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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 8 (1982), S. 1411-1420 
    ISSN: 1573-1561
    Keywords: Coleoptera ; Staphylinidae ; Oxytelinae ; defensive secretion ; glands ; acetates ; lactones ; alkenes ; quinones ; citral
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The secretions of the abdominal glands ofBledius spectabilis Kraatz,Platystethus arenarius Fourcr., andOxytelus piceus L. have been shown to contain four 1-alkenes; toluquinone; toluhydroquinone; C10 −-,C11 −, C12 −-, and C14 − γ-lactones; C12-δ-lactone; citral; and decyl-, undecyl-, and dodecyl acetates. Quantitative results indicate that 1-alkenes are formed probably from present lactones by decarboxylation. According to the known life histories of the beetles, it is suggested that the gland material is not used as an algal growth regulator but represents a unique defensive blend characteristic for the whole subfamily.
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  • 2
    ISSN: 1573-1561
    Keywords: Coleoptera ; Staphylinidae ; Deleaster dichrous ; defensive secretion ; gland system ; iridodial adhesive ; isopropyl esters ; sec-butyl esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The phylogenetically primitive rove beetleDeleaster dichrous (Grav.) (Oxytelinae) has been shown for the first time to possess two pairs of neighboring abdominal glands which are depleted simultaneously on molestation. The morphology of these glands is described. The defensive constituents of theDeleaster glands were elucidated directly from the mixtures by gas chromatographic-mass spectroscopic methods and microchemical reactions. The paired whitish glands secrete iridodial, which polymerizes on exposure to air to form an adhesive that probably deters small predatory arthropods. The red gland system ofD. dichrous contains the toxicp-toluquinone and a variety of isopropyl andsec-butyl esters. Artificial quinoid ester mixtures simulating the secretion ofD. dichrous showed only weak effects on mortality ofLucilia larvae in comparison with more effective secretions of phyiogenetically derived Oxytelinae. The secretion of the primitive genusDeleaster is characterized chemotaxonomically by β, γ-unsaturated C12 acids and esters, which are postulated as precursors for the characteristic defensive compounds of the derived species, thus indicating a clear evolutionary trend at the micromolecular level.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 15-22 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The skin of the aquatic pipid frog, Xenopus laevis, was examined for specific biomechanical features: (1) thickness, (2) maximal strain at break (εf), (3) tensile strength (σm), (4) modulus of elasticity (E, stiffness), and (5) the area under the stress-strain curve (W) (breaking energy, toughness). Skin freshly removed from dorsal, ventral, and lateral areas of the body was subjected to uniaxial tension. In both sexes, the dorsal skin is thicker than the ventral. The skin of male frogs was consistently thinner in all body regions than that of females. Most biomechanical parameters showed a considerable range of values in both males (εf = 59-63%, σm = 15-16.5 MPa, E = 33.5-38.4 MPa, W = 3.8-4.5 MJ/m3) and females (εf = 102-126%, σm = 11.5 MPa, E = 10.4-12 MPa, W = 5.2-6.7 MJ/m3). The disparate εf values in males (low) and females (high) might reflect sexual dimorphism. Static stress-strain curves were typicxally J-shaped; with the exception of “toe,” the curves rose approximately linearly with increasing strain. The skin of X. laevis, although heterogeneous in structure, possesses features similar to those found in tissues with aligned collagen fibers such as tendons or fish skin. However, in anurans, the skin seems to play a more passive mechanical role during locomotion than in fish. © 1995 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 16 (1993), S. 708-712 
    ISSN: 0935-6304
    Keywords: Reversed phase HPLC-GC-MS ; On-line derivatization ; Diazomethane ; MSTFA ; Bromination ; Loop-type interface ; Structure elucidation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Degradation products obtained under severe alkaline stress of the drug substance ENA 713, a compound developed for the treatment of DAT (dementia of the Alzheimer type), have been identified by on-line coupled reversed phase HPLC-GC-MS as 3-hydroxyaceto-phenone and 3-hydroxystyrene. Their structures were proven by mass spectroscopic investigation of the products obtained by on-column derivatization during LC-GC transfer. On-column trimethyl-silylation and bromination of the degradation products during the transfer were achieved by the introduction of the reagent via the loop-type interface. The usefulness of the technique was further demonstrated by the on-column methylation of carboxylic acids with diazomethane solution (using naproxen as model compound). First results are also given of the use of the liquid-liquid extraction unit of the LC-GC interface for extractive derivatization during reversed phase HPLC-GC-MS transfer.
    Additional Material: 8 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1826-1837 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and X-Ray Structure Determination of Bicyclo[4.2.1]non-3-ene-2-one DerivativesMethyl 4-chloro- and methyl 4-bromo-5-oxobicyclo[4.2.1]non-3-ene-1-carboxylate (2) and (3), respectively, 3-bromo-4-chlorobicyclo[4.2.1]non-3-ene-2-one (4), and methyl 5-oxobicyclo[4.2.1]-non-3-ene-1-carboxylate (5) have been prepared from the corresponding bicyclo[3.2.1]oct-2-ene derivatives via the dihalocarbene adducts, and X-ray structure analysis was carried out. In all cases a half-chair conformation was found for the five-membered rings whereas the seven-membered rings possess a twist-chair conformation. The enone system is almost planar in 3 and 5 but somewhat distorted in 2 and 4.
    Notes: 4-Chlor- und 4-Brom-5-oxobicyclo[4.2.1]non-3-en-1-carbonsäure-methylester (2) bzw. (3), 3-Brom-4-chlorbicyclo[4.2.1]non-3-en-2-on (4) und 5-Oxobicyclo[4.2.1]non-3-en-1-carbonsäure-methylester (5) wurden aus den entsprechenden Bicyclo[3.2.1]oct-2-en-Derivaten über die Dihalogencarbenaddukte dargestellt und einer Röntgenstrukturanalyse unterworfen. In allen Fällen liegt der Fünfring in einer Halbsesselkonformation vor, der Siebenring nimmt eine Twist-Sesselkonformation ein. In 3 und 5 ist das Enon-System annähernd planar, in 2 und 4 etwas verdrillt.
    Additional Material: 2 Ill.
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  • 6
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Surenolactone, a Novel Tetranortriterpenoid A/B-Dilactone from Toona sureni [Blume] Merrill (Meliaceae)Surenolactone (1), the first tetranortriterpenoid-A/B-dilactone found in meliaceae has been isolated from ether extracts of leaves of Toona sureni. The structure of 1 was determined by chemical reactions and on the basis of IR, NMR, MS, and X-ray data.
    Notes: Surenolacton (1), das erste in Meliaceen gefundene Tetranortriterpenoid mit A/B-Dilacton-Struktur wurde aus Etherextrakten der Blätter von Toona sureni [Blume] Merrill isoliert. Die Konstitutionsermittlung erfolgte auf Grund der IR-, NMR- und Massenspektren, der Röntgenstrukturananlyse sowie auf chemischem Wege.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 13 (1978), S. 177-178 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron deficient 2,2′-biphenyl benzoates decompose under electron impact conditions by loss of benzoic anhydride. Both stepwise and pericyclic mechanisms are observed as confirmed by the ‘direct analysis of daughter ions’ (DADI) technique.
    Notes: Beim elektronenstoßinduzierten Zerfall von elektronenarmen 2,2′-Biphenolbenzoaten wird die Abspaltung von Benzoesäureanhydrid beobachtet. Die Messung nach der DADI-Methode macht für diese Abspaltung sowohl einen Synchronprozeß als auch einen schrittweisen Zerfall wahrschinlich.
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  • 8
    Publication Date: 1980-01-01
    Print ISSN: 0031-9422
    Electronic ISSN: 1873-3700
    Topics: Biology , Chemistry and Pharmacology
    Published by Elsevier
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  • 9
    Publication Date: 1992-12-01
    Print ISSN: 0021-9673
    Electronic ISSN: 1873-3778
    Topics: Chemistry and Pharmacology
    Published by Elsevier
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