| | 1 | Author
| Snezhana Bakalova | Requires cookie* | | | Title
| S  | | | | Abstract
| o lv e n t E f fe c ts o n th e F lu o re s c e n c e P r o p e r tie s o f M e th y ld ih y d ro q u in o lin o n e s The absorption and fluorescence spectra and the fluorescence quantum yields of two methyl-2,3-dihydro-4(lH)-quinolinones in various solvents are reported. In some solvents deuteration-induced fluorescence enhancement has been observed. The solvent effects in aprotic solvents are consistent with the general type of solvent interaction. For protic solvents, solute-solvent complexation in the excited state is suggested. | | | |
Reference
| Z. Naturforsch. 46a, 823—827 (1991); received May 24 1991 | | | |
Published
| 1991 | | | |
Keywords
| Fluorescence, Dihydroquinolinones, Hydrogen bond | | | |
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| default:Reihe_A/46/ZNA-1991-46a-0823.pdf | | | | Identifier
| ZNA-1991-46a-0823 | | | | Volume
| 46 | |
| 4 | Author
| J.J S Van Rensen, D. Wong, Govindjee | Requires cookie* | | | Title
| Characterization of the Inhibition of Photosynthetic Electron Transport in Pea Chloroplasts by the Herbicide 4,6-Dinitro- o-cresol by Comparative Studies with 3-(3,4-Dichlorophenyl)-l,l- dimethylurea | | | | Abstract
| An attempt to characterize the mechanism of inhibition of photosynthetic electron transport in isolated pea chloroplasts by the herbicide 4,6-dinitro-o-cresol (DNOC) by a comparison with the effects of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) revealed the following: | | | |
Reference
| Z. Naturforsch. 33c, 413 (1978); received April 12 1978 | | | |
Published
| 1978 | | | |
Keywords
| Photosynthesis, Electron Transport, Fluorescence, Herbicides | | | |
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| default:Reihe_C/33/ZNC-1978-33c-0413.pdf | | | | Identifier
| ZNC-1978-33c-0413 | | | | Volume
| 33 | |
| 5 | Author
| Friederike Koenig, Alfons Radunz, GeorgH. Schmid, Wilhelm Menke | Requires cookie* | | | Title
| Antisera to the Coupling Factor of Photophosphorylation and Its Subunits | | | | Abstract
| Stroma-freed chloroplasts were extracted with sucrose palmitate-stearate containing buffer. A fter the addition o f dodecyl sulfate and mercaptoethanol to the extract a series of polypeptides was isolated from the mixture by gel filtration. These polypeptides were later used for immunization. Antisera to four polypeptides reacted in the Ouchterlony double diffusion test with authentic coupling factor yielding a precipitation band. According to the observed apparent molecular weights the polypeptides are the a, ß , 8 and e subunits of the coupling factor. An antiserum to the y subunit has been obtained already previously. A ll antisera inhibit photophosphorylation reactions and electron transport considerably. Addition of gramicidin inhibits photophosphorylation com pletely whereas gramicidin restores electron transport in the assays with the antisera to the a, ß , y and 5 subunit. In the case o f the antiserum to the E subunit gramicidin does not regenerate electron transport. As in the presence of the serum to the £ subunit pH changes in the suspension medium are not observed, this serum seems to open a proton channel. Also, upon addition of dicyclohexyl carbodiimide (D C C D) pH changes in the suspension medium in the assay with antiserum do not reoccur. According to these unexpected results the identity o f the antigen with the e subunit of the coupling factor is not certain. ATP-ase reactions are only inhibited by the antisera to the a and y subunit and what is thought to be the £ subunit. The antiserum to the a subunit uncouples electron transport as the only one when used in sufficient concentrations. The dosis-effect curves o f the inhibition of the electron transport exhibits a maximum. The dosis-effect curves for the other components rise after a lag phase in an approxim ately hyperbolic manner. The inhibitory action on electron transport is exerted by all antisera in the region of the reaction center I or in its immediate vicinity. This is thought to be due to the fact that a protein of the reation center I is inhibited in its function by the increasing proton concentration inside the thylakoid. The inhibition of electron transport by the antiserum to the e subunit is considered to be a direct serum effect. Besides the increase in fluorescence yield, due to the inhibition of electron transport in the region o f photosystem I, decreases of the fluorescence yield are observed in the presence of D CM U, which do not depend on the redox state of Q but rather on the condition of the thylakoid mem brane. Moreover, the antisera affect in a differing manner the energy spill-over o f excitation from photosystem I I to photosystem I. | | | |
Reference
| Z. Naturforsch. 33c, 529 (1978); received June 21 1978 | | | |
Published
| 1978 | | | |
Keywords
| Coupling Factor, Antisera, Chloroplasts, Fluorescence | | | |
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| default:Reihe_C/33/ZNC-1978-33c-0529.pdf | | | | Identifier
| ZNC-1978-33c-0529 | | | | Volume
| 33 | |
| 6 | Author
| P. V. Sane, T. S. Desai, V. G. Tatake | Requires cookie* | | | Title
| Luminescence from Photosystem I at High Temperatures | | | | Abstract
| The changes in the fluorescence and delayed fluorescence intensity of spinach leaf as affected by temperature were studied. It was observed that the delayed fluorescence showed a maximum at about 45 °C whereas the fluorescence maximum was at about 55 °C. An examination of the emission spectra of delayed fluorescence at different temperatures showed that at higher tem peratures the relative emission at 735 nm was increased. It is argued that at higher temperatures the luminescence from photosystem I contributes to delayed fluorescence. | | | |
Reference
| Z. Naturforsch. 35c, 289—292 (1980); received November 1 1979 | | | |
Published
| 1980 | | | |
Keywords
| Fluorescence, Delayed Fluorescence, Photosystem I | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0289.pdf | | | | Identifier
| ZNC-1980-35c-0289 | | | | Volume
| 35 | |
| 7 | Author
| Thomas Vom Bruch, Klaus-Heinrich Röhm | Requires cookie* | | | Title
| Fluorescence Properties of Hog Kidney Aminoacylase I | | | | Abstract
| The state of the tryptophan residues of porcine kidney aminoacylase I (EC 3.5.1.14) was investigated by fluorescence spectroscopy and chemical modification. The pH-dependence of the fluorescence emission spectrum of the enzyme indicates that its native conformation prevails between pH 6 and 9.5. Within this range, the ionization of a residue with an apparent pKa of 7.1 quenches the enzyme fluorescence by about 15%. A similar reduction of fluorescence intensity accompanies the inactivation of aminoacylase I by treatment with N-bromosuccinimide in low excess. This suggests that in both cases a single tryptophyl residue out of eight residues per subunit is affected. Quenching by iodide revealed that, in the native conformation of the enzyme, 5—6 tryptophans per subunit are accessible, while 2—3 are buried within the protein. 8-Anilinonaph-thalene-L-sulfonate (ANS) is tightly bound to aminoacylase I (1 mol/mol dimer, K d < 1 PM). ANS binding does not interfere with substrate turnover; the spectroscopic properties of the amino-acylase-ANS complex are consistent with bound ANS being excited by radiationless energy transfer (RET) from buried tryptophyl residues of the enzyme. | | | |
Reference
| Z. Naturforsch. 43c, 671—678 (1988); received June 3 1988 | | | |
Published
| 1988 | | | |
Keywords
| Aminoacylase, Kidney, Tryptophan, Fluorescence, ANS | | | |
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| default:Reihe_C/43/ZNC-1988-43c-0671.pdf | | | | Identifier
| ZNC-1988-43c-0671 | | | | Volume
| 43 | |
| 8 | Author
| Judit Kissim, Á. Gnes Tantos3, Annam Ária, M. Észáros3, ErzsébetJ. Ám Bor-Benczúrb, G. Ábor Horváth3 | Requires cookie* | | | Title
| Stress Alterations in Growth Parameters, Pigment Content and Photosynthetic Functions of in vitro Cultured Plants | | | | Abstract
| Effects of different concentrations of glucose, sucrose and the natural growth regulator, triacontanol were studied under the unfavourable stress conditions of micropropagation of two woody plants, Sorbus rotundifolia L. and Primus x davidiopersica 'Piroska'. After 4 -6 weeks of cultures, the number and length of shoots, the photosynthetic activity as well as the chlorophyll, carotenoid and anthocyanin contents were investigated. As shown by the growth parameters, the optimal carbohydrate concentration was between 1 .5 -2 .5 % , whereas in higher concentrations, a definite inhibition could be observed. A similar response was found in changes of the anthocyanin content in Prunus x davidiopersica 'Piroska', but this effect was less pronounced with the photosynthetic pigments in both species. The Fv/Fm ratio representing the quantum yield of photosynthesis was low due to the inhibitory effect of stress and altered significantly by changing the carbohydrate concentrations. In all cases, the addition of 2 -4 jig triacontanol/1 further enhanced the stimulating effect of the optimal carbohydrate concentrations, which indicated the specific importance of the appropriate hor mone balance under such stress conditions. | | | |
Reference
| Z. Naturforsch. 54c, 834—8 (1999); received November 28 1998/March 18 1999 | | | |
Published
| 1999 | | | |
Keywords
| Anthocyanin, Fluorescence, Huckberry, Peach, Triacontanol | | | |
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| default:Reihe_C/54/ZNC-1999-54c-0834.pdf | | | | Identifier
| ZNC-1999-54c-0834 | | | | Volume
| 54 | |
| 9 | Author
| HansE. Wilhelm, Horst Gebert, Wolfgang Regenstein | Requires cookie* | | | Title
| Effect of Substituents on the Viscosity Dependence of Fluorescence and on the S l -T l Energy Gap of Donor-Acceptor Substituted Trans-Stilbenes | | | | Abstract
| The dependence of fluorescence quantum yields and Sj-lifetimes of donor-acceptor substituted trans-stilbenes on temperature was measured in the temperature range from 298 to 100 K, using solutions of stilbenes in 3-methylpentane (3-MP). Measurements of fluorescence and phosphores-cence spectra show that the triplet energy is almost independent of the acceptor. The S[-energy and the S r Ti energy gap decrease with increasing acceptor strength. For all compounds intersystem crossing (ISC) S, —» T, is negligible. | | | |
Reference
| Z. Naturforsch. 52a, 837—842 (1997); received November 18 1997 | | | |
Published
| 1997 | | | |
Keywords
| Stilbenes, Fluorescence, Phosphorescence, Singlet-Triplet Energy Gap, Rate Constants | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0837.pdf | | | | Identifier
| ZNA-1997-52a-0837 | | | | Volume
| 52 | |
| 10 | Author
| Peter Nikolov, Irina Petkova, Stefan Stoyanov3 | Requires cookie* | | | Title
| Media Effect upon the Fluorescence Ability of Differently Substituted a-Cyanostilbenes | | | | Abstract
| The steady state and dynamic photophysical characteristics of a-cyanostilbene derivatives have been investigated in solution and in Polyvinylchloride (PVC) film at 300 K as well as in a frozen matrix at 77 K. While no emission is observed in solution, a significant fluorescence ability is registered both in PVC and frozen media. This fact is attributed to the matrix effect, which lessens the possible intramolecular motions around the central double bond. No phosphorescence at 77 K is observed. The fluorescence lifetimes at 77 K are compared with literature data for similar chemically fixed structures. | | | |
Reference
| Z. Naturforsch. 56a, 447—451 (2001); received January 23 2001 | | | |
Published
| 2001 | | | |
Keywords
| a-Cyanostilbene Derivatives, Fluorescence, Matrix Effect | | | |
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| default:Reihe_A/56/ZNA-2001-56a-0447.pdf | | | | Identifier
| ZNA-2001-56a-0447 | | | | Volume
| 56 | |
| 11 | Author
| Herrn, Dr, Dr | Requires cookie* | | | Title
| Transanulare Wechselwirkung bei | | | | Abstract
| [m.n]Phanen, 32 [1]: Modelle für Amin-Aromaten-Exciplexe: [2](l,4)Anthraceno[2](2,6)pyridinophan-l,13-dien Transanular Interaction in [m .n]Phanes, 32 [1 ]: Models for Am ine-A rene-Exciplexes: [2](l,4)A nthraceno[2](2,6)pyridinophan-l,13-dien M atthias W. H a e n e l* 3, Birgit L intnera und D ieter Schweitzer11 a M ax-Planck-Institut für K ohlenforschung, Kaiser-W ilhelm -Platz 1, D-4330 M ülheim a .d . Ruhr b M ax-Planck-Institut für M edizinische Forschung, A bteilung M olekulare Physik, Jahnstraße 29, D -6900 H eidelberg The [2](1.4)A nthracen o[2](2,6)pyridinop han-l,13-d ien (5) and the corresponding [2.2]phane (7) were synthesized as m odels for exciplexes. The dithia[3.3]phanes (9) and (11) were prepared by cyclisation o f the dithiols 13 and 16 with the dibrom ide 19. O xidation of 9 to the disulfone 10 and vapour phase pyrolysis led to 7. Ring contraction o f 9 by S-analogous Wittig ether rearrange ment led to 20 which was converted to the diene 5 via oxidation to the disulfoxide 21 and pyrolytic elim ination o f m ethane sulfenic acid. A ttem pts to prepare 6 and 8 via similar routes from 11 failed. Electron absorption spectra and fluorescence spectra o f 5 and 7 are discussed in terms of n-n interaction in 5 and jt-jt interaction in 7. | | | |
Reference
| Z. Naturforsch. 41b, 223 (1986); eingegangen am 7. Oktober 1985 | | | |
Published
| 1986 | | | |
Keywords
| Cyclophanes, Electronic Interaction, Exciplex M odels U V Spectra, Fluorescence | | | |
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| default:Reihe_B/41/ZNB-1986-41b-0223.pdf | | | | Identifier
| ZNB-1986-41b-0223 | | | | Volume
| 41 | |
| 13 | Author
| G. C. Papavassiliou, G. A. Mousdis, I. B. Koutselas | Requires cookie* | | | Title
| Some Organic-Inorganic Hybrid Compounds Based on «ö-Thiuronium Cations and Lead Halide Anions | | | | Abstract
| Using 1-chlorodecane (C10H21CI), benzyl chloride (C6H5CH2CI), a,a'-dichloro-p-xylene (CICH2C6H4CH2CI), 4-phenylbenzyl chloride (C6H5C6H4CH2CI), 2-bromomethyl-naphthal-ene (CioHyC^Br), 4-bromomethyl-7-methoxycoumarin (CioHzO^C^Br), 2-bromomethyl-anthraquinone (CuH TC ^C ^Br), 9-chloromethyl-anthracene (C14H9CH2CI), thiourea and halides as starting materials, the organic-inorganic hybrid compounds [CioH2iSC(NH2)2]2Pbl4, [C6H5CH2SC(NH2)2]4Pb3l,o, [(H sN h C S C ^ C ö H tC ^ S Q N H jh k sP b ls, [C6H5C6H4CH2S-C(NH2)2]PbI3, [C,oH7CH2SC(NH2)2]Pbl3, [CioH yChC^SQNHzhlPbL, [C^HyOjCHzSC-(NH2)2]PbI3, [C,4H9CH2SC(NH2)2]Pbl3, and [C M H gO ^SQ N H z^hPbB ^ were prepared and characterized analytically and spectroscopically. | | | |
Reference
| (Z. Naturforsch. 56b, 57—61 [2001]; received September 11 2000) | | | |
Published
| 2001 | | | |
Keywords
| Organic-Inorganic Hybrids, Low-Dimensional Semiconductors, Fluorescence | | | |
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| default:Reihe_B/56/ZNB-2001-56b-0057.pdf | | | | Identifier
| ZNB-2001-56b-0057 | | | | Volume
| 56 | |
| 14 | Author
| GeoffreyA. Codd, G. Eorg, H. Schmid | Requires cookie* | | | Title
| Effects of S-^^-DichlorophenyO-N-N'-Dimethylurea on Oxygen Evolution and Fluorescence by Whole Filaments and Isolated Thylakoids of the Cyanobacterium Anabaena cylindrica | | | | Abstract
| The site of inhibition of DCM U against photosystem II in the cyanobacterium (Blue-green alga) Anabaena cylindrica was examined in electron transport and fluorescence studies. Isolated thylakoids catalyzed silicomolybdate photoreduction using H zO as electron donor; the steady-state reaction was completely inhibited by DCM U. This reaction is insensitive to DCM U in chloro plasts, since silicomolybdate accepts electrons from the prim ary photosystem II acceptor, and thus before the site of action o f D CM U in higher plants. DCM U did not increase the steady-state level of fluorescence by inact A. cylindrica, nor affect the monophasic fluorescence induction, with | | | |
Reference
| Z. Naturforsch. 35c, 649—655 (1980); received April 18 1980 | | | |
Published
| 1980 | | | |
Keywords
| Oxygen-Evolving Side, Cyanobacteria, D CM U-Sensitivity, Fluorescence | | | |
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| default:Reihe_C/35/ZNC-1980-35c-0649.pdf | | | | Identifier
| ZNC-1980-35c-0649 | | | | Volume
| 35 | |
| 16 | Author
| T. B. Melø, G. Reisaeter, A. Johnsson, M. Johnsson | Requires cookie* | | | Title
| Photodestruction of Propionibacterium acnes Porphyrins | | | | Abstract
| The fluorescence spectra o f colonies o f Propionibacterium acnes were studied under various experimental conditions. The spectra contained peaks at 580 nm and 620 nm. These bands were due to two different components; the 580 nm component was likely to be a m etalloporphyrin, and there are ind ica tions that the 620 nm component could be a coproporphyrin. The 580 nm fluorescence was destroyed by the com bined action o f light and oxygen (no destruction under strict anaerobic conditions). A dark period interrupting the bleaching light stopped the destruction o f this component for the time o f the dark period. The initial production o f the 620 nm com ponent was due to the oxygen exposure. U pon light irradiation this component was later destroyed by the com bined action o f oxygen and light. | | | |
Reference
| Z. Naturforsch. 40c, 125—128 (1985); received October 22 1984 | | | |
Published
| 1985 | | | |
Keywords
| Propionibacterium acnes, Fluorescence, Porphyrin, Photobleaching, Singlet-O xygen | | | |
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| default:Reihe_C/40/ZNC-1985-40c-0125.pdf | | | | Identifier
| ZNC-1985-40c-0125 | | | | Volume
| 40 | |
| 17 | Author
| B. Ernd, F. Ussm, Ann, P. Ete, D. An | Requires cookie* | | | Title
| Polymerization of Actin in the Absence and Presence of Cytochalasin B: Problems of Determining "Critical Concentration" | | | | Abstract
| A Various concentrations o f actin (0.3 or 1 mM MgCl2, 1 mM A T P , 1 mM E G T A) reached their final degree o f polym erization (m easured by a pyrene dye attached to actin) earlier in the pres ence o f cytochalasin B than in its absence. The curves relating concentrations o f polym eric F-actin to total actin concentration were under these conditions highly nonlinear making an unam biguous extrapolation to zero F-actin concentration (to deduce the "critical concentration" o f actin poly m erization) im possible. The concentration o f actin, above which polym erization occurred, was unaltered by cytochalasin B (although for reasons not yet understood the specific fluorescence intensity of polym erized actin was lower in the presence of cytochalasin B than in its absence). The results show that a distinct "critical concentration" o f actin polymerization must not always be well defined. | | | |
Reference
| Z. Naturforsch. 41c, 781 (1986); received April 23 1986 | | | |
Published
| 1986 | | | |
Keywords
| ctin, Cytochalasin B, Critical Concentration, Fluorescence, Polymerization | | | |
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| default:Reihe_C/41/ZNC-1986-41c-0781.pdf | | | | Identifier
| ZNC-1986-41c-0781 | | | | Volume
| 41 | |
| 18 | Author
| ThorB. Melø, Gro Reisaeter | Requires cookie* | | | Title
| Photodestruction of Endogenous Porphyrins in Relation to Cellular Inactivation of Propionibacterium acnes | | | | Abstract
| of Propionibacterium acnes on Eagles medium protoporphyrin was accumulated inside the cells and coproporphyrin, both as a free base as metalcontaining, outside the cells. The photochemical processes in the endogenous porphyrins were studied by fluorescence spectroscopy during continuous irradiation of Propionibacterium acnes in suspension. The irradiation caused initially an increase in the content of protoporphyrin in the cells in comparison to that which had been accumulated during growth. Maximum light induced protoporphyrin production was achieved in 5 days old cultures. In old cultures where there was practically no initial protoporphy rin release, the fluorescence intensities from all the porphyrins present in the culture vanished exponentially with the irradiation time. The metal containing form of fluorescent coproporphyrin, with a maximum emission at 580 nm, was photobleached about ten times faster than the free base forms of coproporphyrin and protoporphyrin. Among these three fluorescent substances in the cell culture only the free base forms of the porphyrins have longer lifetimes than the cells themselves irradiated at the same conditions. | | | |
Reference
| Z. Naturforsch. 41c, 867 (1986); received February 28/June 3 1986 | | | |
Published
| 1986 | | | |
Keywords
| Propionibacterium acnes, Porphyrins, Photooxidation, Fluorescence, Survival During growth | | | |
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| default:Reihe_C/41/ZNC-1986-41c-0867.pdf | | | | Identifier
| ZNC-1986-41c-0867 | | | | Volume
| 41 | |
| 19 | Author
| S. S. Brody | Requires cookie* | | | Title
| The Position of Carotene in the D-l/D-2 Sub-Core Complex of Photosystem II | | | | Abstract
| When the sub-core complex of photosystem II, D1/D2, is irradiated at 436 or 415 nm (absorp-tion by chlorophyll and pheophytin and ß-carotene) or 540 nm (absorption primarily by pheophy-tin), the low temperature fluorescence spectrum has two maxima, at 685 and 674 nm. This shows the existence of at least two different fluorescent forms of chlorophyll (chlorophyll a and perhaps pheophytin a). When carotene is irradiated at 485 nm (absorption primarily by ß-carotene), only fluorescence at 685 nm is observed: this indicates that carotene is transferring energy to only the long-wavelength form of chlorophyll in the D1/D2 sub-core complex. The band of carotene (at 485 nm) does not appear in the fluorescence excitation spectrum, measured at 674 nm. The position of the carotene molecule relative to each of the fluorescent forms of chlorophyll was determined from the excitation spectra of each of the fluorescence bands. | | | |
Reference
| Z. Naturforsch. 43c, 226—230 (1988); received August 21. 1987/January 11 1988 | | | |
Published
| 1988 | | | |
Keywords
| Photosynthesis Photosystem II, Chlorophyll, Fluorescence, Carotenoids, Energy Transfer | | | |
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| default:Reihe_C/43/ZNC-1988-43c-0226.pdf | | | | Identifier
| ZNC-1988-43c-0226 | | | | Volume
| 43 | |
|
