| | 1 | Author
| Alfred Gieren, Michail Kokkinidis | Requires cookie* | | | Title
| Structure Investigations o f Agonists o f the Natural Neurotransmitter Acetylcholine II [1| X-ray Structure Analysis o f Trimethyl(4-oxopentyl)ammonium-chloride  | | | | Abstract
| The crystal structure of Trimethyl(4-oxopentyl)ammonium-chloride ([(C H 3) 3 N —(CH^aCOCHjJCl-) (1) was determined by an X-ray structure analysis. 1 crystallizes in the orthorhombic space group P21 21 21 with a = 10.440 (3), b = 14.600 (9), c = 6.804 (9) A and with four formula units per unit cell. The structure was solved by a Patterson and a successive Fourier synthesis. The least squares refinement yielded an R-value o f 0.064 for 1077 observed reflections. The cation o f 1 is derived from acetylcholine by replacement o f the ester oxygen with a CH2 group. It shows a potent nicotinic activity and a significant difference in conformation as compared with acetylcholine. In the crystal structure the anions are oriented stereospecifically with respect to the tetrahedron of the quaternary ammonium group. The geometry o f two triangles formed by the quaternary nitrogen atom, the oxygen atom o f the carbonyl group, and by either o f the two anions nearest to the quaternary ammonium group is characteristic for the nicotinic activity o f 1. | | | |
Reference
| Z. Naturforsch. 37c, 282 (1982); received December 231981 | | | |
Published
| 1982 | | | |
Keywords
| X-ray, Neurotransmitter, Cation-Anion Interactions, Structure-Activity Relationships | | | |
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| default:Reihe_C/37/ZNC-1982-37c-0282.pdf | | | | Identifier
| ZNC-1982-37c-0282 | | | | Volume
| 37 | |
| 2 | Author
| Berg, M. Arjo, Brandse Duphar, B. V. Biochemistry | Requires cookie* | | | Title
| G erard van den | | | | Abstract
| The effects of the algicide PH 40-62 on photosynthetic reactions in spinach chloroplasts were studied. The compound proved to be an uncoupler o f photophosphorylation, whereas inhibition of photosynthetic electron transport occurred at higher concentrations. The site of this inhibition was before photosystem II. The uncoupling effect was partially reversible. In a series o f related compounds the uncoupling activity appeared mainly dependent on the lipophilic properties o f the compounds but electronic effects also played a distinct role. C om paring these uncoupling data with those of some known series of uncouplers it appeared that lipophilicity determ ines the uncoupling activity in an identical way and a regression equation was found describing the uncoupling activities of 60 compounds belonging to four chemically different groups of com pounds. | | | |
Reference
| Z. Naturforsch. 39c, 107—114 (1984); received Septem ber 19 1983 | | | |
Published
| 1984 | | | |
Keywords
| Arylethanediamines, Photophosphorylation, U ncouplers, Structure-Activity Relationships | | | |
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| default:Reihe_C/39/ZNC-1984-39c-0107.pdf | | | | Identifier
| ZNC-1984-39c-0107 | | | | Volume
| 39 | |
| 4 | Author
| K. Öm Ívesa, K. Riton, K. Hatziosb | Requires cookie* | | | Title
| Chemistry and Structure-Activity Relationships of Herbicide Safeners | | | | Abstract
| The discovery and commercial success of safeners against thiolcarbamate herbicide injury to corn has stimulated a rapid progress and opened new possibilities for further research and development in the last decade. Compounds with new chemistry, increased efficacy, and a broader selectivity spectrum were synthesized and developed for agricultural use. Structure-activity relationship studies helped to optimize their chemical properties and to understand their biological modes of action. Several examples indicate close similarity between chemical structures possessing herbicidal and safener properties. In some cases this differentiation may be marginal, as shown in crops pretreated with low herbicide doses leading to safening effects. In other examples, however, structural optima for safening and herbicidal efficacy can be clearly differentiated. | | | |
Reference
| Z. Naturforsch. 46c, 798—804 (1991); received March 26 1991 | | | |
Published
| 1991 | | | |
Keywords
| Safeners, Chemical Properties, Structure-Activity Relationships | | | |
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| default:Reihe_C/46/ZNC-1991-46c-0798.pdf | | | | Identifier
| ZNC-1991-46c-0798 | | | | Volume
| 46 | |
| 5 | Author
| HerbertOliver Kolodziej3, HermanJ. Kayser3, Wim Woerdenbagb, Niesko Van Udenb, Pras | Requires cookie* | | | Title
| Structure -Cytotoxicity Relationships of a Series of Natural and Semi-Synthetic Simple Coumarins as Assessed in Two Human Tumour Cell Lines | | | | Abstract
| The cytotoxicity of 22 natural and semi-synthetic simple coumarins was evaluated in G LC4, a human small cell lung carcinoma cell line, and in CO LO 320. a human colorectal cancer cell line, using the microculture tetrazolium (MTT) assay. With IC 50 values > 100 j.i m , following a continuous (96h) incubation, most coumarins exhibited only low cytotoxicity. Several com pounds, however, displayed significant potencies. As far as the structure -cytotoxicity rela tionship is concerned, it is conspicuous that all the potentially active natural compounds possess at least two phenolic groups in either the 6,7-or 6,8-positions. In addition, the 5-formyl-6-hydroxy substituted semi-synthetic analogue was found to be potent, reflecting the importance of at least two polar functions for high cytotoxicity. | | | |
Reference
| Z. Naturforsch. 52c, 240—244 (1997); received November ll/December 5 1996 | | | |
Published
| 1997 | | | |
Keywords
| Coumarins, Cytotoxicity, Structure-Activity Relationships, Pelargonium sidoides, Geraniaceae | | | |
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| default:Reihe_C/52/ZNC-1997-52c-0240.pdf | | | | Identifier
| ZNC-1997-52c-0240 | | | | Volume
| 52 | |
| 6 | Author
| Oliver Kayser, H. Erbert Kolodziej | Requires cookie* | | | Title
| Antibacterial Activity of Simple Coumarins: Structural Requirements for Biological Activity | | | | Abstract
| The antibacterial activity of a series of simple coumarins was evaluated against 8 microor ganisms, including three Gram-positive (Staphylococcus aureus, beta-hemolytic Streptococcus and Streptococcus pneum oniae) and five Gram-negative bacteria (Escherichia coli, Klebsiella pneum oniae, Pseudom onas aeruginosa, Proteus mirabilis and H aemophilus influenzae), using the microdilution broth method. The coumarins tested showed broad diversity regarding growth inhibitory activity with minimum inhibitory concentrations ranging from 0.9 to >12.4 (j.M . This study, presenting the first systematic analysis of structure-activity relationships among this group of coumarins, revealed some interesting structural requirements. While coumarins with a methoxy function at C-7 and, if present, an OH group at either the C-6 or C-8 position are invariably effective against the spectrum of tested standard bacteria (Gram-negative microorganisms including the Gram-positive bacterium Staphylococcus aureus), the presence of an aromatic dimethoxy arrangement is apparently favourable against those mi croorganisms which require special growth factors (beta-hemolytic Streptococcus, Streptococ cus pneum oniae and Haem ophilus influenzae). A combination of these structural features, two methoxy functions and at least one additional phenolic group as reflected by the highly oxygenated coumarins, identify promising candidates with antibacterial broad-spectrum ac tivity. | | | |
Reference
| Z. Naturforsch. 54c, 169—174 (1999); received November 11/December 8 1998 | | | |
Published
| 1999 | | | |
Keywords
| Coumarins, Antibacterial Activity, Structure-Activity Relationships | | | |
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| default:Reihe_C/54/ZNC-1999-54c-0169.pdf | | | | Identifier
| ZNC-1999-54c-0169 | | | | Volume
| 54 | |
| 7 | Author
| Ernst Priesner, Hans-Jürgen Bestmann, Otto Vostrowsky, Peter Rösel | Requires cookie* | | | Title
| Sensory Efficacy of Alkyl-Branched Pheromone Analogues in Noctuid and Tortricid Lepidoptera | | | | Abstract
| The effect of introducing alkyl substituents (methyl to pentyl) to the chain segment n in long-chain alkenyl acetates, CH3(CH2)nCH = CH(CH2) O T -0-C0CH3 (I), was investigated in pheromone receptors of Noctuidae, Tortricidae, and Cochylidae species. The receptor types studied were maximally responsive to (Z)-7-or (Z)-9-dodecen-l-yl acetate, (Z)-l-, (Z)-9-, or (Z)-11-tetradecen-1-yl acetate, or (Z)-11-hexadecen-l-yl acetate, representing key compounds with re = l, n = 3, or n = 5 methylene groups. In terms of the relative stimulus amounts required to elicit equivalent EAG amplitudes, the efficacy of the alkyl-branched derivatives was between 1/1000 to 300 times that of the unbranched chain of the same length and double bond position. The effects of branching were specific to the type of receptor, the length and double bond position of the parent chain, and the kind and position of the alkyl substituent. The most pronounced increase observed occurred with receptors for « = 1 type pheromones, (Z)-9-dodecen-l-yl acetate and (Z) -11-tetradecen-l-yl acetate when an a-methyl group was introduced to elongated derivatives; whereas the greatest decreasing effects were obtained on receptors for the n = 5 type compound, (Z)-7-tetradecen-l-yl acetate. The results show basic differences in structure-response relationships between the Noctuidae vs Tortricidae receptors studied. Various possible effects of the substituent groups during sensory transduction are considered. The data should contribute to further elucidation of interaction mechanisms of unbranched alkenyl acetate pheromones (I) with insect olfactory receptors. | | | |
Reference
| (Z. Naturforsch. 32c, 979 [1977]; received August 15 1977) | | | |
Published
| 1977 | | | |
Keywords
| Pheromones, Alkenyl Acetates, Olfactory Receptors, Structure-Activity Relationships, Lepidoptera | | | |
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| default:Reihe_C/32/ZNC-1977-32c-0979.pdf | | | | Identifier
| ZNC-1977-32c-0979 | | | | Volume
| 32 | |
| 8 | Author
| Frank Beise, Harald Labischinski, Hans Bradaczek | Requires cookie* | | | Title
| On the Relationships between Molecular Conformation, Affinity towards Penicillin-Binding Proteins, and Biological Activity of Penicillin G-Sulfoxide | | | | Abstract
| The binding capacity of penicillin G-sulfoxide towards the penicillin-binding proteins (PBP) of Staphylococcus aureus H was studied. The sulfoxide and its parent compound, penicillin G, differ only in two aspects, the sulfur-bound oxygen and an altered conformation of the five-membered thiazolidine-ring system. These minor alterations of the penicillin structure resulted in a drastical decrease of binding activity (about two orders of magnitude) of the sulfoxide derivative towards its target enzymes. Furthermore, the sulfoxide did not exhibit the selectivity of subinhibitory doses for PBP 3, as could be observed for penicillin G. The biological consequences of this behaviour were monitored via growth curves, uptake of cell wall label, and analysis of the cell wall. Binding studies revealed that comparable growth inhibi-tion and impairment of cell wall label uptake were achieved by at least a 100-fold higher penicillin G-sulfoxide concentration, compared to its parent compound. In cell wall analysis, the application of high doses of the antibiotics, i.e. nearly saturated PBP, verified the above mentioned observation. Surprisingly, small but significant differences in cell wall composition occurred using subinhibitory doses, probably due to the altered affinity towards PBP 3, supporting the hypothesis of an important role of this PBP in peptidoglycan transpeptida-tion. | | | |
Reference
| Z. Naturforsch. 43c, 656—664 (1988); received March 25/June 28 1988 | | | |
Published
| 1988 | | | |
Keywords
| Penicillin G, Penicillin G-Sulfoxide, Penicillin-Binding Proteins, Biological Activity, Structure Activity Relationships | | | |
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| default:Reihe_C/43/ZNC-1988-43c-0656.pdf | | | | Identifier
| ZNC-1988-43c-0656 | | | | Volume
| 43 | |
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