bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anticomplement Activity of Lysine Complexes of Propolis Phenolic Constituents and Their Synthetic Analogs
Authors: Georgieva P. , Ivanovska N. , Bankova V. , Popov S. 
Published: August 2018

Abstract
Several phenolic constituents of propolis and their synthetic analogs were derivatized with ʟ-lysine. The ability of these complexes to alter complement activity was estimated in vitro in human serum. The influence of selected complexes on C3 hemolytic activity via classical pathway (CP) and alternative pathway (AP) and on zymosan-induced AP activation was determined. The results suppose that the anticomplement effect of the complexes might be related to the interaction with C3 complement component.
Binding and Uptake of 125Iodine-Labelled, Oxidized Low Density Lipoprotein by Macrophages: Comparism of the Effects of a-Tocopherol, Probucol, Pyridoxal-5'-phosphate and Magnesium-pyridoxal-5'-phosphate-glutamate
Authors: Selmer Daniela , Senekowitsch-Schmidtke Reingard , Schneider W. , Elstner E. F. 
Published: August 2018

Abstract
Specific and unspecific binding and uptake (internalization) by macrophages of 125iodine -labelled, copper-oxidized human low density lipoprotein is differently influenced by the anti­ oxidants α-tocopherol (α-Toc), probucol (Prob), pyridoxal-5'-phosphate (PP) and the magnesium-pyridoxal-5'-phosphate glutamate complex (MPPG). Binding as well as internalization, mediated by the so-called "scavenger receptor" is lower in the presence of MPPG whereas both specific binding and internalization are enhanced. The comparison of the effects in vitro allows a rating of the potentially anti-atherogenic and thus protective effects of the tested substances as follows: MPPG > PP > α-Toc > Prob.
Trichloroacetate Affects the Redox Active Tyrosine 160 of the D2 Polypeptide of the Photosystem II Core
Authors: Li R. , Lin N. , Xu C. , Shen Y. , Govindjee  
Published: August 2018

Abstract
Trichloroacetate (TCA) affects the redox property of YD (tyrosine-160 on D2 polypeptide) after the removal of 33 kDa extrinsic polypeptide from the photosystem II (PSII) core. However, TCA has no obvious effect on the redox property of YZ , confirming that the environments around YZ and YD are quite different. The conclusion on the effects on YD is based primarily on the observation that Y D
+ is not detected as the EPR signal IIslow when 33 kDa polypeptide is released by TCA -treatment. Dialysis of the TCA -treated sample that allows the rebinding of mostly 33 kDa polypeptide restores Y D+, showing that the loss of the EPR signal IIslow| takes place after the removal of 33 kD a polypeptide but not the release of manganese (Mn). Additionally, treatment of several halogenated acetates on Tris-washed PSII particles shows that the degree of their effects on suppressing EPR signal IIslow is correlated with their hydrophobicity. It is postulated that Y D becomes more accessible to some small hydrophobic molecules depending upon their hydrophobicity when 33 kDa poly­peptide is removed.
Magnesium Chelatase of Hordeum vulgare L. Is Not Activated by Light but Inhibited by Pheophorbide
Authors: Pöpperl Gerhard , Oster Ulrike , Bios Inge , Rüdiger Wolfhart 
Published: August 2018

Abstract
The enzyme activity of magnesium chelatase was determined in intact etioplasts of barley (Hordeum vulgare L.) seedlings. Irradiation of isolated plastids with white light for 15 min does not lead to any activation of the enzyme but to a decrease in activity, especially in etioplasts. The enzyme was inhibited by chlorophyllide and zinc pheophorbide only to a certain extent. Strong inhibition was observed with the metal-free pheophorbide (Ki = 0.92 μM) but not with pheophytin or chlorophyll. Penetration of chlorophyllide through the envelope membrane was confirmed by the chlorophyll synthase reaction that occurs in the inner membranes of etioplasts and chloroplasts. The possible role of inhibition of magnesium chelatase by pheophorbide in senescent leaves and tetrapyrrole transport across the plastid envelope are discussed.
Photodynamic Action of Hypericin on Cyanobacteria, Synechocystis and Synechoccus (Anacystis nidulans)
Authors: Brody Seymour Steven , Papageorgiou George , Alygizaki-Zorba Katerina 
Published: August 2018

Abstract
The photodynamic action of hypericin on photosynthesis and respiration were monitored in Synechocystis sp PCC 6803 and Synechoccus ATCC 6311 (Anacystis nidulans). An oxygen electrode was used to measure net oxygen evolution or consumption. The amount of hypericin required to inhibit photosynthesis was quantitively determined. Photosynthesis was completely inhibited in Synechocystis when the molar ratio of chlorophyll/hypericin was about 70:1. Higher concentrations of hypericin did not stop the uptake of oxygen, but rather stimulated the process in the light. Hypericin was readily washed out of the cells forming no permanent associations in the bacterial cell. Hypericin inhibited electron transfer and consequently oxygen production by PSII particles. For half maximum inhibition of oxygen evolution, with PSII membrane particles, the molar ratio of chlorophyll/hypericin was about 10:1.
Hydrophobicity Scale of Amino Acids as Determined by Absorption Millimeter Spectroscopy: Correlation with Heat Capacities of Aqueous Solutions
Authors: Vorob’ev Mikhail M. 
Published: August 2018

Abstract
Hydration indexes of protein α-amino acids were measured by the new method of absorption millimeter spectroscopy (AMS) at 10 mm wavelength (1.05 cm-1; 31.42 GHz). This region of electromagnetic waves, located between the region of high-frequency dielectric spectroscopy and that of far-infrared spectroscopy, allows to measure hydration on the basis of different rotational and reorientational mobilities of water in hydration shell. Contribution to hydration of the methylene group is shown to be significantly greater than that of polar -OH , -CONH2 and -COOH groups, while the contribution of the charged -CH(N+H3)COO- group is even negative. The high sensitivity of AMS method to hydrophobic hydration allows to build up the hydrophobicity scale which gives an acceptable correlation (r=0.95) with the heat capacities of the aqueous solutions of amino acids. Thus, millimeter absorption spectroscopy, the method of hydration determination at a molecular level (determination of V-structure of water with lifetime ~50 ps), allows to quantitatively distinguish hydration of polar and non-polar groups as well as calorimetry does at a macroscopic level.
Differential Responses of Potato Cell Suspensions to a Culture Filtrate of Phytophthora infestans
Authors: Awan M. F. M. , Maciejewska U. , Kleczkowski K. , Wielgat B. 
Published: August 2018

Abstract
General (polygenic) resistance of plant hosts to an attack by a range of pathogens is an important feature of plant defense responses against the infection. In search of biochemical markers defining this resistance, cell suspensions derived from leaves of potato (Solanum tuberosum L .) cvs. Tarpan and Bzura that are polygenically susceptible and resistant to Phytophthora infestans, respectively, were inoculated with culture filtrate (CF) of the fungus. Cell suspension of Tarpan responded to CF treatment by a higher extracellular alkalinization and more significant reduction in their viability and growth than those of the Bzura cultivar. The stimulation of phenylalanine ammonia-lyase (PAL ) activity but not of β-1,3-glucanase, was significantly higher in CF treated Bzura cells than in Tarpan ones. The obtained results suggest that sensitivity to the fungal toxins and variation of PAL activity may represent useful markers for the evaluation of polygenic resistance in potato.
Induction of Single-and Double-Strand Breaks in Plasmid DNA by Monoenergetic Alpha-Particles with Energies below the Bragg-Maximum
Authors: Scholz Volker , Weidner Jürgen , Köhnlein Wolfgang , Frekers Dieter , Wörtche Heinrich Johannes 
Published: August 2018

Abstract
The yield of single-strand breaks (ssb) and double-strand breaks (dsb) produced by alpha-particles at the end of their track in DNA-films was determined experimentally. Helium nuclei were accelerated to 600 keV in the 400 kV ion accelerator and scattered at a carbon target. The elastically scattered alpha-particles with energies of 344 keV and 485 keV were used to irradiate supercircular plasmid DNA in vacuo.
For the dosimetry of the alpha-particles a surface barrier detector was used and the energy distribution of the alpha-particles determined. The energy loss of the particles in the DNA-layer was calculated. DNA samples were separated into the three conformational isomers using agarose gel electrophoresis. After fluorochromation the number of ssb and dsb per plasmid DNA molecule was established from the band intensities assuming the validity of Poisson statistics.
Linear dose effect correlations were found for ssb and dsb per plasmid molecule. In the case of 344 keV-alpha-particles the yield of dsb was (8.6 ± 0 .9)× 10−11 breaks/Gy × dalton. The ratio of ssb/dsb was 0.5 ± 0.2. This is at least a factor of six larger than the ratio found in experiments with higher energy alpha-particles and from model calculations. Similar experiments with protons yielded a relative biological effectiveness (rbe) value of 2.8 for the induction of double-strand breaks by track end alpha-particles.
Absolute Configuration of the Isopyoverdin Chromophore
Authors: Michalke R. , Taraz K. , Budzikiewicz H. , Thonart Ph. , Jacques Ph. 
Published: August 2018

Abstract
By ozonolytic degradation of the chromophore of isopyoverdin from Pseudomonas putida BTP 1 ʟ-2,4-diaminobutyric acid was obtained. This proves that the C-3 of the chromophore is S-configurated.
The Rieske Protein from Purple Sulfur Bacteria Is an Extrinsic Protein
Authors: Szczepaniak Andrzej , Uhrig Joachim , Gubernator Beata 
Published: August 2018

Abstract
The mode of membrane attachment of the Rieske iron-sulfur protein from cytochrome be, complex of Rhodospirillum rubrum has been studied using biochemical approaches.
In contrast to cytochrome c1 the bacterial Rieske protein was extracted from chromatophores using chaotropic agents (NaSCN, urea, guanidine), an alkaline pH and relatively low concentration of Triton X-100.
The results presented here lead to the conclusion, that the Rieske protein from chromatophores is extrinsic and that their association with the rest of the complex involves hydropho­bic interactions.
Inhibitory Effects of Synthetic Lanthanum-Crown Ether at the Reducing Side of Photosystem II
Authors: Sabat Surendra Chandra , Padhye Subash , Mohanty Prasanna 
Published: August 2018

Abstract
Inhibitory effects of lanthanum-crown [La-(Pic)3 (15-crown-6) 3H2O].was investigated on the O2 evolution activity of photsystem II particles. Lanthanum (La)-crown inhibited the electron flow at the reducing side of PS II complex. Short duration (1-2 min) treatment of PS II membranes with trypsin partly developed resistance to La-crown inhibition. However, longer proteolytic treatment (>2 min) appeared to expose newer site(s) for La-crown inhibi­tion. The inhibitory constant (Ki) for La-crown was nearly 0.17 | μᴍ . This inhibitory capacity is about 4 to 5 times less than the potent PS II inhibitor diuron which also binds at the acceptor side of PS II. The number of binding sites for La-crown was found to be 1 per 20 chlorophyll molecules. The Hill plot analysis showed the presence of three distinct straight lines suggesting that the compound acts at least at three sites. Furthermore, from the slope value (Hill coefficient) it is suggested that two of these sites provide minimum of two binding domains for the inhibitor.
A New Inhibitor of Synovial Phospholipase A2 from Fermentations of Penicillium Sp. 62-92
Authors: Witter Ludwig , Anke Timm , Sterner Olov 
Published: August 2018

Abstract
Penidiamide, a new tripetide containing dehydrotryptamine, glycine and anthranilic acid linked together by two amide bonds, and oxindole were isolated from submerged cultures of Penicillium sp. 62-92 . Both compounds preferentially inhibited human synovial phospholipase A2, penidiamide with an IC50 of 30 μᴍ and oxindole of 380 μᴍ. With the exception of U 937 cells (leukemia, human), no cytotoxic activities were detected against HL-60- (leukemia, human), HeLa S3- (epitheloid carcinoma, human), BHK 21- (kidney fibroblasts, hamster), and L1210-cells (leukemia, mouse). No antimicrobial activity was detected for oxindole, and only weak antibacterial activity for penidiamide. The structure of penidiamide was elucidated by spectroscopic methods.
Structure/Odor-Relationships of Longifolene Derived Esters December 30, 1997
Authors: Spreitzer Helmut , Pichler Andrea , Piringer Iris , Wolf Rainer 
Published: August 2018

Abstract
A series of epimeric esters of longicamphenilol and longifolol are prepared and their odorous properties described. It is shown that there are significant differences between the exo- and endo-series. All esters are well accessable starting from longifolene.
Five New Bioactive Sesquiterpenes from the Fungus Radulomyces confluens (Fr.) Christ
Authors: Fabian Kerstin , Lorenzen Kirsten , Anke Timm , Johansson Martin , Sterner Olov 
Published: August 2018

Abstract
The three protoilludanes radulone A (1), radulone B (2) and radudiol (3), the illudalane radulactone (4) and the illudane radulol (5) were isolated from the extracts of the culture fluids of the basidiomycete Radulomyces confluens. The structures of the five new compounds were determined by spectroscopic techniques. Radulone A (1) is a potent inhibitor of human and bovine platelet aggregation stimulated by different agonists, inhibiting preferentially the aggregation of human platelets induced by ADP with an IC50 value of 2 μᴍ . In addition 1 exhibits cytotoxic and antimicrobial activities. The other four compounds exhibited weak antimicrobial and cytotoxic activity.
Influence of Chemical Treatments on Glutathione S-Transferases of Maize with Activity Towards Metolachlor and Cinnamic Acid
Authors: Cottingham Charles K. , Hatzios Kriton K. , Meredith Sue 
Published: August 2018

Abstract
The subcellular distribution of glutathione S-transferase (GST) activity extracted from
shoots of 3-day-old etiolated seedlings of maize (Zea mays L., Northrup-K ing 9283 hybrid)
and the induction of soluble and m em brane-bound G ST activity by the safener benoxacor,
the herbicide metolachlor and their com bination (CGA -180937) were investigated. GST activity
extracted from maize shoots was detected in both cytosolic and microsomal fractions
and utilized l-chloro-2,4-dinitrobenzene (CDNB ), metolachlor, and trans-cinnamic acid (CA)
as substrates. Soluble GST activity extracted from maize shoots was greater than m icrosom al
with CDNB or metolachlor as substrate. Membrane-bound GT activity was greater than
soluble with cinnamic acid as substrate. W ashing the microsomal preparations from maize
shoots with Triton X-100 increased GST (C A ) activity. Pretreatment with the safener benoxacor
or a form ulated combination of the herbicide metolachlor with benoxacor induced soluble
GST(CDNB ), GST(metolachlor) and GST (C A ) activities in m aize shoots. Benoxacor
and CGA-180937 induced also membrane-bound GST (CDNB ) and GST(CA ) activities in
maize shoots, but did not affect membrane-bound GST (metolachlor) activity. These results
confirm that maize contains multiple GST isozymes that differ in their subsrate specificity
and inducibility by safeners or other chemicals.
Inhibition of the Non-Mevalonate 1-Deoxy-ᴅ-xylulose-5-phosphate Pathway of Plant Isoprenoid Biosynthesis by Fosmidomycin
Authors: Zeidler Johannes , Schwender Jörg , Müller Christian , Wiesner Jochen , Weidemeyer Claus , Beck Ewald , Jomaa Hassan , Lichtenthaler Hartmut K. 
Published: August 2018

Abstract
Various bacterial and plastidic plant terpenoids are synthesized via the non-mevalonate1-deoxy-ᴅ-xylulose-5-phosphate (DOXP) pathway. The antibiotic and herbicidal compound fosmidomycin is known to inhibit growth of several bacteria and plants, but so far its mode of action was unknown. Here we present data which demonstrate that the DOXP pathway of isoprenoid biosynthesis is efficiently blocked by fosmidomycin. The results point to the DOXP reductoisom erase as the probable target enzyme of fosmidomycin.
A New Benzo-γ-pyran Derivative Isolated from Propolis
Authors: Matsuno Tetsuya , Saito Masahiro , Matsumoto Yasuyuki , Morikawa Junji 
Published: August 2018

Abstract
The methanol extract of Brazilian propolis was fractionated by HPLC, based on human hepatocellular carcinoma (HuH 13) cell cytotoxicity assay. A new benzo-y-pyran derivative (PM-3) with a molecular formula of C19H22O3 (MW: 298.38) was isolated. The structure of this colorless compound was determined as 3-[2-dimethyl-8-(3-methyl-2-butenyl) benzopy-ran]-6 -propenoic acid. This compound was chemically synthesized by cyclisation of artepillin C (3-[4-hydroxy-3,5-bis (3-methyl-2-butenyl) phenyl]-2-propenoic acid).
Two Simple Methods for Measuring Isoprene Emission of Leaves by UV-Spectroscopy and GC-MS
Authors: Zeidler Johannes G. , Lichtenthaler Hartmut K. 
Published: August 2018

Abstract
Two new headspace methods for the analysis of iso­prene emission from detached plant leaves are described. The first method is based on the UV-absorption of isoprene emitted by leaves inside quartz cuvettes and can be used for the quantitative spectrophotometric determination of isoprene production. The second tech­nique is a micro-extraction method of isoprene from the cuvette air for GC analysis, and is very suitable for the determination of isotope-labeled isoprene by GC-MS.
ʟ-Phenylalanine Effect on Rat Brain Acetylcholinesterase and Na+,K+-ATPase
Authors: Tsakiris Stylianos , Kouniniotou-Krontiri Panagiota , Schulpis Kleopatra H. , Stavridis John C. 
Published: August 2018

Abstract
The effect of different L-phenylalanine (Phe) concentrations (0 .1-12.1 mᴍ) , on acetylcholinesterase (AChE ) and Na+,K+-ATPase activities of brain homogenate and pure enzymes, was investigated at 37 °C. AChE and Na+,K+-ATPase activities were determined according to Ellman G. L., Courtney D., Andres V. and Featherstone R. M. (1961), Biochem. Pharmacol. 7, 88 - 95 and Bowler K. and Tirri R. (1974), J. Neurochem. 23, 611-613 ) respectively, after preincubation with Phe. AChE activity in brain homogenate or in pure eel E.electricus enzyme showed a decrease, which reached up to 18% with concentrations of 0.9-12.1 mᴍ. Brain homogenate Na+,K+-ATPase activity showed an increase 16-65% with 0.24-0.9 mᴍ of Phe, while an activity increase of 60 -65% appeared with 0.9-12.1 mᴍ of Phe. Pure enzyme activity (from porcine cerebral cortex) was not affected by high Phe concentrations, while it was increased by low concentrations. The above results suggest: a) A direct effect of Phe on AChE, b) A direct effect of low Phe concentrations and an indirect effect of high ones on Na+,K+-ATPase.
Age-Class Differences in Lipids from the Paracloacal Glands of the American Alligator (Alligator mississippiensis)
Authors: Ibrahim Sayed A. , Avery James W. , Weldon Paul J. , Wheeler James W. 
Published: August 2018

Abstract
The paracloacal gland secretions of immature and adult American alligators (Alligator mississippiensis) from Louisiana were analyzed by gas chromatography/mass spectrometry and nuclear magnetic resonance spectroscopy to investigate age-class differences in lipid composition. The secretions of both immature and adult alligators contain saturated C14 and C16 free fatty acids and decyl, undecyl, dodecyl, tetradecyl, and hexadecyl acetates. Com­pounds observed only in immature alligators include dodecanoic acid, C12 and C14 alcohols, C10-C14 butanoates, an array of C8-C18 3-methylbutanoates, C12- C15 hexanoates, C12 and C14 octanoates, a C12 decanoate, C10-C14 dodecanoates, C10- C16 tetradecanoates, C12 and C14 hexadecanoates, a C12 octadecanoate, and a diterpene hydrocarbon identified as (E ,E )- 7,11,15-trimethyl-3-methylenehexadeca-1,6,10,14-tetraene (β-springene). Compounds observed only in adults include several C7-C16 free fatty acids and certain C10- C18 acetates. The age-class differences we observe in the paracloacal gland lipids of alligators from Louisiana are similar to those previously reported for alligators from Texas.
Radical Functions in vivo: A Critical Review of Current Concepts and Hypotheses
Authors: Saran Manfred , Michel Christa , Bors Wolf 
Published: August 2018

Abstract
Most of the basic knowledge about radical reactions comes from radiation chemical studies in vitro. In view of the rapidly increasing knowledge on radical reaction in vivo, it is important to reconcile the fundamental physico-chemical reaction characteristics of radicals with the need to explain their alleged biological effects. Severe problems in the understanding of their in vivo action remain unsolved. An example is phagocytosis, which seems to be a paradigm of a ‘deleterious’ radical process. The exact mechanism is not clear; so it is an open question whether the intruder is eventually killed by radicals (like OH) or by endproducts of radical reactions (like H2O2 and/or HOCl). It is even more difficult to understand signalling by radicals: owing to their chemical nature they are ‘unspecifically’ reacting species -they with­ draw or add electrons-and thus their reactions are governed by redox-properties. Since all radicals have different redox characteristics and different molecular shapes, the usual key-and-keyhole picture for molecular interaction does not apply, as there, is no reactive site conceivable which has the property of reacting with radicals ‘specifically. Our intent in this article is: (i) to briefly review some fundamental characteristics of in vitro radical reactions, (ii) to extrapolate from this to the conditions in vivo, and (iii) to discuss current hypotheses concerning the redox-regulation of cellular signalling. This leads us to the tentative conclusion that radicals per se must be tolerated by the cell and do not threaten its life, if they stay below a certain concentration limit. The main biologi­ cal implication of radical-reactions seems to be that the cell derives signals from the balance of oxidative versus reductive processes and that radicals may interact with pathways of intra-and intercellular communication.