bluuebunny/crossref_metadata_2025 huggingface dataset:
The Coloration of Gladiolus I. Survey of Anthocyanins in Petals of Gladiolus
Authors: Akavia Naaman , Strack Dieter , Cohen Avner
Published: August 2018

The six common anthocyanidins found in Gladiolus petals occur in four types of glycosilation: 3-glucoside, 3-rhamnoglucoside, 3,5-diglucoside, and 3-rhamnoglucoside-5-glucoside. The six monoglucosides appear in minute quantities, whereas any of the other 18 anthocyanins can serve as the major contributor to the coloration of Gladiolus petals. In high performance liquid chromatographic analyses of petal pigment composition of nine cultivars, it was found that the anthocyanins are grouped on the basis of the aglycon substitution. Thus, pelargonidin appears by itself (group I), cyanidin and peonidin constitute group II, and delphinidin, petunidin, and malvidin group III.
⊿2,10-Phytadienol as Esterifying Alcohol of Bacteriochlorophyll b from Ectothiorhodospira halochloris
Authors: Steiner R. , Schäfer W. , Bios I. , Wieschhoff H. , Scheer H.
Published: August 2018

Bacteriochlorophyll b (bchl b) has been isolated from the halophilic photosynthetic bacterium, Ectothiorhodospira halochloris. The pigment and a series of derivatives thereof are different from Bchl b from Rhodopseudomonas viriais by HPLC analysis, but similar by uv-vis spectroscopy.

The chromatographic difference originates in different esterifying alcohols in the two pigments. The one from Rp. viridis (Bchl bp) is esterified with ⊿2-phytaenol (phytol), that from E. halochloris (Bchl b⊿2,10) with ⊿2,10-phytadienol. The structure of the latter has been established by isolation of the alcohol from the purified pigment, followed by (i) gaschromatography-mass spectroscopy and (ii) ozonolysis and dinitrophenylhydrazon-formation of the cleavage products, which were identified by gaschromatography-mass spectroscopy as 6-methyl-heptan-2-one, and 4-methyl-nona-1,8-dione.
Inhibition of Oogenesis and Ovarian Ecdysteroid Synthesis by Azadirachtin in Locusta migratoria migratorioides (R. & F.)
Authors: Rembold Heinz , Sieber Klaus-Peter
Published: August 2018

The sterilizing effect of azadirachtin, an insect growth regulator from the neem tree, Azadirachta indica A. Juss, was tested with mature females of Locusta migratoria. After a single injection of 10 μg into females between 2 and 13 days after emergence, about 60% died during the following four days and all lost weight in the range of about 50%. If the compound was injected into animals of an age between 2 and 10 days, no maturation of the terminal oocytes could be observed. Injection at an age between 10 and 13 days after adult emergence resulted in ovaries which contained almost mature oocytes. Most of the treated locusts had no oviposition and only traces of ecdysteroids were present in their ovaries, as quantified by radioimmunoassay. The inhibition of oogenesis and of ovarian ecdysteroid synthesis by azadirachtin is discussed on the basis of its interference with the neuroendocrine control of hormone synthesis.
Courtship-Like Tracking Behaviour in Wild-Type Female Drosophila melanogaster
Authors: Cook Robert
Published: August 2018

Both male and female Drosophila melanogaster possess systems which enable them to track other walking flies visually. Males use this system predominantly in courtship; females, when of sufficient age but still unmated, have been observed to track other flies, at rates of up to 18 bouts per hour. This behaviour is most conveniently studied in groups of females. Although similar to the courtship tracking of males, fem ale/female tracking lacks the “circling” component of courtship. The data suggest a functional relationship of female/female tracking to reproductive behaviour, although none has yet been identified. Bouts of tracking by females are most frequently terminated by the following female, especially when the target female remains motionless. Comparison of the tracking parameters of males and females has revealed differences in the velocity and pathlength of tracking bouts, and in the position of the fly with respect to the target. Males of Canton and Kapelle strains differ in the translatory component of their courtship tracking, but such a difference was not evident between females of these strains. Furthermore, tracking females do not allow their distance to the target to rise to that permissible in males, which suggests some sex-specificity in a part of the control system for tracking.
Lymphocyte Chalone from Calf Thymus: Problems of Large Scale Extraction and Assay
Authors: Maschler Reinhard , Maurer H. Rainer
Published: August 2018

Large scale extraction and assay of the lymphocyte chalone (LC), the natural lymphocyte proliferation inhibitor, require optimized, reproducible and standardizable methods. To this end we compared the effects on LC yield of storing thymus at different temperatures after collection from calves: Both quick freezing on solid CO2 and slow freezing at -5 0 °C led to a 30% loss of LC yield relative to that from unfrozen tissue kept at 0°C . Moreover we found that the apparent decrease or total loss of LC activity upon storage of a purified LC fraction may result from an occasional lack of LC-responsiveness of human blood lymphocytes depending on the donor's physiological state, in spite of normal PHA reactivity. This suggested the use of LC-responsive, cryopreserved lymphocytes, the advantages of which are documented and discussed in detail.
Interaction of Phloretin with the Human Red Cell Membrane and Membrane Lipids: Evidence from Infrared, Raman and ESR Spectroscopy
Authors: Zimmer Guido , Günther Herbert O. , Schmidt Hartmut
Published: August 2018

Membrane-Phloretin Interaction, Infrared Raman, ESR Spectroscopy The transport inhibitor phloretin was bound to human red cell membrane and the concomitant structural changes were observed by spectroscopic methods. By the spin labeling method a decrease in fluidity of the membrane was found at 1 and 10 |iM concentrations of the reagent. This result was obtained with the 2-(3-Carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl, and the 2-(14-Carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxyl lipid spin labels. Infrared spectroscopy of modified membranes revealed an intensity increase of the POO~ band at about 1250 cm-1. Moreover, a shift of the peak at 1050 cm -1 to 1100 cm-1 was observed in the presence of phloretin. Raman spectroscopy of the membranes did not contradict the results found with infrared and ESR spectroscopy: In the phloretin modified membrane we observed a lack of the band at 1085 cm-1, which leads to suggest that the POO" and/or C-C regions are less fluid. Changes of the extracted red cell membrane lipids were less characteristic, and the results differed from those found in red cell membrane.
Chemical Synthesis of α-Formylphenylacetic Acid, the Postulated Precursor of Tropic Acid
Authors: Gross Georg G. , Koelen Karl J. , Müller Angelika , Schmidtberg Günter
Published: August 2018

a-Formylphenylacetic Acid, Phenylmalonic Semialdehyde, Tropic Acid Biosynthesis a-Formylphenylacetic acid, the postulated immediate precursor of tropic acid, has been synthesized by deacetalization of a-diethoxymethylphenylacetic acid in the presence of silica gel. The compound was reasonably stable in organic solution. In aqueous media, however, a pronounced lability of this semialdehyde was observed at various pH-values (t/2 = 4.5 min at pH 7.4). It is thus very unlikely that this compound can be employed successfully in biosynthetic studies.
Genetic Control of Chalcone Synthase Activity in Flowers of Matthiola incana R.Br
Authors: Spribille R. , Forkmann G.
Published: August 2018

Chalcone synthase activity was demonstrated in enzyme preparations from flowers of defined genotypes of Matthiola incana (stock). The product formed from 4-coumaroyl-CoA and malonyl-CoA was naringenin and not the isomeric chalcone, because chalcone isomerase was also present in the reaction mixture. Chalcone synthase activity could be detected only in flower extracts of genotypes with wild-type alleles at the locus f Thus, the interruption of the anthocyanin pathway in white flowering lines with recessive alleles (ff) of this gene is clearly due to a lack of this enzyme activity. Independent on the genetic state of the locus b which controls the formation of pelargonidin or cyanidin, respectively, in the flowers, 4-coumaroyl-CoA was the only suitable substrate for the condensation reaction.
Properties and Subcellular Localization of ʟ-Alanine: Aldehyde Aminotransferase: Concept of an Ubiquitous Plant Enzyme Involved in Secondary Metabolism
Authors: Wink Coralie , Hartmann Thomas
Published: August 2018

L-Alanine: aldehyde aminotransferase occurs ubiquitously in higher plants. The enzyme catalyzes the reaction: L-alanine + monoaldehyde -> monoamine + pyruvate; it is responsible for the formation of aliphatic plant amines and involved in the biosynthesis of hemlock alkaloids as shown by Roberts. A continuous coupled photometric test was developed to determine the low activities of the transaminase. The enzyme from the "amine-free" plant Spinacia oleracea was purified 77-fold and separated from other aminotransferases. A comparison of the Spinacia enzyme with that isolated from spadix-appendices of the amine-producing Arum maculatum during anthesis revealed very similar characteristics in pH-dependence, ATm-values for alanine and aliphatic aldehydes, and inhibition by 2-oxoacids. In contrast to the Spinacia enzyme the Arum aminotransferase is rapidly inactivated in the absence of pyridoxal-5'-phosphate. The enzymes of S. oleracea, A. maculatum and Mercurialis perennis are localized in mitochondria, but not in chloroplasts or peroxisomes. The results are discussed in relation to the function of alanine: aldehyde aminotransferase in secondary metabolism. It is suggested that some enzymes may be expressed in plants at low levels, even in the absence of any metabolic function.
The Inhibition of Photosynthetic Light Reactions by Halogenated Naphthoquinones
Authors: Pfister Klaus , Lichtenthaler Hartmut K. , Burger Günther , Musso Hans , Zahn Manuel
Published: August 2018

Halogenated naphthoquinones act as inhibitors of photosynthetic electron flow. I50 concentra­ tion for inhibition of methylviologen reduction were found to range between 2 × 10-5 m to 2 × 10-6 M. Comparing their effects on several partial reactions of electron flow, the inhibition site of the naphthoquinones was found to be at the reducing site of PS II. Studies of fluorescence transients in presence of halogenated naphthoquinones give further evidence for a site action similar to that of diuron and different to that of DBMIB. All naphthoquinones act as quenchers of chlorophyll fluorescence with pure chlorophyll a, and with much higher efficiency in green algae and chloroplasts. It is concluded, that the halogenated naphthoquinones act similar to PS II-inhibitors like diuron, but do not share a common binding site at the PS II-complex. Implications of a possible involvement of phylloquinone K 1 in photosynthetic electron transport are discussed. The synthesis of 2-chloro-as well as 2-bromo-3-isopropyl-1,4-naphthoquinone is described.
Site of Action of 2,5-Dimethoxy-3,6-Dichloro-p-Benzoquinone in the Photosynthetic Electron Transport Chain
Authors: Sarojini G. , Daniell H.
Published: August 2018

Electron Acceptors, Photosystem II, Quinones and Quinonediamines Dichlorodimethoxy-/?-benzoquinone (DCDMQ) was tested for its site of action in the photo­ synthetic electron transport chain. Hill reaction mediated by DCDMQ was insensitive to DBMIB (1 nm) but sensitive to DCMU, suggesting its site of action before plastoquinone but after Q -the primary electron acceptor of photosystem II. Extraction of freeze-dried chloroplasts with heptane and analyzing their capacity to photo-oxidize water using various Hill oxidants revealed that silicomolybdate (SiMO) and DCDMQ could effectively restore the activity. Diaminodurene (DAD) in the presence of ferricyanide could restore 40% of the activity. But ferricyanide alone failed to restore the ability to photo-oxidize water in heptane extracted chloroplasts. Similarly, N a2S 0 3 which is known to cause a bottleneck in the electron flow at plastoquinone affected the ferricyanide Hill reaction. Hill reactions mediated by SiMO and DCDMQ were insensitive to the addition of Na2SO3, suggesting that both these oxidants intercept electrons before plastoquinone. But 50% of the activity was lost when sulfite was added to the Hill reaction mediated by DADox. DNP-INT, melittin and picrylhydrazyl were recently introduced as photosystem II inhibitors inhibiting the electron flow between Q and the PQ pool. While DCBQ and DCDMQ Hill reactions were insensitive to DNP-INT, ferricyanide was highly sensitive. The quinonediamines TMPD and DADox showed 50% decrease in the electron transport rate, similar to heptane extracted or sulfite inhibited chloroplasts. Melittin increased the electron transport rate when ferricyanide or TMPD was the Hill oxidant, while DCBQ and DCDMQ reduction remained unaffected. However, DADox Hill reaction showed 50% inhibition in the presence of melittin. Picrylhydrazyl - which inhibits the electron flow between Q and the PQ pool - inhibited the Hill reaction of all the PS II electron acceptors except that of DCDMQ. It is possible that there is another site of intercepting electrons between Q and plastoquinone before the site where most of the quinonediamines accept electrons.
Evidence for a Transcarboxylase Reaction in Maize Chloroplast Extracts
Authors: Pan David , Tan Kim H.
Published: August 2018

The authors have suggested (Can. J. Bot. 49, 631 (1971) that the — COOH group of the C4-P carbonyl compound of the thermostable P-enolpyruvate acid carboxylase reaction may transcarboxylase with a pentose phosphate as ac­ ceptor. We now have considerable evidence supporting this consideration. In an assay system (0.8 ml) containing soni­ cated chloroplast extract in 0.1 m Tris-HCl, pH 6.3; and PEP, 0.1 |imol; Mg2+, 0.5 nmol; NADH, 0.25 nmol; sugar phosphate, 0.5 nmol. The amount of 14C 0 2 fixation is con­ siderably enhanced by either ribose-5-phosphate, fructose-1,6-bisphosphate or ribulose-l,5-bisphosphate in the pres­ ence of PEP. The products of the reaction include malate as a product of /?-carboxylation, and glycerate or 3-phosphate glycerate, their proportion being determined by the ac­ ceptor sugar phosphate. The results provide evidence for a "transcarboxylase" presented in the crude extract of Maize chloroplasts.
Location of Several Enzymes of ʟ-Arginine Catabolism in Evernia prunastri Thallus
Authors: Legaz Estrella , Vicente Carlos
Published: August 2018

Agmatine ureo: hydrolase, which produces both putres-cine and urea from agmatine, and urease, which hydrolyzes this urea, are highly restricted to the phycobiont cells in E. prunastri thallus. Arginase and L-arginine decarboxylase, which catabolize L-arginine, have a more extensive dis­ tribution between both symbiotic partners.
Incorporation of Chlorinated Anilines into Lignin
Authors: Trenck K. T. v. d. , Hunkier D. , Sandermann H.
Published: August 2018

Coniferyl Alcohol, Peroxidase, Lignin, 4-Chloroaniline, 3,4-Dichloroaniline Lignin was formed in vitro by the peroxidase/hydrogen peroxide mediated polymerization of coniferyl alcohol. In the presence of [14C]4-chloroaniline or [14C]3,4-dichloroaniline copolymeri­ zation occurred with incorporation rates of about 45 mol%. Co-elution of UV-absorbing material (reflecting lignin) and of incorporated radioactivity was observed on a calibrated column of Sephadex LH-60. This method indicated a broad molecular weight distribution of the copolymers with values of between about 20000 and 1000. Most of the copolymer products had apparent molecular weights near 1000.

The 1H-NMR and 13C-NMR spectra of the copolymers were compared with those of in vitro lignin. The copolymer spectra showed a relative increase in aromatic peaks and a relative decrease in most of the typical lignin peaks. Three peaks indicative of a new type of phenyl-propanoid side-chain structure were detected in the 'H-NMR and 13C-NMR spectra of the copolymers. The corresponding 1H-NMR chemical shift values were 4.75 ppm (a-C-H), 4.40 ppm (β-C-H) and 3.70/3.50 ppm (y-C-H2). The 13C-NMR chemical shift values were 56.9 ppm (a-C), 84.3 ppm (β-C) and 60.0 ppm (y-C). These peaks were attributed to a 3-aryl-3-anilino-2-aryloxy-propanol-1 structure in the copolymers by analysis of coupling patterns and by comparison with spectral reference data.

The NMR-results and experiments with catalase and inhibitors suggested that a major mechanism of copolymerization consisted of a nucleophilic addition of the anilines to the benzylic ar-carbon of lignol quinone-methide intermediates.
Regulatory Properties of Glutamine Synthetase from the Nitrogen-Fixing Phototrophic Bacterium Rhodopseudomonas palustris
Authors: Alef Kassem , Zumft Walter G.
Published: August 2018

Rhodopseudomonas palustris, Glutamine Synthetase Regulation, Adenylylation Glutamine synthetase from Rhodopseudomonas palustris is regulated via an adenylylation/deadenylylation mechanism. The enzyme purified from ammonia-grown cells, released AMP upon treatment with phosphodiesterase, along with drastic changes in its pH and metal dependency. Kinetic parameters for enzyme-substrate interaction were also dependent on the adenylylation state of the enzyme, as was the influence of several nitrogenous feedback inhibitors on the catalytic activity. The adenylylation state of the enzyme was modified in vivo by the availability of ammonia.
Thalidomide-Like Malformations Caused by a Tween Surfactant in Mice
Authors: Kocher-Becker Ursula , Kocher Walter , Ockenfels Heinrich
Published: August 2018

The nonionic surfactant Tween 20 was applied intra-peritoneally to NMRI and Swiss mice on day 9 of gestation. It caused embryonic death and malformations of the verte­ brae, ribs and, in lower frequency, of the limbs.
Nitrite Inhibition of Bacterial Dinitrogen Fixation
Authors: Castillo F. , Cárdenas J.
Published: August 2018

Dinitrogen fixation by crude extracts from Rhodopseudomonas palustris and Rhodomicrobium vannielii and by purified nitrogenase preparations from Azotobacter vinelandii and Clostridium pasteurianum is inhibited by nitrite, whereas in the same preparations nitrate is without effect. In Clostridium nitrite seems to interact with dinitrogenase reductase component of the bacterial nitrogenase complex.
Vinyl-Olefines and Sesquiterpenes in the Root-Oil of Senecio isatideus
Authors: Boland Wilhelm , Jaenicke Lothar
Published: August 2018

A series of polyunsaturated vinyl-hydrocarbons (n-C15 to n-C17) (10, 11, 12, 15, 16 and 17) including the as yet unknown all-cis-1,7,10,13-hexadecatetraene (15) as well as some rare sesquiterpenes such as isocomene (8) or modhephene (7) have been isolated from the root oil of Senecio isatideus. Unambigous positioning of the double bonds of the polyolefines was easily established by 13C-NMR spectroscopy [16]. A new mass spectroscopical method utilizing NO as a reactant gas for chemical ionization [1] made possible the reliable identification of minor and trace constituents without any chemical pretreatment or further derivatisation.
Mevinolin: A Highly Specific Inhibitor of Microsomal 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase of Radish Plants
Authors: Bach Thomas J. , Lichtenthaler Hartmut K.
Published: August 2018

The fungal metabolite mevinolin, known to be a potent hypocholesterolemic agent, excerts in vitro a strong inhibitory effect on microsomal HMG-CoA reductase from etiolated radish seedlings at a concentration of about three magnitudes lower than the Km towards the natural substrate (S)-HMG-CoA (I50 = 2.5 × 10-9 ᴍ). Beside this, mevinolin significantly inhibits the root elongation of radish as well as of wheat seedlings already at low concentrations of 10 to 100 ppb (= 2.5 × 10-8 to 2.5 × 10-7 ᴍ).
Free Activation Energies and Activation Volumes for the Amide Rotation in Some Peptides Studied by High Pressure 1H-High Resolution NMR
Authors: Hauer H. , Lüdemann H.-D. , Jaenicke R.
Published: August 2018

From the pressure dependence of 1H high resolution NMR spectra of two dipeptides (glycylsarcosine and N-acetyl-ʟ-proline-NH-methylamide in the range 0.1 MPa ≤p ≤ 150 MPa the activation volumes ⊿V≠ for the amide rotation are derived. This conformational transition is characterized for glycylsarcosine by ⊿V≠ = 4 ± 1 cm3 · mol-1 and for. the proline derivative by ⊿V≠ = 7.5±1 cm3 · mol-1. From the given results the maximum contribution of proline cis ⇌ trans isomerisation to the pressure dependence of the rate of reactivation of proteins can be estimated to ~ - 30% per MPa and proline present.
Temperaturabhängiger Farbwechsel bei Larven der grünen Huschspinne Micromata rosea (Sparassidae) / Temperature-Dependent Colour Change in Larvae of the Green Spider Micromata rosea (Sparassidae)
Authors: Holl Arthur
Published: August 2018

In the green coloured larvae of Micromata rosea but not in adults temperature raise above 29 °C causes immediate colour change: green to bluish-green. Colour change is reversible by temperature decline below 29 °C. Qualitative analysis of the yolk pigment reveals the same biliverdin conjugates (micromatabilin) as previously identified for adult spiders. The bluish-green colour (above 29 °C) re­sults from an absorption band (675-680 nm, water phase, purified solution) modified to that of the green solution (below 29 °C). Presumably, the thermodependent, rever­sible colour change is due to a special yolk protein bond to the micromatabilin chromophor.
Bleaching Activity of New 2-Phenylpyridazinones: Structure-Activity Relationship
Authors: Sandmann Gerhard , Böger Peter
Published: August 2018

New 2-phenylpyridazinones, analogs of 4-chloro-5-methylamino-2-phenylpyridazin-3(2H)ones, were assayed for their phytotoxic activity to interfere with plant pigment formation. Six derivatives with - SCF3, - OCF2CHFCF3, - OCHF2, - CN, or - Br in meta position of the phenyl ring exhibited similar or better bleaching activity than the m-CF3 analog (norflurazon). The activity is predominantly determined by positive σ values and by lipophilicity of the substituent. On the basis of 11 analogs, a quantitative structure-activity relationship by a Hansch equation was accomplished with σm and the lipophilicity parameter π as variables.
The Intracellular Distribution of Enzymes of the Glycerol Cycle in the Unicellular Alga Dunaliella parva
Authors: Gimmler H. , Lotter G.
Published: August 2018

The intracellular distribution of the enzymes of the glycerol cycle in the unicellular alga Dunaliella parva was investigated using the technique of differential extraction by the polycation DEAE-dextran.

Results suggest a cytoplasmic localization of the DHA reductase, but a chloroplastic localization of the glycerol-3-phosphate dehydrogenase and phosphatase.
Osmoregulation in Dunaliella. Intracellular Distribution of Enzymes of Glycerol Metabolism
Authors: Brown A. D. , Lilley R. McC. , Marengo Thérèse
Published: August 2018

Dunaliella tertiolecta was disrupted mechanically and resolved by centrifugation into chloro­plast- and cytosol-enriched fractions. Intact chloroplasts could not be isolated because peripheral extensions of the single large chloroplast reached almost to the flagellar pole of the cell. The chloroplast envelope was closely appressed to the plasmalemma and, because of this and its dimensions, was vulnerable to mechanical damage to the cell.

Distribution of enzymes of the glycerol cycle between the two fractions was compared with that of two marker enzymes, phosphoenolpyruvate carboxylase (cytosol) and ribulose bisphosphate carboxylase (chloroplast). The two reversible steps of the cycle were found to be spatially separated; glycerol-3-phosphate dehydrogenase (NAD-specific) was located in the chloroplast whereas glycerol dehydrogenase (NADP-specific) was located in the cytosol. The distribution of the two irreversible enzymes, glycerol phosphate phosphatase and dihydroxyacetone kinase is uncertain. These enzymes might occur about equally in both major compartments (cytoplasm and chloroplast) or be mitochondrial or they might be loosely associated with a membrane system. Implications of these results for regulation of the glycerol cycle are discussed.
Struktur-Wirkungsbeziehungen von Analogen und Homologen von Blepharisma, dem niedermolekularem Konjugationshormon von Blepharisma japonicum / Structure-Activity-Relation of Analogues and Homologues of Blepharismone, the Low-Molecular Conjugation Hormone of Blepharisma japonicum
Authors: Entzeroth Michael , Jaenicke Lothar
Published: August 2018

Some functional derivatives of blepharismone, the low-molecular conjugation hormone of Blepharisma japonicum, were synthesised and tested for their biological activity. The lipophilicity constant of the substituent in 5-position of the aromatic system directly correlates with the conjugation-inducing effect of this substance. Any change in the N-formyl-position leads to compounds less active than blepharismone, non-active or even inhibitory. Blepharismone-related kynurenine derivatives are inhibitors of the gamone activity depending on structural relationship.
X-Ray Studies on Phospholipid Bilayers. II. Polymorphic Forms of Dipalmitoyl Phosphatidylethanolamine
Authors: Suwalsky M. , Knight E.
Published: August 2018

Oriented films and powder samples of the phospholipid ʟ-α-dipalmitoyl phosphatidylethanol­ amine (DPPE) were studied by X-ray fiber diffraction techniques. The specimens were photographed under a complete range of hydration at room temperature. Two polymorphic forms were found. One of them was present in oriented films. It showed a close packing of DPPE molecules lying parallel to the normal to the bilayer plane. The other form, observed in the powder samples, had the molecules tilted by about 25°. Both forms were characterized by their unit cell dimensions, space groups, molecular conformations and packing arrangements.
Exogenous and Endogenous Control of Swimming Activity in Astyanax mexicanus (Characidae, Pisces) by Direct Light Response and by a Circadian Oscillator I. Analyses of the Time-Control Systems of an Epigean River Population
Authors: Erckens Wilhelmine , Martin Wolfgang
Published: August 2018

1. The swimming activity of 6 specimens of an Astyanax mexicanus' river population was tested with regard to its time control under various light-dark(LD)cycles and under constant conditions.

2. Activity is classified into three different forms according to the special experimental arrangement: surface activity, bottom activity and the sum of both (total activity).

3. All applied LD-cycles act as socalled forcing signals (Zeitgeber) and entrain the activity.

4. The maximum values of surface activity correspond to the dark phases of a LD-cycle, those of bottom activity to the light phases. This inversity causes a less strong entrainment of the total activity up to a loss of a significant oscillation in extreme cases.

5. This inverse pattern is kept the more stronger the more the period length of a LD deviates from 24 h. In the range of resonance about 24 h there is a greater flexibility with regard to the phase relation of the maximum values.

6. Activity reacts very sensitive to the differential parameter of the forcing signal. Therefore, no phaseangle difference occurs between forcing and forced signal. Moreover, the system needs no swing-in time to become entrained when starting a LD.

7. After transition from LD to DD (= constant darkness) the forced signal does not die away immediately, but damps out within one or a few cycles with decreasing amplitude and unchanged frequency.

8. In nearly all applied LDs a non-synchronized circadian rhythm can be observed in addition to the entrained frequency, which is dominant.

9. Also, in DD a freerunning circadian rhythm is detectable.

10. We suggest the model that first a passive system with a nearly unlimited range of entrainment controls activity. In contrary to extremely passive systems, it is able to oscillate. Moreover, it acts like a linear system with respect to frequency transfer: In the tested cases, output and input frequency are equal. In addition, activity is under control of an endogenous circadian oscillator. Its effects are overlapped under forcing conditions, but they become obvious under constant conditions. Furthermore, nonstationary processes are features of this circadian rhythm. The proper­ ties of a passive and a circadian system alone do not explain the flexible patterns in the range of resonance. Therefore, a time-dependent controller is demanded to control the phase relation of the maxima.
Exogenous and Endogenous Control of Swimming Activity in Astyanax mexicanus (Characidae, Pisces) by Direct Light Response and by a Circadian Oscillator II. Features of Time-Controlled Behaviour of a Cave Population and their Comparison to a Epigean Ancestral Form
Authors: Erckens Wilhelmine , Martin Wolfgang
Published: August 2018

1. The swimming activity of 6 specimens of the Pachon cave form of Astyanax mexicanus was tested with regard to its time control under various light-dark(LD)cycles and constant conditions, and it is compared to that of a river form.

2. In general, activity is entrainable by all applied LDs, but even if the amplitude of a forcing signal increases the signal energies are lower than in the river fish.

3. In case of entrainment the maximum values of surface activity correspond to the dark phases, those of bottom activity to the light phases of a LD. Flexible patterns -as often observed in the river form in the range of resonance about 24 h - are very seldom. Furthermore, disturbances of­ ten occur in the entrainment of one activity form, or one form runs arrhythmic while the other is still entrained.

4. The activity answers to changing environmental conditions are not as uniformly quick as in the river fish. But the system hardly needs a swing-in time to become entrained when a LD starts.

5. After transition from LD to DD (= constant darkness) the entrained rhythms disappear immediately.

6. In no LD with a period length differing from 24 h a circadian rhythm can be observed in addition to the entrained frequency.

7. These results show that the passive system of the river form has developped into an extremely passive one being unable to oscillate and thus has become simplified during regressive evolution. Concerning the circadian oscillator of the epigean ancestor, it was also subjected to regression, but it has not been completely lost. After a LD with a period length about 24 h the circadian oscillator is able to act as a stable system, clearly shown by the freerunning circadian rhythms of surface activity. But out of this range the oscillator is unable to control activity. In DD after all other LDs activity patterns are arrhythmic.
Monoterpenes from the True Bug Harpocera thoracica (Hemiptera)
Authors: Hanssen Hans-Peter , Jacob Jürgen
Published: August 2018

From the “head space” * of Harpocera thoracica (Miridae; Hemiptera) six monoterpenes have been isolated and identified by GLC and MS data in comparison with authentic reference substances. Predominant component was geranyl acetate. Apart from this, the alcohols geraniol and nerol, neryl acetate, and the corresponding aldehydes geranial and neral could be identified.
Small- and Large-Angle X-Ray Scattering Studies of Counter Ion Influence on tRNA Conformation*
Authors: Wilhelm Peter , Pilz Ingrid , Degovics Gábor , Haar Friedrich von der
Published: August 2018

The determination of cross sectional radii of gyration by small-angle X-ray scattering and comparison of large-angle scattering curves were used to study conformational changes of tRNAs depending on the concentration of mono-and divalent counter ions.
Structure Investigations of Agonists of the Natural Neurotransmitter Acetylcholine II [1]. X-ray Structure Analysis of Trimethyl(4-oxopentyl)ammonium-chloride
Authors: Gieren Gieren , Kokkinidis Michail
Published: August 2018

The crystal structure of Trimethyl(4-oxopentyl)ammonium-chloride ([(CH3)3N+-(CH2)3COCH3]Cl-) (1) was determined by an X-ray structure analysis. 1 crystallizes in the orthorhombic space group P212121 with a = 10.440 (3), b = 14.600 (9), c = 6.804 (9) Å and with four formula units per unit cell. The structure was solved by a Patterson and a successive Fourier synthesis. The least squares refinement yielded an R-value of 0.064 for 1077 observed reflections. The cation of 1 is derived from acetylcholine by replacement of the ester oxygen with a CH2 group. It shows a potent nicotinic activity and a significant difference in conformation as compared with acetylcholine. In the crystal structure the anions are oriented stereospecifically with respect to the tetrahedron of the quaternary ammonium group. The geometry of two triangles formed by the quaternary nitrogen atom, the oxygen atom of the carbonyl group, and by either of the two anions nearest to the quaternary ammonium group is characteristic for the nicotinic activity of 1.
Bile Salt Delipidation, Residual Phospholipids and Reactivation of the Ca2+-ATPase from Sarcoplasmic Reticulum
Authors: Swoboda Gertrude , Hasselbach Wilhelm
Published: August 2018

1. Delipidation of the Ca2+-ATPase of sarcoplasmic reticulum membranes by gel chromatography employing ionic detergents (cholate, deoxycholate and mixtures of both) in the presence of glycerol has been studied with respect to residual phospholipids and ATPase activities.

2. The extent of delipidation depends on the detergent chosen and on the ionic strength of the elution buffer. Increasing ionic strength favours a more effective removal of phospholipids, down to about 1 phospholipid molecule per ATPase molecule.

3. The residual ATPase activities of the delipidated preparations are negligibly low. Extensive restoration of the Ca2+-dependent ATPase activity has been achieved by oleic acid, a lysolecithin (myristoylglycerophosphocholine) and a lecithin (dimyristoylglycerophosphocholine). The per­ centage of reactivation by oleate depends linearly on the amount of residual phospholipids and on the detergent employed.

4. After gel filtration through an Ultrogel or Sepharose column containing 1% cholate in the elution buffer the delipidated ATPase is eluted as a reactivatable high molecular aggregate, whereas 1% deoxycholate favours the formation of completely lipid-free monomeric units which cannot be reactivated, however. A high molecular aggregate is also formed in deoxycholate, the ratio of monomer to polymer depending on the solubilizing and elution conditions.

5. The residual lipids are always composed of a mixture of all different lipid classes present in the native sarcoplasmic vesicles, even at high degrees of delipidation. Specific changes with varying extent of delipidation were not detected.
Screening for Highly Active Plasmid Promoters via Fusion to β-Galactosidase Gene
Authors: Rosner Arie , Gorecki Marian , Aviv Haim
Published: August 2018

A plasmid containing promoter-deleted inactive β-galactosidase gene [1] was used to select promoters of the pEP121 plasmid [2]. Colonies of cells harboring reactivated β-galactosidase gene were identified by their red color on McConkey plates. The quantitative amounts of β-galactosidase produced in each clone were estimated by assaying enzyme activity and by measuring the specific β-galactosidase protein following fractionation of total cells′ proteins on polyacrylamide gel. A wide range of enzyme activities was observed. The most active promoter isolated was shown to promote β-galactosidase production more efficiently, compared with the original β-galactosidase promoter, amounting to 20% of all cell proteins. Such highly active promoters may be utilized in the future, to promote expression of cloned genes in bacteria.
Functional Significance of Quaternary Organization of the Sarcoplasmic Reticulum Ca2+-ATPase
Authors: Møller Jesper V. , Mahrous Talaat S. , Andersen Jens P. , Maire Marc le
Published: August 2018

There is both structural and functional evidence for protein-protein interaction between Ca2+-ATPase polypeptide chains in the sarcoplasmic reticulum membrane. Studies on detergent solubilized ATPase indicate that the monomeric form is capable of performing a normal cycle of ATP hydrolysis, but some of the modulatory effects of the substrates disappear after detergent solubilization. However, the necessity of protein-protein interactions for the Ca2+ transport function remains unclarified. A new approach is described, employing ATPase reconstituted with a large excess of phospholipid, which may help to resolve this question.
ESR Studies on Platinum Uracil Blue
Authors: Neubacher Harald , Seul Michael , Lohmann Wolfgang
Published: August 2018

ESR spectra of platinum uracil “blue” are discussed. Two main types o f paramagnetic species have been found, one of which can be explained by assuming an unpaired electron spin delocalized over dz²-orbitals of two equivalent Pt centers, the other one is attributed to a more localized d7 Pt(III) center. In both cases the hyperfine structure suggests an additional smaller probability density of the unpaired electron at one adjacent platinum center. The smallest possible oligomers to realize this facts are tetramers in the first case and dimers in the latter one.
Formation of Flavonol 3-O-Diglycosides and Flavonol 3-O-Triglycosides by Enzyme Extracts from Anthers of Tulipa cv. Apeldoorn / Characterization and Activity of Three Different O -Glycosyltransferases during Anther Development
Authors: Kleinehollenhorst G. , Behrens H. , Pegels G. , Srunk N. , Wiermann R.
Published: August 2018

Three distinct glycosyltransferases have been isolated and partially purified from anthers of Tulipa cv. Apeldoorn. The following designations are proposed; UDP-glucose: flavonol 3-O-glucosyltransferase (GT-I), UDP-rhamnose: flavonol 3-O-glucoside rhamnosyltransferase (GT-II) and UDP-xylose: flavonol 3-glycoside xylosyltransferase (GT-III). The three enzymes exhibited an identical pH optimum within the range of 8.5 -9.0. The estimated molecular weight of GT-I and GT-II was about 40 000, GT-III showed a molecular weight of 30 000. GT-III required ions like NH4
+or Ca2+ whereas these ions have almost no influence on GT-I and GT-II activity. The enzymes have a slight requirement for SH-reagents, particularly DTE. As opposed to GT-II activity of GT-I and GT-III is significantly influenced by SH reagents and PCMB. Sucrose enhanced GT-III activity but only slightly GT-I activity, GT-II activity is not influenced.

Flavonol aglycones can function as glycosyl acceptor for the GT-I, whereas flavonol 3-O-glycosides, luteolin, dihydroquercetin, naringenin, cyanidin, p-coumaric acid and some other phenols were inactive as acceptor. The best acceptors were isorhamnetin and quercetin (Km: 0.9 × 10-6 ᴍ). GT-II did not accept aglycones as substrates. For this enzyme flavonol 3-O-glucosides were the most attractive substrates. GT-III did not have any affinity towards aglycones, too. This enzyme exhibited a high specificity for flavonol 3-O-glucosides as well as flavonol 3-O-galactosides. Both enzymes, the GT-II and GT-III, were able to glycosylate flavonol 3-O-diglycosides forming triglycosides. UDP-glucose (Km = 1.0 × 10-4 ᴍ), UDP-rhamnose and UDP-xylose where shown to be the best glycosyl donors for GT-I, GT-II or GT-III respectively. The glycosyl transfer catalysed by the GT-I was shown to be a freely reversible reaction.

In the whole anthers, highest specific activities of GT-I and GT-II were found during late stages of anther development. Similar results were obtained using the contents of anthers or the tapetum fraction. In contrary, high GT-III activity can be detected already in young stages of anther devel­opment. The highest activities of the three glycosyltransferases were found in the tapetum fraction, whereas the pollen fraction exhibited only poor activities.
Effects of Substituted 2-Phenylamino-1,4,5,6-tetrahydropyrimidines on ATP Formation in Isolated Spinach Chloroplasts
Authors: Berg Gerard van den , Brandse Marjo , Tipker Jacobus
Published: August 2018

The effects of a series of 2-arylamino-1,4,5,6-tetrahydropyrimidines on photosynthesis in spinach chloroplast were studied. The compounds proved to be uncouplers of photophosphorylation, while inhibition of electron transport occurred at higher concentrations. These effects were rather irreversible and the activity increased with lipophilicity. Inhibition of electron transport could not be reversed by trypsin treatmeni. Loss of membrane integrity might be the underlying mechanism of these effects.
Electromechanical Coupling III. Estimation of the Ca Storage Capacity of the SR by Analysing the Time Course of Caffeine- Induced Tension Transients of Skinned Muscle Fibres
Authors: Thieleczek Rolf
Published: August 2018

The Ca uptake of the SR of a skinned fibre, which was studied with an indirect method, shows a biphasic time course. A total Ca concentration between 8 and 23 mᴍ was accumulated in the SR by an initial fast process (τ ≈ 4.7 s). This Ca-uptake activity of the SR is high enough to bring about relaxation o f twitch contraction in vivo. The magnitude of a subsequent slow process (τ ≈ 103s) indicates that the total Ca storage capacity of the SR of skeletal muscle is in the order of 60 - 75 mᴍ.
Intracellular Membranes as Boundaries for Ionic Distribution. In Situ Elemental Distribution in Guinea Pig Heart Muscle in Different Defined Electro-Mechanical Coupling States
Authors: Wendt-Gallitelli M. F. , Jacob R. , Wolburg H.
Published: August 2018

Using x-ray microanalysis and cryoultramicrotomy, calcium and other diffusible elements were localized in heart muscle strips which had been shock frozen under different, defined conditions of electromechanical coupling. Guinea pig papillary muscles were shock frozen: 1) 1 1/2 seconds after paired stimulation, 2) 5 minutes after rest in normal bath medium and 3) 5 minutes after rest in bath medium to which noradrenaline was added. In 1) high calcium concentrations of 11.5 mmol/kg d.w. were regularly detected in sites at the level of Z-lines, which probably corre- spond to the Z rete of SR. In 2) in which the mechanogram of the first contraction after rest normally showed a small and retarded peak, the cell stores seemed to be nearly empty, with exception of a few regions between the mitochondria which revealed calcium accumulations of 77 mmol/kg d.w. These regions included JSR and/or T-tubuli. In 3) in which the mechanogram of the first contraction after rest normally showed a retarded peak with high tension, calcium was found in several cell structures. The highest amount, 25 mmol/kg d.w., was detected over the cell membrane. Measurable amounts were also detected over Z-lines and sarcomeres.

In the present experiments, the respective rate of rise of tension, and time to peak tension, were extremely different. Possible correlations between different contraction patterns and different calcium stores involved in the various experiments have been discussed.
2-Methoxystypandron, ein neues Naphthochinon aus Rhamnus fallax B. / 2-Methoxystypandrone, a New Naphthoquinone from Rhamnus fallax B.
Authors: Rauwald Hans-W. , Miething Holger
Published: August 2018

The structure of 2-methoxystypandrone, a new naphthoquinone from the stem bark of Rhamnus fallax B., was elucidated by UV, IR, 1H-NMR, 13C-NMR, MS and chemical degradation as 6-Acetyl-5-hydroxy-2-methoxy-7-methyl-1,4-naphthoquinone. This is the first described occurrence of a naphthoquinone in a Rhamnus species. Free alaternin, 2-hydroxyemodin, was found for the second time in plant material.
OH Radical-Induced Main-Chain Scission of Poly(Ribonucleic Acids) under Anoxic Conditions
Authors: Washino Komei , Denk Otmar , Schnabel Wolfram
Published: August 2018

Poly(ribonucleic acids), poly A, poly C and poly U, were irradiated in O2-free dilute aqueous solution at pH 7 to 8 with single pulses (50 to 200 ns) of 16MeV electrons. With the aid of Rayleigh light scattering measurements main-chain scission, induced by OH radicals, was observed with the three polynucleotides. From the time dependence of the decrease of the light scattering intensity (LSI), the existence of two modes of decrease was inferred, indicating at least two different chemical mechanisms were operative in main-chain degradation. Evidence for the assignment of the slow mode of LSI decrease to the lifetime of a free radical was obtained from quenching experiments with cysteamine. It is noteworthy, that the extent and the lifetime of LSI decrease are not the same for the three polynucleotides. The differences indicate the influence of the chemical nature of the bases on main-chain scission. Consequently, it is concluded that OH attack at carbons in 1′ and/or 2′ position of the ribose moiety contributes essentially to the degradation mechanism.
Effect of Streptococcal Extracellular Nuclease on the Carrier Activity of RNA for Streptolysin S
Authors: Taketo Akira , Taketo Yoriko
Published: August 2018

Upon digestion with a streptococcal extracellular nuclease, yeast RNA yielded acid-insoluble core having increased carrier activity for streptolysin S. The carrier activity was found in minor fractions of the core which were eluted from a DEAE-cellulose column at higher salt concentrations. Upon gel filtration through a Sephadex G-75 column, the effective component (Fr. I) was eluted earlier than bulk oligonucleotides (Fr. II). Nucleotide composition (in mol %) of Fr. I was AMP: 21.8; GMP: 55.1; CMP: 8.2; UMP: 14.9, whereas that of Fr. II was AMP: 38.0; GMP: 33.1; CMP: 8.0; UMP: 20.9. Chromatographic patterns of SLS complex induced by Fr. I were similar to those of the toxin formed in the presence of active fraction prepared from RNase I core. Hemolytic activity of the latter complex was, like the former, unaffected by streptococcal nuclease treatment. The carrier activity of DNA digested with the nuclease was also investigated.
DNA Content and Synthesis in Several Tissues and Variation of Moulting Hormone-Level in Gryllus bimaculatus DEG (Ensifera, Insecta)
Authors: Römer Franz , Eisenbeis Ilona
Published: August 2018

The mode of growth of several tissues in Gryllus bimaculatus was investigated during postembryonic development by cytophotometric methods. In contrast to the situation in holo- metabolous insects, the tissues growing by endomitosis reach only moderate levels of polyploidy. In this case the growth of tissues is achieved by mitotic divisions of small cells with subsequent polyploidization.

The time courses of DNA synthesis were measured within the 3rd and, for comparison, the 8th larval instar by incorporation of labelled thymidine followed by autoradiography. Hemocytes, cells of the regeneration crypts of the midgut, gonads and nervous tissue showed a continuous incorporation rate; by contrast, DNA synthesis in other tissues was confined to a given time within the moulting cycle.

The changes in moulting hormone titre of the 3rd larval instar were investigated. The quantities of ecdysone and 20-OH-ecdysone were estimated by radioimmunoassay, and the hormones were identified by high pressure liquid chromatography (HPLC). The titre changes in time with at least 2 distinct maxima. The DNA synthesis periods are correlated with the hormone peaks, that of epidermis and tracheae with the first peak, and that of pylorus, ileum, rectum, Malpighian tubules and fat body with the second. DNA synthesis in prothoracic glands and oenocytes exhibits a time course that is the inverse of the hormone-secretion time course. The question whether moulting hormones have an influence on DNA synthesis is discussed.