bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of Labeled Lipoprotein from Escherichia coli and Proteus mirabilis after Incubation with [14C]Penicillin
Authors: Gruner Gerhard , Tadros Monier H. , Plapp Roland
Published: August 2018

[14C]penicillin binding experiments and membrane analysis were carried out with cell envelope preparations from Escherichia coli and Proteus mirabilis. After incubation with [14C] penicillin G labeled free lipoprotein could be identified. The analysis of the isolated lipoprotein by SDS polyacrylamide gel electrophoresis indicates that there is only one protein with an apparent molecular weight of 7000. The amino acid composition of isolated labeled free lipoprotein from E. coli was identical to the lipoprotein already found in E. coli. It is a point of interest that the amino acid composition of the isolated labeled free lipoprotein from P. mirabilis D52 differs from that found in other mutants of this strain. The free form of lipoprotein from P. mirabilis D52 is composed of 61 amino acids and has glycine, phenylalanine and proline as specific components.
Diversification of Chemoreceptors in Ectocarpus, Sphacelaria, and Adenocystis (Phaeophyceae)
Authors: Müller Dieter G. , Boland Wilhelm , Jaenicke Lothar , Gassmann Günter
Published: August 2018

Ectocarpene, (+)-(6S)-(1Z-butenyl)-2,5-cycloheptadiene, is the mating pherom one of the three distantly related seaweeds Ectocarpus siliculosus, Sphacelaria rigidula and Adenocystis utricularis. Analogu es of this pheromone, dif­fering in position and π-electron density of the double bond in the C4-side chain, were synthesized and assayed for biological activity. The results suggest, that the fundamen­tal molecular recognition process is conservative in all species, while receptor dynamics and -topologies have been modified by individual developments and expressions dur­ing plant phylogeny.
Nature of Yeast Cells Immobilized by Radiation Polymerization Activity Dependence on the Molecular Motion of Polymer Carriers
Authors: Fujimura Takashi , Kaetsu Isao
Published: August 2018

Higher activity of ethanol production due to higher density of yeast cells, was observed in yeast cells immobilized with artificial polymer carriers of higher molecular motion. These polymer carriers were prepared by radiation-induced polymerization below 0 °C. Yeast cells were­ immobilized with these carriers by adsorption method during multiplication. Molecular motion of polymer carriers in swollen state was evaluated by the line width of nuclear magnetic resonance spectrum. A possible reason for higher activity was discussed. This study of relation between molecular motion of polymer carriers and activity of yeast cells immobilized with these carriers, is very useful to design the chemical and physical structure of polymer carriers for immobilization of microorganisms.
Chicoree-Säure und deren Derivate aus Echinacea-Arten / Chichoric Acid and Its Derivatives from Echinacea Species
Authors: Becker H. , Hsieh W. Ch.
Published: August 2018

Echinacea angustifolia and E. purpurea contain in all plant parts chichoric acid as well as chichoric acid derivatives: chichoric acid methyl ester and chichoric mono and dimethylether.
Degradation of Bacteriochlorophyll a in Rhodopseudomonas sphaeroides R26
Authors: Haidl H. , Knödlmayr K. , Rüdiger W. , Scheer H . , Schoch S. , Ullrich J.
Published: August 2018

A series of pigments of the bacteriopheophytin a spectral type have been isolated from ageing cultures of Rhodopseudomonas sphaeroides strain R26. These pigments are formed in varying amounts, and can be most readily analyzed in vivo by their absorption in the 530 nm spectral range. They are enriched in sedimenting cells, but their formation is not affected by light. By chromatographic comparison with authentic pigments and chemical correlation, the following pigments have been identified: bacteriopheophytin a, bacteriopheophorbide a (which is the predominant product), pyrobacteriopheophorbide a and a fourth, very polar bacteriopheophytin a-type product of unknown structure. The major portion of these newly formed pigments is present in the cells in a state, in which the near-infrared absorption band is shifted to longer wavelengths. As shown by low temperature fluorescence spectroscopy, these forms are very similar to bacteriopheophorbide a aggregates.
Water Relations in Young Growing Wheat Leaves after Application of (2-Chloroethyl)trimethyl- ammoniumchloride (CCC) to the Roots of Wheat Seedlings
Authors: Bode Jutta , Wild Aloysius
Published: August 2018

The influence on the water relations of the third developing leaf of (2-chloroethyl)trimethylammoniumchloride, a synthetic growth regulator, applied to the roots of young wheat plants (Triticum aestivum L.) has been investigated. The tissue water potential and the pressure potential were found to be reduced by several bars in comparison to the untreated controls, whereas the osmotic potential remained unchanged. The content of soluble reducing sugars was considerably increased in the cell sap of CCC-treated leaves. With this accumulation, however, the turgor was not maintained. Additionally, CCC-treated leaves showed considerably lower transpiration rates and higher diffusive resistance than the controls. Thus, the application of CCC to the roots causes alterations in the water relations of developing wheat leaves, which resemble those induced by water deficiency.
Relative Hypertrehalosaemic Activities of Naturally Occurring Neuropeptides from the AKH/RPCH Family
Authors: Gäde Gerd
Published: August 2018

Dose-response curves for the ability to increase blood carbohydrates of the cockroach are compared for various naturally occurring neuropeptides from the corpus cardiacum of different insect species. The peptides investigated are the (decapeptides) locust adipokinetic hormone I (AKH I) and stick insect hypertrehalosaem ic factor II. as well as the (octapeptides) cockroach hypertrehalosaemic horm ones I and II (M I and M II), adipokinetic hormone II from the migratory locust (AKH II-L), and the crustacean red pigment-concentrating hormone (RPCH ). The data show clearly that M I and M II display almost identical dose-response curves with a maximal response at about 5 pmol and ED50 values (the amount of peptide which is needed to produce 50% of the hypertrehalosaemic response) of 1.9 and 1.8 pmol. respectively. The stick insect peptide is remarkably more potent (ED 50 value: 0.9 pmol), but the other decapeptide. AKH I, gives only about a 70% response com pared with M I and M II. as does the octapeptide RPCH. The ED 50 values of those peptides are 5.9 and 4.5 pmol, respectively. Biological activity after injection of AKH II-L, which lacks a proline residue in the molecule, is only measurable at pharmacologically high doses. An attempt is made to relate the observed differences in the doseresponse relationships to the amino acid sequences of the neuropeptides.
Transepithelial Cytophagy by Trichoplax adhaerens F. E. Schulze (Placozoa) Feeding on Yeast
Authors: Wenderoth Heinz
Published: August 2018

After accidental observations of unicellular algae trapped in the intermediate layer of Trichoplax, dead yeast cells were offered systematically as a food. Some of them could be found several hours later engulfed by the big tetraploid fibre cells closely beneath the dorsal epithelium of the animal. This thin epithelial sheet not only allows the expulsion of accumulated waste substances by temporal separation of the cell connections but obviously gives also access to food particles collected previously on the dorsal surface by flagellar movements. Thus, the uppermost cell layer of Trichoplax permits the passage of corpuscles of limited size between its cells.
Notizen: Effect of Magnetic Field on Ascorbic Acid Oxidase Activity, I
Authors: Ghole V. S. , Damle P. S. , Thiemann W. H.-P.
Published: August 2018

A homogeneous magnetic field of 1.1 T strength exhibits a significant influence on the activity of the enzyme ascorbic acid oxidase in vitro. A Lineweaver-Burk plot of the reaction shows the typical pattern of a mixed-type inhibition, i.e. a larger rate of reaction at low substrate concentrations and a smaller rate of reaction at high substrate concentration than that of the control without magnetic field applied.
Indole Alkaloids from Ochrosia elliptica Plant Cell Suspension Cultures
Authors: Pawelka Karl-Heinz , Stöckigt Joachim
Published: August 2018

From cell suspension cultures of Ochrosia elliptica Labill. eight different monoterpenoid indole alkaloids were isolated and comprised three alkaloid classes viz. Corynanthe/Heteroyohimbine (tetrahydroalstonine, cathenamine, pleiocarpamine and two methoxylated heteroyohimbines), Strychnos (norfluorocurarine), Apparicine (apparicine and epchrosine). A ll these compounds except the Strychnos alkaloid are biogenetically closely related to the known alkaloids occurring in Ochrosia plants, although such alkaloids have not previously been detected in O. elliptica. Epchrosine has not before been described as a natural product.
Tyrosine Biosynthesis in Sorghum bicolor: Isolation and Regulatory Properties of Arogenate Dehydrogenase
Authors: Connelly James A. , Conn Eric E.
Published: August 2018

The conversion of prephenic acid to tyrosine can occur by two different routes: (a) oxidative decarboxylation (prephenate dehydrogenase) followed by transamination (aromatic aminotrans­ ferase); (b) transamination of prephenate forming the non-aromatic amino acid arogenic acid (prephenate am inotransferase) followed by oxidative decarboxylation (arogenate dehydrogenase).

High activity of arogenate dehydrogenase was found in extracts of etiolated sorghum seedlings, while no evidence of prephenate dehydrogenase was observed. Arogenate dehydrogenase from sorghum eluted, with high recovery of activity (93%), as a single peak on DEAE-cellulose chromatography. The enzyme was strongly inhibited by tyrosine but was unaffected by phenylala­nine, prephenate, or tryptophan. Kinetic analysis showed that tyrosine inhibition was competitive with arogenate and that the Ki for tyrosine (61 μm) was much smaller than the Km for arogenate (350 μm).

The properties of arogenate dehydrogenase indicate that this enzyme is important in the regula­tion of tyrosine biosynthesis in sorghum. Strong inhibition of the enzyme by tyrosine may indicate that arogenate is a branch point in the shikimate pathway in plants and therefore arogenate may be a precursor to phenylalanine and the numerous phenylpropanoid secondary metabolites deriv­ed from phenylalanine.
High Performance Liquid Chromatography Coupled with Radioactivity Detection: A Powerful Tool for Determining Drug Metabolite Profiles in Biological Fluids
Authors: Vollmer K.-O. , Klemisch W. , Hodenberg A. von
Published: August 2018

High performance liquid chromatography coupled with continuous radioactivity detection rep­resents an advancement in drug metabolism research. Using radioactive substances labelled in biologically stable positions, all metabolites can be specifically detected by radioactivity measure­ment. Thus no clean-up of biological fluids is required prior to HPLC. This can prevent artefact formation from unstable metabolites, reduces recovery problems and facilitates quantitation. Separation of highly polar and unpolar metabolites is possible in a single chromatographic run using gradient elution and reversed phase materials. This technique is also well-suited for prepara­tive isolation and purification of metabolites for subsequent structure elucidation.

Various metabolite profiles of drugs labelled with carbon-14 or tritium are shown. Metabolites of the following drugs are presented: norfenefrine, etozolin, thymoxamine, naloxone, and levobunolol. We review the general methodology and report our experience with this technique. In principle, this technique may be useful for all biological systems in which tracer techniques are applied.
Cyanophora paradoxa: Fatty Acids and Fatty Acid Synthesis in vitro
Authors: Kleinig Hans , Beyer Peter , Schubert Carmen , Liedvogel Bodo , Lütke-Brinkhaus Friedhelm
Published: August 2018

The fatty acid pattern of Cyanophora paradoxa membrane lipids is highly unusual with 16:0, 20:3 and 20:4 as the main acids. The 20:4 acid is preferentially distributed among the cyanelle lipids. In isolated cyanelles a relatively low in vitro synthesis of only saturated and monounsatu­rated fatty acids from [l-14C]acetate was observed which corresponds to the relatively low photo­synthetic oxygen evolution.
Phosphoenolpyruvate Carboxylase from Maize Leaves. Studies Using β-Methylated Phosphoenolpyruvate Analogues as Inhibitors and Substrates
Authors: Gonzalez Daniel H. , Andreo Carlos S.
Published: August 2018

1. The phosphoenolpyruvate analogues phosphoenol-α-ketobutyrate and phosphoenol-α-ketoisovalerate are linear competitive inhibitors of maize leaf phosphoenolpyruvate carboxylase with respect to phosphoenolpyruvate. Phosphoenol-α-ketobutyrate is an excellent inhibitor (Ki: 18 μm in the presence of 5 mM MgCl2). The inhibition constant for phosphoenol-α-ketoisovalerate is 0.38 mᴍ under the same conditions. For both compounds, the inhibition is greater in the presence of Mn2+ than with Mg2+. 2. The analogues are dephosphorylated, but apparently not carboxylated, by the enzyme. For the reaction with phosphoenol-α-ketobutyrate, α-ketobutyrate and inorganic phosphate are the reaction products. Bicarbonate and a divalent cation are required for the dephosphorylation reaction. 3. The dephosphorylation reaction is activated by glucose-6-phosphate and the Vmax has the same pH dependence as that of the carboxylation of phosphoenol­ pyruvate. The Km for phosphoenol-α-ketobutyrate is reduced in the presence of 5 mᴍ MnCl2 (55 μᴍ versus 140 μᴍ with 5 mM MgCl2). The Vmax is essentially the same in the presence of either MgCl2 or MnCl2. These results suggest that the dephosphorylation of the analogues occurs by a mechanism which is similar to that of the carboxylation of phosphoenolpyruvate, and that both reactions have a common rate-determining step.
Purification of the Chloroplast Pyruvate Dehydrogenase Complex from Spinach and Maize Mesophyll
Authors: Treede Hans-Jürgen , Heise Klaus-Peter
Published: August 2018

This paper deals with the partial purification of the pyruvate dehydrogenase complex (PDC) from chloroplasts of spinach and maize mesophyll which hitherto has been isolated only from pea chloroplasts. Starting with membrane free suspensions of lyophilized chloroplasts, and following a high-speed (140000 Xg) centrifugation of this “stromal extract”, the initial specific PDC-activities were concentrated by a factor 10 in the sediment. While most of the purification procedures described earlier resulted in almost complete loss of enzyme activities, a rate zonal sedimentation on linear glycerol gradients allowed for an additional up to 100-fold enrichment of the labile multienzyme complex, albeit with low yields. In contrast to chloroplast PDC from maize mesophyll, inactivation of the spinach complex during glycerol fractionation was due to the dissociation of its loosely bound dihydrolipoyl dehydrogenase component which collected in a lower density fraction of the gradient. Its recombination with PDC constituents of the bottom layer nearly restored initial activities.

The chloroplast complex has been identified as true PDC by its substrate specificity for pyru­vate, NAD+, and coenzyme A and the 1:1:1 stoichiometry of its reaction products NADH, CO2, and acetyl-CoA.

The chloroplast PDC of both plant species showed the well known higher pH-and Mg-requirements than the mitochondrial complex. The observed species-specific differences in the stability of this multienzyme system suggest a connection with the aggregation state of its components. Apparently, the individual subcomplexes are able to function either together in acetyl-CoA formation or independently from each other, e.g. in the synthesis of acetolactate via hydroxy-ethyl-thiamine pyrophosphate or dihydrolipoyl dehydrogenase activities.
Adsorbent Culture of Tobacco Cell Suspensions with Different Adsorbents
Authors: Maisch R. , Knoop B. , Beiderbeck R.
Published: August 2018

The release of secondary substances from plant cell suspensions can be enhanced by the addition of adsorbents to the culture medium. Tobacco cells react to a variety of different adsor­bents (Florisil. raw silk. Polyclar AT. and the adsorber resins XAD-4 and XAD-7) with important qualitative and quantitative changes of their secondary substance pattern, in some cases without changes of growth.
Evidence for the Intercalation of Thalidomide into DNA: Clue to the Molecular Mechanism of Thalidomide Teratogenicity?
Authors: Koch Heinrich P. , Czejka Martin J.
Published: August 2018

The intercalation of thalidomide (a-phthalimidoglutarimide) into nucleic acids was studied by spectrophotometric titrations, displacement of known intercalators, viscosity changes of DNA solutions, and by phase partition analysis. Specific binding of thalidomide was found to DNA of various specimens (human placenta, calf thymus, salmon sperm), but not to RNA (from bakers yeast, torula yeast).
Formation and Structure of Radicals from ᴅ-Ribose and 2-Deoxy- ᴅ-ribose by Reactions with SO4
·̅ Radicals in Aqueous Solution. An in-situ Electron Spin Resonance Study
Authors: Herak Janko N. , Behrens Günter
Published: August 2018

ESR spectroscopy has been used to analyse the conformation of the radicals produced by the reaction of SO4
·̅ with ᴅ-ribose (1), and 2-deoxy-ᴅ-ribose (6), at pH 1.3-5. From ribose three different types of radicals formed by H abstraction at C-1, C-2 and C-3 followed by a regio-selective α,β-water elimination have been identified: the 2-deoxy-ribonolacton-2-yl (3), the 1-deoxy-pentopyranos-2-ulos-1-yl (4). and the 4-deoxy-pentopyranos-3-ulos-4-yl (2). Using deoxyribose two radicals of similar type, formed by H abstraction at C-3 and C-4 followed by water elimination, have been observed: the 2,4-dideoxy-3-ulos-4-yl (7) and the 2,3-dideoxy-4-ulos-3-yl (8). In addition, from both sugars an a-hydroxyalkyl radical has been identified based in part on the timing of their conformational motions: the ribos-3-yl (5) (the precursor of 2) and the 2-deoxy-ribos-1-yl (9), respectively. For radical 5 the rate constant k(e) for the water elimination and hence transformation into radical 2 was estimated. From the analysis of selective line broadening the frequencies of conformational changes of radicals 2 and 7 have been estimated. For 7 the frequencies of exchange of the two methylene groups were found to differ by more than 3 orders of magnitude.
Alkylene-bis-isothiocyanates: Novel Insect Growth Regulators
Authors: Matolcsy György , Ujváry István
Published: August 2018

In search for selective anti-insect agents some mono- and bis-isothiocyanates were prepared and tested on third instar larvae of Manduca sexta. The alkylene-bis-isothiocyanates 4, 5 and 6 had a novel effect preventing formation of the abdominal spiracles and of the hooks (crochets) at the following molt to the 4th instar. Some of these larvae died in the molt, while spiracles remained absent also in the larvae which were able to molt to the 5th instar. Histological examination indicated a selective destruction of spiracle forming cells. This novel action might serve as starting point of a new approach in selective insect control.
The Effect of Volatile Anesthetics on Giant Neurons in the Lobula Plate in the Fly
Authors: Kirschfeld K.
Published: August 2018

Movement sensitive giant neurons in the lobula plate of the fly (H1-neurons, V-neurons) are affected by low con­centrations of volatile anesthetics (halothane, N2O): the spike frequency generated by motion in the preferred di­rection decreases, that in the opposite direction increases. This means that the response to the motion stimulus de­fined as the spike frequency modulation decreases. Higher concentrations of the anesthetics lead to an increasing spike frequency which is unaffected by the motion stimulus, until eventually no spikes are generated any longer. The results are in agreement with the assumption that the anesthetics increase the membrane permeability of these neurons.
Pflanzenabwehrstoffe XXIX [1]. Isolierung, Charakterisierung und Synthese von Turgorinen aus Gleditsia triacanthos L. / Plant Defense Substances XXIX [1]. Isolation, Characterization and Synthesis of Turgorines from Gleditsia triacanthos L.
Authors: Schildknecht Hermann , Muley Ralf , Kresbach Gerhard M. , Kunzelmann Peter , Krauß Dietlinde
Published: August 2018

Gleditsia triacanthos L. (honey locust), a plant of the widespread family Leguminosae, shows strong nyctinastic behaviour. Guided by the bioassay, a number of turgor influencing substances - PLMF 1, PLMF 3, PLMF 4, PLMF 5 and PLMF 6 - could be isolated and characterized from aqueous extracts of this plant. Structure and biological relevance of this phenolic-acid-glycosidesulfates are confirmed by synthesis. The multitude and the graduated biological activity of that factors suggests a biological way of irritation, who is after all responsible for the nyctinasty of G. triacanthos.
Effects of Adenosine-3′: 5′-monophosphate (cAMP) on the Activity of Soluble Protein Kinases in Maize (Zea mays) Coleoptile Homogenates
Authors: Janistyn B.
Published: August 2018

Seven protein kinases (PI-PVII) from maize (Zea mays) coleoptile homogenates could be detected which phosphorylate a histone-substrate in a polyacrylamide-matrix. The kinases PI, PII and PVI were stimulated by 6 μм cAMP, PHI, PIV and PV were cAMP independent, while PV II was inhibited by 6 μм cAMP.
The Activation of the Cytochrome P-450 Dependent Monooxygenase System by Light
Authors: Müller-Enoch D. , Gruler H.
Published: August 2018

The cytochrome P-450 dependent monooxygenase system of rat liver microsomes is investi- gated by light dosimetry (action spectroscopy). The scoparone-O-demethylation activity is en- hanced by light and depends on the wavelength of the irradiating light. The relative increase of the activity (about 15%) by the irradiating light (~ 0.5 mW/cm2) is maximal at a wavelength of 400 nm.

The light induced enhancement of the 7-ethoxycoumarin-O-deethylase activity was measured in reconstituted systems, consisting of one of the two P-450 enzymes (P-450βNF-B and P-450PB-B) with the NADPH-cytochrome P-450 reductase. The action spectrum of the reconstituted P-450βNF-B: NADPH-P-450 reductase complex shows a maximum between 420 and 440 nm. The relative increase of the activity induced by light of 420 nm was 7.3% and 9% for the reconstituted systems of P-450βNF-B and P-450PB-B. respectively. The results are discussed in analogy to the classic experiments of Warburg with its blocked CO- enzyme-complex.

The results can best be explained by the assumption that the light induced enhancement of the enzyme activity is due to an excitement of those intermediate states of the P-450 catalytic cycle (ferric and ferrous state of the heme iron) which are rate limiting.
Polymerization of Actin in the Absence and Presence of Cytochalasin B: Problems of Determining "Critical Concentration"
Authors: Fussmann Bernd , Dancker Peter
Published: August 2018

Various concentrations of actin (0.3 or 1 mᴍ MgCl2, 1 mᴍ ATP , 1 mᴍ EGTA) reached their final degree of polymerization (measured by a pyrene dye attached to actin) earlier in the presence of cytochalasin B than in its absence. The curves relating concentrations of polymeric F-actin to total actin concentration were under these conditions highly nonlinear making an unam biguous extrapolation to zero F-actin concentration (to deduce the “critical concentration” of actin poly­ merization) im possible. The concentration of actin, above which polymerization occurred, was unaltered by cytochalasin B (although for reasons not yet understood the specific fluorescence intensity of polymerized actin was lower in the presence of cytochalasin B than in its absence). The results show that a distinct “critical concentration” of actin polymerization must not always be well defined.
Triplet-Selective Chemistry : a Possible Cause of Biological Microwave Sensitivity
Authors: Keilmann Fritz
Published: August 2018

A hypothesis is proposed to explain resonant biological effects of microwaves. The interaction is thought to occur with low-frequency electronic transitions of transient triplet (or quartet etc.) molecules. As the transient molecules’ substate populations can be assumed to be far from thermal equilibrium the effect of resonant microwaves would be to equalize the population of two substates. Since the overall chemical reactivity of a molecule depends on its substate the result is an overall change of the molecules’ reaction rate which may cause further changes in the biochemical pathway.

The model can in principle account for fixed frequencies, narrow linewidths and low saturation thresholds as are reported to be characteristic of biological sensitivity to millimeter waves [1-4], The interaction at the molecular level predicts identical resonances in widely different living objects. These resonances may offer a useful tool in biology and they can furthermore influence the discussion of microwave environmental impact.
2-Hydroxy-4-methoxy-5-methyIpyridin-N-oxid, ein Al3+ bindender Metabolit von Pseudomonas cepacia [1] / 2-Hydroxy-4-methoxy-5-methyl Pyridine N-Oxide, an Al3+ Complexing Metabolite from Pseudomonas cepacia [1]
Authors: Winkler St. , Ockels W. , Budzikiewicz H. , Korth H. , Pulverer G.
Published: August 2018

It is shown that 2-hydroxy-4-methoxy-5-methyl pyridine N-oxide isolated from Pseudomonas cepacia which is known as a siderophore has a comparable complexing capacity for Al3+.
An Elicitor of the Hypersensitive Lignification Response in Wheat Leaves Isolated from the Rust Fungus Puccinia graminis f. sp. tritici I. Partial Purification and Characterization
Authors: Moerschbacher B. , Kogel K. H. , Noll U. , Reisener H. J.
Published: August 2018

Several biotic and abiotic clicitors of the hypersensitive reaction in wheat leaves are described. The elicitors induce enhanced activity of phenylalanine ammonia-lyase with subsequent lignifica­tion, visible as a yellow autofluorescence. The deposited material stains positively with phloroglucinol. DEAE-dextran, epoxystearic acid and chitosan are strong elicitors, while the glucans tested have no activity.

A biotic elicitor (genuine Pgt-elicitor) was isolated from the germ tube walls of uredospores of Puccinia graminis f. sp. tritici. The high molecular weight, water soluble elicitor is heat stable and unaffected by mild acid and mild alkaline treatments. It seems to be a glycoprotein with the carbohydrate moiety bearing the active residues, as indicated by periodate sensitivity and pro­tease stability. The carbohydrate moiety consists mainly of glucose with some galactose and mannose.

Upon ultrafiltration and gel chromatography elicitor activity was associated with fractions of molecular weight of more than 100 kD.

When injected into the intercellular space of primary wheat leaves, the elicitor induces lignifica­tion, preceded by an increase in phenylalanine ammonia-lyase activity.
Photodestruction of Endogenous Porphyrins in Relation to Cellular Inactivation of Propionibacterium acnes
Authors: Melø Thor B. , Reisæter Gro
Published: August 2018

During growth of Propionibacterium acnes on Eagles medium protoporphyrin was accumulated inside the cells and coproporphyrin, both as a free base as metalcontaining, outside the cells. The photochemical processes in the endogenous porphyrins were studied by fluorescence spectroscopy during continuous irradiation of Propionibacterium acnes in suspension. The irradiation caused initially an increase in the content of protoporphyrin in the cells in comparison to that which had been accumulated during growth. Maximum light induced protoporphyrin production was achieved in 5 days old cultures. In old cultures where there was practically no initial protoporphy­rin release, the fluorescence intensities from all the porphyrins present in the culture vanished exponentially with the irradiation time. The metal containing form of fluorescent coproporphyrin, with a maximum emission at 580 nm, was photobleached about ten times faster than the free base forms of coproporphyrin and protoporphyrin. Among these three fluorescent substances in the cell culture only the free base forms of the porphyrins have longer lifetimes than the cells themselves irradiated at the same conditions.
Specific Binding of Calcium to Soluble Chromatin
Authors: Brust Rüdiger
Published: August 2018

Equilibrium dialysis studies and sedimentation experiments with soluble rat liver chromatin and radioactive 45Ca support the hypothesis that there is a specific binding of Ca2+ to chromatin molecules. At low ionic strength the binding constant is about 12 1/mᴍ indicating that more than half of the negative charges of the chromatin molecules are neutralized due to the binding of Ca2+ at appropriate concentrations. This effect possibly accounts for low concentration of Ca2+ and other divalent cations being effective in inducing compact higher order structures of chromatin. Monovalent cations are not specifically bound, but high concentrations cause unspecific shielding of the charges on the chromatin molecules and thus structural transformation. Even under these high salt conditions a specific binding of Ca2+ to chromatin occurs. The binding constant is, however, only 0.4 1/mᴍ due to the lower effective concentration of the charged chromatin molecules which is reduced by unspecific neutralizing.
(R)MandeIonitrile and Prunasin, the Sources of Hydrogen Cyanide in All Stages of Paropsis atomaria (Coleoptera: Chysomelidae)
Authors: Nahrstedt A. , Davis R. H.
Published: August 2018

(R)Mandelonitrile and the cyanogenic glucoside prunasin have been established as the source of HCN in all stages of the Australian beetle Paropsis atomaria. Quantitative data for both compounds and all life stages are presented. The larvae contain a β-glucosidase activity capable of hydrolysing prunasin and also β-cyanoalanine synthase activity enabling the disposal of free cyanide.
Cell-Free Synthesis of the Alkaloids Ammodendrine and Smipine
Authors: Wink Michael , Witte Ludger
Published: August 2018

The bipiperidyl alkaloid ammodendrine was detected in 28 plant species as a minor alkaloid besides quinolizidine alkaloids. Cadaverine serves as a precursor for both quinolizidine alkaloids and for ammodendrine, since labelled cadaverine is incorporated into both rings of ammoden­drine. Cell-free extracts of Lupinus arboreus and of Pisum sativum, which contain an active diamine oxidase form ammodendrine from cadaverine and pyruvate. In addition to ammoden­drine other alkaloids such as smipine, tetrahydroanabasine and tripiperideine could be detected. Possible reaction schemes are discussed.
Molecular Mechanics Investigation on Side-Chain Conformations of a 17α-Ethyl-17β-hydroxy Steroid with Regard to Receptor Binding
Authors: Bohl Martin
Published: August 2018

Energetically favourable conformations for simultaneous intramolecular rotations of both the 17 α ethyl side chain and the 17 β hydroxyl group of a model steroid are calculated by MM2 molecular mechanics. In accordance with recent IR and NMR interpretations, the 17α substituent is found to preferably adopt conformations which may sterically hinder the formation of hydrogen bonds between the steroidal 17β oxygen atom and the receptor protein. Furthermore, the 17a ethyl substitution is computed to influence the D-ring conformation and to alter the location of the 17β oxygen function by 28 pm in space.
Further Characterization of Chickpea Isoflavone 7-O-Glucoside- 6"-O-malonate: malonylesterase: Evidence for a Highly Specific, Membrane-Bound Enzyme in Roots of Cicer arietinum L.
Authors: Hinderer Walter , Köster Johannes , Barz Wolfgang
Published: August 2018

The specific malonylesterase from chickpea (Cicer arietinum L.), hydrolyzing biochanin A 7-O- glucoside-6″-O-malonate (BGM), has been purified to apparent homogeneity and characterized recently (Hinderer et al., Arch. Biochem. Biophys. 248, 570-578 [1986]). Its substrate specificity as well as the high molecular mass of the native enzyme were further investigated. The 5-deoxy- isoflavone conjugate corresponding to BGM, the formononetin 7-O-glucoside-6,,-O-malonate (FGM), was shown to be a substrate of the malonylesterase essentially as BGM. By contrast, methyl-BGM, a diester of malonic acid was a poor substrate. The purified enzyme completely lacked thioesterase activity with malonyl-CoA as substrate. The inability of the malonylesterase to hydrolyze synthetic acetyl or propionyl esters was further demonstrated with a highly sensitive fluorometric assay using esters of 4-methylumbelliferone. The enzyme-catalyzed hydrolysis of BGM was stimulated in the presence of dissociated carboxylic acids like citrate which was most effective at 30 mM and pH 7.5-8.0.

The purified malonylesterase as well as the enzyme activity in crude extracts were totally excluded in gelchromatography with Ultrogel AcA 22. The enrichment of the enzyme activity in microsomal fractions gave strong evidence that the malonylesterase is membrane-bound in vivo. Stimulation of the enzyme activity in vitro by detergents indicates the presence of lipid material in the enzyme and the activity profiles obtained after sedimentation analyses suggest that purifica­tion of a distinct membrane-protein complex had been achieved.
The Effect of Phosphinothricin (Glufosinate) on Photosynthesis I. Inhibition of Photosynthesis and Accumulation of Ammonia
Authors: Wild Aloysius , Sauer Heidrun , Rühle Wolfgang
Published: August 2018

Phosphinothricin (glufosinate) is an irreversible inhibitor of glutamine synthetase in plants. En­zyme inhibition results in substantial light-dependent accumulation of ammonia, inhibition of photosynthesis and ultimately the death of the plants. First of all the metabolic processes in which NH3 is liberated were established. Comparative investigations under photorespiratory and non- photorespiratory conditions with Sinapis alba plants revealed that about 60% of the accumulated NH3 derives from photorespiration. Trials with PPT and KNO3 showed that nitrate assimilation is insignificant as a source of NH3, and so the remaining 40% is accumulated in catabolic or anabolic processes. Under photorespiratory conditions CO2 fixation after treatment with 1 mᴍ PPT finally fell below the compensation point, and this was independent of the addition of nitrate. In non- photorespiratory conditions, by contrast, photosynthesis continued at a level of over 80% for several hours in entire plants and in severed leaves, although at the same time substantial amounts of ammonia had accumulated.
Phenylalanine and Tyrosine Biosynthesis in Sporeforming Members of the Order Actinomycetales
Authors: Hund Hilda-K. , Keller Brigitte , Lingens Franz
Published: August 2018

The enzymes of the terminal steps of phenylalanine and tyrosine biosynthesis, chorismate mutase, prephenate dehydratase, arogenate dehydratase, prephenate dehydrogenase and aroge­ nate dehydrogenase were studied in 13 sporeforming members of the order Actinomycetales. In these organisms tyrosine is synthesized exclusively via arogenate, phenylalanine, however, via phenylpyruvate. The regulation pattern of the corresponding enzymes was determined: No feed­ back inhibition of arogenate dehydrogenase by L-phenylalanine and ʟ-tyrosine was observed. Chorismate mutase was found to be inhibited in all organisms by ʟ-tyrosine and in most organisms by ʟ-tryptophan. ʟ-Phenylalanine was shown to inhibit prephenate dehydratase in the majority of bacteria tested and ʟ-tyrosine activated this enzyme in most cases.

The elution profiles for the phenylalanine and tyrosine biosynthetic enzymes were studied in three members of the order Actinomycetales by anion exchange chromatography on DEAE-cellulose.
Enzymatic Synthesis of Riboflavin and FMN Specifically Labeled with 13C in the Xylene Ring
Authors: Sedlmaier Helmut , Müller Franz , Keller Paul J. , Bacher Adelbert
Published: August 2018

The condensation of 3-hydroximino-2-butanone (1) with 5-amino-6-ribitylamino-2,4(1H,3H)- pyrimidinedione (2) yields 6,7-dimethyl-8-ribityllumazine (3). At slightly alkaline pH, the car­bonyl group of 1 reacts preferentially with the 5-amino group of 2 (regioselectivity, 4:1). Under acidic conditions, the reaction occurs with higher yield and marginal regioselectivity of opposite direction (1:1.4). Appropriately 13C-labeled samples of 1 afford 3 labeled at C-6α, C-6, C-7 or C-7α. [6α,7α-13C2]-3 was prepared by condensation of 2 with [1,4-13C2]diacetyl. The lumazines 3 were converted to riboflavin by the enzyme, riboflavin synthase, with almost quantitative yield. By this procedure, any C-atom of the carbocyclic moiety of riboflavin can be selectively labeled with 13C at high abundance. Phosphorylation yields the respectively 13C-labeled FMN samples.
Biopterin Synthesis in Mouse Spleen during Bone Marrow Transplantation Correlates with Unimpaired Hemopoietic Engraftment
Authors: Ziegler Irmgard , Thierfelder Stefan
Published: August 2018

Normal engraftment of bone marrow transplants depends on histocompatibility between donor and recipient. In this case reconstitution of hemopoiesis and lymphopoiesis in the mouse spleen is correlated with transient biopterin synthesis in these cells. Allogeneic bone marrow progeny cells undergo donor cell proliferation in the spleen prior to the incidence of graft-versus-host reaction. These cells are not committed to biopterin synthesis. Thy-1 monoclonal antibody fully repairs engraftment of allogeneic transplants together with biopterin synthesis.
Effect of pH on Glycolate and Ammonia Excretion in L-MSO Treated Chlorella Cells
Authors: Shiraiwa Yoshihiro , Schmid Georg H.
Published: August 2018

The effect of pH changes on the excretion of ammonia and glycolate from algal cells into the medium was investigated in L-MSO (final concentration, 0.5 mм) -treated High-and Low CO2-cells of Chlorella vulgaris 211-11 h. The excretion was analyzed in the condition in which the cells were continuously gassed with air at 25 °C. At the values tested, generally more ammonia was excreted in L-MSO-treated Low CO2-cells than in L-MSO treated High CO2-cells. In both kinds of algal cells more ammonia was excreted at low pH-values and absolutely no ammonia was excreted at pH 8. In the dark, no or only slight ammonia excretion was observed in both L-MSO-treated High and Low CO2-cells. Under all these conditions no or only very low glycolate excretion was observed in both L-MSO treated High and Low CO2-cells.

In High CO2-cells rates of photosynthesis were high at pH 6 and lower at higher pH values. On the other hand Low CO2-cells showed practically little dependence of photosynthetic rates on the pH. This result might indicate that the major part of the ammonia excretion observed, was not due to the inhibition of photosynthesis at acid pH values. It is known that ammonia excretion in L-MSO treated algal cells is due to the inhibition of the refixation of ammonia which originates from the glycine-serine aminotransferase reaction in the glycolate pathway. Our results demonstrate that glycolate production and glycolate metabolism are more intense at low pH values when compared to high pH values. This is valid for both High and Low CO2-cells. Low CO2-cells in Chlorella vulgaris 211-11 h exhibit a more active glycolate metabolism than High CO2-cells.
Enzymatic Acyloin Condensation of Acyclic Aldehydes
Authors: Abraham Wolf-Rainer , Stumpf Burghard
Published: August 2018

Corynespora cassiicola DSM 62474 and Diplodia gossypina ATCC 10936 were found to cleave some acyclic terminal terpendiols and prolongate them later by addition of a C2-unit to afford 1,2-dihydroxy-propyl-compounds. The enzymes involved in this reaction from both microorganisms displayed a strong stereoselectivity which is completely different in both strains. The stereochemi­cal requirements of the substrates for both strains and the mechanism were elucidated by using closely related substrates. The absolute configuration of the diols were solved by correlation with com pounds of known absolute configuration.
Spontaneous Release of Malondialdehyde from Ultraviolet Light Exposed Liposomal Membranes
Authors: Agarwal Sanjiv , Ghosh Anusua , Chatterjee S. N.
Published: August 2018

UV absorption spectroscopy revealed the presence of MDA with characteristic maximum at about 266 nm in the dialysate of the UV irradiated liposomal suspension. The amount of MDA released increased linearly with increasing UV dose. The fluorescence method for the assay of MDA was found nearly 1500-fold more sensitive than the TBA colour reaction method.
Pyrimidine Homoribonucleosides: Synthesis, Solution Conformation, and Some Biological Properties
Authors: Lassota Piotr , Kuśmierek Jarosław T. , Stolarski Ryszard , Shugar David
Published: August 2018

Conversion of uridine and cytidine to their 5′-O-tosyl derivatives, followed by cyanation with tetraethylammonium cyanide, reduction and deamination, led to isolation of the hitherto un- known homouridine (1-(5′-deoxy-β-D-allofuranosyl)uracil) and homocytidine (1-(5′-deoxy-β-ᴅ-allofuranosyl)cytosine), analogues of uridine and cytidine in which the exocyclic 5′-CH2OH chain is extended by one carbon to CH2CH2OH. Homocytidine was also phosphorylated to its 6′-phosphate and 6′-pyrophosphate analogues. In addition, it was converted, via its 2,2′-anhydro derivative, to arahomocytidine, an analogue of the chemotherapeutically active araC.

The structures of all the foregoing were established by various criteria, including 1H and 13C NMR spectroscopy, both of which were also applied to analyses of the solution conformations of the various compounds, particularly as regards the conformations of the exocyclic chains.

The behaviour of the homo analogues was examined in several enzymatic systems. Homo- cytidine was a feeble substrate, without inhibitory properties, of E. coli cytidine deaminase. Homocytidine was an excellent substrate for wheat shoot nucleoside phosphotransferase; while homouridine was a good substrate for E. coli uridine phosphorylase. Although homoCMP was neither a substrate, nor an inhibitor, of snake venom 5′-nucleotidase, homoCDP was a potent inhibitor of this enzyme (Ki~6 μм). HomoCDP was not a substrate for M. luteus polynucleotide phosphorylase. None of the compounds exhibited significant activity vs herpes simplex virus type 1, or cytotoxic activity in several mammalian cell lines.
Cyanoacrylate Inhibitors of Photosynthetic Electron Transport in Atrazine Susceptible and Atrazine Resistant Brassica Chloroplasts
Authors: Phillips John N. , Huppatz John L.
Published: August 2018

Comparison of the p/50 values for a series of cyanoacrylate derivatives in chloroplasts isolated from atrazinc susccptiblc (wild type) and atrazine resistant (mutant) Brassica napus biotvpes reveal that the degree and direction of discrimination can vary from being 200- fold more active against the wild type to 10-fold more active against the mutant. There appears to be a direct correlation between the level of inhibitory activity in thylakoids isolated from “susceptible” chloroplasts and the level of discrimination between “susceptible” and “resistant” chloroplasts - a correlation which can be improved by allowing for variations in molecular hydrophobicity. Studies with optically active ethoxyethyl-3-alkyl-2-cyano-3-α-methylbenzylamino acrylates suggest that there are specific receptor sites present in both “susceptible” and “resistant” chloroplasts for both the a-methylbenzyl chiral centre and the 3-alkyl moiety. There is a direct relationship between photosynthetic electron transport inhibitory activity and herbicidal activity of optical isomers.
Irreversibly Binding Photosynthetic Electron Transport Inhibitors II. Halogen-Substituted 1,4-Naphthoquinones and Halogenmethyl-1,4-quinones
Authors: Oettmeier Walter , Dostatni Ralf , Santel Hans-Joachim
Published: August 2018

Several halogen-substituted 1,4-naphthoquinones have been synthesized and found to be effective photosystem II inhibitors. Due to their properties as vinylogous acid halides they can react with nucleophiles under formation of a covalent linkage. In their presence other photosystem II herbicides show a decreased binding affinity. This decrease is dependent from the preincubation time. Halogenmethyl-1,4-quinones also turned out to be efficient photosystem II inhibitors and. in addition, possessed herbicidal in vivo activity. They function as “bioreductive alkylating agents” in a way that after reduction they can split off hydrogen halide under formation of a o-quinonemethide. This quinonemethide can react with nucleophilic groups in proteins.
Effects of Plant Bioregulators on the Production of Iridoid Derived Terpenoids in Valeriana wallichii and Fedia cornucopiae Cell Suspension Cultures
Authors: Förster Wolfram , Becker Hans
Published: August 2018

Four plant bioregulators were tested for their effects on production of valepotriates in Valeriana

wallichii and Fedia cornucopiae cell suspension cultures. Concentrations of more than 10 ppm reduced valepotriate yield. At lower concentrations production was increased. For optimal activity, bioregulators had to be applied during early exponential growth, up to day 8 of the growth cycle. At equimolar concentrations dim ethylm orpholinium bromide (4 ppm) and dimethylpiperidinium chloride (3 ppm) significantly im proved total valepotriates in V. wallichii (up to 23%) and in F cornucupiae (up to 50% ) 2-(3,4-dichlorophenoxy ) - triethylamine (6 ppm ) and 2-(3,5-diisopropylphenoxy)-triethylam ine (6.4 ppm) increased valepotriate production in both cell cultures up to 40%. With dimethylpiperidinium chloride and dimethylmorpholinium bromide the ratio of m onoene to diene valepotriates in both cell systems was significantly shifted to the m onoene com pounds. A general use of these bioregulators to increase production of terpenoid secondary m etabolites in plant tissue cultures is indicated.
Enzymatic Synthesis of 1,6-Digalloylglucose from β-Glucogallin by β-Glucogallin: β-Glucogallin 6-O-Galloyltransferase from Oak Leaves
Authors: Schmidt Stephan W. , Denzel Klaus , Schilling Gerhard , Gross Georg G.
Published: August 2018

Cell-free extracts from oak (Quercus robur) leaves catalyze the transfer of the galloyl-moiety of β-glucogallin (1-O-galloyl-β-D-glucopyranose) specifically to the 6-position of the same compound, yielding 1,6-di-O-galloyl-β-D-glucopyranose, an intermediate of gallotannin biosynthesis, β- Glucogallin thus functions as both donor and acceptor molecule in this reaction. The partial purification and some general properties of this new acyltransferase are reported.
Uptake of Protoporphyrin and Violet Light Photodestruction of Propionibacterium acnes
Authors: Melø Thor B.
Published: August 2018

The uptake of protoporphyrin IX by Propionibacterium acnes in suspension has been studied by fluorescence spectroscopy. Protoporphyrin, after it was injected into a cell suspension, was firstly bound to receptors on the cell surface and in this state protoporphyrin was non-fluorescent. Subsequently, probably as a result of lateral diffusion in the cell wall, these protoporphyrinreceptor complexes formed dimers. The final step in the overall uptake process of protoporphyrin by the cells from the surroundings consisted in a jum p of such dimers from waterlike to lipidlike com partm ents in the cell mem brane where protoporphyrin became fluorescent. The lipidlike com partm ents in the cells had a limited binding capacity of protoporphyrin.

The fraction of surviving cells versus light dose has also been studied for varying amounts of protoporphyrin added to the cell suspensions. The survival curves were exponentially decaying with the irradiation time and there was a direct proportionality between the inverse slope of the survival curves and the intensity of protoporphyrin fluorescence from the lipidlike compartm ents. The relevance of these results to the therapy of Acne vulgaris is also discussed.