bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Induced Spectral Changes of Chlorophyll in Micelles and Solution
Authors: Brody Seymour Steven 
Published: August 2018

Effects of temperature on the spectral properties of chlorophyll in solution and in micelles are reported. After correcting for the volume expansion coefficient of the solvent, it is observed that temperature has no detectable effects on the spectral properties of chlorophyll (between 14 °C to 35 °C). Solutions examined include acetone, chloroform and ethyl alcohol. It is concluded that the temperature induced change in refractive index, of the solvent, has no significant affect on the chlorophyll spec­trum.
In micelles containing chlorophyll there are significant temperature induced spectral changes. Heating and cooling results in an irreversible redistribution of monomeric and oligomeric forms of chlorophyll.
6-Hydroxyflavones and Other Flavonoids of Crocus
Authors: Harborne Jeffrey B. , Williams Christine A. 
Published: August 2018

Abstract
6-Hydroxyflavones have been identified for the first time in the Iridaceae, in leaves of three Crocus species. Three new glycosides have been characterised: 6 -hydroxyluteolin 7- rhamnosylglucoside, scutellarein 7-glucoside and scutellarein 7-methyl ether 6 -glucoside, as well as two known glycosides: 6 -hydroxyluteolin 7-glucoside and 6 -hydroxyluteolin 7-methyl ether 6 - glucoside. 6 -Hydroxyluteolin and scutellarein glycosides have been found before in Bromeliaceae. Commelinaceae, Cyperaceae and Orchidaceae, but this is the first record of the respective 7-methylethers in the Monocotyledoneae. Acacetin and tricin have been identified as aglycones in C. laevigatus an d C. heuffelianus leaves, respectively and the occurrence of mangiferin confirmed in C. aureus leaves. Two of the major flavonol glycosides present in flowers of cultivated species were identified as kaempferol 3-sophoroside and kaempferol 3- rutinoside-7-glucoside. However none of the flavonoids identified appears to contribute to yellow petal colour in Crocus, which is probably entirely carotenoid-based.
Aliphatic 1-Amino Acid Decarboxylase from Ferns (Filicopsida)
Authors: Hartmann Thomas , Bax Klaus , Scholz Renate 
Published: August 2018

Abstract
A screening of 27 fern species (Filicopsida) out of 9 families revealed that 25 species were able to decarboxylate 1-leucine to 3-methylbutylamine (isoamylamine). The enzyme of Polvpodium vulgäre has partially been purified and characterisized. All attempts to solubilize it from acetone preparations failed; however, approx. 50% of total activity could be extracted from dry material in the presence of detergents at high concentration. The soluble enzyme was purified 132-fold. 1-Methionine was found the best substrate followed by norvaline, leucine, norleucine, isoleucine, homocysteine, valine. It has been confirmed that these substrates are decarboxylated by a single enzyme. The pH -optimum was at pH 5.0 (particulate preparation) and pH 4.5 (soluble enzyme). Decarboxylation is dependent on pyridoxal-5′-phosphate (PLP). A strictly substrate dependent coenzyme dissociation was observed which could largely be prevented by addition of 2-oxo-acids, such as glyoxylate or pyruvate. A podecarboxylase prepared by prolonged substrate incubation was found to be extremely labile at pH 4.5 but stable at pH 6.5. A comparison of the fernenzyme with bacterial valine decarboxylase (EC 4.1.1.14) and leucine decarboxylase of red algae revealed great similarities especially in substrate specificity. It is suggested to unify these activities as “aliphatic 1-amino acid decarboxylase”.
Hormone Induced Changes in Carotenoid Composition in Ricinus Cell Cultures. I. Identification of Rhodoxanthin
Authors: Kayser Hartmut , Gemmrich Armin R. 
Published: August 2018

Abstract
When cell cultures of Ricinus communis are grown in light and with kinetin as the sole growth factor red cells are formed. The red pigmentation is due to the accumulation of rhodoxanthin which is the major carotenoid in these cultures. The identification of this retro-type carotenoid is based on electronic and mass spectra, on chemical transformation to zeaxanthin, and on comparison with an authentic sample. Rhodoxanthin is not present in any part of the intact plant. The major yellow carotenoid in the red cultures is lutein.
Purification and Partial Characterization of the Soluble NADH Dehydrogenase from the Phototrophic Bacterium Rhodopseudomonas capsulata
Authors: Ohshima Toshihisa , Ohshima Matsumi , Drews Gerhart 
Published: August 2018

Abstract
Soluble NADH dehydrogenase was purified to homogeneity from chemotrophically grown cells of Rhodopseudomonas capsulata by ammonium sulfate fractionation, AH -Sepharose 4B chromatography and FMN-Sepharose 6B affinity chromatography. The enzyme contains a single polypeptide chain of an apparent M, of 37000, suggesting that the subunit structure is different from that of the membrane-bound enzyme. The purified soluble NADH dehydrogenase requires flavin compounds, e.g., FMN, FAD and riboflavin, for activity. Addition of FMN and FAD. but not riboflavin, to the enzyme solution stabilized the enzyme. The pH optimum for activity was at 7.5. The enzyme was specific for NADH as an electron donor while NADPH was inert. Menadione, ferricyanide, cytochrome c and DCIP served as an electron acceptor. The M ichaelis constants for NADH. DCIP, FM N. and cytochrome c were 45, 2.9. 7.9 and 15 μM, respectively. Many properties of soluble NADH dehydrogenase were substantially different from those of the membrane-bound enzyme, suggesting different functions.
Light Dependent Ammonium Inhibition of Nitrate Assimilation in Rhodopseudomonas capsulata AD2
Authors: Alef Kassem 
Published: August 2018

Abstract
Nitrate assimilation by Rhodopseudomonas capsulata AD2 was completely inhibited by ammonium only in young well illuminated cultures. At higher densities (A660 about 0.5) the addition of ammonium had no inhibitory effect, but the nitrate was only reduced to the level of nitrite, which appeared in the medium. Under both conditions the cellular level of nitrate reductase activity remained unaffected. In marked contrast to other R. capsulata strains both ammonium sensitive and insensitive cells could reduce nitrate in the light and in the darkness. In the light up to 90% of the reduced nitrate was assimilated, but in the dark the reduced nitrate was stoichiometrically excreted as nitrite. This behaviour was only shown by R. capsulata AD2 and BK5, while in other strains the nitrate assimilation was always completely inhibited by ammonium.
The role of photosynthesis and respiration by the regulation of nitrate reduction is discussed.
Immune Serum against Anti-DNA-8-Methoxypsoralen Photoadduct
Authors: Zarębska Z. , Jarząbek-Chorzelska M. , Jabłońska S. 
Published: August 2018

Abstract
Specific immune serum against photo-damaged DNA with the photoadducts of 8 -methoxypsoralen (8-MOP) was obtained. The antigenic determinant is a polynucleotide chain with a mono-photoadduct: a coumarin moiety of psoralen linked through a cyclobutane ring to the 5,6-bond of thymine. The specific rabbit antiserum was used in the immunofluorescence method, for the detection of photodamaged DNA in the kinetoplasts and nuclei of unicellular organisms Crithidia luciliae, in the nuclei of snap-frozen tissue of mammals, and in human blood lymphocytes. Detection by the immunofluorescence method was limited by psoralen availability in situ; the psoralen concentration should be in the range 0.05 -0.2 μg/cm2 on specimens submitted to a topical application or about 1 μg/ml in cell suspension. The long-wave ultraviolet light (UV-A) exposure dose applied to the nuclei should exceed 1J/cm2.
X-Ray Studies on Phospholipid Bilayers, in. Structure and Morphology of L-α-Dilaurylphosphatidylethanolamine (DLPE)
Authors: Suwalsky M. , Seguel C.G. , Neira F. 
Published: August 2018

Abstract
Phospholipid, Bilayer, X-Ray Diffraction, Morphology, Dilaurylphosphatidylethanolam ine, Membrane Powder samples and oriented films of the synthetic phospholipid L-α-dilaurylphosphatidyl-ethanolamine (DLPE) were studied by X-ray diffraction over a wide range of hydration. Only small differences were found between the unit cell dimensions of DLPE powder and oriented-film specimens. These dimensions did not vary appreciably with hydration. In the multilayer DLPE structure, the molecules pack with polar groups parallel to the bilayer plane and hydro­ carbon chains perpendicular to it. Examination of oriented films by scanning electron microscopy gave information on the surface morphology. Complementary data on the lamellar packing of the molecules and the average thickness of the bilayers was provided by thin-section and shadow-cast preparations studied by transmission electron microscopy.
New Cinnamoyl Esters of Quinic Acid from Meumathamanticum
Authors: Barron Denis , Kaouadji Mourad , Mariotte Anne-Marie 
Published: August 2018

Abstract
Two new cinnamoyl quinic acid esters were isolated from the methanolic extract of Meumathamanticum rhizome. They were identified as l-trans-O-caffeoyl quinic acid methyl ester and l-trans-O-feruloyl quinic acid methyl ester by the spectral data of the natural products and those of the acetylated derivatives.
Salmonella/ Microsome Mutagenicity of 1-Nitropyrene-2-ol, a Nitropyrene Phenol Formed in the Photolysis of 1-Nitropyrene
Authors: Löfroth Göran , Nilsson Lena , Agurell Eva , Yasuhara Akio 
Published: August 2018

Abstract
1-Nitropyrene-2-ol is not detectably mutagenic in the Salmonella test in the absence of mammalian activation. It is activated by the rat liver microsom e-containing preparation S9 and gives a mutagenic response similar to that of benzo(a)pyrene.
Constituents of Agaricus xanthodermus Genevier: The First Naturally Endogenous Azo Compound and Toxic Phenolic Metabolites
Authors: Gill Melvyn , Strauch Richard J. 
Published: August 2018

Abstract
Extraction of fresh sporophores of the fungus Agaricus xanthodermus yields 4,4′-dihydroxy-azobenzene, phenol, p-quinol, and 4,4′-dihydroxybiphenyl. This is the first report of an azo compound arising endogenously in nature, while phenol, p-quinol and 4,4′-dihydroxybiphenyl have not previously been isolated from higher fungi. Phenol is present in fruitbodies in sufficiently high concentration to account for the toxicity of A. xanthodermus.
Flash Pattern of Oxygen Evolution in Greening Etioplasts of Oat
Authors: Franck Fabrice , Schmid Georg H. 
Published: August 2018

Abstract
Etioplasts isolated from oat leaves that have received two 5 min illumination periods, spaced apart by a 90 min dark interval, are able to evolve oxygen. If this oxygen evolution is measured as consequence of short saturating light flashes a pattern is obtained which in agreement with the Kok-Joliot model shows a damped oscillation with a periodicity of four. As usual for most other systems the maximum flash yield is observed under the third flash. In continuous light such slightly greened etioplasts show a small oxygen gush. From our studies it appears that the second 5 min illumination period is obligatory for oxygen evolution. Omission of this period leads to a condition in which under flashes strictly no oxygen is evolved. In continuous light under these conditions no oxygen gush but rather an uptake is observed after onset of illumination. It appears that in greening etioplasts the flash pattern shows some peculiarities when compared to the normal green conditions. Thus, a flash sequence of a greening etioplast always shows a substantial positive amperometric signal under the first flash. The half time of the state which would belong to this signal is 3 to 4 min in a greening etioplast, isolated from leaves that have received 2 h light. In the course of greening this half time decreases continuously and reaches a normal and constant value of approx. 10 s in chloroplasts from green oat or etiochloroplasts that are prepared from leaves that have received 15 h of light. The result is discussed in terms of metastable S3 which seems to be a property of the developing oxygen evolving system in greening oat leaves. In the greening system as we use it is shown for the first time that the photoenzyme protochlorophyllide chlorophyllide reductase is DCMU sensitive.
Properties of Membrane Fractions Prepared by Chromatophore-Liposome Fusion
Authors: Garcia Augusto F. , Drews Gerhart 
Published: August 2018

Abstract
Intracytoplasmic membrane vesicles (chromatophores) isolated from Rhodopseudomonas capsulata cells were fused with liposomes by a pH transition procedure. Vesicles of lower density and higher lipid contents and larger diameter than chromatophores were obtained. Similar results were observed by Ca2+ induced fusion and by the freeze-thawing method. Respiratory and light-induced electron transport were measured in chromatophores and fused vesicles. Light-induced reaction center bleaching was observed in all types of vesicles, whereas repiratory electron transport was substantially diminished by lipid incorporation. Ubiquinone 10 restored to some extent respiratory electron transport and oxidative phosphorylation and it modified the photophosphorylation kinetics under continuous light. Electrochromic carotenoid band-shift and the 9-aminoacridine fluorescence quenching indicate that the capacity of the fused vesicles to maintain an electrochemical proton gradient has not been substantially diminished. From the kinetics of 9-aminoacridine quenching an increased K+-permeability seems to be apparent.
Metabolie Effects of Direct Current Stimulation on Cultured Vascular Smooth Muscle Cells
Authors: Heinle Helmut , Sigg Gerhard , Reich Amo , Thiedemann Klaus-Ulrich 
Published: August 2018

Abstract
Vascular smooth muscle cells from rabbit arteries were grown in tissue culture and stimulated by DC impulses (1 mA, 1V, 10 Hz, 1 ms/imp). Scanning microscopic examination disclosed that in stimulated cultures the cell surface was enlarged by numerous microvilli. This was interpreted as being indicative of an increase in cell activity. Cellular metabolism was character­ized by analyzing the incubation medium for glucose, glutamate/glutamine, and lactate. When compared to unstimulated controls, stimulation caused an increase in the uptake of glucose and glutamine as well as an increased lactate production. The enhancing effect on metabolism was prevented when the “calcium antagonist” verapamil was present (5 × 10-6ᴍ). Although the exact mechanism by which DC stimulation influences the cells remains obscure, this finding indicates an important mediating role of Ca2+ ions.
A High Frequency Mutation Starts Sexual Reproduction in Volvox carteri
Authors: Weisshaar Bernd , Gilles Rainer , Moka Regina , Jaenicke Lothar 
Published: August 2018

Abstract
Pheromone-initiated sexual reproduction of Volvox carteri f. nagariensis is started by a “spontaneous” generation of sexual male spheroids at a rate of 10-4. As previously suggested, these males are mutants (sexc) which become independent of pheromone-controlled sex-induction. Unequivocal evidence for a mutative event now comes from the observation that the sexc trait is transmitted through cell lineages during embryogenesis, thus confirming earlier morphological analysis, Mutation semms to be restricted to cell division, The high frequency of mutation points to a special enchacing mechanism for whick the possibility of a genome rearrangement is discussed.
Arboxeniolide-1, a New, Naturally Occurring Xeniolide Diterpenoid from the Gorgonian Paragorgia arborea of the Crozet Is. (S. Indian Ocean)
Authors: D’Ambrosio Michele , Guerriero Antonio , Pietra Francesco 
Published: August 2018

Abstract
The gorgonian Paragorgia arborea, collected in the Crozet Is. waters at a depth of 280 m during the cruise MD.30/BIOMASS of M/S “Marion Dufresne”, is shown, in what constitutes the first organic-chemical study of a Paragorgiidae, to possess three C20H28O2 xeniolide diter­penoids, two of which are identical with those from a Corallium sp. of the Hawaii. The third xeniolide, arboxeniolide-1, is new as a naturally occurring compound.
Comparison of the Polypeptide Complement of Different Plastid Types and Mitochondria of Narcissus pseudonarcissus
Authors: Hansmann Paul , Sitte Peter 
Published: August 2018

Abstract
The protein complement of chloroplasts, prochromoplasts, chromoplasts, and mitochondria of the daffodil (Narcissus pseudonarcissus) has been investigated comparatively by gel electrophoresis. Mitochondria do not share common proteins with plastids. On the other hand, there is a broad overlap of the protein complement of the three plastid types investigated, in spite of their different fine structures. There are, however, remarkable differences regarding the relative amounts of many protein species, and certain plastid proteins are entirely absent either from the chloroplasts (e.g., 2 chromoplast proteins in the 60 kDa range) or the chromoplasts (e.g., LHCP). The protein complement of prochromoplasts, which contain chlorophylls and the LHCP, is nevertheless quite more similar to the protein pattern of the chromoplasts than to the one of the chloroplasts.
System Analysis of the Circadian Rhythm of Euglena gracilis, II: Masking Effects and Mutual Interactions of Light and Temperature Responses
Authors: Kreuels T. , Joerres R. , Martin W. , Brinkmann K. 
Published: August 2018

Abstract
Motility of Euglena gracilis shows free running circadian rhythms. The circadian system is sensitive to light and temperature signals, but it is always masked by direct responses of motility to light (photokinesis) and temperature (thermokinesis). By means of a compartimental model which defines the interrelations between the pathways of thermokinesis, photokinesis and the circadian system a unifying view of effects of temperature and light input signals is outlined. According to the model, and using double sine input signals the dynamics of thermokinesis is described by a differential amplifier with constant gain.
Although thermokinesis heavily masks circadian responses to temperature signals, the limited range of circadian entrainment is indirectly demonstrated by a limited reappearance of free running circadian oscillations after stopping the temperature program. Free running circadian oscillations do reappear only after pretreatment with temperature periods near the circadian eigenperiod.
A white mutant lacking photosynthesis is used to investigate the role of photosynthesis in the signal processing. Although light synchronizes the circadian rhythms of the white mutant if applied as single input, it does not affect the motility if applied together with temperature inputs near the circadian eigenperiod. These results indicate frequency dependent mutual interactions between the model compartments.
Inorganic Bromide in Higher Fungi
Authors: Stijve T. 
Published: August 2018

Abstract
A total of 138 samples of higher fungi, representing 35 species (15 belonging to the genus Amanita), were analysed for the trace element bromine using spectrophotometric and gas chromatographic methods. High concentrations of bromine, up to 100 mg/kg on dry weight, were encountered in Amanitaceae, especially in members of the subsections Phalloideae and Eu-Amanita, whereas in other fungi the mean value for this element was only 3,3 m g/kg. Some bromine-accumulating Amanitas also contained unusually high chlorine levels. Am axi­mum concentration of 3 percent on dry weight was measured in A. phalloides. It could be demonstrated that most, if not all of bromine and chlorine was present in the fungi as ionisable inorganic salts. Two organochlorine metabolites, previously reported in some mushrooms, were absent in A. phalloides and A. muscaria.
Phthalide Derivatives from Meum athamanticum Jacq
Authors: Kaouadji Mourad , Mariotte Anne-Marie , Reutenauer Henri 
Published: August 2018

Abstract
A detailed investigation of non polar extracts of Meum athamanticum Jacq. rhizome (Um- belliferae) has led to the isolation of three phthalide derivatives. Sedanenolide, 6.6′,7.3′a-dili- gustilide and ligustilidiol have been identified by their spectral data. Furthermore, occurrence of such compounds seems to suggest assignment of intermediate biogenetic part to (Z)-ligustilide, the most accumulated phthalide in umbelliferous plants.
Alkaloid Sequestration by Papaver somniferum Latex
Authors: Homeyer B. C. , Roberts Margaret F. 
Published: August 2018

Abstract
The 1000 x g organelles of Papaver somniferum latex have been shown to accumulate rapidly, large quantities of alkaloids (0.05- 1 mg/mg organelle protein), particularly morphine, thebaine, codeine and papaverine and have been found to exhibit a surprising degree of specificity for the accumulation of these alkaloids. The uptake of alkaloid is independent of temperature and does not show a requirement for ATP 10-3 ᴍ, Mg2+ 10-3 ᴍ, or KCl 10-3 ᴍ. It is unaffected by known ATPase inhibitors (chlormadinone acetate 2.5 × 10-5 ᴍ, N,N-dicyclohexylcarbo- diimide 5 × 10-4 ᴍ and sodium vanadate 10-4 ᴍ) but showed considerable increase in morphine accumulation in the presence of 4-chloromercumbenzoate 5 x 10-4 ᴍ, while N-methylmaleimide 5 × 10-4 ᴍ had no effect, and carbonylcyanide 4-(trifluoromethoxy)phenylhydrazone 5 × 10-4 ᴍ caused a reduction (ca. 30%) of morphine uptake. An acid medium, pH 4.5-5.5, also results in decreased morphine uptake.
Degradation of the Isoflavone Biochanin A-7-O-glucoside-6"O-inalonate and Phenylacetic Acids by Fusarium javanicum
Authors: Schlieper Dittmar , Komoßa Dieter , Barz Wolfgang 
Published: August 2018

Keywords
The isoflavone conjugate biochanin A-7-O-glucoside-6″-O-malonate is degraded by Fusarium javanicum with an esterase to yield biochanin A-7-O-glucoside which is further cleaved by a glucosidase to the aglycone. Biochanin A is funnelled into a known catabolic sequence (Z. Naturforsch. 37c, 861 (1982)). Induction of the catabolism of p-methoxyphenylacetic acid is linked to biochanin A degradation, whereas p-hydroxyphenylacetic acid and 3,4-dihydroxy- phenylacetic acid degradation is substrate-induced.
Cytochromes of the Purple Sulfur Bacterium Ectothiorhodospira shaposhnikovii
Authors: Kusche Werner H. , Trüper Hans G. 
Published: August 2018

Abstract
Two c-type cytochromes (a high spin cytochrome c′ and a low spin cytochrome c-553(549) with asymmetrical α-band) and a low spin cytochrome b-558 from the purple sulfur bacterium Ectothiorhodospira shaposhnikovii were purified by ion exchange chromatography and gel filtration and characterized. Cytochrome c′ has a molecular weight of 33000 (determined by sodium dodecylsulfate electrophoresis), an isoelectric point at pH 4.5 and a redox potential of +37 mV. Absorption spectra show in the oxidized state maxima at 404 nm and in the range of 635 nm, in the reduced form maxima at 426.5 nm, 549 nm and a shoulder at 435 nm. The best purity index obtained was 0.48 (A280/A426.5). Reduced cytochrome c′ reacts with carbon monoxide. Cytochrome c-553(549) has a molecular weight of 10400, an isoelectric point at pH 5.1 and a redox potential of +248 mV. The oxidized form shows the Soret-band at 410 nm. The reduced protein reveals an asymmetrical a-band at 553 nm with a shoulder at 549 nm, the a-band at 522 nm with a shoulder at 528 nm and the γ-band at 416 nm. The best purity index obtained was 0.18 (A280/A416). Roth cytochromes could be isolated from the soluble fraction as well as from Triton X-100 treated membranes. Furthermore very low amounts of cytochromes c-553 and c-552.5 could be detected in detergent treated chromatophores. Cytochrome 6-558 - obtained from cells grown in the presence of reduced sulfur compounds in the medium - seems to be soluble or only weakly bound to the membrane. It has a molecular weight of 15800. an isoelectric point at pH 4.1 and a redox potential of -210 mV. The hemoprotein shows absorption maxima at 424.5 nm. 526.5 nm and 556.5 nm in the reduced form and at 416 nm in the oxidized state. The best purity index obtained was 0.26 (A280/A42,4.5). In addition, there were hints for the occurrence of a high spin cytochrome b′. The cytochrome pattern as well as the amount of cytochromes were dependent on growth conditions.