was investigated. The essential oil was isolated from the aromatic root and its repellent effect was assessed. A bout 40 com po­ nents of the oil were identified using gas chromatography-mass spectrometry and other spec­ troscopic methods. The repellence of the roots, the oil and the chromatography fractions were also evaluated. Some fractions had a higher 
  Reference    Z. Naturforsch. 56c, 575 (2001); received February 6/March 20 2001 
  Published    2001 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0575.pdf 
 Identifier    ZNC-2001-56c-0575 
 Volume    56 
89Author    Axel Mithöfer3, ArvindA. Bhagwatb, D. Onald, L. Keisterc, Jürgen EbelaRequires cookie*
 Title    Bradyrhizobium japonicum Mutants Defective in Cyclic /?-GIucan Synthesis Show Enhanced Sensitivity to Plant Defense Responses  
 Abstract    Bradyrhizobium japonicu m , Cyclic ß-Glucans, Plant D efence Susceptibility of the nitrogen-fixing soybean symbiont B radyrhizobium japonicum to in­ ducible plant defense metabolites such as phytoalexin and H 20 2, was investigated. On the wild-type strain U S D A 110 the soybean phytoalexin, glyceollin, showed bacteriostatic activ­ ity. Viable bacteria isolated from intact nodules were adapted to glyceollin. H 20 2 in physio­ logical concentrations did not affect wild-type bacteria. B. japonicum mutants defective in the biosynthesis of cyclic ß -(l—>3)-(l—>6)-glucans showed higher susceptibility to both phyto­ alexin and H20 2. 
  Reference    Z. Naturforsch. 56c, 581 (2001); received April 3 2001 
  Published    2001 
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 Identifier    ZNC-2001-56c-0581 
 Volume    56 
90Author    JogadhenuS S Prakasha, MasroorA. Baigb, PrasannaM. Ohanty3Requires cookie*
 Title    Differential Changes in the Steady State Levels of Thylakoid Membrane Proteins during Senescence in Cucumis sativus Cotyledons  
 Abstract    Cucumis sativus, Senescence, Thylakoids Chloroplast structure and function is known to alter during foliar senescence. Besides, the alterations in the structural organisation of thylakoid membranes changes in the steady state levels of thylakoid membrane proteins occur due to leaf ageing. We m onitored temporal changes in som e of the specific proteins of thylakoid membrane protein com plexes by w est­ ern blotting in the Cucumis sativus cotyledons as a function o f the cotyledon age. We ob­ served that the levels of D1 and D2 proteins o f photosystem II started declining at the early stages of senescence of Cucumis cotyledons and continued to decline with the progress of cotyledon age. Similarly the level of C y t /o f Cyt b j f complex declined rapidly with progress of senescence in these cotyledons. The reaction centre proteins of photosystem I were rela­ tively found to be more stable than that of photosystem II reaction centre proteins reflecting possibly the disorganisation of photosystem II prior to photosystem I. The 33 kD a extrinsic protein (M SP) of oxygen evolving complex, the LHCII apoprotein and the ß-subunit of ATPsynthase showed the declined levels with the progress o f cotyledon age. However, the extents of loss of these proteins were not as high as the reaction centre proteins of photosys­ tem II and the Cyt f. These results provide that during senescence, proteins of thylakoid membranes degrade in a specific temporal sequence and thereby affect the temporal photo­ chemical functions in Cucumis sativus cotyledons. 
  Reference    Z. Naturforsch. 56c, 585 (2001); received January 26/March 26 2001 
  Published    2001 
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 Identifier    ZNC-2001-56c-0585 
 Volume    56 
91Author    Milena Popova, Vassya Bankova3, Stefan Spassov3, Iva Tsvetkovab, Christo Naydenskib, MarioVides Silva, Maria TsartsarovadRequires cookie*
 Title    New Bioactive Chalcones in Propolis from El Salvador  
 Abstract    El Salvador Propolis, Chalcones, Antibacterial and Antifungal Activity 2',3'-Dihydroxy-4,4'-dimethoxychalcone (1) and 2',3',4-trihydroxy-4'-methoxy-chalcone, two new chalcones, were isolated from propolis from El Salvador. The compounds showed significant antibacterial ana antifunfag activity and moderate toxicity to Artemia salina nauplii. 
  Reference    Z. Naturforsch. 56c, 593—5 (2001); received February 5/March 27 2001 
  Published    2001 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-0593.pdf 
 Identifier    ZNC-2001-56c-0593 
 Volume    56 
92Author    Maria Tsoukatou3, Lanna Chengb, Constantinos Vagias3, Vassilios Roussis3-Requires cookie*
 Title    Halobates hawaiiensis (Heteroptera: Gerridae)  
 Abstract    Sex Attractant, Pheromone, Marine Insects, Halobates hawaiiensis Halobates is the only insect genus with representatives in the open ocean. How adults find one another at sea has long been an intriguing issue. Since chemical communications have been demonstrated in a related marine veliid Trochopus, and laboratory bioassays indicated behavioral differences between males and females when insect extracts were presented, we carried out similar studies on Halobates. Analyses of surface lipid constituents of female and male Halobates hawaiiensis revealed marked differences. Palmitic and oleic acid, major constituents in the male extracts, were absent in the female extract, whereas nonacosenol, dominating the female extracts, was not detected in the male extracts. Analyses of nymphal extracts indicated an intermediate chemical profile. Surface waxes of all insect stages investi­ gated showed nonacosanol and isononacosanol to be main components. "Headspace" analy­ ses of airborne chemicals showed high levels of 4-hydroxy-4-methyl-2-pentanone and benzal­ dehyde from the male, whereas benzyl alcohol was the main component in the female mixture. 
  Reference    Z. Naturforsch. 56c, 597 (2001); received December 27 2000/March 5 2001 
  Published    2001 
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 Identifier    ZNC-2001-56c-0597 
 Volume    56 
93Author    CarlosL. Céspedes3, JulioA. Larcó Nc, EduardoA. Randab, JoséB. Ecerrad, Mario SilvadRequires cookie*
 Title    from Maytenus spp. (Celastraceae)  
 Abstract    ß-Dihydroagarofurans, Acute Toxicity, Acetylcholinesterase From the aerial parts of Maytenus disticha, we have isolated 9ß-benzoyloxy-la,2a,6ß,8a,15-penta-acetoxy-dihydro-ß-agarofuran (1) and from seeds of Maytenus boaria 
  Reference    Z. Naturforsch. 56c, 603 (2001); received February 14/March 27 2001 
  Published    2001 
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 Identifier    ZNC-2001-56c-0603 
 Volume    56 
94Author    Mario Suwalsky3, Carlos Schneider3, Fernando Villenab, Beryl Norrisb, HernanC. Árdenasb, Francisco Cuevasc, CarlosP. SotomayorcRequires cookie*
 Title    Dibucaine-Induced Modification of Sodium Transport in Toad Skin and of Model Membrane Structures  
 Abstract    The interaction of the local anesthetic dibucaine with the isolated toad skin and membrane models is described. The latter consisted of human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), large unilamellar vesicles (LUV) of dimyristoylphosphati-dylcholine (DMPC) and phospholipid multilayers built-up of DMPC and dimyristoylphos-phatidylethanolamine (D M PE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. Results indicate a significant decrease in the potential difference (PD) and in the short-circuit current (Isc) after the application of dibucaine in toad skin, which may be interpreted as reflecting inhibition of the active transport of ions. This finding might be explained on the basis of the results ob­ tained from fluorescence spectroscopy and X-ray diffraction studies on membrane models. In fact, dibucaine induced structural perturbations in IUM, DMPC LUV and phospholipid multilayers. Scanning electron microscopy revealed that dibucaine induced erythrocyte sto-matocytosis. According to the bilayer couple hypothesis an echinocytic type of shape change would have been expected given the preferential interaction of dibucaine with DMPC. Al­ though it is still premature to define the molecular mechanism of action of dibucaine, the experimental results confirm the important role played by the phospholipid bilayers in the association of the anesthetic with cell membranes. 
  Reference    Z. Naturforsch. 56c, 614 (2001); received January 29/March 8 2001 
  Published    2001 
  Keywords    Local Anesthetic, Dibucaine, Membrane 
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 Identifier    ZNC-2001-56c-0614 
 Volume    56 
95Author    Bozenna Rözycka-Roszak, Hanna PruchnikRequires cookie*
 Title    Influence of Dodecyltrimethylammonium Halides on Interaction of Phenyltin Compounds with Model Membranes  
 Abstract    The effects were studied of dodecyltrimethylammonium chloride (DTAC), dodecyltrimeth­ ylammonium bromide (DTAB) and dodecyltrimethylammonium iodide (DTAI) on thermo­ tropic phase behaviour of phosphatidylcholine bilayers, as well as on 'H NMR and 31P NMR spectra, in the presence of diphenyltin dichloride (DPhT) and triphenyltin chloride (TPhT). The obtained results indicate that in the presence of the surfactant studied the interaction of phenyltin compounds with model membranes was changed and the changes depended on the kind of the counterion. The surfactants studied (especially DTAC) decrease the ability of phenyltin compounds to induce structural changes in the bilayer. It is suggested that DTAB, and especially DTAC, prevent DPhT induced interdigitated phase formation as well as formation of an inverted hexagonal phase (Hn) 
  Reference    Z. Naturforsch. 56c, 623 (2001); received December 27 2000/February 19 2001 
  Published    2001 
  Keywords    Dodecyltrimethylammonium Halides, Phenyltin Compounds, Model Membranes 
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 Identifier    ZNC-2001-56c-0623 
 Volume    56 
96Author    P.Sreenivasula Reddy, Md Riyaz BashaRequires cookie*
 Title    On the Mode of Action of Methionine Enkephalin, FK 3 3 -8 2 4 and Naloxone in Regulating the Hemolymph Glucose Level in the Fresh Water Field Crab Oziotelphusa senex senex  
 Abstract    The possible involvement of opioid system in the regulation of hemolymph glucose level in the fresh water crab Oziotelphusa senex senex Fabricius, was investigated. Opioid agonist and antagonist was also used in addition to methionine-enkephalin itself. Injection of the opioid, methionine-enkephalin and FK 3 3 -8 2 4 significantly elevated hemolymph glucose level. In contrast, injection of naloxone in to crab resulted in decrease in hemolymph glucose level. Injection of naloxone prior to injection of methionine-enkephalin blocked the hyper­ glycemic action of methionine-enkephalin. Injection of methionine-enkephalin, FK 33824 and naloxone produced no significant effect on hemolymph glucose level in eyestalk-less crab. The alterations in the intact crab hemolymph glucose level hypothesised to be due to stimulation of release of hyperglycemic hormone during methionine-enkephalin and FK 33824 treatment and blocking of release of hyperglycemic hormone during naloxone treat­ ment from the eyestalks of crab Oziotelphusa senex senex. 
  Reference    Z. Naturforsch. 56c, 629 (2001); received January 29/March 23 2001 
  Published    2001 
  Keywords    Methionine Enkephalin, Naloxone, Oziotelphusa 
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 Identifier    ZNC-2001-56c-0629 
 Volume    56 
97Author    Susanne Hippeli3, Kerstin Dornisch3, ThorstenW. Iethegeb, Adrian Gillissenc, Klaus-Michael Müllerb, ErichE. Elstner3Requires cookie*
 Title    Biological Durability and Oxidative Potential of Man-Made Vitreous Fibres as Compared to Crocidolite Asbestos Fibres  
 Abstract    In this study we investigated relationships between redox properties and biodurability of crocidolite asbestos fibres and three different man-made vitreous fibres (MMVF): traditional stone wool fibres (MMVF 21), glass fibres (MMVF 11) and refractory ceramic fibres (RCF). Each fibre type was incubated up to 22 weeks in four different incubation media: gamble solution (GS) pH 5.0 and pH 7.4, representing blood plasma without proteins, and surfactant­ like solution (SLS) pH 5.0 and pH 7.4. During incubation time aliquots of incubation mix­ tures were removed and analysed in a biochemical model reaction, mimicking activated phagocytes. In addition, changes of fibre morphology and chemical composition were exam­ ined using SEM-and EDX-technology. In the presence of crocidolite asbestos fibres and MMVF 21 the formation of OH -radicals according to the Haber-Weiss sequence could be demonstrated, whereas MMVF 11 and RCF showed no reactivity. Crocidolite asbestos fibres exhibited a significant higher activity com­ pared with the stone wool fibres at the onset of incubation. The oxidative capacities of these fibre types were shown to depend on both specific surface area and iron content. The oxida­ tive potentials of crocidolite asbestos fibres as well as MMVF 21 were not constant during incubation over several weeks in each incubation medium. The reactivities showed sinoidal curves including reactivities much higher than those at the onset of incubation time. These irregular changes of oxidative capacity may be explained by changes of the redox state of fibre surface-complexed iron. Furthermore our results showed clear differences between incubation of fibres in GS and SLS, respectively, indicating that phospholipids play an important part in fibre dissolution behaviour and oxidative reactivity. In conclusion we suggest, that biodurability testing procedures should not exclusively con­ centrate on dissolution rates of fibres. They should include fibre characteristics concerning known pathogenic mechanisms to evaluate the real toxic potential of the fibre type looking at. Secondly we suggest, that phospholipids should be constituents of incubation liquids used for standardised fibre biodurability test procedures thus representing more realistic incuba­ tion conditions. 
  Reference    Z. Naturforsch. 56c, 633—648 (2001); receiced January 22/February 12 2001 
  Published    2001 
  Keywords    Biodurability, Mineral Fibres, Oxidative Potential 
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 Identifier    ZNC-2001-56c-0633 
 Volume    56 
98Author    Meinrad Boll, LutzW D Weber, Eberhard Becker, Andreas StampflRequires cookie*
 Title    Mechanism of Carbon Tetrachloride-Induced Hepatotoxicity. Hepatocellular Damage by Reactive Carbon Tetrachloride Metabolites  
 Abstract    Liver Damage, Carbon Tetrachloride, Peroxidation CCl4-induced liver damage was modeled in monolayer cultures of rat primary hepatocytes with a focus on involvement of covalent binding of CC14 metabolites to cell components and/ or peroxidative damage as the cause of injury. (1) Covalent binding of 1 4 C-labeled metabolites was detected in hepatocytes immediately after exposure to CC14. (2) Low oxygen partial pressure increased the reductive metabolism of CC14 and thus covalent binding. (3) [1 4 C]-CC14 was bound to lipids and to proteins throughout subcellular fractions. Binding occurred preferentially to triacylglycerols and phos­ pholipids, with phosphatidylcholine containing the highest amount of label. (4) The lipid peroxidation potency of CC14 revealed subtle differences compared to other peroxidative substances, viz., A D P-Fe3+ and cumol hydroperoxide, respectively. (5) CC14, but not the other peroxidative substances, decreased the rate of triacylglycerol secretion as very low density lipoproteins. (6) The anti-oxidant vitamin E (a-tocopherol) blocked lipid peroxidation, but not covalent binding, and secretion of lipoproteins remained inhibited. (7) The radical scav­ enger piperonyl butoxide prevented CCl4-induced lipid peroxidation as well as covalent bind­ ing of CCI4 metabolites to cell components, and also restored lipoprotein metabolism. The results confirm that covalent binding of the CC13* radical to cell components initiates the inhibition of lipoprotein secretion and thus steatosis, whereas reaction with oxygen, to form CCI3 -O O * , initiates lipid peroxidation. The two processes are independent of each other, and the extent to which either process occurs depends on partial oxygen pressure. The former process may result in adduct formation and, ultimately, cancer initiation, whereas the latter results in loss of calcium homeostasis and, ultimately, apoptosis and cell death. 
  Reference    Z. Naturforsch. 56c, 649 (2001); received February 23/March 28 2001 
  Published    2001 
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 Identifier    ZNC-2001-56c-0649 
 Volume    56 
99Author    VaniaL. Tsoncheva3, KrassimirS. Kirovb, ChristinaA. Valkova3, GeorgiI. Milchev3Requires cookie*
 Title    Evaluation of Delayed Apoptotic Response in Lethally Irradiated Human Melanoma Cell Lines  
 Abstract    Melanoma. Radiation, Apoptosis To assess the lethal doses of gamma radiation and corresponding apoptotic response in new established human melanoma cell lines we exposed exponentially growing cultures to 8 -1 0 0 Gy gamma radiation. The apoptosis and cell survival were determined by trypan blue exclusion, terminal deoxynucleotidvl transferase-mediated dUTP nick end labeling (TU -NEL) reaction, agarose gel electrophoresis, colony forming assay, and long-term survival assay. The maximal DNA fragmentation 3 days after irradiation was observed in cultures irradiated with 20 Gy (36.9% TU N E L positive cells). The cultures irradiated with 50 and 100 Gy contained 18.7% and 16.4% T U N E L positive cells, respectively. Cultures exposed to 8 and 20 Gy gamma radiation recovered by week 3 -4 . Lethally irradiated (50 and 100 Gy) cultures which contained less apoptotic cells by day 3 died by week 5. A detectable increase in melanoma cell pigmentation after irradiation was also observed. The survival of human melanoma cell cultures after exposure to gamma radiation does not correlate with the level of apoptotic cells by day 3. At high radiation doses (> 50 Gy) when the radiation induced cell pigmentation is not inhibited the processes of apoptotic DNA fragmentation might be preferentially inactivated. 
  Reference    Z. Naturforsch. 56c, 660 (2001); received November 14/December 20 2000 
  Published    2001 
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 Identifier    ZNC-2001-56c-0660 
 Volume    56 
100Author    Kadriye Sorkun3, Banu Slier3, Bekir SalihbRequires cookie*
 Title    D e te rm in a  
 Abstract    tio n o f C h em ical C om p o sitio n o f Turkish P ro p o lis The aim of the present work is to study the chemical composition of Turkish propolis. Propolis samples were collected from different regions of Turkey (Bursa. Er-zurum-Askale, Gumushane-Sogutagil and Trabzon-Cag-layan) in 1999. Ethanol extracts of propolis (E E P) were prepared for chemical analysis, using gas chromatograph coupled with mass spectrometry (GC-M S). Our findings show that propolis samples from Trabzon and Gumu-shane region have a similar chemical composition. In both samples aromatic acids, aliphatic acids and their es­ ters, and also ketone derivatives are the main compound groups. The chemical composition of the single sample that was collected from Erzurum region shows a very different pattern than the other two samples. In this propolis, the main compounds are aromatic acid esters and alcohols. However, it contains a high amount of amino acids compared to the other samples. The other samples collected from three different region of Bursa City are rich with flavavones, aromatic acids and their esters, terpenoids, flavones and ketones. 
  Reference    Z. Naturforsch. 56c, 666 (2001); received January 1/February 23 2001 
  Published    2001 
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 Identifier    ZNC-2001-56c-0666_n 
 Volume    56 
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