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  • Digitale Medien  (11)
  • Zeitschrift/Serie
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  • 1995-1999  (3)
  • 1990-1994
  • 1960-1964  (8)
  • 1955-1959
  • 1940-1944
  • 1995  (3)
  • 1964  (2)
  • 1962  (6)
  • 1959
  • Dyes/Pigments
  • Natural products
Materialart
  • Digitale Medien  (11)
  • Zeitschrift/Serie
  • Loseblatt
Erscheinungszeitraum
  • 1995-1999  (3)
  • 1990-1994
  • 1960-1964  (8)
  • 1955-1959
  • 1940-1944
Jahr
  • 1
    ISSN: 1572-9702
    Schlagwort(e): Natural products ; Ocimum suave ; acaricides ; Rhipicephalus appendiculatus ; tick control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An oil extracted from the leaves of a tropical shrub Ocimum suave was found to repel as well as kill all stages of the tick Rhipicephalus appendiculatus. In an in vitro bioassay for the larvae, the LC50 of the oil in liquid paraffin was 0.024%. A 10% solution was found to kill all immatures and more than 70% of adults feeding on rabbits. Rabbits were protected for 5 days against attaching larvae using a 10% solution. Preliminary experiments undertaken with cattle kept in the field suggest that the oil may have potential in tick control, and a role in integrated tick management.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 34 (1995), S. 2079-2090 
    ISSN: 0570-0833
    Schlagwort(e): natural products ; taxol ; total syntheses ; Taxol ; Natural products ; Total synthesis ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Much has been written about taxol, one of the newest weapons against cancer, and its producer, the Pacific Yew tree (Taxus brevifolia).K. C. Nicolaou, W.-M. Dai, R. K. Guy, Angew. Chem. 1994, 106, 38-69; Angew. Chem. Int. Ed. Engl. 1994, 33, 15-44. In this article, the authors give a frank and behind-the-scenes account of their encounter with this well-known molecule, which they and their collaborators faced as a synthetic target.K. C. Nicolaou, Z. Yang, J.-J. Liu, H. Ueno, P. G. Nantermet, R. K. Guy, C. F. Claiborne, J. Renaud, E. A. Couladouros, K. Paulvannan, E. J. Sorensen, Nature (London) 1994, 367, 630-634.K. C. Nicolaou, J.-J. Liu, Z. Yang, H. Ueno, R. K. Guy, E. A. Couladouros, E. J. Sorensen, J. Am. Chem. Soc. 1995, 117, 624-633.K. C. Nicolaou, J.-J. Liu, Z. Yang, H. Ueno, E. J. Sorensen, C. F. Claiborne, R. K. Guy, C.-K. Hwang, M. Nakada, P. G. Nantermet, J. Am. Chem. Soc. 1995, 117, 634-644.K. C. Nicolaou, Z. Yang, J.-J. Liu, P. G. Nantermet, C. F. Claiborne, J. Renaud, R. K. Guy, K. Shibayama, J. Am. Chem. Soc. 1995, 117, 645-652.K. C. Nicolaou, H. Ueno, J.-J. Liu, P. G. Nantermet, Z. Yang, J. Renaud, K. Paulvannan, R. Chadha, J. Am. Chem. Soc. 1995, 117, 653-659. Once again total synthesis is found to offer excellent opportunities for developing new synthetic strategies and novel reactions. The team of chemists who took up this challenge emerged with valuable experience and confidence in their skills.
    Zusätzliches Material: 26 Ill.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 34 (1995), S. 1795-1811 
    ISSN: 0570-0833
    Schlagwort(e): aromaticity ; biomimetic syntheses ; dyes ; porphyrins ; tumor therapy ; Biomimetic synthesis ; Dyes/Pigments ; Porphyrinoids ; Antitumor agents ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: In 1926 Hans Fischer and Bruno Walach synthesized the first porphyrins.H. Fischer, B. Walach, Justus Liebigs Ann. Chem. 1926, 450, 164-181. Currently more than 1400 new articles concerning the synthesis and uses of porphyrins are published every year.CAS Online search for 1994. However, the strong interest in these compounds indicated by this is in sharp contrast to their restricted availability. This is reflected in the current price of up to 500 DM for 5 mg of the most important porphyrins used in research and other applications (see Scheme 3).Biomimetic syntheses offer possibilities for an improved approach to porphyrins. By following the example set by nature it is also possible to obtain novel porphyrinoids which are different from naturally occurring porphyrins. This is exemplified by N,N′-bridged porphyrinogens, which have cage structures, inverted porphyrinoids (N atoms in the outer periphery) and, in particular, porphyrins with expanded systems. Among the family of expanded porphyrins are superarenes with up to 34 π electrons. Their pronounced aromaticity is indicated by 1H NMR spectra, bond length equivalence, planar structures, and electrophilic substitution. With their strong absorption bands, the strongest of which have ∊ values of 〉 1000000, a value which exceeds the absorption intensity of all other organic pigments observed until now, and their ability to act as efficient photosensitizers, the expanded porphyrins open interesting perspectives in the fields of photochemistry and photomedicine.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 73-82 
    ISSN: 0570-0833
    Schlagwort(e): Defensive substances ; Arthropods ; Insects ; Natural products ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Numerous orders of arthropods have organs which produce and store defensive substances. The purpose of our studies was to learn more about the chemical composition of these defensive secretions. In this work, we had to forego a priori many of the possibilities of classical organic-chemical analysis, since some of the insects were difficult to obtain and operation with substantial amounts of material was precluded. However, the defensive substances of various families of Arthropoda were characterized by using modern chemical and physical analytical procedures and our own methods of separation, purification, and enrichment which we developed specifically for this purpose.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 3 (1964), S. 408-416 
    ISSN: 0570-0833
    Schlagwort(e): Reactive dyes ; Dyes/Pigments ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Two new groups of reactive dyestuffs have been developed. One group (Levafix® dyes) comprises compounds which contain —SO2NH—CH2—CH2—OSO3H or —CH2—N(alkyl)-CH2—CH2—OSO3H as reactive groups. The dyes of this group react with cellulose fibers to form cellulose ethers, e.g. R—SO2NH—CH2—CH2—O—cellulose. The substances in the second group (Levafix-E® dyes) consist of the amides formed from 2,3-dichloroquinoxaline-6-carboxylic acid and dyestuffs containing primary or secondary amino groups.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 41-45 
    ISSN: 0570-0833
    Schlagwort(e): Dyes/Pigments ; Rutile structure ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Until the present time, new color pigments have been developed by isotypic and homotypic mixed-phase formation. This paper deals primarily with heterotypic mixed-phase formation for the preparation of new colored and white pigments with the rutile structure. Dioxides and difluorides crystallizing in the rutile lattice-form were chosen as host-lattices for the mixed-phase formation. Hosts of the general formula AB2 can accommodate, as guests, in the form of solid solutions, oxides and/or fluorides with different structures. Characteristically, the mean statistical cation-radius lies between 0.55 and 0.98 Å, with single radii between 0.46 and 0.98 Å. Relative quantities are so chosen that the cation to anion ratio of 1:2 prescribed by the host lattice, as well as electroneutrality, is maintained.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 98-111 
    ISSN: 0570-0833
    Schlagwort(e): Mass spectrometry ; Natural products ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Mass spectrometry is a very useful method for the determination of the structure of organic compounds although the technique has not yet been widely employed in this field. Of particular interest is the high sensitivity of the instrument, making possible the use of very small amounts of sample, and the information obtainable regarding the size of the molecule and position of the groups therein. A certain volatility is required and the choice of a suitable derivative is, therefore, sometimes of importance. The fragmentations of the molecules in the ion source may be considered as reactions of “carbonium ions without solvent.” The application of the method in the determination of the structure of some natural products is outlined, using lipids, amino acids, peptides and alkaloids as examples.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 178-195 
    ISSN: 0570-0833
    Schlagwort(e): Enzyme catalysis ; Natural products ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Micro-organisms form enzymes that catalyze many reactions which are difficult to carry out in the laboratory or which involve many steps. Enzymes even react with substances which are normally foreign to them. The frequently high stereospecificity of microbiological reactions is of particular significance. The most important types of reactions are: hydroxylations, dehydrogenations (oxidations), and hydrogenations (reductions), cleavage of ester and C-C bonds, and transglycosidations. The variety of the compounds converted is extremely great.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    ISSN: 0570-0833
    Schlagwort(e): Azo dyes ; Dyes/Pigments ; Oxidative coupling ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: New findings in the field of oxidative coupling reactions are reported. These involve: extension of this type of reaction to amidrazone system displaying (vinylogous) tautomerism and to unsymmetrical diarylhydrazines; elucidation of the coupling mechanism for these arylhydrazines and for the amidrazone systems previously described; the properties of some dyes, complexed with heavy metals, and the synthesis of tetraazapentamethine and penta-azapentamethine dyes.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 532-537 
    ISSN: 0570-0833
    Schlagwort(e): Polyacrylonitrile ; Fibers ; Azatrimethinecyanines ; Dyes/Pigments ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Like all basic dyes, azatrimethinecyanines possess a good dyeing affinity for acrylic fibers. Compounds with isolated nitrogen atoms in the trimethine chain show insufficient light fastness, whereas good to excellent fastness to light is displayed by compounds having neighboring nitrogen atoms in the chain. Thus, a working hypothesis stating that the light fastness of trimethinecyanines on acrylic fibers is improved by progressive replacement of methine groups by nitrogen atoms has been partially confirmed.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
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  • 11
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 1 (1962), S. 568-572 
    ISSN: 0570-0833
    Schlagwort(e): Trichloropyrimidyl dyes ; Dyes/Pigments ; Dichloropyrimidyl dyes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Several examples are used to show that the reactivity of dichloro- and trichloropyrimidyl dyes and the sensitivity of their dyeings to hydrolysis are determined by the nature of the bridge unit between the chromophore and the reactive system. The tendency of the dyeings to hydrolyze in acid and, more particularly, in alkaline media increases with increasing reactivity of the dyes. In alkaline media, dyeings made with dyes containing oxygen bridges are cleaved mainly between the reactive system and the chromophore, while in dyeings made with dyes containing imino or methylimino bridges, the linkage between the reactive system and the cellulose is hydrolyzed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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