| | 61 | Author
| BoźennaR. Óźycka-Roszak, Romuald Żyłka, Janusz Sarapuk | Requires cookie* | | | Title
| Hydration of Alkylammonium Salt Micelles -Influence of Bromide and Chloride Counterions  | | | | Abstract
| Fax: (+48)-71 -2 0 5 -1 7 2 . E-mail: BO RO @ozi.ar.w roc.pl The micellization process of dodecyltrimethylammonium chloride (D TA C) and bromide (D T A B) was studied. N uclear magnetic resonance method was used. The 'H N M R and 13C N M R spectra were taken at higher and lower concentrations than the critical micelle concentrations (CM C) of the compounds studied. Chemical shifts were analysed. The studies perform ed were prompted by earlier calorim etric measurements which showed that there were significant qualitative and quantitative differences in the micellization process of the compounds studied. Namely, D T A B micelle dissociation was found to be an endothermic process while that of DTA C was exothermic. The differences found must be the result of differentiated influence of bromide and chloride counterions on the micellization process, including the phenomenon of micelle hydration. The objective of the work was to check whether cationic surfactant counterions can influence the micelle hydration process. Indeed, D TA B and D TAC, as monomers, exhibit similar hydrophobic hydration, but D TA B micelles are m ore hydrated than D TA C ones. It seems that the differences found in micellization of both salts studied may be attributed to different physicochemical properties of bromide and chloride ions, such as their mobilities and radii of their hydrated forms. M oreover, the effect of anions on the water structure must be taken into account. It is important whether the anions can be classified as water ordering kosmotropes, that hold the first hydration shell tightly, or water disordering chaotropes, that hold water molecules in that shell loosely. | | | |
Reference
| Z. Naturforsch. 55c, 413 (2000); received January 10/March 6 2000 | | | |
Published
| 2000 | | | |
Keywords
| Micelle Hydration, Calorimetry, Counterions | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0413.pdf | | | | Identifier
| ZNC-2000-55c-0413 | | | | Volume
| 55 | |
| 62 | Author
| Marek Langner3, Hanna Pruchnikb, Krystian Kubicab, A.R W | Requires cookie* | | | Title
| The Effect of the Lipid Bilayer State on Fluorescence Intensity of Fluorescein-PE in a Saturated Lipid Bilayer Fax: +48-71-3205172. E-mail: K ub ica@ O Z I | | | | Abstract
| Fluorescein-PE, Lipid Bilayer, Phase Transition Fluorescein-PE is a fluorescence probe that is used as a membrane label or a sensor of surface associated processes. Fluorescein-PE fluorescence intensity depends not only on bulk pH, but also on the local electrostatic potential, which affects the local membrane interface proton concentration. The pH sensitivity and hydrophilic character of the fluorescein moiety was used to detect conformational changes at the lipid bilayer surface. When located in the d ip a lm ito y lp h o sp h a tid y lch o lin e (D P PC) bilayer, probe fluorescence depends on conform a tional changes that occur during phase transitions. Relative fluorescence intensity changes more at pretransition than at the main phase transition temperature, indicating that interface conformation affects the condition in the vicinity of the membrane. Local electrostatic poten tial depends on surface charge density, the local dielectric constant, salt concentration and water organisation. Initial increase in fluorescence intensity at temperatures preceding that of pretransition can be explained by the decreased value of the dielectric constant in the lipid polar headgroups region related in turn to decreased water organisation within the membrane interface. The abrupt decrease in fluorescence intensity at tem peratures between 25 °C and 35 °C (D P PC pretransition) is likely to be caused by an increased value of the electrostatic potential, induced by an elevated value of the dielectric constant within the phosphate group region. Further increase in the fluorescence intensity at temperatures above that of the gel-liquid phase transition correlates with the calculated decreased surface electro static potential. Above the main phase transition temperature, fluorescence intensity increase at a salt concentration of 140 m M is larger than with 14 m M . This results from a sharp decline of the electrostatic potential induced by the phosphocholine dipole as a function of distance from the membrane surface. | | | |
Reference
| Z. Naturforsch. 55c, 418 (2000); received December 2 1999/February 3 2000 | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0418.pdf | | | | Identifier
| ZNC-2000-55c-0418 | | | | Volume
| 55 | |
| 64 | Author
| Vassilios Roussis, Constantinos Vagias3, Christina Tsitsimpikoub, Nina Diamantopoulou30 | Requires cookie* | | | Title
| Chemical Variability of the Volatile Metabolites from the Caribbean Corals of the Genus Gorgonia | | | | Abstract
| a School of P harm acy, D ep artm en t o f P harm acognosy, U n iversity o f A thens, Panepistim ioupolis Z o g rafo u , A th en s 15771, G re e ce . Fax: + + 3 0 1 7 2 7 4 5 9 2 . E -m ail: R o u ssis@ p h arm .u o a.g r b D oping C o n trol L a b o ra to ry o f A then s, O lym pic A th letic C en tre o f A then s " Spiros L ou is", Kifissias 37 , 1 5 1 2 3 , M aroussi, G re e ce c M ed iterran ean A g ro n o m ic In stitu te o f C h ania, P. O. B o x 85, 7 3 1 0 0 , C hania, G reece * A uth or for co rre sp o n d en ce and rep rin t requests Z . N aturforsch. 5 5 c , 4 3 1 -4 4 1 (2 0 0 0); received Ja n u a ry 10/F eb ru ary 16, 2000 Gorgonia, V olatile M etabolites, Terpen es The chem ical com p osition o f the investigated go rg o n ian s show ed a high level o f individual variation and the colonies, acco rd in g to their m ajo r con trib u tors, w ere assigned to 10 distinct chem ical profiles, am on g which A , C, E , and G w ere the m ost abundant ones. F ro m the m etab olites identified in the p resen t study, eith er by m eans o f G C /M S or using N M R tech niques after co n ven tio n al sep aratio n p roced ures, the novel cyclic eth er 5,10-ep o xy m u u ro lan e is found in significant quantities in D and I ch em ical profiles. F u ran o trien e, isofuranotriene and furanodiene could be referred as the m ost co m m o n m etab olites o f the genus, since they are found in 6 o u t of 10 ch em ical profiles. Isosericen in e is, also, a significant co n trib u to r of H and I ch em ical profiles. A n um ber of sesq u iterp en e h yd rocarbon s, such as cu rzerene, b icyclogerm acren e, valen cen e, ß -b ourbonen e and ß -elem en e, along with the o xy g en ated ses quiterpenes elem an olid e and fu roven talene, are p resen t at varying con cen tration s in the m a jority o f the ch em ical profiles. M etab olites of high discrim inant value are: a-h im ach alen e for the K chem ical profile, a -sa n ta le n e and its o xy g en ated derivatives for the G ch em ical profile and the three g eo m etrical isom ers of g erm acro n e fo r the F ch em ical profile. Several ch em ical profiles show ed narrow g eo g rap h ic distribution. M ost o f the chem ical profiles are lo cated in the n orth , while F inhabits mainly sou th ern sites and the oth ers are equally distributed. Finally, 9 1 % o f the chem ical p rofiles o f the gorgonian colonies appeared to grow in all depths, while 9 % did not inhabit d eep -w ater environm ents. M ost chem ical profiles are less frequ en t at higher w ater depths with the excep tio n of chem ical profiles A and C. | | | |
Reference
| Z. Naturforsch. 55c, 431 (2000) | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0431.pdf | | | | Identifier
| ZNC-2000-55c-0431 | | | | Volume
| 55 | |
| 65 | Author
| UtaGerhard Seibt, Kasang, Wolfgang Wickler | Requires cookie* | | | Title
| Phymateus leprosus (Fabricius) (Pyrgomorphidae, Orthoptera) | | | | Abstract
| The bushhopper Phymateus leprosus (Fabricius) in the field shows a special appetite for the milkweed Asclepias fruticosa. Asclepiadaceae, like Apocynaceae and Scrophulariaceae, contain cardiac glycosides. Raw and purified extracts of these plants phagostimulate larval and adult P. leprosus. We also screened natural and half-synthetic compounds found in those plant extracts. While saponins and sapogenins did not stimulate the animals, many cardiac glycosides and aglycones, offered on filter paper, proved to be phagostimulants. | | | |
Reference
| Z. Naturforsch. 55c, 442 (2000); received D ecem ber 13. 1999/March 7 2000 | | | |
Published
| 2000 | | | |
Keywords
| Phymateus leprosus, Asclepiadaceae, Pharmacophagy | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0442.pdf | | | | Identifier
| ZNC-2000-55c-0442 | | | | Volume
| 55 | |
| 67 | Author
| Petteri Nieminen, Heikki Hyvärinen | Requires cookie* | | | Title
| Seasonality of Leptin Levels in the BAT of the Common Shrew (Sorex araneus) | | | | Abstract
| Shrew, Sorex araneus, Leptin Leptin concentrations in the interscapular brown adipose tissue (IBA T) of the common shrew (Sorex araneus) were measured in different seasons. The leptin concentrations in IBAT were much higher than in the liver, where leptin is supposed to be of blood origin. In the heart muscle no detectable amount of leptin was found. There were clear seasonal variations in the leptin concentrations in IBAT. Leptin levels in IBAT were the lowest in November at the beginning of the winter. The concentrations increased, however, strongly after the onset of the permanent snow cover, and the highest concentrations were measured in D ecember-January, when the weight of the animals was very low. In April-May, at the time when shrews attain sexual maturity, leptin concentrations in IBA T were lower than in the mid-winter, but significantly higher than in November. In overwintered adults the leptin concentrations were at the same level as in nonwintered subadults. Leptin originating from BAT may inform the central nervous system about the amount of nonshivering thermogenesis as well as the amount of feeding necessary for survival in the winter months. | | | |
Reference
| Z. Naturforsch. 55c, 455 (2000); received February 2/March 10 2000 | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0455.pdf | | | | Identifier
| ZNC-2000-55c-0455 | | | | Volume
| 55 | |
| 68 | Author
| Mario Suwalsky3, Pedro Hernández3, Fernando Villenab, CarlosP. Sotomayorc | Requires cookie* | | | Title
| The Anticancer Drug Cisplatin Interacts with the Human Erythrocyte Membrane | | | | Abstract
| Cisplatin, A nticancer Drug, Erythrocyte Membrane Drugs which exert their effects by interacting with DNA cause structural and functional membrane alterations which may be essential for growth inhibition by these agents. This paper describes the interaction of cisplatin with the human erythrocyte mem brane and mod els constituted by bilayers of dimyristoylphosphatidylethanolamine (D M P E) and diacylphos-phatidylserine (D A PS), representative of phospholipid classes located in the inner monolayer of the erythrocyte membrane, and of dimyristoylphosphatidylcholine (D M P C), a class pre sent in its outer monolayer. Cisplatin ability to perturb D M P E, DAPS and D M PC bilayer structures was determined by X -ray diffraction and fluorescence spectroscopy. Electron mi croscopy disclosed that human erythrocytes incubated with 35 ^im cisplatin, which is its thera peutical concentration in serum, developed cup-shaped forms (stom atocytes). According to the bilayer couple hypothesis, this means that the drug is inserted into the inner monolayer of the erythrocyte membrane, a conclusion supported by the studies on model systems. | | | |
Reference
| Z. Naturforsch. 55c, 461 (2000); received January 27/M arch 6 2000 | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0461.pdf | | | | Identifier
| ZNC-2000-55c-0461 | | | | Volume
| 55 | |
| 71 | Author
| ZornitzaG. Kamenarska3, StefkaD. Dimitrova-Konaklievab, Christina Nikolovac, AthanasIi Kujumgievd, KamenL. Stefanov3, SimeonS. Popov3 | Requires cookie* | | | Title
| Volatile Components of the Freshwater Algae Spirogyra and Mougeotia | | | | Abstract
| Several species of freshwater green algae belonging to the order Zygnematales (Spirogyra crassa (K tz.) Czurda, S. longata (Vauch.) Ktz., and Mougeotia viridis (K tz.) W ittr.) were found to have a specific composition of the volatile fraction, which confirms an earlier pro posal for the existence of two groups in the genus Spirogyra. Antibacterial activity was found in volatiles from S. longata. | | | |
Reference
| Z. Naturforsch. 55c, 495—4 (2000); received February 4/M arch 13 2000 | | | |
Published
| 2000 | | | |
Keywords
| Antibacterial Activity, Mougeotia, Spirogyra, Volatile Compounds | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0495.pdf | | | | Identifier
| ZNC-2000-55c-0495 | | | | Volume
| 55 | |
| 72 | Author
| Laxminarain Misra, ShahzadA. Siddiqi | Requires cookie* | | | Title
| w-Alkanes and a-Palmitin from Paspalum scrobiculatum Seeds# | | | | Abstract
| Paspalum scrobiculatum, Poaceae, /j-Alkanes, ci-Palmitin, Antitumour Hexane and methanol extracts of Paspalum scrobiculatum seeds have yielded several known fatty acids, sterols, unusual straight chain hydrocarbons which are well known for their insect pheromone activity along with the antitumour glyceride, a-palmitin. | | | |
Reference
| Z. Naturforsch. 55c, 500 (2000); received February 2/February 24 2000 | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0500.pdf | | | | Identifier
| ZNC-2000-55c-0500 | | | | Volume
| 55 | |
| 73 | Author
| Rosemary Webby, Stephen Bloor | Requires cookie* | | | Title
| Pigments in the Blue Pollen and B ee Pollen of Fuchsia excorticata | | | | Abstract
| Fuchsia excorticata, Onagraceae, Anthocyanins A comparison of the pigments in Fuchsia extorticata pollen with the pigments extracted from the unusually coloured blue-black "fuchsia" bee pollen confirms the New Zealand tree fuchsia as the source of the bee pollen. The pigments were identified as the p-trans-coumaro-ylated derivatives of delphindin-, petunidin and malvidin-3-O-glucosides and delphinidin-3-0-(/?-c/s-coum aroyl-glucoside). The anthocyanins are accompanied by several flavonol glyco sides; kaempferol-3-sophoroside, quercetin-3-sophoroside and kaempferol 3-neohesperido-side. | | | |
Reference
| Z. Naturforsch. 55c, 503 (2000); received March 20/April 27 2000 | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0503.pdf | | | | Identifier
| ZNC-2000-55c-0503 | | | | Volume
| 55 | |
| 74 | Author
| Patrí Cia Máximo3, Ana Lourenço3, Savluchinske Sónia, Jose Feiob, Carlos Roseirob | Requires cookie* | | | Title
| Flavonoids from Ule.x Species | | | | Abstract
| Nine flavonoids have been isolated from Ulex jussiaei and U. minor (Leguminosae). From both species the isoflavonoids ulexin A and the new naturally occurring ulexin B have been identified, together with isoderrone, the pterocarpans (-)-maackiain and (-)-4-m ethoxy-maackiain. and the chalcone isobavachromene. The pterocarpan (-)-2-m ethoxym aackiain was only present in the first species and the isoflavones isolupalbigenin and ulexone A have been identified in the second one. 13C NM R data of isobavachromene, isolupalbigenin and ulexone A are also included. The antifungal activity of the isolated compounds was tested by the bioautographic method against Cladosporium cucumerinum. The most active compounds were the pterocarpans, the chalcone and the isoflavones with non-hydroxylated open chain prenyl substituents. | | | |
Reference
| Z. Naturforsch. 55c, 506 (2000); received March 27/April 20 2000 | | | |
Published
| 2000 | | | |
Keywords
| Ulex Species, Isoflavones, Pterocarpans | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0506.pdf | | | | Identifier
| ZNC-2000-55c-0506 | | | | Volume
| 55 | |
| 75 | Author
| Günter Lang3, ClausM. Passreiter3 ', BeatrizE. Medinillab, Juan-Jose Castillo0 | Requires cookie* | | | Title
| of Eupatorium semialatumA | | | | Abstract
| Fax: +49 211 8 1 1 1 9 2 3 , E-m ail: passreit@uni-duesseldorf.de b Facultad Ciencias Qufmicas y Farmacfa, Universidad de San Carlos, Guatemala Ciudad. Guatemala c Facultad de Agronomfa, Universidad de San Carlos, G uatem ala Ciudad, Guatemala d Part of a current dissertation of G. Lang, Heinrich-Heine-Universität, Düsseldorf A collection of Eupatorium semialatum from Guatem ala was investigated for the occur rence of sesquiterpene lactones. In addition to the sesquiterpene cinnamoyloxyoplopanone (5), lactones of the eudesmanolide type were found and identified by NM R as derivatives of 8ß-hydroxyreynosin and 8ß-hydroxybalchanin, esterified with 2-substituted acrylic acids. The acid moieties were determined to be the enantiomeric (R)-and (5)-(2-hydroxy-l-m ethoxy-ethyl)acrylic acid, in 1, 2 and 4 respectively, and (1 | | | |
Reference
| Z. Naturforsch. 55c, 511 (2000); received March 23 2000 | | | |
Published
| 2000 | | | |
Keywords
| Eupatorium semialatum, Sesquiterpene Lactones, Eudesmanolides | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0511.pdf | | | | Identifier
| ZNC-2000-55c-0511 | | | | Volume
| 55 | |
| 78 | Author
| ClóvisA. Rodrigues3, AnaE. Oliveira3, F. Ana, Schürmann Da Silva3, Cechinel Valdir, ClaudioL. Filho3, RosendoA. Guimarãesb, Franco Yunesc, Delle Monached | Requires cookie* | | | Title
| Rheedia gardneriana Using Column Chromatography | | | | Abstract
| a Nücleo de In v e s tig a te s Qinmico-Farmaceuticas (N IQ F A R), Curso de Farmäcia/CCS, Universidade do Vale do Itajaf (U N IV A L I), C E P 8 8 .3 0 2 -2 0 2 . Itajaf, SC, Brazil. Fax: 47 341 7601. E-mail: clovis@mboxl.univali.br Rheedia gardneriana, Biflavonoids, Chitosan This paper describes a comparative study by using different chromatographic supports (silica gel, chitin and chitosan) to separate biflavonoids from Rheedia gardneriana by column chromatography. The results indicated that chitin can be used as alternative method, but the yield of the compounds is lower than when silica gel is employed. In contrast, chitosan is not a good chromatographic support for the separation of the biflavonoids under the same experimental conditions. | | | |
Reference
| Z. Naturforsch. 55c, 524 (2000); received February 28/April 11 2000 | | | |
Published
| 2000 | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0524.pdf | | | | Identifier
| ZNC-2000-55c-0524 | | | | Volume
| 55 | |
| 80 | Author
| Helen Skaltsa3, Diamanto Lazari3, Begona Garciab, JoseR. Pedrob, Marina Sokovicc, Theophanis Constantinidisd | Requires cookie* | | | Title
| Sesquiterpene Lactones from Centaurea achaia, a Greek Endemic Species: Antifungal Activity | | | | Abstract
| The aerial parts of Centaurea achaia afforded, in addition to several known sesquiterpene lactones and sesquiterpene hydroxyesters, a new germacranolide and a new elemanolide. Their structures were determined as the 8a-0-(4,5-dihydroxy-tigloyloxy) esters of saloniteno-lide and of 11,13-dihydromelitensin, respectively. The in vitro antifungal activity of most compounds was tested against nine fungal species using the micro-dilution method. All the tested compounds showed strong antifungal activity. | | | |
Reference
| Z. Naturforsch. 55c, 534 (2000); received March 27/April 28 2000 | | | |
Published
| 2000 | | | |
Keywords
| Centaurea achaia, Sesquiterpene Lactones, Antifungal Activity | | | |
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| default:Reihe_C/55/ZNC-2000-55c-0534.pdf | | | | Identifier
| ZNC-2000-55c-0534 | | | | Volume
| 55 | |
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