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1994[X]
41Author    IfeanyiI M Adubunyi, KlausPeter Adam, Hans BeckerRequires cookie*
 Title    Anthocleista nobilis  
 Abstract    Anthocleista nobilis, Loganiaceae, R oot Bark, Secoiri­ doid, Anthocleistol The root bark of Anthocleista nobilis is used in Nige­ ria against liver diseases, malaria and gastrointestinal worms. The secoiridoid pattern of the root bark was in­ vestigated. Sweroside and Anthocleistol a new secoiri­ doid have been isolated from the methanol extract. The structures were elucidated from spectroscopic data. 
  Reference    Z. Naturforsch. 49c, 271—272 (1994); received December 30 1993 
  Published    1994 
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 Identifier    ZNC-1994-49c-0271_n 
 Volume    49 
42Author    Requires cookie*
 Title    Glassy State in Plant Cuticles during Growth  
 Abstract    Cuticles are thin extracellular layers that cover the aerial parts o f all higher plants in areas lacking secondary growth. Their chemical and m orpho­ logical roles as protective barriers between the plant and its environm ent has been reported (H ol­ loway, 1982). Plant cuticles are heterogeneous in nature. They consist o f epi-and intracuticular wax fractions and, mainly, cutin which is a highly cross-linked polyester made o f hydroxy fatty acids. In animal skin, mechanical strength and m olecular barrier functions are distinct than in plants and both o f these properties are served by proteins. As opposed to the anim al barriers, our knowledge of the molecular dynamic and thermal properties o f plant cuticles is very limited (Lend-zian and Kerstiens, 1991). 
  Reference    Z. Naturforsch. 49c, 273 (1994) 
  Published    1994 
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 Identifier    ZNC-1994-49c-0273_n 
 Volume    49 
43Author    Requires cookie*
 Title    Pheromone 97*. Der Sexualpheromonkomplex des weiblichen Blutbär Thyria jacobaeae  
 Abstract    Pheromones, 97*. The Sex Pherom one Complex of the Female Arctiid M oth Thyria jacobaeae (Lepidoptera, Arctiidae) 
  Reference    Z. Naturforsch. 49c, 276 (1994) 
  Published    1994 
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 Identifier    ZNC-1994-49c-0276_n 
 Volume    49 
44Author    Dieter Gross, Andrea Porzel, Jürgen SchmidtRequires cookie*
 Title    Phytoalexine mit Indolstruktur aus Kohlrabi {Brassica oleracea var. gongylodes)+ Indole Phytoalexins from the Kohlrabi (Brassica oleracea var. gongylodes)  
 Abstract    UV-irradiation of sliced stem tubers of kohlrabi (Brassica oleracea var. gongylodes) fol­ lowed by incubation for 4 days, resulted in the production of two new sulphur-containing indole phytoalexins, cyclobrassinone and 1 -methoxyspirobrassinin, whose structures were elucidated on the basis of spectroscopic data. Three known indole phytoalexins, spirobrassi­ nin, methoxybrassitin and methoxybrassinin, and several m inor phytoalexin-like com pounds not yet identified were also isolated. The accum ulation o f these indole phytoalexins was also induced by abiotic elicitation with CuCl2. Feeding both of L-[ß-14C]tryptophan and L-[14C H 3]methionine to U V -irradiated stem tuber tissue of kohlrabi indicated that the S-containing indole phytoalexins were biosynthesized from these amino acids. Einführung 
  Reference    Z. Naturforsch. 49c, 281—285 (1994); eingegangen am 23. Dezember 1993 
  Published    1994 
  Keywords    Phytoalexins, Kohlrabi, Cyclobrassinone, 1-Methoxyspirobrassinin, Spirobrassinin 
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 Identifier    ZNC-1994-49c-0281 
 Volume    49 
45Author    A. Nette Sigler, HansW. RauwaldRequires cookie*
 Title    Aloe Plants Accumulate Anthrone-Type Anthranoids in Inflorescence and Leaves, and Tetrahydroanthracenes in Roots  
 Abstract    The accumulation and distribution of characteristic secondary products in the different organs of an A loe plant (A. succotrina Lam.) were studied by high perform ance liquid chro­ matography for the first time. In the leaves of the A loe plant, only anthrone-C-glycosyls of the 7-hydroxyaloin type and, for the first time in plant material, the free anthraquinone 7-hydroxyaloeemodin were found. In contrast to previous reports on the distribution of sec­ ondary products in A lo e plants, anthrone-C-glycosyls were also detected in flowers, bracts and the inflorescence axis of the species examined. Aloesaponol I, a tetrahydroanthracene aglycone, was only present in the underground organs and in the stem. The 2-alkylchromone-C-glucosyl aloeresin B showed no specific occurrence as it was found in every type of organ. Based on these results and the findings of recent studies on A loe roots and flowers, a distri­ bution scheme of polyketide types in the A loe plant was established. It suggests a separate and independent anthranoid metabolism for underground A loe organs and stem on the one hand, and for leaves and inflorescence organs on the other hand. In the latter structures anthranoid metabolism seems to be additionally compartmentalized as the anthranoid pro­ files of inflorescence organs and leaves differ in two points relevant to anthranoid biosynthe­ sis: firstly, the occurrence of anthrone aglycones and secondly, the individual content of corre­ sponding anthrone-C-glucosyl diastereomers. 
  Reference    Z. Naturforsch. 49c, 286—292 (1994); received February 4/March 21 1994 
  Published    1994 
  Keywords    Aloe, Asphodelaceae, Anthraquinones, Chromones, Polyketides, High Performance Liquid Chromatography 
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 Identifier    ZNC-1994-49c-0286 
 Volume    49 
46Author    Cornelia Fuchs, G.Erd HansenRequires cookie*
 Title    Partial Purification and Some Properties of Brassica napus Lipase  
 Abstract    Lipase (triacylglycerol acylhydrolase EC 3.1.1.3) from rape (Brassica napus cv. Ceres) was isolated from cotyledons of dark-grown seedlings. The enzyme was partially purified by poly­ ethylene glycol precipitation. Delipidation of the lipase with «-hexane was required prior to further purification by anion exchange chromatography and size exclusion chromatography. A purification factor of 337 was ultimately achieved and the purification process was moni­ tored by SDS-PAGE. Here, at least two protein bands with molecular masses of 62 and 64 kD a respectively were found in the active fraction obtained by size exclusion chrom atogra­ phy. Sodium deoxycholate was found to stimulate the lipase activity, but appeared to cause aggregation of the enzyme. It was not possible to estimate the isoelectric point of the dialyzed rape lipase due to the high molecular mass of the aggregates. Two simple methods to detect lipase activity directly on polyacrylamide gel were applied. No esterase activity was found by using p-nitrophenyl acetate as substrate. 
  Reference    Z. Naturforsch. 49c, 293—301 (1994); received November 3 1993/March 7 1994 
  Published    1994 
  Keywords    Lipase, Rape, Purification, Properties 
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 Identifier    ZNC-1994-49c-0293 
 Volume    49 
47Author    A. Kio, K. Obayashi, K. Ohki, A. Kiyam, K. Azuyoshi, K. Aw AzuRequires cookie*
 Title    Partially N-Deacetylated Chitin Fragments are Strong Elicitors for (+)-Pisatin Induction in Epicotyls of Pea  
 Abstract    Chitosan derivatives classed into three groups according to their molecular size were exam­ ined for the relationships between degree of N -acetylation and phytoalexin (+)-pisatin-induc-ing activity in pea epicotyl assay. Partially N-deacetylated chitin with degree o f N-acetylation 56% (DAC 56%) was the most potent inducer o f (+)-pisatin am ong sparingly water-soluble polysaccharides including chitosan (degree o f N -acetylation 0%), DAC 32%, and chitin. Among the intermediate-sized molecules obtained from degradation of the chitosan and the DACs by N a N 0 2, the chitosan fragment was the most powerful elicitor for (+)-pisatin induc­ tion. The N a N 0 2-degraded DAC 56% exhibited a com parable activity to the N a N 0 2 -degrad-ed chitosan at low concentrations. The N a N 0 2-degraded fragments as well as the native poly­ mer induced a relatively high am ount of (+)-pisatin, while the acetone precipitate of chitosan oligomers from the HCl-catalyzed hydrolysate and their partially N-acetylated derivatives ex­ hibited a m oderate (+)-pisatin-inducing activity. These findings suggest the possibility that partially N-deacetylated chitin fragments could be one o f the most promising elicitors in the pea system. 
  Reference    Z. Naturforsch. 49c, 302—308 (1994); received January 14/February 24 1994 
  Published    1994 
  Keywords    Elicitor, Chitosan, Chitin Pea, Phytoalexin 
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 Identifier    ZNC-1994-49c-0302 
 Volume    49 
48Author    FriedhelmK. Ring, P. Eter, B. ÖgerRequires cookie*
 Title    Histone Acetylation is not Affected by Chloroacetamides in vitro  
 Abstract    The effects of chloroacetamides on the acetylation of histone protein in maize (Zea mays) were studied in an in vitro assay. N either alachlor nor metazachlor showed any influence on both of the investigated acetylating enzymes, the nuclear histone acetyltransferase A and the cytoplasmic histone acetyltransferase B. Furtherm ore, an effect of these herbicides on deacetylation of histones could be excluded. 
  Reference    Z. Naturforsch. 49c, 309—311 (1994); received February 28 1994 
  Published    1994 
  Keywords    Acetylation, Alachlor, Histone Acetyltransferase, Histone Deacetylase, Metazachlor 
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 Identifier    ZNC-1994-49c-0309 
 Volume    49 
49Author    K. Irsten Lorenzen, Tim, H. Erm, H. Inderm Ayr, F. Ritz HansskeRequires cookie*
 Title    4-Epidihydrocochlioquinone B and 14-Epicochlioqumone B, Antibiotics from Fermentations of the Ascomycete Neobulgaria pur a: Structure Elucidation and Effects on Platelet Aggregation  
 Abstract    14-Epicochlioquinone B (1) and 14-epidihydrocochlioquinone B (2) were isolated from sub­ merged cultures of Neobulgaria pura (Pers. ex Fr.) Petrak. 14-Epicochlioquinone B is a potent inhibitor of hum an and bovine platelet aggregation stimulated by different inducers. 14-Epidihydrocochlioquinone B does not inhibit the aggregation of platelets. In addition, both 1 and 2 exhibited cytotoxic and antimicrobial activites. 
  Reference    Z. Naturforsch. 49c, 312—320 (1994); received September 9 1993/ 
  Published    1994 
  Keywords    Ascomycetes, Helotiales, Platelet Aggregation, Antibiotics, Cochlioquinones 
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 Identifier    ZNC-1994-49c-0312 
 Volume    49 
50Author    Z. NaturforschRequires cookie*
 Title    Natural Inhibitors of Germination and Growth, VII Synthesis of Ribulosebisphosphate Carboxylase in Darkness and Its Inhibition by Coumarin  
 Abstract    Dedicated to Prof. Aloysius Wild on the occasion o f his 65th birthday Lepidium sativum, Cruciferin, Ribulosebisphosphate Carboxylase, Inhibition of Transcription Cress (Lepidium sativum) seeds were germinated in darkness. Seedlings were investigated for soluble proteins by SDS-PAGE. Two proteins were identified by microsequencing: the small subunit of ribulosebisphosphate carboxylase (SSU) and the alpha subunit of the storage protein cruciferin. Net synthesis of small and large subunits of ribulosebisphosphate carbox­ ylase (SSU and LSU) was investigated by Western blot. Net synthesis of both subunits was inhibited by coumarin. To the contrary, net synthesis of cruciferin was increased by coumarin. With specific cDNA probes, we determined steady state levels of the corresponding mRNAs (rbcS mRNA for SSU, rbcL mRNA for LSU). Both mRNAs can be detected in dry seeds; their am ount increases during germination in the dark. Incubation with coumarin inhibits this increase. Inhibition of development by coumarin on the level of transcription is discussed. 
  Reference    Z. Naturforsch. 49c, 321—326 (1994); received 
  Published    1994 
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 Identifier    ZNC-1994-49c-0321 
 Volume    49 
51Author    M. Au, S. Ola-, P. Enna, B. Erto, M. Eyer-FernandesRequires cookie*
 Title    Protective Role of Trehalose in Thermal Denaturation of Yeast Pyrophosphatase  
 Abstract    Thermal D enaturation, Trehalose, Yeast Pyrophosphatase, W ater Activity, Carbohydrates Trehalose, a disaccharide o f glucose, is accumulated in yeast cytosol when this organism is submitted to a stress condition. Recently it was shown that the level of trehalose increase up to 15 times when yeast cells are submitted to heat shock (De Virgilio et al., 1991). In this report we give evidence how trehalose may play an im portant role on the stress-survival o f yeasts when submitted to a heat shock. We show that 1.5 M trehalose increases 13-fold the half-time for thermal inactivation (/ 0 5) o f yeast cytosolic pyrophosphatase at 50 °C. This thermal pro­ tection conferred by trehalose is dose-dependent, after 10 min at 50 °C, a condition which inactivated pyrophosphatase, the presence of 2 m trehalose preserves 95% of total activity. O ther carbohydrates were tested but were not so effective as trehalose. The presence o f tre­ halose at high concentrations in the reaction medium at 35 °C inhibits pyrophosphatase activ­ ity. This inhibition is less effective at 50 °C suggesting that under this condition the enzyme is tem perature-protected and active. 
  Reference    Z. Naturforsch. 49c, 327—330 (1994); received January 7 1994 
  Published    1994 
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 Identifier    ZNC-1994-49c-0327 
 Volume    49 
52Author    L. O. Th, Ttsc H A Lk, FriedrichL. Ottspeichb, H.Ugo ScheeraRequires cookie*
 Title    Reconstitution of an Allophycocyanin Trimer Complex Containing the C-Terminal 2 1 -2 3 kDa Domain of the Core-Membrane Linker Polypeptide Lcm  
 Abstract    Allophycocyanin (AP) was isolated from extracts of the cyanobacterium Mastigocladus laminosus. A fraction enriched in AP-associated polypeptides with apparent molecular masses of 2 1 -2 3 kD a in SDS-PAGE, was isolated on a preparative scale and identified as a hom olo­ gous mixture of C-terminal fragments o f the core-membrane linker polypeptide Lcm. The com ­ plex (aAPßAP)3-21 -2 3 kD a was reconstituted and characterized by sucrose density gradient ultracentrifugation, absorption, fluorescence emission and circular dichroism spectroscopy. The 2 1 -2 3 kD a polypeptides were found to induce spectral changes in AP similar to those induced by the small core linker polypeptide Lc8 9. Possible functions of the complex in phy-cobilisomes are discussed. 
  Reference    Z. Naturforsch. 49c, 331—336 (1994); received February 18 1994 
  Published    1994 
  Keywords    Allophycocyanin, Linker, Anchor Protein, Phycobilisome Core, Mastigocladus laminosus 
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 Identifier    ZNC-1994-49c-0331 
 Volume    49 
53Author    G. Rzegorz, Jackow Ski, EwA. KluckRequires cookie*
 Title    The Oligomeric Arrangement of the Light-Harvesting Chlorophyll a/6-Protein Complex of Photosystem II  
 Abstract    The light-harvesting chlorophyll a/b-protein complex of photosystem II (LHC II) was iso­ lated from carnation (Dianthus caryophyllus L.) leaves by K+-induced aggregation of «-hep-tylthioglucoside-treated photosystem II particles. When solubilized with a mixture of lithium docedyl sulphate, octyl-ß-D-glucopyranoside and dodecyl-ß-D-maltoside the LHC II was re­ solved by mild sodium dodecyl sulphate-polyacrylamide gel electrophoresis into four oligo­ meric forms and a monomeric one. LHC II contained five major polypeptides only two of which (27 and 26 kDa) were found to be its authentic components. The oligomeric forms of LHC II were found to differ in the stoichiometric ratios of the polypeptides present. The 26 kD a polypeptide was enriched in the largest oligomeric forms while the 27 kDa polypep­ tide tended to form a m onomer or to assemble as lower oligomeric states of LHC II. 
  Reference    Z. Naturforsch. 49c, 337—342 (1994); received October 26 1993/March 4 
  Published    1994 
  Keywords    1994 Carnation, Light-Harvesting Chlorophyll a/b-Protein Complex, Oligomer, Polypeptide, Stoichiometric Ratio 
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 Identifier    ZNC-1994-49c-0337 
 Volume    49 
54Author    B. Ern, H. Ard, E. Pping, A.Lex An, ErP H Ansen, B. Ahm, D. Jalali, P. Eter, M. ArtinRequires cookie*
 Title    Symbiotic Effectivity of Four Phaseolus vulgaris Genotypes after Inoculation with Different Strains of Rhizobium under Controlled Conditions  
 Abstract    Phaseolus vulgaris L., Plant x Bacterium Interaction, Rhizobium leguminosarum bv. phaseoli, Rhizobium tropici, Symbiotic Effectivity Four varieties of P. vulgaris L. were tested for their symbiotic nitrogen fixation effectivity in combination with nine different strains of Rhizobium leguminosarum bv. phaseoli and Rhizobium tropici. Plants were grown under controlled conditions and harvested 23 days after planting. Acetylene reducing activity, total N-content and dry weight of individual plant com ponents were determined. Significant differences due to plant x bacterium interaction were assessed by ANOVA, especially for the total nodule mass per plant and the acetylene reducing activity per nodule dry weight. D ata for acetylene reducing activity per plant corre­ lated highly with the corresponding data for the total N-content. The comparison of the total N-content in symbiotically grown plants, lacking supply of mineral N, with plants luxuriously supplied with mineral N (relative N-accumulation rate) revealed high values (between 60% and 70% of maximal N-uptake) for some symbiotically active plant/bacterium combinations for this early developmental stage of the symbiosis N2 fixation potential for such symbioses. 
  Reference    Z. Naturforsch. 49c, 343—351 (1994); received February 4 1994 
  Published    1994 
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 Identifier    ZNC-1994-49c-0343 
 Volume    49 
55Author    IgorY A Belyaev An, V. Yacheslav, G. K. RavchenkoRequires cookie*
 Title    Resonance Effect of Low-Intensity Millimeter Waves on the Chromatin Conformational State of Rat Thymocytes  
 Abstract    Cellular Biology, Microwave Bioaction, Chromosom al DNA The method of anom alous viscosity time dependencies (AVTD) was modified for the study of the changes in the chrom atin conform ational state (CCS) of rat thymocytes of the Wistar line. The response of the thymocytes of male rats to low-intensity millimeter waves (MMW) was examined. It was shown that M M W at power densities (PD) of 1 (iW/cm2 produced a resonance effect on the CCS in the frequency range of 41.56-41.67 GHz. The resonance fre­ quency of the cell response did not vary significantly among five examined rats and was deter­ mined to be 41.61 ±0.01 GHz. A halfwidth of resonances was averaged to 40 MHz. The power dependence of the resonance effect was measured in the range of 10"11 — 10-4 W/cm2. Statistically significant changes in CCS were registered, starting with 10-9 W /cm2. Right-and left-handed circularly polarized M M W were shown to differ in efficiency at the resonance fre­ quency. The established regularities in the thymocyte response to low-intensity M M W was very similar to those which have been previously found for E. coli cells. 
  Reference    Z. Naturforsch. 49c, 352—358 (1994); received December 8 1993 
  Published    1994 
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 Identifier    ZNC-1994-49c-0352 
 Volume    49 
56Author    Z., ZlochRequires cookie*
 Title    Temporal Changes of the Lipid Peroxidation in Rats after Acute Intoxication by Ethanol  
 Abstract    received O ctober 23, 1993/March 1, 1994 Ethanol, Microsomes, Mitochondria, Lipid Peroxidation, Hepatotoxicity A group of male rats were intoxicated within 24 h by three successive i.p. doses of ethyl alcohol (7.5 g per 1 kg of the body weight). In parallel, a control group of rats were dosed i.p. with a physiological saline. At time intervals of 0 h, 4 h, 24 h, and 48 h after the intoxi­ cation, the content of thiobarbiturate-reactive substances (TBARS) as product of lipid per­ oxidation within the liver and brain microsomes and mitochondria was followed. In liver microsomes of the experimental rats there was a rapid increase (by 220%) in the content of TBARS during 4 h after the last application of ethanol, later on the level of lipid peroxidation decreased to the low original value. In other organelles examined only an insignificant increase in the content of TBARS was found. The results prove that an acute intoxication by ethanol does elicit an oxidative stress of the organism, expressed by a tran­ siently increased production of TBARS. These oxidative and harmful changes for the cell structures are mostly located in the liver microsomes but a rapid repair of this damage fol­ lows. However, if such a short-term excessive abuse of alcohol is repeated more often, the above changes may lead to severe alcoholic injury 
  Reference    Z. Naturforsch. 49c, 359—362 (1994) 
  Published    1994 
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 Identifier    ZNC-1994-49c-0359 
 Volume    49 
57Author    G. Gries, R. Gries, A. L. Perez, A. C. Oehlschlager, L. M. Gonzales, H. D. Pierce, M. Zebeyou, B. KouameRequires cookie*
 Title    Aggregation Pheromone of the African Rhinoceros Beetle, Oryctes monoceros (Olivier) (Coleoptera: Scarabaeidae)  
 Abstract    Coleoptera, Oryctes monoceros, African Rhinoceros B eetle, Aggregation Pheromone, Ethyl 4-M ethyloctanoate Ethyl 4-m ethyloctanoate is a male-produced aggregation pheromone of the African rhinoc­ eros beetle, Oryctes m onoceros (Olivier). It was identified by coupled gas chromatographic-electroantennographic detection (G C -E A D) and coupled GC-mass spectrometry (M S) of Porapak Q-trapped male-produced volatiles. Natural and synthetic ethyl 4-m ethyloctanoate elicited comparable antennal responses. In a field experiment (La Me Research Station, Cote d'Ivoire), synthetic ethyl 4-methyloctanoate released at 30 mg/day attracted both male and fem ale Oryctes, whereas the known, non-beetle-produced attractant, ethyl chrysanthemate, did not attract any Oryctes. U pon improvement of trap design and placem ent, and the identi­ fication o f synergistic (plant) volatiles, pheromone-based mass trapping may becom e an alternative and/or additional strategy to manage O. monoceros, one of the most destructive pests of commercial coconut, oil, and date palms in Africa. 
  Reference    Z. Naturforsch. 49c, 363 (1994); received October 4 1993/March 4 1994 
  Published    1994 
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 Identifier    ZNC-1994-49c-0363 
 Volume    49 
58Author    Karl-Heinz TomaschkoRequires cookie*
 Title    Defensive Secretion of Ecdysteroids in Pycnogonum litorale (Arthropoda, Pantopoda)  
 Abstract    In response to disturbance, the pycnogonid Pycnogonum litorale discharges a mixture o f eight ecdysteroids (ES). Repeated intensive m olestation causes 99% secretion o f the endogenous ES present. The concentration o f the total ES in the defensive effluent is 1.0 x 10" 3 m o lT '1. 20-Hydroxyecdysone 22-acetate, the predominant ES, reaches 0.8 x 10" 3 m ol T_1. This is sufficient to deter significantly feeding by the com m on shore crab Carcinus maenas, a generalist predator in the habitat o f the pycnogonid. There is evidence that the secreted ES o f P. litorale contribute to its unpalatability. The present paper describes for the first time defensive secretion in marine arthropods. 
  Reference    Z. Naturforsch. 49c, 367—371 (1994); received February 10 1994 
  Published    1994 
  Keywords    Pycnogonids, Pycnogonum litorale, Ecdysteroids, Defensive Secretion, Chemical Defense 
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 Identifier    ZNC-1994-49c-0367 
 Volume    49 
59Author    Hennig Stieve, Gabriele Rüsing, Weijia Yuan, H.Thomas HennigRequires cookie*
 Title    The Effects of Externally Applied Lithium and Strontium on the Arsenazo-Monitored Cytosolic Calcium Signal of the Limulus Ventral Photoreceptor  
 Abstract    The intracellular arsenazo signal indicating the transient light-evoked change in cytosolic Ca2+ (or Sr2+) concentration was measured in Lim ulus ventral photoreceptor simultaneously with the receptor potential at 15 °C. The decline of the arsenazo signal has two phases (D 1 and D 2) when the photoreceptor is bathed in physiological saline. 1. When calcium is replaced by strontium in the superfusate both receptor potential and arsenazo signal are markedly increased in amplitude and the membrane potential is hyper­ polarized. The decline of the arsenazo signal is prolonged and becom es monophasic; the fast phase D 1 of the decline disappears. 2. In strontium saline under voltage clamp conditions the slope o f the monophasic decline of the arsenazo signal is the steeper the more negative the membrane voltage. 3. After replacing sodium by lithium in the superfusate the rise of the receptor potential and of the arsenazo signal are not much altered. The decline of the arsenazo signal, however, is slowed down more than 3-fold; this is due to the complete suppression of the fast phase D1 and the retardation o f the slow phase D 2 of the calcium re-decline. Interpretation: 1. The N a -C a exchanger can accept strontium as a calcium substitute. Strontium has a weaker desensitizing action than calcium. Strontium is not -or only very little -taken up by the endoplasmic cisternae. 2. In sodium-free lithium saline the N a -C a exchanger, the N a -K ATPase and the calcium uptake system of the endoplasmic cisternae do not function. Therefore the intracellular calcium level rises. Abbreviations: Arsenazo III, 2,2'-(l,8-dihydroxy-3,6-di-sulfo-2-naphthalene-bis(azo)dibenzenearsonic acid; AS, arsenazo signal; cGMP, guanosine 3':5'-cyclic m ono­ phosphate; D l , D 2 , fast and slow phase o f decline of the arsenazo signal; EGTA, ethylene glycol-bis(ß-aminoethylether)-N,N,N',N'-tetraacetic acid; calcium chelating agent; F, area, time integral of light-evoked sig­ nal; Hmax, peak height of a light-evoked signal; IP3, ino­ sitol 1,4,5-trisphosphate; Mi, initial slope, mean slope of rise from end of latency until half height o f the signal; Mm, median slope of rise, slope of rise at half height of the signal; PMP, prestimulus membrane potential; PS, physiological saline; ReP, receptor potential, light-evoked membrane voltage signal; SRC, subrhabdomeric cisternae; Tlat, latency, time from stimulus onset to first significant start of the response; Tmax, time-to-peak from stimulus onset; Tr, rise time (Tmax -Tlat); T2, decay time, time during which the response decays from its maximum to 50% of that value. 
  Reference    Z. Naturforsch. 49c, 372 (1994); received March 14 1994 
  Published    1994 
  Keywords    Limulus Photoreceptor, R eceptor Potential, Intracellular Arsenazo Signal, Cytosolic Calcium or Strontium Transient, Lithium 
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 Identifier    ZNC-1994-49c-0372 
 Volume    49 
60Author    JamesN. Roitman, F.Javier Arriaga-GinerRequires cookie*
 Title      
 Abstract    H ypericum balearicum, Guttiferae, Glandular Products, Triterpenes, N ovel Xanthone Leaves and young twigs of Hypericum balearicum L. exhibit lipophilic glandular products that can be re­ covered by rinsing green aerial parts with acetone. Major com ponents of the resinous material are the triterpenes lupeone and lupeol. The intensely yellow col­ our of the acetone solution is due to a novel natural product, identified as 1,2,5-trihydroxyxanthone. 
  Reference    Z. Naturforsch. 49c, 393—3 (1994); received February 21 1994 
  Published    1994 
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 TEI-XML for    default:Reihe_C/49/ZNC-1994-49c-0393_n.pdf 
 Identifier    ZNC-1994-49c-0393_n 
 Volume    49 
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