bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tetrapyrrol Derivatives Shown by Fluorescence Emission and Excitation Spectroscopy in Cells of Rhodopseudomonas capsulata Adapting to Phototrophic Conditions
Authors: Beck Jürgen , Drews Gerhart 
Published: August 2018

Abstract
Aerobically in the dark grown cells were incubated semiaerobically (30 min) and afterwards 180 min anaerobically in the light During phototrophic induction the bacteriochlorophyll concentra­ tion increased from 0.26 to 2.10 nmol/mg cell protein.
In samples taken at different times after lowering of oxygen partial pressure the following tetrapyrrol derivatives were identified by fluorescence emission and excitation spectroscopy at 1.7 K: Mg-protoporphyrin EX-monomethylester, Mg-2,4-divinylphaeoporphyrin a5-monomethylester, 2-de-vinyl-2 -hydroxyethyl-chlorophyllide, 2 -devinyl-2 -hydroxyethyl-pheophorbide, chlorophyllide a, pheophorbide, bacteriopheophorbide, bacteriopheophytin, bacteriochlorophyllide and bacte­ riochlorophyll a in different pigment complexes. The highest relative concentrations of bacte­ riochlorophyll precursors normalized to the total amount o f bacteriochlorophyll a were found in cells during the first hour of adaptation at 0.5 μg Bchl/mg cell protein or less.
On the Occurrence of Monoacylglycerol Derivatives in Lipid Metabolism of Chloroplasts
Authors: Sauer Andreas , Heise Klaus-Peter 
Published: August 2018

Abstract
The aim of this investigation was to elucidate the rapid synthesis o f monogalactosyl mono­ glycerides and their role as intermediary acyl-acceptors in galactolipid synthesis of spinach chlo­ roplasts. The problem was attacked by studying the incorporation o f sn-[14C]glycerol-3-phosphate and [l-14C]acetate into the lipid fraction o f gently shocked and reconstituted preparations. The data revealed: 1 . a concurrent accumulation o f both monoglycerides and monogalactosyl monoglycerides under acidic incubation conditions, with C16-fatty acid species predominating, 2 . similarities in the fatty acid incorporation of both monoacyllipids, 3. the occurrence o f two isomeric forms viz. 1 -and 2-O-acyl-isomers o f these lipids. Thus, it appears that monogalactosyl monoglycerides are synthesized by galactosylation o f mo­ noglycerides rather than by galactolipase hydrolysis. Both monoacyllipids are likely to be derived from the corresponding lysophosphatidic acids by dephosphorylation. Their fatty acid incorporation pattern therefore may contribute to an under­ standing of the specific esterification o f different fatty acids at the Ct-and exp osition of the gly­ cerol moiety of galactolipids. Analysis o f the specific acylation o f monoglycerides and monogalac­ tosyl monoglycerides as well as the nature of the acyl donors involved in this fatty acid transfer yielded the following observations: 5. The position of the fatty acids within the monoacyllipids seems to depend on whether acyl-ACP or acyl-CoA is the primary acyl donor. 6 . The characteristics of the fatty acid incorporation into monoglycerides and their galactosylated derivatives support the notion that a successive acylation o f sn-glycerol-3-phosphate occurs first in the C2-and then in the Q-position. 7. In contrast, the chain length o f the fatty acids incorporated seems to be determined by such fac­ tors as pH and the concentration o f sn-glycerol-3-phosphate. This observation suggests that these parameters may act by controlling the elongation o f ACP-bound C16-fatty acids to their C18-species.
Possible Models of Murein and Their Fourier Transforms
Authors: Formanek Helmut 
Published: August 2018

Abstract
Murein, Models, Fourier Transforms Murein, the rigid layer of the cell walls of almost all bacteria can be regarded as derivative of chitin. Within the sterically allowed region its polysaccharide chain can perform conformations with two-to threefold screw axes. Two dimensional Fourier transforms calculated from different possible conformations have been compared with data of density measurements, X-ray and electron diffraction. The Fourier transform of murein with a chitin-like conformation of the poly­ saccharide chain and an elementary cell of 4.5 × 10.4 × 21.5 Å3 provides the best agreement with the experimental results.
Photophosphorylation by Chloroplasts: Effects of Low Concentrations of Ammonia and Methylamine
Authors: Giersch Christoph 
Published: August 2018

Abstract
Intact chloroplasts exposed to hypotonic assay conditions are capable of photophosphorylating exogenous ADP. The rate of phosphorylation by these unbroken plastids is increased by 10-50% upon the addition of low concentrations (<mм) of NH3 or CH3NH2. Stimulation of phosphorylation is abolished by washing chloroplasts with MgCl2. Evidence is presented that washing removes a factor responsible for amine-induced increase of ATP production and that this factor is associated with the thylakoid membrane. Addition of CH3NH2 increased the proton permeability of the thylakoid membrane of unbroken and washed chloroplasts during the light/dark transition. Hence, differences of the membrane permeability for protons between the two preparations seem not to be responsible for an increase of ATP production upon the addition of amines. Stimulation of photophosphorylation by methylamine is observed even at light itensities which do not saturate the proton motive force, which in turn is reduced upon the addition of the uncoupler. Apparently, phosphorylation can be stimulated, although the limiting driving force is diminished. It is concluded that phosphorylation by unbroken chloroplasts under low light illumination is limited kinetically, not energetically. Consequences of these findings for observation made with intact chloroplasts are discussed.
Herbicides which Inhibit Electron Transport or Produce Chlorosis and Their Effect on Chloroplast Development in Radish Seedlings I. Chlorophyll a Fluorescence Transients and Photosystem II Activity
Authors: Grumbach K. H. 
Published: August 2018

Abstract
Diuron and bentazon are very strong inhibitors of the photosynthetic electron transport in isolated radish chloroplasts. The chlorosis producing herbicide SAN 6706 also inhibited the photosystem II dependent oxygen evolution. Aminotriazole had no effect. The inhibitor concentration for 50% inhibition of photosystem II activity was 10-7 m for diuron and 10-4 m for bentazon and SAN 6706 respectively.
Diuron and bentazon quenched the chlorophyll a fluorescence transients in isolated radish chloroplasts drastically, while aminotriazole was not effective. It was of particular interest that the bleaching herbicide SAN 6706 inhibited photosystem II dependent oxygen evolution in a similar concentration as bentazon but had no effect on the chlorophyll a-fluorescence transients suggesting that SAN 6706 is not binding to the same site of the electron transport chain as diuron and bentazon.
Apart from their direct influence on electron transport in isolated photosynthetically active chloroplasts the photosystem II and bleaching herbicides assayed also strongly affected photosynthesis in radish seedlings that were grown in the presence of the herbicides for a long time. As already obtained using isolated chloroplasts, photosystem II dependent oxygen evolution like the chlorophyll a fluorescence transients were strongly inhibited by the photosystem II herbicides diuron and bentazon. A reduction but no inhibition of photosystem II activity was observed in plants that were grown in the presence of aminotriazole. The pyridazinone SAN 6706 was behaving contradictory. In partly green plants photosystem II activity was still maintained and even higher than in untreated plants while in albinistic plants no photosynthetic activity was detected.
Subcellular Fractionation of Bone Marrow-Derived Macrophages: Localization of Phospholipase A1 and A2 and Acyl-CoA:1-Acylglycero-3-phosphorylcholine-0-acyltransferase
Authors: Krüner Ellen E. , Fischer Herbert , Ferber Ernst 
Published: August 2018

Abstract
Phospholipase A1 and A2, Lysolecithin-Acyltransferase, Macrophage, Subcellular Localization Analysis of the subcellular distribution of lipid-metabolizing enzymes was carried out in bone marrow-derived macrophages with special respect to a comparison of the subcellular localisation of phospholipase A1 and A2 and to acyl-CoA: 1-acylglycero-3-phosphorylcholine-0-acyltransferase.
After cell disruption differential centrifugation was followed by additional sucrose gradient purification of three main fractions.
Satisfactory enrichment factors were obtained by this method for the following marker enzymes. The plasma-membrane enzyme alkaline phosphodiesterase I was enriched up to 25-fold and the acyl-CoA:1-acylglycero-3-phosphorylcholine-0-acyltransferase was enriched up to 30-fold. The marker enzyme for the endoplasmic reticulum, NADPH-cytochrome c reductase showed a similar enrichment and distribution as the acyltransferase. Therefore it was concluded that the acyl-CoA:1-acylglycero-3-phosphorylcholine-O-acyltransferase of bone marrow-derived macrophages is mainly located in the endoplasmic reticulum. Phospholipase A1 and A2 occurred in a high proportion together with the lysosomal marker enzyme N-acetyl-β-glucosaminidase in the soluble supernatant and in the gradient fractions. In the endoplasmic reticulum phospholipase A2 occurred only in trace activities whereas phospholipase A 1 was maximally enriched in this subcellular fraction. No subcellular fraction could be obtained where phospholipase A2 was enriched exclusively. However, it can be concluded that the two enzymes which are responsible for the balance of fatty acid liberation and re-acylation are located in two different cellular compartments. Furthermore it can be claimed that in the cell there has to exist an exchange of substrates and products between these compartments to achieve a complete metabolic cycle of the de-and re-acylation reaction of phospholipids in bone marrow-derived macrophages.
Spurorientierung bei Waldameisen (Formica polyctena Förster) / Trail Orientation of Wood Ants (Formica polyctena Förster)
Authors: Horstmann K. 
Published: August 2018

Abstract
Workers of Formica polyctena Förster (Hymenoptera, Formicidae) follow artificial trails made with the contents of mandibular glands, poison glands, Dufour glands and rectal glands of their own species, as well as recruitment trails of Lasius fuliginosus (Latreille) or Myrmica ruginodis Nylander. Some specialized out-door workers prefer poison trails, as do workers irritated by a marking procedure. After withdrawal of sugared water the workers prefer rectal trails. Workers of hungry colonies also follow trails made with sugared water or faeces of tortricid larvae.
Biosynthesis of Isoflavonoid Phytoalexins: Incorporation of Sodium [1,2-13C2] Acetate into Phaseollin and Kievitone
Authors: Dewick Paul M. , Steele Melanie J. , Dixon Richard A. , Whitehead Ian M. 
Published: August 2018

Abstract

13C-NMR analysis of the isoflavonoid phytoalexins phaseollin and kievitone produced by feeding sodium [1,2-13C2]acetate to wounded bean (Phaseolus vulgaris) cotyledons has demonstrated the incorporation of intact acetate units into the aromatic A rings. Phaseollin shows a specific folding of the polyketide chain, whereas kievitone exhibits a randomisation of label in accordance with the intermediacy of a 2′,4′,6′-trihydroxylated chalcone during its formation. In neither case was sufficient label incorporated into analysis.
Effects of Trypan Blue and Related Compounds on Production and Activity of Streptolysin S
Authors: Taketo Yoriko , Taketo Akira 
Published: August 2018

Abstract
Most dyes related to trypan blue inhibited hemolytic activity of oligonucleotide-streptolysin S (SLS) complex, an exotoxin produced by Streptococcus pyogenes. Order of the inhibition was: trypan blue > benzo blue 2B > Congo red > Evans blue > benzo purpurine 4B > thiazine red > trypan red. When resting streptococcal cells were incubated with these dyes, significant amount of the hemolysin was produced. The carrier (or inducing) activity for SLS was further manifested in growing cell system and the potency of the compounds was as follows: Congo red > benzo blue 2B > trypan blue > Evans blue > Benzo purpurine 4B > thiazine red > trypan red. In this system, Congo red was more effective than oligonucleotide fraction rich in guanyl residue. Chromotrope 2B, H acid and o-tolidine were ineffective, as the carrier as well as the inhibitor. Based on these results, structure-function relationship among SLS, the carrier and the inhibitor was discussed.
Equilibrium Constants for Some Steps of the Reaction Cycle of the Sarcoplasmic Reticulum Calcium Pump
Authors: Tanford Charles , Martin Dwight W. 
Published: August 2018

Abstract
This paper summarizes true equilibrium measurements for some partial reactions of the sarcoplasmic reticulum calcium pump transport cycle. The most important result is the estimation of the equilibrium constant for the interconversion of the two major conformational states of the protein, E (Ca2+ binding sites facing the cytoplasm) and E′ (Ca2+ binding sides facing the sar­coplasmic reticulum lumen). The value of K0 = [E′]/[E] cannot be evaluated directly by any method available at present, but observed cooperativity in the binding of Mg2+ and Ca2+ to unliganded protein strongly indictes that K0 ⪢ 1. The most probable value, valid within an order of magnitude, is K0 ≃ 103, i.e., the E′ state is more stable than the E state by about 4 kcal/mol.
Roseanolone: A New Diterpene from Hypoestes rosea
Authors: Okogun Joseph I. , Adesomoju Akinbo A. , Adesida George A. , Lindner Hans Jörg , Habermehl Gerhard 
Published: August 2018

Abstract
Roseanolone is a new diterpene from the African plant Hypoestes rosea (Acanthaceae). The isolation is described; the structure has been determined to be 1,2,3,3a,4,5,6,6a,7,8,9,10a-dodecahydro-5-hydroxy-3-isopropyl-3a, 6-oxa-6,9,10a-trimethyl-dicyclopenta[a,d] cycloocten-1-one by X-ray crystallography.
Irregularities in the Circular Dichroism of Oligoribonucleotides
Authors: Zacharias Wolfgang , Follmann Hartmut 
Published: August 2018

Abstract
Marked anomalies, previously unresolved, exist in the CD spectra of oligoadenylates and oligouridylates at the pentamer or tetramer stage, indicating that these molecules differ in conformation from the preceding and the following member of the series. The CD of oligoadenylates retains a positive Cotton effect even at 80 °C. Caution must be exerted when predicting oligonucleotide structures from CD spectra.
Adult T-Cell Leukemia-Associated Antigen (ATLA): Detection of a Glycoprotein in Cell- and Virus-Free Supernatant
Authors: Yamamoto Naoki , Schneider Josef , Hinuma Yorio , Hunsmann Gerhard 
Published: August 2018

Abstract
A glycoprotein of an apparent molecular mass of 46000, gp 46, was enriched by affinity chromatography from the virus-and cell-free culture medium of adult T-cell leukemia virus (ATLV) infected cells, gp 46 was specifically precipi­tated with sera from patients with adult T-cell leukemia known to react with the adult T-cell leukemia associated antigen (ATLA). Thus, gp 46 is a novel component of the ATLA antigen complex.
Characterisation of the Enzyme Intermediates of the Sarcoplasmic Transport ATPase by the Use of Inhibitors
Authors: Boll W. , Makinose M. 
Published: August 2018

1. Based on a detailed reaction scheme of the phosphorylation process of the sarcoplasmic transport ATPase the inhibition mechanisms of benzoctamine, DIO 9, AMP-PNP and of Ca2+-ions at relatively high concentrations (1 ~ 100 μᴍ) were determined.
2. The inhibition mechanisms were analyzed by measuring the γ-phosphate exchange between ATP and ADP and evaluated by applying conventional and an extended Dixon plot procedures.
3. The kinetic patterns of the inhibition were shown to be compatible with the assumed reaction scheme.
4. Each inhibitor combines with definite intermediates: Benzoctamine with the interm ediate species

~ P; DIO 9 with E and MgE and Ca2+ at relatively hign concentrations with E.
5. The central interm ediate blocked by benzoctamine can partially exist as

-benzoctamine which is detected as phosphoprotein after acid denaturation
Adsorbenskultur — ein Weg zur Steigerung der Sekundärstoffproduktion in pflanzlichen Suspensionskulturen / Adsorbent Culture -Method for the Enhanced Production of Secondary Substances in Plant Suspension Cultures
Authors: Knoop Bernd , Beiderbeck Rolf 
Published: August 2018

A crown-gall suspension of Matricaria chamomilla L. was cultivated in the presence of an adsorbent (activated charcoal, AC). The culture produces besides other secondary products coniferyl aldehyde which is excreted by the cells and distributed between cells, medium, and the AC according to equilibrium distributions with more than 95% of the substance adsorbed to the AC. This deprivation of coniferyl aldehyde from the medium enables the cells to increase the production of this substance up to 60-fold.
The system Matricaria/coniferyl aldehyde serves as a model for the improvement of the production of secondary products by means of plant cell suspensions.
Flavonoids from the Leaf Resin of Hymenoclea salsola T. & G. (Asteraeeae)
Authors: Proksch Peter , Wollenweber Eckhard , Rodriguez Eloy 
Published: August 2018

Abstract
Hymenoclea salsola (Asteraceae), a dominant shrub of the desert areas of California and Baja California, Mexico, secretes high amounts of resin on the leaf surface. Chemi­cal analysis of the resin revealed the presence of a complex mixture of flavonoid aglycones. Among the compounds identified is the rare 2',4',6'-OH chalcone, previously not known to occur in the Asteraceae.
Time-Shifted Mating Periods in Two Closely Related Corixid Species
Authors: Theiß Joachim 
Published: August 2018

Abstract
The water boatmen Corixa dentipes and C. punctata produce an acoustic mounting signal when beginning to copulate. Automated recording of this signal over the entire life cycle of the anim als reveals that the main mating period of C. punctata occurs in autumn and that of C. dentipes, in the spring. In the case of C. punctata, mounting signals were routinely recorded even during the winter, at water temperatures below 4 °C.
Chemistry and Morphology of Epicuticular Waxes from Various Organs of Jojoba (Simmondsia chinensis [Link] Schneider)
Authors: Gülz Paul-Gerhard , Hängst Kurt 
Published: August 2018

Abstract
The surface of leaves and seed coats of Jojoba is covered with similar amounts of epicuticular waxes per surface area. The composition of these waxes was analysed by chemical methods, whereas their microscopic structures in situ were revealed by scanning electron microscopy. Differences in the chemical structure and com position of the complex mixtures cause differences in the morphological appearance of wax on the surface of both organs. The predominance of saturated and long chain components in leaf wax results in a crystalline wax layer on this organ. In contrast, the seed coat carries a cover of non-crystalline fluid consistency. The lower melting point of this wax mixture is caused by shorter chain and unsaturated compounds predominating on this organ.
Isolation and Structural Determination of a New Methylated Triterpenoid from Rhizomes of Iris versicolor L.
Authors: Krick Wolfgang , Marner Franz-Josef , Jaenicke Lothar 
Published: August 2018

Abstract
A monocyclic C31-triterpenoid was isolated from rhizomes of Iris versicolor L. Its structure was elucidated as 12 by spectroscopy combined with oxidative degradation. The identity of the degradation-products was proven by comparison with synthetic references.
Structure Activity Correlation of Herbicides Affecting Plastoquinone Reduction by Photosystem II: Electron Density Distribution in Inhibitors and Plastoquinone Species
Authors: Trebst A. , Donner W. , Draber W. 
Published: August 2018

Molecular orbital calculations of the net charge and the π charge distribution in several inhibitors and herbicides of the functionally related group of the diuron and dinoseb type are reported. They confirm the model that urea, aminotriazinone and triazine herbicides all have in common a positive π-charge at a particular atom considered to be essential for binding. Phenol type inhibitors have different charge distribution and a model for their essential features is presented. The calculations support the finding that two different subunits with different binding characteristics are involved in inhibitor and plastoquinone function on the acceptor side of photosystem II.
Force-field model building and MO calculations of the charge distribution of a plastoquinone analogue with a butenyl side chain, of two of its semiquinone forms and of the hydroquinone, are reported, as well as their conformation with the lowest energy content and their likely anionic forms.
Increased Synthesis of Photosystem II in Triticum vulgare when Grown in the Presence of BAS 13-338
Authors: Bose Salil , Mannan R. Mannar , Arntzen C.J. 
Published: August 2018

Addition of BAS 13-338 (4-chloro-5-dimethylamino-2-phenyl-3(2H)-pyridazinone) to a suspension of chloroplast thylakoids caused an increase in the / level of chlorophyll fluorescence induction without affecting the F0 level and with a slight decrease in the Fmax level in a manner similar to the addition of DCMU to a thylakoid suspension. Addition of BAS 13-338 also inhibited the rate of Hill reaction H2O → dichlorophenol indophenol with 50% inhibition occurring at about 10 μм BAS 13-338. The inhibition was not reversed by diphenyl carbazide used as an artificial electron donor to photosystem II. These results suggest that the site of inhibition by BAS 13-338 is between Q (next to the primary electron acceptor) and plastoquinone.
When the plants were grown in the presence of sublethal dose of BAS 13-338, the following changes were noted in the thylakoids of the treated plants as compared to the thylakoids isolated from the control plants: The F0 and the normalized variable fluorescence (⊿F/F0) levels increased, chlorophyll a/b ratio decreased, chlorophyll/P700 ratio increased. Furthermore, the rate of photosystem II electron transport both under saturated intensity and the limiting intensity of illumination increased, and the ratio of plastoquinone to Q decreased. These observations have been interpreted as due to an increase in the ratio of photosystem II to photosystem I in plants grown in the presence of BAS 13-338.
Common Identity of UDP-Glucose: Anthocyanidin 3-O-Glucosyltransferase and UDP-Glucose: Flavonol 3-O-Glucosyltransferase in Flowers of Petunia hybrida
Authors: Jonsson L. M. V. , Aarsman M. E. G. , Bastiaannet J. , Donker-Koopman W. E. , Geräts A G. M. , Schram A. W. 
Published: August 2018

In an attempt to distinguish between the UDP-glucose: flavonol 3-O-glucosyltransferase (3GT) and the UDP-glucose: anthocyanidin 3-O-glucosyltransferase in flower buds of Petunia hybrida, several properties of these activities were determined. The 3-glucosylation of anthocyanidin had a pH-activity optimum of 7.2, that of flavonol pH 9.2 to 9.5. Anthocyanidin 3GT activity was lowered in the presence of EDTA or β-mercaptoethanol, but this was due to an effect on the anthocyanidin substrate. The two 3-glucosylating activities were to a similar extent inhibited by an increasing ionic strength in the enzyme assay and showed an identical iso-electric point (5.2) as determined by chromatofocusing. Molecular weights were identical: 26000, 52000 or 78000 daltons as determined by gel-filtration. Antiserum raised against partially purified 3GT gave identical immunoprecipitation curves with flavonol 3GT and anthocyanidin 3GT.
Special attention was given to the 3-O-glucosyltransferase in mutants with low levels of 3GT activity. These mutants are unable to form significant amounts of anthocyanins but contain wild- type amounts of flavonols. The enzyme of such mutants had the same iso-electric point and identical titration-curves with antiserum as the enzyme from wildtype plants. 3GT from wildtype or mutant plants glucosylated flavonols at higher rates than anthocyanidins.